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Report . Reducing the Risk of Runway Excursions: Report of the Runway Safety Initiative

. Appendixes

Reducing the Risk of Runway Excursions

Report of the Runway Safety Initiative

This information is not intended to supersede operators’ or manufacturers’ policies, practices or requirements, and is not intended to supersede government regulations. Reducing the Risk of Runway Excursions

Report of the Runway Safety Initiative Contents 1. Introduction 4 1.1 Definitions 4 2. Background 5 3. Data 6 Reducing the Risk of 4.0 Common Risk Factors inRunway Excursion Events 9 Runway Excursions 4.1 Flight Operations 9

4.1.1 Takeoff Excursion Risk Factors 9 Report of the Runway Safety Initiative 4.1.2 Landing Excursion Risk Factors 9 4.2 Air Traffic Management 9 Table of Contents

4.3 Airport 9 1. Introduction ...... 4 1.1 Definitions...... 4 4.4 Aircraft Manufacturers 9 2. Background...... 5 4.5 Regulators 9 3. Data...... 6 5. Multiple Risk Factors 10 4. Common Risk Factors in Runway Excursion Events 5.2 Landing Excursion Risk Factor Interactions 11 4.1 Flight Operations...... 9 4.1.1 Takeoff Excursion Risk Factors...... 9 6. Recommended Mitigations 12 4.1.2 Landing Excursion Risk Factors...... 9 4.2 Air Traffic Management...... 9 6.1 General 12 4.3 Airport Operators...... 9 4.4 Aircraft Manufacturers...... 9 6.2 Flight Operations 12 4.5 Regulators...... 9

6.2.1 Policies 12 5. Multiple Risk Factors ...... 10 5.1 Takeoff Excursion Risk Factor Interactions ...... 10 6.2.2 Standard Operating Procedures (SOPs) 12 5.2 Landing Excursion Risk Factor Interactions ...... 11

6.3 Airport Operators 13 6. Recommended Mitigations...... 12 6.1 General...... 12 6.3.1 Policies 13 6.2 Flight Operations...... 12 6.2.1 Policies...... 12 6.2.2 Standard Operating Procedures (SOPs)...... 12 6.3 Airport Operators...... 13 6.3.1 Policies...... 13 6.3.2 Standard Operating Procedures (SOPs)...... 13 6.4 Air Traffic Management...... 13 6.4.1 Policies...... 14 6.4.2 Standard Operating Procedures (SOPs)...... 14 6.5 Regulators...... 14 6.6 Aircraft Manufacturers...... 14

7. Conclusions and Recommendations...... 14 APPENDIXES

I. Runway Excursion Risk Awareness Tool

II. Briefing Notes Updated ALAR Briefing Notes New Runway Safety Initiative Briefing Notes

III. Report on the Design and Analysis of a Runway Excursion Database

IV. Selected Flight Safety Foundation Publications

V. Additional Resources Australian Transport Safety Bureau Excursion Report U.S. Federal Aviation Administration Takeoff Training Aid Direction Générale de l’Aviation Civile, France, Unstabilized Approach Plan U.S. Federal Aviation Administration Advisory Circular on Runway Excursions

VI. Runway Safety Initiative Participating Organizations Reducing the Risk of Runway Excursions

An approach is stabilized when all of the following 1. Introduction conditions are met:

At the request of several international aviation organizations 1. The aircraft is on the correct flight path; in late 2006, the Flight Safety Foundation initiated a 2. Only small changes in heading/pitch are required to project entitled Runway Safety Initiative (RSI) to address maintain the correct flight path; the challenge of runway safety. This was an international 3. The aircraft speed is not more than VREF + 20 knots effort with participants representing the full spectrum of indicated airspeed and not less than VREF; stakeholders from the aviation community. The effort 4. The aircraft is in the correct landing configuration; initially reviewed the three areas of runway safety: runway 5. Sink rate is no greater than 1,000 feet per minute; incursions, runway confusion, and runway excursions. After if an approach requires a sink rate greater than a review of current runway safety efforts, specific data on the 1,000 feet per minute, a special briefing should be various aspects of runway safety were obtained. conducted; 6. Power setting is appropriate for the aircraft After reviewing the initial data, the RSI Group determined configuration and is not below the minimum power for that it would be most effective to focus its efforts on approach as defined by the aircraft operating manual; reducing the risk of runway excursions. 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system 1.1 Definitions (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Runway Excursion: When an aircraft on the runway Category III ILS approach must be flown within the surface departs the end or the side of the runway surface. expanded localizer band; during a circling approach, Runway excursions can occur on takeoff or landing. wings should be level on final when the aircraft They consist of two types of events: reaches 300 feet above airport elevation; and Veer-Off: A runway excursion in which an aircraft 9. Unique approach procedures or abnormal departs the side of a runway conditions requiring a deviation from the above Overrun: A runway excursion in which an aircraft elements of a stabilized approach require a departs the end of a runway special briefing.

Stabilized approach: All flights must be stabilized by An approach that becomes unstabilized below 1,000 1,000 feet above airport elevation when in instrument feet above airport elevation in IMC or below 500 feet meteorological conditions (IMC) or by 500 feet above above airport elevation in VMC requires an immediate airport elevation in visual meteorological conditions (VMC). go-around.

4 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 2. Background (Table 2). Over the past 14 years, there has been an average of almost 30 runway excursion accidents per year for commercial aircraft, while runway incursion and confusion All data in this report are from the World Aircraft Accident accidents combined have averaged one accident per year. Summary (WAAS), published by Ascend, and have been augmented by appropriate investigative reports when Figure 1 shows that the largest portion of runway-related available. The specific data in Section 2 represent a high- accidents is, by far, excursion accidents. level analysis of all major and substantial-damage accidents involving Western- and Eastern-built commercial jet and Confusion – turboprop aircraft from 1995 through 2008. These data were Incursion – Turbojet used to determine the overall number of accidents during Turboprop this period and the number of runway-related accidents.

The data in Section 3 are from a more in-depth look at Excursion – Aircraft Type Turbojet Turboprop Excursion – Turbojet runway excursion accidents to all aircraft with a maximum Turboprop takeoffDamage weight (MTOW)Major greaterSubstantial than 12,500Major lb/5,700Substantial kg from 1995 through March 2008 to determine high-risk areas and to develop possible286 interventions. 372 528 243 Incursion – Total 658 771 Turboprop Confusion – Turbojet Commercial Transport Aircraft 1,429 Total Accidents Figure 1. Proportions of Runway-Related Accidents for Western- and Eastern-built Turbojet and Turboprop Aircraft Turbojet and Turboprop Commercial Aircraft

Table 1. Total Commercial Transport Accidents, Forty-one of the 431 runway accidents involved fatalities. 1995 through 2008 Excursion accidents accounted for 34 of those fatal accidents, or 83% of fatal runway-related accidents. In During the 14-year period from 1995 through 2008, general, the likelihood of fatalities in a runway-related commercial transport aircraft were involved in a total of accident is greater in incursion and confusion accidents. 1,429 accidents involving major or substantial damage However, the much greater number of runway excursion (Table 1). Of those, 431 accidents (30%) were runway- accidents results in a substantially greater number of fatal related. The specific RSI focus on excursion accidents was excursion accidents (Figure 2). driven by the fact that of the 431 runway-related accidents, 417, or 97%, were runway excursions.

The number of runway excursion accidents is more than 40 Fatal times the number of runway incursion accidents, and more Runway Confusion Non-Fatal than 100 times the number of runway confusion accidents

Accident Number of Average % of Total Type Accidents Annual Rate Accidents Runway Incursion

Incursion 10 0.7 0.6%

Runway Excursion Confusion 4 0.3 0.3%

Excursion 417 29.8 29.0% Number of Accidents

Table 2. Runway-Related Accidents for Turbojet and Turboprop Figure 2. Proportions of Fatal and Non-Fatal Runway Accidents

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 5 Only a small percentage of runway excursion accidents The RSI effort brought together multiple disciplines that are fatal. However, since the overall number of runway included aircraft manufacturers, operators, management, excursion accidents is so high, that small percentage pilots, regulators, researchers, airports, and air traffic accounts for a large number of fatalities. Over the 14-year management organizations. It used the expertise and period, 712 people died in runway excursion accidents, experience of all the stakeholders to address the challenge while runway incursions accounted for 129 fatalities and of runway excursions. A list of the organizations that runway confusion accidents accounted for 132 fatalities. participated in the RSI effort can be found in Appendix VI.

During the 14-year period, the number of takeoff excursion The RSI team fully supports the many activities that have accidents decreased. However, the takeoff excursion been responsible for the low number of runway incursion accident trend (black line in Figure 3) has leveled off. accidents. The specific goal of the RSI team was to provide During the same period the number of landing excursions data that highlight the high-risk areas of runway excursions show an increasing trend (Figure 4). and to provide interventions and mitigations that can reduce those risks.

3. Data 14

12 An in-depth data study was conducted of all runway excursion accidents from 1995 through March 2008 to 10 investigate the causes of runway excursion accidents and 8 to identify the high-risk areas. The entire study, including the study basis, data set, and constraints, can be found in 6

Accidents Appendix I. Following are some of the basic data from the 4 study.

2 Landing excursions outnumber takeoff excursions 0 approximately 4 to 1 (Figure 5). 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

79% Figure 3. Takeoff Excursions for Commercial Turbojet and Turboprop Aircraft

40 21% 35

30

25

20

Accidents 15 Figure 5. Runway Excursions, by Type 10

5 Almost two-thirds of the takeoff excursions are overruns (Figure 6). 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Figure 4. Landing Excursions for Commercial Turbojet and Turboprop Aircraft

6 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 For landing excursions, the proportions between jet 63% transports and turboprops were approximately reversed — jets were involved in more excursions than turboprops (Figure 9).

37% 43%

35%

19%

Figure 6. Takeoff Excursions, by Type

Landing excursion overruns and veer-offs occur at nearly 3% the same rate (Figure 7).

53% Figure 9. Landing Excursions, by Fleet Composition 47% The data were analyzed to identify the most common risk factors, both in takeoff excursions (Figure 10) and landing excursions (Figure 11). More than one risk factor could be assigned to an accident.

The most common risk factor in takeoff excursions was a rejected takeoff (RTO) initiated at a speed greater than V1. Loss of pilot directional control was the next most common, followed by rejecting the takeoff before V1 was reached.

For landing excursions, the top risk factors were go-around Figure 7. Landing Excursions, by Type not conducted, touchdown long, landing gear malfunction, and ineffective braking (e.g., hydroplaning, contaminated Among aircraft fleet types, turboprops are involved in the runway). largest percentage of takeoff excursions, followed closely by jet transports (Figure 8).

41% 36%

17%

6%

Figure 8. Takeoff Excursions, by Fleet Composition

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 7 RTO: IniCated aUer V1 Pilot direcConal control RTO: before V1 No rotaConSbelow VR Non‐compliance SOP RotaCon: No aRempt CRM Degraded engine perf Tire failure Unable to rotate Eeight calculaCon error Sudden engine pwr loss RTO: No Cme Thrust asymmetry RotaCon: +bove VR RTO: Not considered Pilot Technique: x‐wind PIC supervision Improper Checklist Use RotaCon: >elow VR

0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% Figure 10. Takeoff Excursion Risk Factors

Go‐around not conducted Touchdown: Long IneffecCve JraKing: rwy contamLn Landing gear malfuncCon Approach Fast Touchdown: Fast Touchdown: Hard Flight Crew: CRM Pilot direcConal control Non‐compliance SOP Wheels: Assym decel‐malf Approach: High Pilot Technique: AlCtude control Landing gear damaged Pilot Technique: Speed Control Touchdown: Bounce Pilot Technique: Crosswind Pilot Technique: Flare Touchdown: Off‐center Reverse thrust: Asymmetric

0% 5% 10% 15% 20% 25% 30% 35% 40% Figure 11. Landing Excursion Top Risk Factors

8 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 4.0 Common Risk Factors in - Pilot technique — speed control - Touchdown — bounce Runway Excursion Events - Pilot technique — crosswind Runway excursion events can happen on takeoff or landing. - Pilot technique — flare They are typically the result of one or more of the following - Touchdown — off-center operational factors and circumstances. 4.2 Air Traffic Management 4.1 Flight Operations • Lack of awareness of the importance of stabilized 4.1.1 Takeoff Excursion Risk Factors approaches • Lack of awareness of stabilized approach criteria - Rejected takeoff (RTO) initiated at speed • Failure to descend aircraft appropriately for the greater than V1 approach - Directional control during takeoff or RTO is • Failure to allow aircraft to fly appropriate approach inadequate speeds - RTO before V1 is reached • Failure to select the appropriate runway based on - No rotation because VR not reached the wind - Crew noncompliance with standard operating • Late runway changes (e.g., after final approach fix) procedures (SOPs) • Failure to provide timely or accurate wind/weather - Rotation not attempted information to the crew - Failure of crew resource management (CRM) • Failure to provide timely or accurate runway - Degraded engine performance condition information to the crew - Tire failure - Unable to rotate - Aircraft weight calculation error 4.3 Airport - Sudden engine power loss - RTO — no time to abort before veer-off • Runways not constructed and maintained to - Thrust asymmetry maximize effective friction and drainage - Rotation above VR • Late or inaccurate runway condition reports - RTO not considered • Inadequate snow and ice control plan - Pilot technique — crosswind • Not closing a runway when conditions dictate - Failure of pilot-in-command (PIC) supervision • Incorrect or obscured runway markings of first officer • Failure to allow use of wind-preferential runways - Improper checklist use • Inadequate runway end safety area (RESA) or - Premature rotation — before VR equivalent system • Inappropriate obstacle assessments 4.1.2 Landing Excursion Risk Factors

- Go-around not conducted 4.4 Aircraft Manufacturers - Touchdown long - Ineffective braking — runway contamination • Lack of appropriate operational and performance - Landing gear malfunction information for operators that accounts for - Approach fast the spectrum of runway conditions they might - Touchdown fast experience - Touchdown hard - Flight crew CRM - Inadequate pilot directional control 4.5 Regulators - Noncompliance with SOPs - Wheels — asymmetric-deceleration • Lack of a regulatory requirement to provide flight malfunction crews a consistent format of takeoff and landing - Approach high data for all runway conditions - Pilot technique — glideslope/altitude control • Inadequate regulation for the provision of correct, - Landing gear damaged up-to-date and timely runway condition reports

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 9

Number of Gusts/ Engine Runway Perf. Calc.: Perf. Calc.: Events With the Crosswind Tailwind Turbulence/ Abort ≤ V1 Abort > V1 Power Loss Contamination Weight/CG Cited Pairs of V1/Rwy. Length (1 event) (0 events) Wind Shear (14 events) (46 events) (17 events) (8 events) (11 events) Factors* (7 events) (0 events)

Abort ≤ V1 3 2 2 2 0 0 0 Abort > V1 9 5 7 3 1 0 0 Engine Power 3 9 3 1 2 0 0 0 Loss Runway 2 5 3 2 2 0 0 0 Contamination Perf. Calc.: 2 7 1 2 1 0 0 0 Weight/CG Perf. Calc.: 2 3 2 2 1 0 0 0 V1/Rwy. Length Crosswind 0 1 0 0 0 0 0 0 Tailwind 0 0 0 0 0 0 0 0 Gusts/ Turbulence/ 0 0 0 0 0 0 0 0 Wind Shear * Cells highlighted in yellow are those where the co-existence of two factors is greater than or equal to 20 percent. Table 3. Takeoff Excursion Veer-Offs — Risk Factor Interactions

Number of Gusts/ Engine Runway Perf. Calc.: Perf. Calc.: Events With the Abort > V Crosswind Tailwind Turbulence/ Abort ≤ V1 1 Power Loss Contamination Weight/CG Cited Pairs of V1/Rwy. Length (8 events) (0 events) Wind Shear (18 events) (5 events) (12 events) (8 events) (2 events) Factors* (1 event) (5 events)

Abort ≤ V1 8 5 1 0 3 0 2 Abort > V1 2 1 1 0 2 0 0 Engine Power 8 2 2 0 0 0 0 1 Loss Runway 5 1 2 0 0 3 0 1 Contamination Perf. Calc.: 1 1 0 0 1 0 0 0 Weight/CG Perf. Calc.: 0 0 0 0 1 0 0 0 V1/Rwy. Length Crosswind 3 2 0 3 0 0 0 4 Tailwind 0 0 0 0 0 0 0 0 Gusts/ Turbulence/ 2 0 1 1 0 0 4 0 Wind Shear * Cells highlighted in yellow are those where the co-existence of two factors is greater than or equal to 20 percent. Table 4. Takeoff Excursion Overruns — Risk Factor Interactions

• No international standard for measuring and 5.1 Takeoff Excursion Risk Factor reporting runway conditions Interactions Data breakdowns for takeoff excursions clearly show that some factors are more frequently present than others. The 5. Multiple Risk Factors next logical question is whether there are combinations of factors that are more significant than others. Also The risk of a runway excursion increases when more than of interest is whether certain factors are more or less one risk factor is present. Multiple risk factors create a conducive to veer-offs than to overruns. Table 3 shows synergistic effect (i.e., two risk factors more than double various risk combinations of selected factors in veer-off the risk). Combining the effects of the risk indicators via accidents during takeoff. The yellow highlighted cells a proper safety management system (SMS) methodology indicate combinations of factors where there is a 20% could effectively identify increased-risk operations. or greater overlap of the factor and the column total Applying proper mitigation strategies could reduce the risk (minimum value greater than or equal to 2). of a runway excursion.  The small number of events comprising the takeoff excursions data set — made even smaller when considering only veer-offs — limits our ability to

10 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009

Number of Go-Around Touchdown Gusts/ Stabilized Unstabilized Touchdown Runway Crosswind Events With Not Hard/ Tailwind Turbulence/ Approach Approach Long/Fast Contamination (47 the Cited Pairs Conducted Bounce (8 events) Wind Shear (114 events) (39 events) (54 events) (90 events) events) of Factors* (44 events) (50 events) (32 events) Stabilized 5 4 17 39 24 5 14 Approach Unstabilized 36 7 20 20 8 1 11 Approach Go-Around Not 5 36 9 24 25 10 1 10 Conducted Touchdown 4 7 9 5 4 2 1 9 Long/Fast Touchdown 17 20 24 5 21 17 2 12 Hard/Bounce Runway 39 20 25 4 21 24 5 21 Contaminated Crosswind 24 8 10 2 17 24 3 22 Tailwind 5 1 1 1 2 5 3 1 Gusts/ Turbulence/ 14 11 10 9 12 21 22 1 Wind Shear * Cells highlighted in yellow are those where the co-existence of two factors is greater than or equal to 20 percent

Table 5. Landing Excursion Veer-Offs — Risk Factor Interactions

Number of Go-Around Touchdown Gusts/ Stabilized Unstabilized Touchdown Runway Tailwind Events With Not Hard/ Crosswind Turbulence/ Approach Approach Long/Fast Contamination (30 the Cited Pairs Conducted Bounce (18 events) Wind Shear (47 events) (87 events) (118 events) (101 events) events) of Factors* (107 events) (17 events) (22 events) Stabilized 13 13 3 25 3 8 6 Approach Unstabilized 84 77 8 43 7 14 13 Approach Go-Around Not 13 84 91 14 53 10 19 18 Conducted Touchdown 13 77 91 15 53 9 20 14 Long/Fast Touchdown 3 8 14 15 5 2 7 5 Hard/Bounce Runway 25 43 53 53 5 10 15 16 Contamination Crosswind 3 7 10 9 2 10 7 16 Tailwind 8 14 19 20 7 15 7 8 Gusts/ Turbulence/ 6 13 18 14 5 16 16 8 Wind Shear * Cells highlighted in yellow are those where the co-existence of two factors is greater than or equal to 20 percent Table 6. Landing Excursion Overruns — Risk Factor Interactions

know whether differences in the tabulated values are and aborts initiated above V1, as well as an association significant. However, it is interesting to note where between these high-speed aborts and the presence of there are associations of factors that may warrant runway contaminants. further, more detailed study. For instance, aborts at or below V1 often still resulted in a veer-off when there 5.2 Landing Excursion Risk Factor was an engine power loss, a runway contaminant, or Interactions a crosswind. There is also some indication that the increased risks created by crosswinds and tailwinds are magnified when gusts, turbulence, or wind shear is Tables 5 and 6 show risk interactions for landing present. excursion veer-offs and landing excursion overruns, respectively. In contrast to the takeoff excursion data, Table 4 shows similar risk interactions for takeoff the landing excursion data are not nearly as affected by overruns. Though the number of overruns during the inaccuracies inherent in small numbers. In each takeoff is considerably larger than the number of veer- table, yellow highlighted cells are those values greater offs, it is still a relatively small value, which makes than or equal to 20% of the column total. comparisons difficult when further subdivided. The numbers in these data suggest that there might be The number of highlighted cells for both veer-offs and interesting associations between engine power loss overruns shows that the landing excursion data have

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 11 some strong associations between pairs of factors. For organizations working together in an integrated way instance, Table 5 shows that, for veer-offs, the factor(s) will offer added value. “touchdown long/fast” have little association with the other listed factors. However, the next column, Therefore, as far as practicable, organizations should “touchdown hard/bounce,” shows strong associations work together to address runway safety. with many of the other factors. • Local level: This could be achieved by local Conversely, Table 6 shows that “touchdown long/fast” runway safety teams consisting of at least is much more strongly associated with factors inherent representatives of the airport, air traffic control, in overruns, whereas “touchdown hard/bounce” has aircraft operators, and pilot representatives, should relatively weak associations. In veer-offs, “touchdown address all runway safety–related topics, including hard/bounce” is somewhat associated with both stabilized runway incursions, runway confusion, and runway and unstabilized approaches to a very similar degree. excursions. This implies that other factors may be of equal or greater • National level: Runway excursions as a separate importance than a stabilized approach for landing veer- subject should be addressed by the national safety/ off accidents. Looking at overruns, however, the factor aviation authority in close cooperation with “touchdown long/fast” has a very strong correlation with the aircraft operators, air traffic control, airport unstabilized approaches, and a much weaker correlation operators and pilot representatives. with stabilized approaches. Similar observations can be • International level: It is strongly recommended made with respect to various wind factors and runway that international organizations continue to address contamination. For example, tail winds are clearly a runway excursions as a significant safety issue. frequent contributor to overruns, while crosswinds have a stronger presence with veer-offs. 6.2 Flight Operations The risk factor interaction tables present the possibility of many associations between various 6.2.1 Policies contributing factors, but determining whether any pair of associated factors has a causal connection • Operators should have a process for actively would require deeper study and analysis. The strong monitoring their risk during takeoff and associations displayed in the tables suggest areas landing operations where more detailed investigation may be fruitful. • Operators should define training programs for For instance, the “go-around not conducted” columns takeoff and landing performance calculations exemplify strong associations with other factors such • Operators should have an ongoing process as “unstabilized approaches,” “long/fast landings,” to identify critical runways within their “runway contamination,” and “hard/bounced landings.” operations Logically, these factors may have a causal connection • Operators should define and train the execution to each other that significantly increases the probability of the RTO decision of a runway excursion accident. However, a final • Operators should stress that CRM and determination requires explicit study of events where adherence to SOPs are critical in RTOs these factors were present. • Operators should define, publish, and train the elements of a stabilized approach • Operators should implement, train, and support 6. Recommended Mitigations a no-fault go-around policy

The following prevention strategies should be implemented 6.2.2 Standard Operating Procedures (SOPs) to address the risk factors involved in runway excursions. • Management and flight crews should mutually develop and regularly update SOPs 6.1 General • Operators should define criteria and required callouts for a stabilized approach The prevention strategies embrace five areas: flight • Operators should define criteria that require a operations, air traffic management, airport operators, go-around aircraft manufacturers, and regulators. Although • Operators should ensure that flight crews strategic areas are separately listed in this document, understand

12 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 - Factors affecting landing and takeoff end safety area (RESA) as required by distances International Civil Aviation Organization - Conditions conducive to hydroplaning (ICAO) Annex 14 or appropriate mitigations - Criteria upon which landing distance such as an arrestor bed calculations are based • Define criteria to determine when to close a - Crosswind and wheel cornering issues runway to prevent runway excursions - Wind shear hazards • Ensure that runways are constructed and - Braking action, runway friction maintained to ICAO specifications, so that coefficient, runway-condition index, effective friction levels and drainage are and maximum recommended crosswind achieved (e.g., runway grooving, porous component depending on runway friction overlay) condition • Ensure that the maneuvering area including - That landing with a tailwind on a the runway conform to ICAO Annex 14 contaminated runway is not recommended specifications • Operators should define and train procedures for • Ensure that aircraft rescue and fire fighting − Assessment of runway excursion risk (ARFF) personnel are trained and available at using the Runway Excursion Risk all times during flight operations Awareness Tool (RERAT), Appendix I • Ensure that ARFF personnel are familiar with − Critical runway operations crash/fire/rescue procedures for all aircraft − Rejected takeoff, rejected landing, and types serving the airport bounced landing • Provide means for flight crews to visually − Assessment of landing distance prior to determine runway distance remaining every landing − Crosswind operations 6.3.2 Standard Operating Procedures (SOPs) − Appropriate flare technique • Ensure that visual aids, specifically touchdown − Go-around, including during flare and zone location and markings, are visible and in after touchdown accordance with ICAO Annex 14 − Landing on wet, slippery, or contaminated • Ensure that infrastructure restrictions such runways as changes to the published takeoff run − Using brakes, spoilers, and thrust available (TORA) and runway width available reversers as recommended by the are communicated in a timely and effective manufacturer and maintaining their use manner until a safe taxi speed is assured • Ensure that runway conditions are reported in − Use of autobrake system and thrust a timely manner reversers on wet and/or contaminated • Provide an active process that ensures runways adequate runway braking characteristics − Use of rudder, differential braking, and • Mitigate the effects of environmental (e.g., nosewheel steering for directional control snow, ice, sand) and other deposits (e.g., during aircraft deceleration and runway rubber and de-icing fluids) on the runway exit − Recognizing when there is a need for, and appropriate use of, all available 6.4 Air Traffic Management deceleration devices to their maximum capability Air traffic management/air traffic control (ATM/ATC) − Runway condition reporting by flight has two primary roles in reducing the risk of runway crews excursions:

• Provide air traffic services that allow flight crews to fly a stabilized approach 6.3 Airport Operators • Provide flight crews with timely and accurate information that will reduce the risk of a runway 6.3.1 Policies excursion

• Ensure that all runway ends have a runway

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 13 6.4.1 Policies 7. Conclusions and Recommendations

• Ensure all ATC/ATM personnel understand the 1. A mishandled rejected takeoff (RTO) increases concept and benefits of a stabilized approach the risk of takeoff runway excursion • Encourage joint familiarization programs - Operators should emphasize and train for between ATC/ATM personnel and pilots proper execution of the RTO decision • ATC/ATM and operators should mutually - Training should emphasize recognition of develop and regularly review and update takeoff rejection issues arrival and approach procedures • Sudden loss or degradation of thrust • Require the use of aviation English and ICAO • Tire and other mechanical failures phraseology • Flap and spoiler configuration issues - Training should emphasize directional control 6.4.2 Standard Operating Procedures during deceleration (SOPs) - CRM and adherence to SOPs are essential in time-critical situations such as RTOs • Controllers should assist flight crews in meeting stabilized approach criteria by 2. Takeoff performance calculation errors increase - Positioning aircraft to allow a stabilized the risk of a takeoff runway excursion approach − Operators should have a process to ensure a - Avoiding late runway changes, especially proper weight-and-balance, including error after the final approach fix detection - Providing approaches with vertical − Operators should have a process to ensure guidance accurate takeoff performance data - Not using speed control inside the final approach fix 3. Unstable approaches increase the risk of landing • Controllers should runway excursions - Select the preferred runway in use based - Operators should define, publish, and train the on wind direction elements of a stabilized approach - Communicate the most accurate - Flight crews should recognize that fast and meteorological and runway condition high on approach, high at threshold, and fast, information available to flight crews in a long, and hard touchdowns are major factors timely manner leading to landing excursions - ATC/ATM personnel should assist aircrews in meeting stabilized approach criteria

6.5 Regulators 4. Failure to recognize the need for and to execute a go-around is a major contributor to runway • Develop a policy to ensure the provision of correct, excursion accidents up-to-date and timely runway condition reports - Operator policy should dictate a go-around • Develop a policy to standardize takeoff and landing if an approach does not meet the stabilized data format as a function of runway condition approach criteria provided to airlines by aircraft manufacturers - Operators should implement and support no- • Develop a standard measurement system for fault go-around policies runway condition reporting - Training should reinforce these policies

5. Contaminated runways increase the risk of runway excursions 6.6 Aircraft Manufacturers - Flight crews should be given accurate, useful, and timely runway condition information Manufacturers should provide appropriate operational - A universal, easy-to-use method of runway and performance information to operators that account condition reporting should be developed to for the spectrum of runway conditions they might reduce the risk of runway excursions experience. - Manufacturers should provide appropriate operational and performance information to

14 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 operators that accounts for the spectrum of - SOPs should be regularly reviewed and runway conditions they might experience updated by a management and flight crew team

6. Thrust reverser issues increase the risk of 9. The survivability of a runway excursion depends runway excursions on the energy of the aircraft as it leaves the - Flight crews should be prepared for runway surface and the terrain and any obstacles mechanical malfunctions and asymmetric it will encounter prior to coming to a stop deployment - All areas surrounding the runway should - Flight crew application of reverse thrust is conform to ICAO Annex 14 specifications most effective at high speeds - All runway ends should have a certified runway end safety area (RESA) as required by 7. Combinations of risk factors (such as abnormal ICAO Annex 14 or appropriate substitute (e.g., winds plus contaminated runways or unstable an arrestor bed) approaches plus thrust reverser issues) - Aircraft rescue and fire fighting (ARFF) synergistically increase the risk of runway personnel should be trained and available at all excursions times during flight operations - Flight crews should use a Runway Excursion Risk Awareness Tool (Appendix I) for each 10. Universal standards related to the runway and landing to increase their awareness of the risks conditions, and comprehensive performance data that may lead to a runway excursion. related to aircraft stopping characteristics, help reduce the risk of runway excursions 8. Establishing and adhering to standard operating - Regulators should develop global, uniform procedures (SOPs) will enhance flight crew standards for runway condition measuring and decision making and reduce the risk of runway reporting, and aircraft performance data excursions - Management and flight crews should mutually develop SOPs

This information is not intended to supersede operators’ or manufacturers’ policies, prac­tices or requirements, and is not intended to supersede government regulations.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 15

APPENDIX I

Report of the Runway Safety Initiative

Runway Excursion Risk Awareness Tool Reducing the Risk of Runway Excursions

Runway Excursion Risk Awareness Tool Elements of this tool should be integrated, as appropriate, with the standard approach and departure briefings to improve aware- ness of factors that can increase the risk of a runway excursion. The number of warning symbols ( ) that accompany each factor indicates a relative measure of risk. Generally, the higher the number of warning symbols that accompany a factor, the greater the risk presented by that factor. Flight crews should consider carefully the effects of multiple risk factors, exercise appropriate vigilance and be prepared to take appropriate action.

Failure to recognize the need for and to properly conduct a rejected takeoff on departure or a go-around at any time during an approach, flare or touchdown is a primary factor in runway excursions.

Type of Operation Environment Nonscheduled/air taxi/freight Visibility restrictions — e.g., darkness, fog, Training/observation IMC, low light Contaminated runway — e.g., standing water, Flight Crew snow, slush, ice Reduced state of alertness — long duty period, Tail wind greater than 5 kt fatigue Single-pilot operation High crosswinds/gusty winds Airport Heavy rain/thunderstorm on field No current/accurate weather/runway condition Aircraft Equipment information No wind shear warning system Unfamiliar airport or unfamiliar procedures Inoperative braking system — e.g., wheel Familiar airport — potential complacency brakes, anti-skid, spoilers, thrust reversers Inadequate/obscured runway markings Operating Procedures Cockpit distractions/non-sterile cockpit Excessive rubber/no porous friction coating or grooves on runway surface Absence of no-fault go-around policy Minimal or no approach/runway/taxiway lights Schedule pressures/delays Air Traffic Services Absent/inadequate descent/approach briefing(s) No airport traffic control service Absent/inadequate briefing/planning for braking Late runway change/unreasonable clearances management after touchdown Expected Approach No vertical approach guidance — e.g., ILS, Definitions: RNP, VASI/PAPI ILS = instrument landing system Nonprecision approach, especially with multiple step-downs IMC = instrument meteorological conditions Visual approach in darkness LAHSO = land and hold short operations LAHSO/partial runway closure PAPI = precision approach path indicator Planned long landing RNP = required navigation performance VASI = visual approach slope indicator

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 1 Runway Excursion Risk Reduction Strategies

Flight Planning Planning and training for a rejected takeoff are essential. Flight crews and aircraft operations staff can mitigate some of the risk of a runway excursion by increased planning and vigi- Landing lance. For example, when adverse environmental factors are Planning for the landing should start before takeoff. Risks can present, such as a contaminated runway or a strong crosswind, be reduced by selecting a runway that either has a precision the selection of the longest runway with the most favorable approach or other means of vertical guidance and provides the wind conditions should be considered. The use of maximum most favorable overall performance. At critical airports (e.g., thrust for takeoff, instead of reduced thrust, will reduce risk on those with contaminated runways, short runways, adverse a contaminated runway. wind conditions, etc.), consideration should be given to not In many cases, delaying a takeoff or landing by just a few scheduling aircraft with inoperative braking systems (e.g., minutes allows for unfavorable weather conditions to improve wheels brakes, anti-skid, spoilers, thrust reversers), and extra and/or allows the airport to better treat a contaminated runway weight (e.g., tankered fuel) should be minimized. and measure braking action on the runway. Accurate weather information and timely runway condition information are essential. Takeoff Crews should carefully review all aircraft performance com- Crews should carefully review all aircraft loading computations putations and be alert for FMS data entry errors (e.g., weights, and be alert for flight management system (FMS) data entry er- speeds, runway length, etc.). The effects of all environmental rors (e.g., weights, speeds, trim settings, runway length and take- conditions on aircraft performance must be evaluated (e.g., off thrust). The effects of all environmental conditions on aircraft temperature, pressure, wind, runway contamination and slope, performance must be evaluated (e.g., temperature, pressure, wind, obstacles, etc.), and the effects of inoperative aircraft systems runway contamination and slope, obstacles, etc.), and the effects (e.g., wheel brakes, anti-skid, thrust reversers, spoilers) must of inoperative aircraft systems (e.g., wheel brakes, anti-skid, be considered. Adequate landing performance safety margins thrust reversers, spoilers) must be considered. Adequate takeoff should be applied. performance safety margins should be applied. Crews should consider flying the full instrument approach at Directional control issues should be discussed, especially during unfamiliar airports and during darkness instead of electing to strong or gusty crosswinds. Application of power should be in ac- conduct a visual approach to expedite arrival. Use should be cordance with the aircraft manufacturer’s recommendations, and made of all raw data to enhance position awareness and ensure a rolling takeoff should be made when appropriate. a stabilized approach (Table 1, below).

Table 1 Recommended Elements of a Stabilized Approach All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabilized when all of the following criteria are met: 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet per minute, a special brief- ing should be conducted; 6. Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Category III ILS approach must be flown within the expanded localizer band; during a circling approach, wings should be level on final when the aircraft reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a stabilized approach require a special briefing. An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate go-around. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1, November 2000)

2 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 APPENDIX II

Report of the Runway Safety Initiative

Approach and Landing Accident The Go-Around Reduction (ALAR) Briefing Notes 6.1 Being Prepared to Go Around...... 118 1.1 Operating Philosophy...... 1 6.2 Manual Go-around...... 122 1.2 Automation...... 11 6.3 Terrain-avoidance (Pull-up) Maneuver...... 126 1.3 Golden Rules...... 17 6.4 Bounce Recovery ñ Rejected Landing...... 130 1.4 Standard Calls...... 22 Approach Techniques 1.5 Normal Checklists...... 26 7.1 Stabilized Approach...... 133 1.6 Approach Briefing...... 30 7.2 Constant-angle Nonprecision Approach...... 139 Crew Coordination 7.3 Visual References...... 146 2.1 Human Factors...... 35 7.4 Visual Approaches...... 152 2.2 Crew Resource Management...... 41 Landing Techniques 2.3 Pilot-Controller Communication...... 46 8.1 Runway Excursions and Runway Overruns..157 2.4 Interruptions/Distractions...... 53 8.2 The Final Approach Speed...... 162 Altimeter and Altitude 8.3 Landing Distances...... 166 3.1 Barometric Altimeter and Radio Altimeter...... 58 8.4 Braking Devices...... 172 3.2 Altitude Deviations...... 65 8.5 Wet or Contaminated Runways...... 178 8.6 Wind Information...... 185 Descent and Approach 8.7 Crosswind Landing...... 190 4.1 Descent-and-approach Profile Management.71 4.2 Energy Management...... 76 Runway Safety Initiative Approach Hazards Awareness (RSI) Briefing Notes 5.1 Approach Hazards Overview...... 82 Pilot Braking Action Reports...... 1 5.2 Terrain...... 94 Runway Condition Reporting...... 6 5.3 Visual Illusions...... 104 5.4 Wind Shear...... 111 FSF ALAR Briefing Note 1.1 — Operating Philosophy

Adherence to standard operating procedures (SOPs) is an effective ing flight-testing programs and route-proving programs. method of preventing approach-and-landing accidents (ALAs), including those involving controlled flight into terrain (CFIT). After they are introduced into service, SOPs are reviewed pe- riodically and are improved based on feedback received from Crew resource management (CRM) is not effective without users (in training and in line operations). adherence to SOPs. Customized SOPs Statistical Data An airframe manufacturer’s SOPs can be adopted “as is” by a The Flight Safety Foundation Approach-and-landing Accident company or can be used to develop customized SOPs. Reduction (ALAR) Task Force found that “omission of action/ inappropriate action” (i.e., inadvertent deviation from SOPs) was Changes to the airframe manufacturer’s SOPs should be co- a causal factor1 in 72 percent of 76 approach-and-landing acci- ordinated with the manufacturer and should be approved by dents and serious incidents worldwide in 1984 through 1997.2 the appropriate authority.

The task force also found that “deliberate nonadherence to SOPs must be clear and concise; expanded information should procedures” was a causal factor in 40 percent of the accidents reflect the company’s operating philosophy and training phi- and serious incidents. losophy.

U.S. Federal Aviation Administration (FAA) Advisory Circular Manufacturer’s SOPs 120‑71, Standard Operating Procedures for Flight Deck Crew- members, published Aug. 10, 2000, includes a list of generic SOPs published by an airframe manufacturer are designed topics that can be used for the development of company SOPs to: (see Standard Operating Procedures Template). • Reflect the manufacturer’s flight deck design philosophy and operating philosophy; Company SOPs usually are developed to ensure standardiza- tion among different aircraft fleets operated by the company. • Promote optimum use of aircraft design features; and, • Apply to a broad range of company operations and Company SOPs should be reassessed periodically, based on environments. revisions of the airframe manufacturer’s SOPs and on internal company feedback, to identify any need for change. The initial SOPs for a new aircraft model are based on the manufacturer’s objectives and on the experience acquired dur- Flight crews and cabin crews should participate with flight

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 1 standards personnel in the development and revision of com- pany SOPs to: Table 1 • Promote constructive feedback; and, Recommended Elements • Ensure that the SOPs, as well as the reasons for their Of a Stabilized Approach adoption, are understood fully by users. All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual Scope of SOPs meteorological conditions (VMC). An approach is stabi- lized when all of the following criteria are met: The primary purpose of SOPs is to identify and describe the 1. The aircraft is on the correct flight path; standard tasks and duties of the flight crew for each flight 2. Only small changes in heading/pitch are required to phase. maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than V ; SOPs generally are performed by recall, but tasks related to the REF selection of systems and to the aircraft configuration should 4. The aircraft is in the correct landing configuration; be cross-checked with normal checklists. 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be con- SOPs are supplemented usually by information about specific ducted; operating techniques or by recommendations for specific types 6. Power setting is appropriate for the aircraft configura- of operations (e.g., operation on wet runways or contaminated tion and is not below the minimum power for approach runways, extended operations [ETOPS] and/or operation in as defined by the aircraft operating manual; reduced vertical separation minimums [RVSM] airspace). 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they SOPs assume that all aircraft systems are operating normally also fulfill the following: instrument landing system and that all automatic functions are used normally. (A system (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Cat- may be partially inoperative or totally inoperative without egory III ILS approach must be flown within the ex- affecting the SOPs.) panded localizer band; during a circling approach, wings should be level on final when the aircraft SOPs should emphasize the following items: reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions • operating philosophy; requiring a deviation from the above elements of a stabilized approach require a special briefing. • Task-sharing; An approach that becomes unstabilized below 1,000 • optimum use of automation; feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate • “Golden rules” (see FSF ALAR Briefing Note 1.3 — go-around. Golden Rules); Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) • Standard calls; • Normal checklists; • Approach briefings; • Approach procedures and techniques; • Altimeter-setting and cross-checking procedures; • landing and braking techniques; and, • descent profile management; • Preparation and commitment to go around. • Energy management; General Principles • Terrain awareness; • Approach hazards awareness; SOPs should contain safeguards to minimize the potential for inadvertent deviations from SOPs, particularly when operating • Radio altimeter; under abnormal conditions or emergency conditions, or when interruptions/distractions occur. • Elements of a stabilized approach (see Table 1) and 3 approach gate ; Safeguards include:

2 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Action blocks — groups of actions being accomplished various types of approaches. in sequence; • Triggers — events that initiate action blocks; Training

• Action patterns — instrument panel scanning sequences Disciplined use of SOPs and normal checklists should begin or patterns supporting the flow and sequence of action during transition training, because habits and routines ac- blocks; and, quired during transition training have a lasting effect. • Standard calls — standard phraseology and terms used for effective crew communication. Transition training and recurrent training provide a unique opportunity to discuss the reasons for SOPs and to discuss the Standardization consequences of failing to adhere to them.

SOPs are the reference for crew standardization and establish Conversely, allowing deviations from SOPs and/or normal the working environment required for CRM. checklists during initial training or recurrent training may encourage deviations during line operations. Task-sharing

The following guidelines apply to any flight phase but are Deviations From SOPs particularly important to the high-workload approach-and- landing phases. To ensure adherence to published SOPs, it is important to understand why pilots intentionally or inadvertently deviate The pilot flying (PF) is responsible for controlling the hori- from SOPs. zontal flight path and the vertical flight path, and for energy management, by: In some intentional deviations from SOPs, the procedure that was followed in place of the SOP seemed to be appropriate • Supervising autopilot operation and autothrottle for the prevailing situation. operation (maintaining awareness of the modes armed or selected, and of mode changes); or, The following factors and conditions are cited often in discuss- ing deviations from SOPs: • hand-flying the aircraft, with or without flight director (FD) guidance, and with an appropriate navigation • Inadequate knowledge or failure to understand the display (e.g., horizontal situation indicator [HSI]). procedure (e.g., wording or phrasing was not clear, or the procedure was perceived as inappropriate); The pilot not flying (PNF) is responsible for monitoring tasks and • Insufficient emphasis during transition training and for performing the actions requested by the PF; this includes: recurrent training on adherence to SOPs; • Performing the standard PNF tasks: • Inadequate vigilance (e.g., fatigue); – SOP actions; and, • Interruptions (e.g., communication with air traffic – FD and flight management system (FMS) mode control); selections and target entries (e.g., altitude, airspeed, • distractions (e.g., flight deck activity); heading, vertical speed, etc.), when the PF is hand- flying the aircraft; • Task saturation; • Monitoring systems and aircraft configuration; and, • Incorrect management of priorities (e.g., lack of a • Cross-checking the PF to provide backup as required decision-making model for time-critical situations); (this includes both flight operations and ground • Reduced attention (tunnel vision) in abnormal conditions operations). or high-workload conditions;

Automation • Inadequate CRM (e.g., inadequate crew coordination, cross-check and backup); With higher levels of automation, flight crews have more options and strategies from which to select for the task to be accomplished. • Company policies (e.g., schedules, costs, go-arounds and diversions); Company SOPs should define accurately the options and • other policies (e.g., crew duty time); strategies available for the various phases of flight and for the

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 3 • Personal desires or constraints (e.g., schedule, mission fatal approach-and-landing accidents (ALAs) that occurred completion); in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 kilograms, detailed studies • Complacency; and, of 76 ALAs and serious incidents in 1984 through 1997 and • overconfidence. audits of about 3,300 flights. 3. The FSF ALAR Task Force defines approach gate as These factors may be used to assess company exposure to “a point in space (1,000 feet above airport elevation in deviations and/or personal exposure to deviations, and to instrument meteorological conditions or 500 feet above develop corresponding methods to help prevent deviations airport elevation in visual meteorological conditions) at from SOPs. which a go-around is required if the aircraft does not meet defined stabilized approach criteria.” Summary Deviations from SOPs occur for a variety of reasons; inten- Related Reading From FSF Publications tional deviations and inadvertent deviations from SOPs have been identified as causal factors in many ALAs. Flight Safety Foundation (FSF) Editorial Staff. “ATR 42 Strikes Mountain on Approach in Poor Visibility to Pristina, Kosovo.” CRM is not effective without adherence to SOPs, because SOPs Accident Prevention Volume 57 (October 2000). provide a standard reference for the crew’s tasks on the flight deck. SOPs are effective only if they are clear and concise. FSF Editorial Staff. “Crew Fails to Compute Crosswind Component, Boeing 757 Nosewheel Collapses on Landing.” Transition training provides the opportunity to establish the Accident Prevention Volume 57 (March 2000). disciplined use of SOPs, and recurrent training offers the op- portunity to reinforce that behavior. FSF Editorial Staff. “Ice Ingestion Causes Both Engines to Flame Out During Air-taxi Turboprop’s Final Approach.” Ac- The following FSF ALAR Briefing Notes provide information cident Prevention Volume 56 (February 1999). to supplement this discussion: • 1.2 — Automation; FSF Editorial Staff. “Attempted Go-around with Deployed Thrust Reversers Leads to Learjet Accident.” Accident Preven- • 1.3 — Golden Rules; tion Volume 56 (January 1999). • 1.4 — Standard Calls; Simmon, David A. “Boeing 757 CFIT Accident at Cali, Co- • 1.5 — Normal Checklists; lombia, Becomes Focus of Lessons Learned.” Flight Safety • 1.6 — Approach Briefing; Digest Volume 17 (May–June 1998). • 2.1 — Human Factors; and, FSF Editorial Staff. “Collision with Antenna Guy Wire Severs • 2.2 — Crew Resource Management.◆ Jet’s Wing During Nonprecision Approach.” Accident Preven- tion Volume 54 (October 1997).

References FSF Editorial Staff. “Flight Crew’s Failure to Perform Land- ing Checklist Results in DC-9 Wheels-up Landing.” Accident 1. The Flight Safety Foundation Approach-and-landing Prevention Volume 54 (May 1997). Accident Reduction (ALAR) Task Force defines causal factor as “an event or item judged to be directly instrumental FSF Editorial Staff. “Commuter Captain Fails to Follow in the causal chain of events leading to the accident [or Emergency Procedures After Suspected Engine Failure, Loses incident].” Each accident and incident in the study sample Control of the Aircraft During Instrument Approach.” Accident involved several causal factors. Prevention Volume 53 (April 1996). 2. Flight Safety Foundation. “Killers in Aviation: FSF Task FSF Editorial Staff. “Captain’s Inadequate Use of Flight Con- Force Presents Facts About Approach-and-landing and trols During Single-engine Approach and Go-around Results in Controlled-flight-into-terrain Accidents.”Flight Safety Digest Loss of Control and Crash of Commuter.” Accident Prevention Volume 17 (November–December 1998) and Volume 18 Volume 52 (November 1995). (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on analyses of 287 Pope, John A. “Developing a Corporate Aviation Department

4 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Operations Manual Reinforces Standard — and Safe — Op- Reprinted May 2000, incorporating Amendments 1–10. erating Procedures.” Flight Safety Digest Volume 14 (April 1995). ICAO. Manual of All-Weather Operations. Second edition – 1991.

Overall, Michael. “New Pressures on Aviation Safety Chal- ICAO. Preparation of an Operations Manual. Second edi- lenge Safety Management Systems.” Flight Safety Digest tion – 1997. Volume 14 (March 1995). U.S. Federal Aviation Administration (FAA). Federal Lawton, Russell. “Breakdown in Coordination by Commuter Aviation Regulations. 91.3 “Responsibility and authority Crew During Unstabilized Approach Results in Controlled- of the pilot in command,” 121.133 “Preparation,” 121.141 flight-into-terrain Accident.”Accident Prevention Volume 51 “Airplane Flight Manual,” 121.401 “Training program: (September 1994). General,” 125.287 “Initial and recurrent pilot testing re- quirements,” 135.293 “Initial and recurrent pilot testing FSF Editorial Staff. “Cockpit Coordination, Training Issues requirements.” January 1, 2000. Pivotal in Fatal Approach-to-Landing Accident.” Accident Prevention Volume 51 (January 1994). FAA. Advisory Circular (AC) 120-71, Standard Operating Procedures for Flight Deck Crewmembers. August 10, 2000. Arbon, E. R.; Mouden, L. Homer; Feeler, Robert A. “The Practice of Aviation Safety: Observations from Flight Safety FAA. AC 120-48, Communication and Coordination Between Foundation Safety Audits.” Flight Safety Digest Volume 9 Flight Crewmembers and Flight Attendants. July 13, 1988. (August 1990). FAA. AC 120-51C, Crew Resource Management Training. Pope, John A. “Manuals, Management and Coordination.” October 30, 1998. Flight Safety Digest Volume 7 (September 1988). FAA. AC 120-54, Advanced Qualification Program. August 9, 1991. Regulatory Resources FAA. AC 121-32, Dispatch Resource Management Training. International Civil Aviation Organization (ICAO). International February 7, 1995. Standards and Recommended Practices, Annex 6 to the Conven- tion of International Civil Aviation, Operation of Aircraft. Part I, Joint Aviation Authorities (JAA). Joint Aviation Requirements – Op- International Commercial Air Transport – Aeroplanes. Appendix erations (JAR-OPS 1), Commercial Air Transportation (Aeroplanes). 2, “Contents of an Operations Manual,” 5.9. Seventh edition – July 1.1040 “General Rules for Operations Manuals.” March 1, 1998. 1998, incorporating Amendments 1–25. JAA. JAR-OPS 1. 1.1045 “Operations Manual – structure and ICAO. Procedures for Air Navigation Services – Aircraft Op- contents.” March 1, 1998. erations. Volume I, Flight Procedures. Fourth edition, 1993.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 5 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

6 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Standard Operating Procedures Template

[The following template is adapted from U.S. Federal Aviation Administration (FAA) Advisory Circular 120 71, Standard Op- ‑ erating Procedures for Flight Deck Crewmembers.]

A manual or a section in a manual serving as the flight crew’s guide to standard operating procedures (SOPs) may serve also as a training guide. The content should be clear and comprehensive, without necessarily being lengthy. No template could include every topic that might apply unless it were constantly revised. Many topics involving special operating authority or new technology are absent from this template, among them extended operations (ETOPS), precision runway monitor (PRM), surface movement guidance system (SMGS), required navigation performance (RNP) and many others.

The following are nevertheless viewed by industry and FAA alike as examples of topics that constitute a useful template for developing comprehensive, effective SOPs: • Captain’s authority; – Before taxi;

• Use of automation, including: – Before takeoff; – The company’s automation philosophy; – After takeoff; – Specific guidance in selection of appropriate levels of – Climb check; automation; – Cruise check; – Autopilot/flight director mode selections; and, – Approach; – Flight management system (FMS) target entries (e.g., airspeed, heading, altitude); – landing; – After landing; • Checklist philosophy, including: – Parking and securing; – Policies and procedures (who calls for; who reads; who does); – Emergency procedures; and, – Format and terminology; and, – Abnormal procedures; – Type of checklist (challenge-do-verify, or do-verify); • Communication, including: • Walk-arounds; – Who handles radios; • Checklists, including: – Primary language used with air traffic control (ATC) and on the flight deck; – Safety check prior to power on; – Keeping both pilots “in the loop”; – originating/receiving; – Before start; – Company radio procedures; – After start; – Flight deck signals to cabin; and, – Cabin signals to flight deck;

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 7 • Briefings, including: – Visual flight rules/instrument flight rules (VFR/IFR); – Controlled-flight-into-terrain (CFIT) risk considered; – Icing considerations; – Special airport qualifications considered; – Fuel loads; – Temperature corrections considered; – Weather-information package; – Before takeoff; and, – Where weather-information package is available; – descent/approach/missed approach; and, – departure procedure climb gradient analysis; • Flight deck access, including: – on ground/in flight; • Boarding passengers/cargo, including: – Jump seat; and, – Carry-on baggage; – Access signals, keys; – Exit-row seating; – hazardous materials; • Flight deck discipline, including: – Prisoners/escorted persons; – “Sterile cockpit”1; – Firearms onboard; and, – Maintaining outside vigilance; – Count/load; – Transfer of control; – Additional duties; • Pushback/powerback; – Flight kits; • Taxiing, including: – headsets/speakers; – Single-engine; – Boom mikes/handsets; – All-engines; – Maps/approach charts; and, – on ice or snow; and, – Meals; – Prevention of runway incursion;

• Altitude awareness, including: • Crew resource management (CRM), including crew – Altimeter settings; briefings (cabin crew and flight crew); – Transition altitude/flight level; • Weight and balance/cargo loading, including: – Standard calls (verification of); – Who is responsible for loading cargo and securing – Minimum safe altitudes (MSAs); and, cargo; and, – Temperature corrections; – Who prepares the weight-and-balance data form; who checks the form; and how a copy of the form is • Report times; including: provided to the crew; – Check in/show up; • Flight deck/cabin crew interchange, including: – on flight deck; and, – Boarding; – Checklist accomplishment; – Ready to taxi; • Maintenance procedures, including: – Cabin emergency; and, – logbooks/previous write-ups; – Prior to takeoff/landing; – open write-ups; • Takeoff, including: – Notification to maintenance of write-ups; – Who conducts the takeoff; – Minimum equipment list (MEL)/dispatch deviation – Briefing, VFR/IFR; guide (DDG); – Reduced-power procedures; – Where MEL/DDG is accessible; – Tail wind, runway clutter; – Configuration deviation list (CDL); and, – Intersections/land and hold short operations (LAHSO) – Crew coordination in ground deicing; procedures; – Noise-abatement procedures; • Flight plans/dispatch procedures, including:

8 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 – Special departure procedures; – Stabilized approaches standard; – Use/nonuse of flight directors; – Use of navigation aids; – Standard calls; – FMS/autopilot use and when to discontinue use; – Cleanup; – Approach gate3 and limits for stabilized approaches, – loss of engine, including rejected takeoff after V1 (Table 1); (actions/standard calls); – Use of radio altimeter; and, – Flap settings, including: – go-arounds (plan to go around; change plan to land • Normal; when visual, if stabilized); • Nonstandard and reason for; and, • Crosswind; and, • Individual approach type (all types, including engine- out approaches); – Close-in turns; • For each type of approach: • Climb, including: – Profile; – Speeds; – Flap/gear extension; – Configuration; – Standard calls; and, – Confirm compliance with climb gradient required in departure procedure; and, – Procedures; – Confirm appropriate cold-temperature corrections • go-around/missed approach, including: made; – Initiation when an approach gate is missed; • Cruise altitude selection (speeds/weights); – Procedure; • Position reports to ATC and to company; – Standard calls; and, – Cleanup profile; and, • Emergency descents; • landing, including: • holding procedures; – Actions and standard calls; • Procedures for diversion to alternate airport; – Configuration for conditions, including: • Normal descents, including: • Visual approach; – Planning top-of-descent point; • low visibility; and, – Risk assessment and briefing; • Wet or contaminated runway; – Use/nonuse of speed brakes; – Close-in turns; – Use of flaps/gear; – Crosswind landing; – Icing considerations; and, – Convective activity; – Rejected landing; and, – Transfer of control after first officer’s landing. • ground-proximity warning system (GPWS) or terrain awareness and warning system (TAWS)2 recovery (“pull- References up”) maneuver; 1. The sterile cockpit rule refers to U.S. Federal Aviation • Traffic-alert and collision avoidance system (TCAS)/ Regulations Part 121.542, which states: “No flight crew- airborne collision avoidance system (ACAS); member may engage in, nor may any pilot-in-command permit, any activity during a critical phase of flight • Wind shear, including: which could distract any flight crewmember from the performance of his or her duties or which could inter- – Avoidance of likely encounters; fere in any way with the proper conduct of those duties. – Recognition; and, Activities such as eating meals, engaging in nonessen- – Recovery/escape maneuver; tial conversations within the cockpit and nonessential communications between the cabin and cockpit crews, • Approach philosophy, including: and reading publications not related to the proper con- – Precision approaches preferred; duct of the flight are not required for the safe operation of the aircraft. For the purposes of this section, critical

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 9 Table 1 Recommended Elements of a Stabilized Approach All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabilized when all of the following criteria are met: 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be conducted; 6. Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Category III ILS approach must be flown within the expanded localizer band; during a circling approach, wings should be level on final when the aircraft reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a stabilized approach require a special briefing. An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate go-around. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1, November 2000)

phases of flight include all ground operations involv- warning system (GPWS) equipment that provides pre- ing taxi, takeoff and landing, and all other flight opera- dictive terrain-hazard warnings. “Enhanced GPWS” and tions below 10,000 feet, except cruise flight.” [The FSF “ground collision avoidance system” are other terms used ALAR Task Force says that “10,000 feet” should be to describe TAWS equipment. height above ground level during flight operations over 3. The Flight Safety Foundation Approach-and-landing Ac- high terrain.] cident Reduction (ALAR) Task Force defines approach 2. Terrain awareness and warning system (TAWS) is the term gate as “a point in space (1,000 feet above airport elevation used by the European Joint Aviation Authorities and the in instrument meteorological conditions or 500 feet above U.S. Federal Aviation Administration to describe equip- airport elevation in visual meteorological conditions) at ment meeting International Civil Aviation Organization which a go-around is required if the aircraft does not meet standards and recommendations for ground-proximity defined stabilized approach criteria.”

Copyright © 2009 Flight Safety Foundation Suite 300, 601 Madison Street, Alexandria, VA 22314-1756 U.S. • Telephone: +1 (703) 739-6700, Fax: +1 (703) 739-6708 www.flightsafety.org In the interest of aviation safety, this publication may be reproduced, in whole or in part, in all media, but may not be offered for sale or used commerciallywithout the express written permission of Flight Safety Foundation’s director of publications. All uses must credit Flight Safety Foundation.

10 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 1.2 — Automation

Three generations of system automation for airplane flight AP-A/THR Integration guidance — autopilot/flight director (AP/FD), autothrottles (A/THR) and flight management system (FMS) — are cur- Integrated AP-A/THR automatic flight systems (AFSs) feature rently in service: pairing of the AP pitch modes (elevator control) and the A/ • The first generation features a partial integration of the THR modes (throttles/thrust control). AP/FD and A/THR modes, offering selected AP/FD modes and lateral navigation only; An integrated AP-A/THR flies the aircraft the same way as a human pilot: • The second generation features complete integration (pairing) of AP/FD and A/THR modes and offers • The elevator is used to control pitch attitude, airspeed, selected modes as well as lateral navigation and vertical vertical speed, altitude, flight path angle or VNAV navigation (FMS); and, profile, or to track a glideslope; and,

• The third generation features full-regime lateral • The throttle levers are used to maintain a given thrust navigation (LNAV) and vertical navigation (VNAV). setting or a given airspeed.

High levels of automation provide flight crews with more op- Depending on the task to be accomplished, maintaining a tions from which to select for the task to be accomplished. given airspeed is assigned either to the AP or to the A/THR, as shown in Table 1.

Table 1 Statistical Data Autothrottle/Autopilot Integration

The Flight Safety Foundation Approach-and-landing Ac- Autothrottles Autopilot cident Reduction (ALAR) Task Force found that inadequate Throttles/thrust Elevators flight crew interaction with automatic flight systems was Thrust or idle Airspeed a causal factor1 in 20 percent of 76 approach-and-landing accidents and serious incidents worldwide in 1984 through Airspeed Vertical speed 2 Vertical navigation 1997. Altitude Glideslope The task force said that these accidents and incidents involved crew unawareness of automated system modes or crew unfa- Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force. miliarity with automated systems.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 11 Design Objective • how is the system operated in normal conditions and abnormal conditions? The design objective of the AFS is to provide assistance to the crew throughout the flight, by: Pilot-Automation Interface

• Relieving the pilot flying (PF) from routine tasks, To use the full potential of automation and to maintain situ- thus allowing time and resources to enhance his/her ational awareness, a thorough understanding of the interface situational awareness or for problem-solving tasks; between the pilot and the automation is required to allow the and, pilot to answer the following questions at any time:

• Providing the PF with adequate attitude guidance and • What did I tell the aircraft to do? flight-path guidance through the FD for hand-flying the aircraft. • Is the aircraft doing what I told it to do? • What did I plan for the aircraft to do next? The AFS provides guidance along the defined flight path and at the intended airspeed, in accordance with the modes selected (The terms “tell” and “plan” in the above paragraph refer to by the crew and the targets (e.g., altitude, airspeed, heading, arming or selecting modes and/or entering targets.) vertical speed, waypoints, etc.) entered by the crew. The functions of the following controls and displays must be The AFS control panel is the main interface between the pilot and the understood: AFS for short-term guidance (i.e., for the current flight phase). • AFS mode-selection keys, target-entry knobs and display The FMS control display unit (CDU) is the main interface windows; between the pilot and the AFS for long-term guidance (i.e., for the current flight phase and subsequent flight phases). • FMS CDU keyboard, line-select keys, display pages and messages; On aircraft equipped with an FMS featuring LNAV and VNAV, two types of guidance (modes and associated targets) are avail- • Flight-mode annunciator (FMA) annunciations; and, able: • Primary flight display (PFD) and navigation display (ND) data. • Selected guidance: Effective monitoring of these controls and displays promotes – The aircraft is guided along a flight path defined by and increases pilot awareness of: the modes selected and the targets entered by the crew on the AFS control panel; and, • The status of the system (modes armed and selected); and, • FMS guidance: • The available guidance (for flight-path control and – The aircraft is guided along the FMS lateral flight airspeed control). path and vertical flight path; the airspeed and altitude targets are optimized by the FMS (adjusted for Effective monitoring of controls and displays also enables the restrictions of altitude and/or airspeed). pilot to predict and to anticipate the entire sequence of flight- mode annunciations throughout successive flight phases (i.e., throughout mode changes). Automated Systems

Understanding any automated system, but particularly the AFS Operating Philosophy and FMS, requires answering the following questions: FMS or selected guidance can be used in succession or in • how is the system designed? combination (e.g., FMS lateral guidance together with selected vertical guidance) as best suited for the flight phase and pre- • Why is the system designed this way? vailing conditions. • how does the system interface and communicate with Operation of the AFS must be monitored at all times by: the pilot?

12 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Cross-checking the status of AP/FD and A/THR modes • Inadvertent arming of a mode or selection of an incorrect (armed and selected) on the FMA; mode;

• observing the result of any target entry (on the AFS • Failure to verify the armed mode or selected mode by control panel) on the related data as displayed on the reference to the FMA; PFD or ND; and, • Entering an incorrect target (e.g., altitude, airspeed, • Supervising the resulting AP/FD guidance and A/ heading) on the AFS control panel and failure to confirm THR operation on the PFD and ND (e.g., attitude, the entered target on the PFD and/or ND; airspeed and airspeed trend, altitude, vertical speed, heading, etc.). • Changing the AFS control panel altitude target to any altitude below the final approach intercept altitude The PF always retains the authority and the capability to use during approach; the most appropriate guidance and level of automation for the task. This includes: • Inserting an incorrect waypoint;

• Reverting from FMS guidance to selected guidance • Arming the LNAV mode with an incorrect active (more direct level of automation); waypoint (i.e., with an incorrect “TO” waypoint);

• Selecting a more appropriate lateral mode or vertical • Preoccupation with FMS programming during a mode; or, critical flight phase, with consequent loss of situational awareness; • Reverting to hand-flying (with or without FD, with or without A/THR) for direct control of the aircraft • Inadequate understanding of mode changes (e.g., mode trajectory and thrust. confusion, automation surprises); • Inadequate task-sharing and/or inadequate crew If doubt exists about the aircraft’s flight path or airspeed con- resource management (CRM), preventing the PF from trol, no attempt should be made to reprogram the automated monitoring the flight path and airspeed (e.g., both systems. Selected guidance or hand-flying with raw data3 pilots being engaged in the management of automation should be used until time and conditions permit reprogram- or in the troubleshooting of an unanticipated or ming the AP/FD or FMS. abnormal condition); and,

If the aircraft does not follow the intended flight path, check • Engaging the AP or disengaging the AP when the aircraft the AP engagement status. If engaged, the AP must be discon- is in an out-of-trim condition. nected using the AP-disconnect switch to revert to hand-flying with FD guidance or with reference to raw data. Recommendations When hand-flying, the FD commands should be followed; otherwise, the FD command bars should be cleared from the Proper use of automated systems reduces workload and PFD. increases the time and resources available to the flight crew for responding to any unanticipated change or abnormal/ If the A/THR does not function as desired, the A/THR must emergency condition. be disconnected using the A/THR-disconnect switch to revert to manual thrust control. During normal line operations, the AP and A/THR should be engaged throughout the flight, including the descent and the AP systems and A/THR systems must not be overridden manu- approach, especially in marginal weather or when operating ally (except under conditions set forth in the aircraft operating into an unfamiliar airport. manual [AOM] or quick reference handbook [QRH]). Using the AFS also enables the flight crew to give more atten- Factors and Errors tion to air traffic control (ATC) communications and to other aircraft, particularly in congested terminal areas. The following factors and errors can cause an incorrect flight path, which — if not recognized — can lead to an approach- The AFS/FMS also is a valuable aid during a go-around or and-landing accident, including one involving controlled flight missed approach. into terrain:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 13 When the applicable missed approach procedure is included minimum safe altitude (MSA) — if the entered in the FMS flight plan and the FMS navigation accuracy has altitude is below the MEA or MSA, obtain altitude been confirmed, the LNAV mode reduces workload during confirmation from ATC; and, this critical flight phase. – during final approach, set the go-around altitude Safe-and-efficient use of the AFS and FMS is based on the on the AFS control panel altitude window (the following three-step method: minimum descent altitude/height [MDA(H)] or decision altitude/height [DA(H)] should not be set • Anticipate: in the window);

– Understand system operation and the result(s) of any • Prepare the FMS for arrival before beginning the action, be aware of modes being armed or selected, and descent; seek concurrence of other flight crewmember(s); • An expected alternative arrival routing and/or runway • Execute: can be prepared on the second flight plan;

– Perform the action on the AFS control panel or on • If a routing change occurs (e.g., “DIR TO” [direct to a the FMS CDU; and, waypoint]), cross-check the new “TO” waypoint before • Confirm: selecting the “DIR TO” mode (making sure that the intended “DIR TO” waypoint is not already behind the – Cross-check armed modes, selected modes and target aircraft): entries on the FMA, PFD/ND and FMS CDU. – Caution is essential during descent in mountainous The following recommendations support the implementation areas; and, of the three-step method: – If necessary, the selected heading mode and raw data • Before engaging the AP, ensure that: can be used while verifying the new route; – The modes selected for FD guidance (as shown by the • Before arming the LNAV mode, ensure that the correct FMA) are the correct modes for the intended flight active waypoint (i.e., the “TO” waypoint) is displayed phase; and, on the FMS CDU and ND (as applicable); – The FD command bars do not show large flight- • If the displayed “TO” waypoint is not correct, the desired path-correction commands (if large corrections “TO” waypoint can be restored by either: are commanded, hand-fly the aircraft to center the FD command bars [engaging the AP while large – deleting an intermediate waypoint; or, flight-path corrections are required may result in overshooting the intended target]); – Performing a “DIR TO” the desired waypoint; and then, • Before taking any action on the AFS control panel, check that the knob or push-button is the correct one for the – Monitoring the interception of the lateral flight desired function; path;

• After each action on the AFS control panel, verify the • If a late routing change or runway change occurs, result of the action by reference to the FMA (for mode reversion to selected modes and raw data is arming or mode selection) and to other PFD/ND data recommended; (for entered targets) or by reference to the flight path and airspeed; • Reprogramming the FMS during a critical flight phase (e.g., in terminal area, on approach or go-around) is not • Monitor the FMA and call all mode changes in accordance recommended, except to activate the second flight plan, with standard operating procedures (SOPs); if needed. Primary tasks are, in order of priority:

• When changing the altitude entered on the AFS control – lateral flight path control and vertical flight path panel, cross-check the selected-altitude readout on the control; PFD: – Altitude awareness and traffic awareness; and, – during descent, check whether the entered altitude is below the minimum en route altitude (MEA) or – ATC communications;

14 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • No attempt should be made to analyze or to correct an target entries); and, anomaly by reprogramming the AFS or the FMS until the desired flight path and airspeed are restored; – System-to-pilot feedback (modes and target cross- check); • If cleared to leave a holding pattern on a radar vector, the holding exit prompt should be pressed (or the • Awareness of available guidance (AP/FD and A/THR holding pattern otherwise deleted) to allow the correct status, modes armed or engaged, active targets); and, sequencing of the FMS flight plan; • Alertness and willingness to revert to a lower level of • on a radar vector, when intercepting the final approach automation or to hand-flying/manual thrust control, if course in a selected mode (e.g., heading, localizer required. capture, etc. [not LNAV]), the flight crew should ensure that the FMS flight plan is sequencing normally by The following FSF ALAR Briefing Notes provide information checking that the “TO” waypoint (on the FMS CDU to supplement this discussion: and the ND, as applicable) is correct, so that the LNAV mode can be re-selected for a go-around; • 1.1 — Operating Philosophy;

• If the FMS flight plan does not sequence correctly, the • 1.3 — Golden Rules; and, correct sequencing can be restored by either: • 1.4 — Standard Calls.◆ – deleting an intermediate waypoint; or,

– Performing a “DIR TO” a waypoint ahead in the approach; References

– otherwise, the LNAV mode should not be used for the 1. The Flight Safety Foundation Approach-and-landing remainder of the approach or for a go-around; and, Accident Reduction (ALAR) Task Force defines causal factor as “an event or item judged to be directly instrumental • Any time the aircraft does not follow the desired flight in the causal chain of events leading to the accident [or path and/or airspeed, do not hesitate to revert to a lower incident].” Each accident and incident in the study sample (more direct) level of automation. For example: involved several causal factors. – Revert from FMS to selected modes; 2. Flight Safety Foundation. “Killers in Aviation: FSF Task – disengage the AP and follow FD guidance; Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety – disengage the FD, select the flight path vector (FPV Digest Volume 17 (November–December 1998) and [as available]) and fly raw data or fly visually (if in Volume 18 (January–February 1999): 1–121. The facts visual meteorological conditions); and/or, presented by the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents – disengage the A/THR and control the thrust (ALAs) that occurred in 1980 through 1996 involving manually. turbine aircraft weighing more than 12,500 pounds/5,700 kilograms, detailed studies of 76 ALAs and serious incidents in 1984 through 1997 and audits of about 3,300 Summary flights. 3. The FSF ALAR Task Force defines raw data as “data For optimum use of automation, the following should be received directly (not via the flight director or flight emphasized: management computer) from basic navigation aids (e.g., • Understanding of AP/FD and A/THR modes integration ADF, VOR, DME, barometric altimeter).” (pairing);

• Understanding of all mode-change sequences; Related Reading from FSF Publications • Understanding of the pilot-system interface: Flight Safety Foundation (FSF) Editorial Staff. “Crew Fails – Pilot-to-system communication (mode selection and to Compute Crosswind Component, Boeing 757 Nosewheel

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 15 Collapses on Landing.” Accident Prevention Volume 57 Change, Boeing 757 Flight Crew Loses Situational Aware- (March 2000). ness, Resulting in Collision with Terrain.” Accident Prevention Volume 54 (July–August 1997). Wiener, Earl L.; Chute, Rebecca D.; Moses, John H. “Transi- tion to Glass: Pilot Training for High-technology Transport FSF Editorial Staff. “Stall and Improper Recovery During ILS Aircraft.” Flight Safety Digest Volume 18 (June–August Approach Result in Commuter Airplane’s Uncontrolled Collision 1999). with Terrain.” Accident Prevention Volume 52 (January 1995).

Australia Department of Transport and Regional Development, Lawton, Russell. “Airframe Icing and Captain’s Improper Bureau of Air Safety Investigation. “Advanced-technology Use of Autoflight System Result in Stall andL oss of Control Aircraft Safety Survey Report.” Flight Safety Digest Volume of Commuter Airplane.” Accident Prevention Volume 51 18 (June–August 1999). (November 1994).

Sumwalt, Robert L., III. “Enhancing Flight-crew Monitoring Roscoe, Alan H. “Workload in the Glass Cockpit.” Flight Skills Can Increase Flight Safety.” Flight Safety Digest Volume Safety Digest Volume 11 (April 1992). 18 (March 1999). King, Jack L. “Coping with High-tech Cockpit Complacency.” FSF Editorial Staff. “Preparing for Last-minute Runway Accident Prevention Volume 49 (January 1992).

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

16 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 1.3 — Golden Rules

“Golden rules” guide human activities in many areas. Golden Rules

In early aviation, golden rules defined the basic principles of Automated Aircraft Can Be Flown airmanship. Like Any Other Aircraft With the development of technology in modern aircraft and To promote this rule, each trainee should be given the oppor- with research on human-machine interface and crew coordi- tunity to hand-fly the aircraft — that is, to fly “stick, rudder nation, the golden rules have been broadened to include the and throttles.” principles of interaction with automation and crew resource management (CRM). The flight director (FD), autopilot (AP), autothrottles (A/THR) and flight management system (FMS) should be introduced The following golden rules are designed to assist trainees (but progressively in the training syllabus. are useful for experienced pilots) in maintaining basic airman- ship even as they progress to highly automated aircraft. These The progressive training will emphasize that the pilot flying rules apply with little modification to all modern aircraft. (PF) always retains the authority and capability to revert:

• To a lower (more direct) level of automation; or, Statistical Data • To hand-flying — directly controlling the aircraft The Flight Safety Foundation Approach-and-landing Accident trajectory and energy condition. Reduction (ALAR) Task Force, in a study of 76 approach-and- landing accidents and serious incidents worldwide in 1984 Aviate (Fly), Navigate, Communicate and Manage through 1997,1 found that: — In That Order • Inadequate professional judgment/airmanship was a During an abnormal condition or an emergency condition, causal factor2 in 74 percent of the accidents and serious PF PNF (pilot not flying) task-sharing should be adapted to incidents; ‑ the situation (in accordance with the aircraft operating manual • Failure in CRM (crew coordination, cross-check and [AOM] or quick reference handbook [QRH]), and tasks should backup) was a causal factor in 63 percent of the events; be accomplished with this four-step strategy: and, Aviate. The PF must fly the aircraft (pitch attitude, thrust, • Incorrect interaction with automation was a causal factor sideslip, heading) to stabilize the aircraft’s pitch attitude, bank in 20 percent of the events. angle, vertical flight path and horizontal flight path.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 17 The PNF must back up the PF (by monitoring and by making Procedures should be performed as set forth in the AOM/QRH call-outs) until the aircraft is stabilized. or in the following sequence: • Emergency checklists; Navigate. Upon the PF’s command, the PNF should select or should restore the desired mode for lateral navigation and/or • Normal checklists; and, vertical navigation (selected mode or FMS lateral navigation • Abnormal checklists. [LNAV]/vertical navigation [VNAV]), being aware of terrain and minimum safe altitude. These should be performed in accordance with the published task-sharing, CRM and standard phraseology. Navigate can be summarized by the following: • Know where you are; Critical actions or irreversible actions (e.g., selecting a fuel le- ver or a fuel-isolation valve to “OFF”) should be accomplished • Know where you should be; and, by the PNF after confirmation by the PF. • Know where the terrain and obstacles are. Know Your Available Guidance at All Times Communicate. After the aircraft is stabilized and the abnormal condition or emergency condition has been identified, the PF The AP/FD-A/THR control panel(s) and the FMS control should inform air traffic control (ATC) of the situation and of display unit (CDU) are the primary interfaces for the crew his/her intentions. to communicate with the aircraft systems (to arm modes or select modes and to enter targets [e.g., airspeed, heading, If the flight is in a condition of distress or urgency, the PF altitude]). should use standard phraseology: • “Pan Pan, Pan Pan, Pan Pan,”3 or, The primary flight display (PFD), the navigation display (ND) and particularly the flight-mode annunciator (FMA) are the • “Mayday, Mayday, Mayday.”4 primary interfaces for the aircraft to communicate with the crew to confirm that the aircraft system has accepted correctly Manage. The next priority is management of the aircraft sys- the crew’s mode selections and target entries. tems and performance of the applicable abnormal procedures or emergency procedures. Any action on the AP/FD-A/THR control panel(s) or on the FMS CDU should be confirmed by cross-checking the cor- Table 1 shows that the design of highly automated aircraft responding FMA annunciation or data on the FMS display fully supports the four-step strategy. unit and on the PFD/ND.

At all times, the PF and the PNF should be Table 1 aware of the guidance modes that are armed Display Use in Abnormal or Emergency Situations or selected and of any mode changes. Golden Rule Display Unit Aviate (Fly) PFD Cross-check the Accuracy of the Navigate ND FMS With Raw Data Communicate Audio Control Unit When within navaid-coverage areas, the Manage ECAM or EICAS FMS navigation accuracy should be cross- 5 PFD = Primary flight display checked with raw data. ND = Navigation display ECAM = Electronic centralized aircraft monitor FMS navigation accuracy can be checked EICAS = Engine indication and crew alerting system usually by: Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force • Entering a tuned very-high- frequency omnidirectional radio/distance- Implement Task-sharing and Backup measuring equipment (VOR/DME) station in the bearing/distance (“BRG/DIST TO” or “DIST FR”) field After the four-step strategy has been completed, the actions of the appropriate FMS page; associated with the abnormal condition or emergency condition • Comparing the resulting FMS “BRG/DIST TO” (or should be called by the PF. “DIST FR”) reading with the bearing/distance raw data

18 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 on the radio magnetic indicator (RMI) or ND; and, Reversion to hand-flying and manual thrust control may be the optimum level of automation for a specific condition. • Checking the difference between FMS and raw data against the criteria applicable for the flight phase (as required by standard operating procedures [SOPs]). Golden Rules for Abnormal Conditions If the required accuracy criteria are not met, revert from LNAV And Emergency Conditions to selected heading and raw data, with associated ND display. The following golden rules may assist flight crews in their One Head Up decision making in any abnormal condition or emergency condition, but particularly if encountering a condition not Significant changes to the FMS flight plan should be performed covered by the published procedures. by the PNF. The changes then should be cross-checked by the other pilot after transfer of aircraft control to maintain one Understand the Prevailing Condition Before Acting head up at all times. Incorrect decisions often are the result of incorrect recognition of the prevailing condition and/or incorrect identification of When Things Do Not Go as Expected, Take Control the prevailing condition.

If the aircraft does not follow the desired horizontal flight path Assess Risks and Time Pressures or vertical flight path and time does not permit analyzing and solving the anomaly, revert without delay from FMS guidance Take time to make time when possible (e.g., request a holding to selected guidance or to hand-flying. pattern or radar vectors).

Evaluate the Available Options Use the Optimum Level of Automation for the Task Weather conditions, crew preparedness, type of operation, On highly automated and integrated aircraft, several levels of airport proximity and self-confidence should be considered automation are available to perform a given task: in selecting the preferred option. • FMS modes and guidance; Include all flight crewmembers, cabin crewmembers, ATC and • Selected modes and guidance; or, company maintenance technicians, as required, in this evalu- ation. • hand-flying. Match the Response to the Condition The optimum level of automation depends on: An emergency condition requires immediate action (this does • Task to be performed: not mean rushed action), whereas an abnormal condition may – Short-term (tactical) task; or, tolerate a delayed action.

– long-term (strategic) task; Consider All Implications, Plan for Contingencies • Flight phase: Consider all the aspects of continuing the flight through the – En route; landing.

– Terminal area; or, Manage Workload – Approach; and, Adhere to the defined task-sharing for abnormal/emergency • Time available: conditions to reduce workload and to optimize crew re- sources. – Normal selection or entry; or, – last-minute change. Use the AP and A/THR to alleviate PF workload. Use the proper level of automation for the prevailing condition. The optimum level of automation often is the one that the flight crew feels the most comfortable with, depending on their Communicate knowledge of and experience with the aircraft and systems. Communicate to all aircraft crewmembers the prevailing condi-

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 19 tion and planned actions so they all have a common reference as that the words “Pan Pan” (pronounced “Pahn, Pahn”) at the they work toward a common and well-understood objective. beginning of a communication identifiesurgency — i.e., “a condition concerning the safety of an aircraft … or of some Apply Procedures and Other Agreed Actions person on board or within sight, but which does not require immediate assistance.” ICAO says that “Pan Pan” should Understand the reasons for any action and the implications of be spoken three times at the beginning of an urgency call. any action before acting and check the result(s) of each action before proceeding with the next action. 4. ICAO says that the word “Mayday” at the beginning of a communication identifiesdistress — i.e., “a condition Beware of irreversible actions (cross-check before acting). of being threatened by serious and/or imminent danger and of requiring immediate assistance.” ICAO says that Summary “Mayday” should be spoken three times at the beginning of a distress call. If only one golden rule were to be adopted, the following is suggested: 5. The FSF ALAR Task Force defines raw data as “data received directly (not via the flight director or flight Ensure always that at least one pilot is controlling and is management computer) from basic navigation aids (e.g., monitoring the flight path of the aircraft. ADF, VOR, DME, barometric altimeter).”

The following FSF ALAR Briefing Notes provide information to supplement this discussion: Related Reading from FSF Publications Wiener, Earl L.; Chute, Rebecca D.; Moses, John H. “Transi- • 1.1 — Operating Philosophy; tion to Glass: Pilot Training for High-technology Transport Air- • 1.2 — Automation; craft.” Flight Safety Digest Volume 18 (June–August 1999). • 1.5 — Normal Checklists; and, Flight Safety Foundation (FSF) Editorial Staff. “Poorly Flown • 2.2 — Crew Resource Management.◆ Approach in Fog Results in Collision With Terrain Short of Runway.” Accident Prevention Volume 52 (August 1995). References Lawton, Russell. “Steep Turn by Captain During Approach 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Results in Stall and Crash of DC-8 Freighter.” Accident Pre- Force Presents Facts About Approach-and-landing and vention Volume 51 (October 1994). Controlled-flight-into-terrain Accidents.” Flight Safety Rosenthal, Loren J.; Chamberlin, Roy W.; Matchette, Robert Digest Volume 17 (November–December 1998) and Volume D. “Flight Deck Confusion Cited in Many Aviation Incident 18 (January–February 1999): 1–121. The facts presented by Reports.” Human Factors & Aviation Medicine Volume 41 the FSF ALAR Task Force were based on analyses of 287 (July–August 1994). fatal approach-and-landing accidents (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing King, Jack L. “Coping with High-tech Cockpit Complacency.” more than 12,500 pounds/5,700 kilograms, detailed studies Accident Prevention Volume 49 (January 1992). of 76 ALAs and serious incidents in 1984 through 1997 and audits of about 3,300 flights. Regulatory Resources 2. The Flight Safety Foundation Approach-and-landing Accident International Civil Aviation Organization. Human Factors Reduction (ALAR) Task Force definescausal factor as “an Training Manual. First edition – 1998, incorporating Circular event or item judged to be directly instrumental in the causal 216. chain of events leading to the accident [or incident].” U.S. Federal Aviation Administration. Advisory Circular 60- 3. The International Civil Aviation Organization (ICAO) says 22, Aeronautical Decision Making. December 13, 1991.

20 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 21 FSF ALAR Briefing Note 1.4 — Standard Calls

Standard phraseology is essential to ensure effective crew flight deck or between pilots and controllers. communication, particularly in today’s operating environment, which increasingly features: Standard calls reduce the risk of tactical (short-term) decision- making errors (in selecting modes or entering targets [e.g., • Two-person crew operation; and, airspeed, heading, altitude] or in setting configurations). • Crewmembers from different cultures and with different native languages. The importance of using standard calls increases with increased workload. Standard calls — commands and responses — are designed to enhance overall situational awareness (including awareness of Standard calls should be practical, concise, clear and consistent the status and the operation of aircraft systems). with the aircraft design and operating philosophy.

Standard calls may vary among aircraft models, based upon Standard calls should be included in the flow sequence of the flight deck design and system designs, and among company manufacturer’s SOPs or the company’s SOPs and with the standard operating procedures (SOPs). flight-pattern illustrations in the aircraft operating manual (AOM).

Statistical Data Standard calls should be performed in accordance with the defined PF/PNF task-sharing (i.e., task-sharing for hand-flying The Flight Safety Foundation Approach-and-landing Acci- vs. autopilot operation, or task-sharing for normal condition dent Reduction (ALAR) Task Force found that an absence of vs. abnormal/emergency condition). standard calls was a factor in approach-and-landing accidents and serious incidents worldwide in 1984 through 1997 that Nevertheless, if a standard call is omitted by one pilot, the were attributed, in part, to failure in crew resource manage- other pilot should suggest the call, per CRM. ment (CRM).1 Sixty-three percent of the 76 accidents and serious incidents during the period involved failure in CRM The absence of a standard call at the appropriate time or the 2 as a causal factor. absence of an acknowledgment may be the result of a system malfunction or equipment malfunction, or possible incapacita- Use of Standard Calls — General Rules tion of the other crewmember.

Standard calls should be alerting, so that they are clearly Standard calls should be used to: identified by the pilot flying (PF) or pilot not flying (PNF), • give a command (delegate a task) or transfer and should be distinguished from communication within the information;

22 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Acknowledge a command or confirm receipt of • Traffic-alert and collision avoidance system (TCAS) information; traffic advisory (TA) or resolution advisory (RA); • give a response or ask a question (feedback); • PF/PNF transfer of controls; • Call a change of indication (e.g., a flight-mode • Excessive deviation from a flight parameter; annunciator [FMA] mode change); or, • Specific points along the instrument approach • Identify a specific event (e.g., crossing an altitude or procedure; flight level). • Approaching minimums and reaching minimums; • Acquisition of visual references; and, General Standard Calls • decision to land or to go around. The following are standard calls: The use of standard calls is of paramount importance for • “Check” (or “verify”): A command for the other pilot the optimum use of automation (autopilot, flight director and to check an item or to verify an item; autothrottle mode arming or mode selection, target entries, • “Checked”: A confirmation that an item has been FMA annunciations, flight management system [FMS] mode checked; selections): • “Cross-check(ed)”: A confirmation that information has • Standard calls should trigger immediately the question been checked at both pilot stations; “What do I want to fly now?” and thus clearly indicate which: • “Set”: A command for the other pilot to enter a target value or a configuration; – Mode the pilot intends to arm or select; or, • “Arm”: A command for the other pilot to arm a system – Target the pilot intends to enter; and, (or a mode); • When the intention of the PF is clearly transmitted to • “Engage”: A command for the other pilot to engage a the PNF, the standard calls also will: system or select a mode; and, – Facilitate cross-check of the FMA (and primary flight • “On” (or “off”) following the name of a system: A display or navigation display, as applicable); and, command for the other pilot to select (or deselect) – Facilitate crew coordination, cross-check and the system; or a response confirming the status of the backup. system. Standard calls also should be defined for flight crew/cabin crew Specific Standard Calls communication in both: • Normal conditions; and, Specific standard calls should be defined for the following events: • Abnormal conditions or emergency conditions (e.g., cabin depressurization, on-ground emergency/ • Flight crew/ground personnel communication; evacuation, forced landing or ditching, crewmember • Engine-start sequence; incapacitation). • landing gear and slats/flaps selection (retraction or extension); Harmonization of Standard Calls • Initiation, interruption, resumption and completion of The harmonization of standard calls across various aircraft normal checklists; fleets (from the same aircraft manufacturer or from different • Initiation, sequencing, interruption, resumption and aircraft manufacturers) is desirable but should not be an over- completion of abnormal checklists and emergency riding demand. checklists; Standard calls across fleets are essential only for crewmembers • FMA mode changes; operating different fleets (i.e., communication between flight • Changing the altimeter setting; deck and cabin or flight deck and ground). • Approaching the cleared altitude or flight level;

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 23 Within the flight deck, pilots must use standard calls appropri- of 76 ALAs and serious incidents in 1984 through 1997 and ate for the flight deck and systems. audits of about 3,300 flights. 2. The Flight Safety Foundation Approach-and-landing With the exception of aircraft models with flight deck common- Accident Reduction (ALAR) Task Force defines causal ality, flight deck layouts and systems are not the same; thus, factor as “an event or item judged to be directly instrumental similarities as well as differences should be recognized. in the causal chain of events leading to the accident [or incident].” Each accident and incident in the study sample When defining standard calls, standardization and operational involved several causal factors. efficiency should be balanced carefully.

Related Reading from FSF Publications Summary

Standard calls are a powerful tool for effective crew interaction Rosenthal, Loren J.; Chamberlin, Roy W.; Matchette, Robert and communication. D. “Flight Deck Confusion Cited in Many Aviation Incident Reports.” Human Factors & Aviation Medicine Volume 41 The command and the response are of equal importance to (July–August 1994). ensure timely action or correction. Flight Safety Foundation Editorial Staff. “Cockpit Coordina- The following FSF ALAR Briefing Notes provide information tion, Training Issues Pivotal in Fatal Approach-to-Landing to supplement this discussion: Accident.” Accident Prevention Volume 54 (January 1994). • 1.1 — Operating Philosophy; • 1.2 — Automation; Regulatory Resources • 1.5 — Normal Checklists; • 2.3 — Pilot-Controller Communication; and, International Civil Aviation Organization (ICAO). Interna- tional Standards and Recommended Practices, Annex 6 to • 2.4 — Interruptions/Distractions.◆ the Convention of International Civil Aviation, Operation of Aircraft. Part I, International Commercial Air Transport – References Aeroplanes. Appendix 2, “Contents of an Operations Manual,” 5.13. Seventh edition – July 1998, incorporating Amendments 1. Flight Safety Foundation. “Killers in Aviation: FSF Task 1–25. Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.”Flight Safety Digest ICAO. Preparation of an Operations Manual. Second edi- Volume 17 (November–December 1998) and Volume 18 tion – 1997. (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on analyses of 287 Joint Aviation Authorities. Joint Aviation Requirements – Op- fatal approach-and-landing accidents (ALAs) that occurred erations. Commercial Air Transportation (Aeroplanes). 1.1045 in 1980 through 1996 involving turbine aircraft weighing “Operations Manual – structure and contents.” March 1, 1998. more than 12,500 pounds/5,700 kilograms, detailed studies

24 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 25 FSF ALAR Briefing Note 1.5 — Normal Checklists

Adherence to standard operating procedures (SOPs) and use ing (PF) and read by the pilot not flying (PNF). of normal checklists are essential in preventing approach-and- landing accidents (ALAs), including those involving controlled This should not prevent the PNF from applying an important flight into terrain (CFIT). crew resource management (CRM) principle by suggesting the initiation of a normal checklist if the PF fails to do so. Statistical Data Normal checklists should be conducted during low-workload The Flight Safety Foundation Approach-and-landing Accident periods — conditions permitting — to help prevent any rush Reduction (ALAR) Task Force found that omission of action or that could defeat the safety purpose of the normal checklists. inappropriate action (i.e., inadvertent deviation from SOPs) was a causal factor1 in 72 percent of 76 approach-and-landing acci- Time management and availability of other crewmember(s) dents and serious incidents worldwide in 1984 through 1997.2 are key factors in the initiation of normal checklists and the effective use of normal checklists. Scope and Use of Normal Checklists Conducting Normal Checklists SOPs are performed by recall using a defined flow pattern for each flight deck panel;safety-critical points (primarily related Normal checklists are conducted usually by challenge and to the aircraft configuration) should be cross-checked with response (exceptions, such as the “After Landing” checklist, normal checklists. are conducted as defined by SOPs).

Normal checklists enhance flight safety by providing an op- Most checklist items require responses by the PF; some items portunity to confirm the aircraft configuration or to correct the may be challenged and responded to by the PNF. aircraft configuration. To enhance crew communication, the following procedures Normal checklists usually are not read-and-do lists and should and phraseology should be used: be conducted after performing the flow of SOPs. • The responding pilot should respond to the challenge only after having checked or achieved the required Completion of normal checklists is essential for safe operation, configuration; particularly during approach and landing. • If achieving the required configuration is not possible, the Initiating Normal Checklists responding pilot should call the actual configuration;

Normal checklists should be initiated (called) by the pilot fly- • The challenging pilot should wait for a positive response

26 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 (and should cross-check the validity of the response) The following factors often are cited in discussing the partial before proceeding to the next item; and, omission or complete omission of a normal checklist: • The PNF should call the completion of the checklist • out-of-phase timing, whenever a factor (such as a tail (e.g., “checklist complete”). wind or a system malfunction) modifies the time scale of the approach or the occurrence of the trigger event Some aircraft have electronic normal checklists or mechanical for the initiation of the normal checklist; normal checklists that allow positive identification of: • Interruptions (e.g., because of pilot-controller • Items completed; communication); • Items being completed; and, • distractions (e.g., because of flight deck activities); • Items to be completed. • Task saturation; • Incorrect management of priorities (e.g., lack of a Interrupting and Resuming Normal Checklists decision-making model for time-critical situations); If the flow of the normal checklist is interrupted for any reason, • Reduced attention (tunnel vision) in abnormal conditions the PF should call “hold (stop) checklist at [item].” or high-workload conditions; • Inadequate CRM (e.g., inadequate coordination, cross- “Resume (continue) checklist at [item]” should be called check and backup); before resuming the normal checklist after an interruption. When the checklist resumes, the last completed item should • overreliance on memory (overconfidence); be repeated. • less-than-optimum checklist content, task-sharing and/ or format; and, Information introducing the SOPs in the aircraft operating manual (AOM), the normal checklists or the quick reference • Possible inadequate emphasis on use of normal checklists handbook (QRH) should be referred to for aircraft-model- during transition training and recurrent training. specific information. Summary Training Timely initiation and completion of normal checklists is the Adherence to SOPs and disciplined use of normal checklists most effective method of preventing omission of actions or should begin during transition training, because habits and rou- preventing inappropriate actions. tines acquired during transition training have a lasting effect. Calls should be defined in the SOPs for the interruption (hold) Transition training and recurrent training provide a unique and resumption (continuation) of a normal checklist (in case opportunity to discuss the reasons for SOPs, and to discuss of interruption or distraction). the consequences of failing to adhere to them. Disciplined use of normal checklists should be: Conversely, allowing deviations from SOPs and/or normal • Emphasized at all stages of initial training, transition checklists during initial training or recurrent training may training and line training; and, encourage deviations during line operations. • Enforced during all checks and audits performed during Line checks and line audits should reinforce adherence to SOPs line operations. and use of normal checklists. The following FSF ALAR Briefing Notes provide information to supplement this discussion: Factors That May Affect Normal Checklists • 1.1 — Operating Philosophy; To ensure effective use of normal checklists, it is important to • 1.3 — Golden Rules; understand why pilots inadvertently may omit some checklist • 1.4 — Standard Calls; and, items or omit completely a normal checklist. • 2.4 — Interruptions/Distractions.◆ Such omissions often are the result of operational circum- stances that disrupt the normal flow of flight-deck duties.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 27 References Flight Safety Digest Volume 14 (May 1995). 1. The Flight Safety Foundation Approach-and-landing Pope, John A. “Checklists — Guideposts Often Ignored.” Ac- Accident Reduction (ALAR) Task Force defines causal cident Prevention Volume 48 (May 1991). factor as “an event or item judged to be directly instrumental in the causal chain of events leading to the accident [or Wilson, Donald. “A Tool for Communication.” Accident Pre- incident].” Each accident and incident in the study sample vention Volume 46 (July 1989). involved several causal factors. 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Regulatory Resources Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety International Civil Aviation Organization (ICAO). Internation- Digest Volume 17 (November–December 1998) and Volume al Standards and Recommended Practices, Annex 6 to the Con- 18 (January–February 1999): 1–121. The facts presented by vention of International Civil Aviation, Operation of Aircraft. the FSF ALAR Task Force were based on analyses of 287 Part I, International Commercial Air Transport – Aeroplanes. fatal approach-and-landing accidents (ALAs) that occurred Chapter 4, “Flight Operations,” 4.2.5. Chapter 6, “Aeroplane in 1980 through 1996 involving turbine aircraft weighing Instruments, Equipment and Flight Documents,” 6.1.3. Ap- more than 12,500 pounds/5,700 kilograms, detailed studies pendix 2, “Contents of an Operations Manual,” 5.10. Seventh of 76 ALAs and serious incidents in 1984 through 1997 and edition – July 1998, incorporating Amendments 1–25. audits of about 3,300 flights. ICAO. Procedures for Air Navigation Services. Aircraft Op- Related Reading from FSF Publications erations. Volume I, Flight Procedures. Fourth edition, 1993. Reprinted May 2000, incorporating Amendments 1–10. Flight Safety Foundation (FSF) Editorial Staff. “Ice Inges- tion Causes Both Engines to Flame Out During Air-taxi ICAO. Preparation of an Operations Manual. Second edi- Turboprop’s Final Approach.” Accident Prevention Volume tion – 1997. 56 (February 1999). ICAO. Human Factors Training Manual. First edition – 1998, FSF Editorial Staff. “Flight Crew’s Failure to Perform Land- incorporating Circular 216. ing Checklist Results in DC-9 Wheels-up Landing.” Accident Prevention Volume 54 (May 1997). U.S. Federal Aviation Administration. Federal Aviation Regu- lations. 121.315 “Instrument and Equipment Requirements.” Adamski, Anthony J.; Stahl, Albert F. “Principles of Design January 1, 2000. and Display for Aviation Technical Messages.” Flight Safety Digest Volume 16 (January 1997). Joint Aviation Authorities. Joint Aviation Requirements – Op- Gross, Richard L.; FSF Editorial Staff. “Studies Suggest Meth- erations 1. Commercial Air Transportation (Aeroplanes). 1.1045 ods for Optimizing Checklist Design and Crew Performance.” “Operations Manual – structure and contents.” March 1, 1998.

28 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 29 FSF ALAR Briefing Note 1.6 — Approach Briefing

To ensure mutual understanding and effective cooperation than an uninterrupted recitation terminated by the final query, among flight crewmembers and air traffic control (ATC), a thor- “Any questions?” ough approach briefing should be conducted on each flight. An interactive briefing fulfills two important purposes: Care should be taken to conduct a thorough briefing regard- • To provide the pilot flying (PF) and the PNF with an less of: opportunity to correct each other (e.g., confirm the • how familiar the destination airport and the approach correct approach chart and confirm the correct setup of may be; or, navaids for the assigned landing runway); and, • how often the crewmembers have flown together. • To share a common mental image of the approach.

The briefing should be structured (i.e., follow the logical se- Statistical Data quence of the approach and landing) and concise. The Flight Safety Foundation Approach-and-landing Accident Routine and formal repetition of the same information on each Reduction (ALAR) Task Force found that omission of an flight may become counterproductive; adapting and expanding the approach briefing or the conduct of an inadequate approach briefing by highlighting the special aspects of the approach or the briefing were factors in the particular approach-and-landing actual weather conditions will result in more effective briefings. accidents and serious incidents worldwide in 1984 through 1997 that were attributed, in part, to omission of action/inap- In short, the briefing should attract the PNF’s attention. propriate action. Seventy-two percent of the 76 accidents and serious incidents during the period involved omission of action/ Thus, the briefing should be conducted when the workload and inappropriate action.1 availability of the PNF permit an effective briefing.

Briefing Techniques Anything that may affect normal operation (e.g., system fail- ures, weather conditions or other particular conditions) should The importance of briefing techniques often is underestimated, be carefully evaluated and discussed. although effective briefings enhance crew standardization and crew communication. The briefing should help the PF (giving the briefing) and the PNF (acknowledging the briefing) to know the sequence of An interactive briefing style — e.g., confirming the agreement events and actions, as well as the special hazards and circum- and understanding of the pilot not flying (PNF) after each stances of the approach. phase of the briefing — will provide a more effective briefing

30 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Whether anticipated or not, changes in ATC clearance, weather conditions or landing runway require a partial review of the initial briefing. Table 1 Recommended Elements Timeliness of Briefings Of a Stabilized Approach All flights must be stabilized by 1,000 feet above To prevent any rush (and increased workload) in initiating and airport elevation in instrument meteorological conditions conducting the descent and the approach, descent preparation (IMC) or by 500 feet above airport elevation in visual and the approach briefing typically should be conducted 10 meteorological conditions (VMC). An approach is stabi- lized when all of the following criteria are met: minutes before reaching the top-of-descent point. 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to Scope of Briefing maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than V ; The approach briefing should include the following aspects of REF the approach and landing, including a possible missed approach 4. The aircraft is in the correct landing configuration; and a second approach or diversion: 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 • Minimum safe altitude (MSA); feet per minute, a special briefing should be con- ducted; • Terrain, man-made obstructions and other hazards; 6. Power setting is appropriate for the aircraft configura- • Approach conditions (weather conditions, runway tion and is not below the minimum power for approach conditions); as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; • Instrument approach procedure details, including the 8. Specific types of approaches are stabilized if they initial steps of the missed approach procedure; also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of • Stabilization height (Table 1); the glideslope and localizer; a Category II or Cat- • Final approach descent gradient (and vertical speed); egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, • Use of automation (e.g., lateral navigation [LNAV] and wings should be level on final when the aircraft vertical navigation [VNAV]); reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions • Communications; requiring a deviation from the above elements of a stabilized approach require a special briefing. • Abnormal procedures, as applicable; and, An approach that becomes unstabilized below 1,000 • Flight Safety Foundation Approach-and-landing Risk feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate Awareness Tool (review and discuss [see FSF ALAR go-around. Briefing Note5.1 — Approach Hazards Overview]). Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) Approach Briefing

The flight management system (FMS) pages and the naviga- Fuel Status tion display (ND) should be used to guide and illustrate the briefing, and to confirm the various data entries. Review the following items:

An expanded review of the items to be covered in the approach • Fuel on board; briefing —as practical and appropriate for the conditions of • Minimum diversion fuel; and, the flight — is provided below. • Available holding fuel and time. Aircraft Status Automatic Terminal Information Service (ATIS) Review the status of the aircraft (i.e., any failure or malfunc- tion experienced during the flight) and discuss the possible Review and discuss the following items: consequences in terms of operation and performance (i.e., • Runway in use (type of approach); final approach speed and landing distance).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 31 • Expected arrival route (standard terminal arrival [STAR] – Final descent point (if different from FAF); or radar vectors); – Visual descent point (VDP); • Altimeter setting (QNH [altimeter setting that causes – Missed approach point (MAP); the altimeter to indicate height above sea level (i.e., field elevation after landing)] or QFE [altimeter setting that – Typical vertical speed at expected final approach causes the altimeter to indicate height above the QFE groundspeed; and, datum (i.e., zero feet after landing)], as required); – Touchdown zone elevation (TDZE); – For international operations, be aware of the applicable • Missed approach: altimeter-setting unit (hectopascals or inches of mercury); – lateral navigation and vertical navigation; • Transition altitude/flight level (unless standard for the – Airspeed restrictions; country or for the airport); – Minimum diversion fuel; and, • Terminal weather (e.g., runway condition, likely – Second approach (discuss the type of approach if a turbulence, icing or wind shear conditions); and, different runway and/or type of approach is expected) • Advisory messages (as applicable). or diversion to the alternate airport; • Ceiling and visibility minimums: Notices to Airmen (NOTAMs) – decision altitude/height (DA[H]) setting (Category [CAT] I with or without radio altitude, CAT II and Review and discuss en route and terminal NOTAMs (as ap- CAT III with radio altitude); or, plicable). – Minimum descent altitude/height (MDA[H]) setting and radio altimeter setting in DH window Top-of-descent Point (nonprecision approaches); and, Confirm or adjust the top-of-descent point, computed by the • local airport requirements (e.g., noise restrictions on FMS, as a function of the expected arrival (i.e., following the the use of thrust reversers, etc.). published STAR or radar vectors). CAT II/CAT III Instrument Landing System (ILS) Approach Charts Review and discuss as applicable, depending on the type of Review and discuss the following items using the approach approach. chart and the FMS/ND (as applicable): • designated runway and approach type; Airport Charts • Chart index number and date; Review and discuss the following items using the airport • Minimum safe altitude (MSA) — reference point, charts: sectors and altitudes; • Runway length, width and slope; • let-down navaids — frequencies and identifications • Approach lighting and runway lighting, and other (confirm the correct navaids setup); expected visual references; • Airport elevation; • Specific hazards (as applicable); and, • Approach transitions (fixes, holding pattern, altitude and • Intended exit taxiway. airspeed restrictions, required navaids setup); • Final approach course (and lead-in radial); If another airport is located in the close vicinity of the destina- tion airport, relevant details or procedures should be discussed • Terrain features (location and elevation of hazardous for awareness purposes. terrain or man-made obstacles); • Approach profile view: – Final approach fix (FAF);

32 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Use of Automation applicable); and, • Intentions (second approach or diversion). Discuss the use of automation for vertical navigation and lateral navigation: Crews should briefly recall the main points of the go-around • Use of FMS or selected modes; and, and missed approach when established on the final approach course or after completing the landing checklist. • Step-down approach (if a constant-angle nonprecision approach [CANPA] is not available). Summary

Landing and Stopping The approach briefing should be adapted to the conditions of the flight and focus on the items that are relevant for the ap- Discuss the intended landing flaps configuration (if different proach and landing (such as specific approach hazards). from full flaps). The approach briefing should include the following items: Review and discuss the following features of the intended landing runway: • MSA; • Surface condition; • Terrain and man-made obstacles; • Intended use of autobrakes and thrust reversers; and, • Weather conditions and runway conditions; • Expected runway turn-off. • other approach hazards, as applicable; • Minimums (ceiling and visibility or runway visual Taxi to Gate range);

Review and discuss the taxiways expected to be used to reach • Stabilization height; the assigned gate (with special emphasis on the possible cross- • Final approach descent gradient (and vertical speed); ing of active runways). As required, this review and discussion and, can be delayed until after landing. • go-around altitude and missed-approach initial steps. Deviations from Standard Operating Procedures The following FSF ALAR Briefing Notes provide information (SOPs) to supplement this discussion: Any intended deviation from SOPs or from standard calls • 1.1 — Operating Philosophy; should be discussed during the briefing. • 2.1 — Human Factors; Go-around • 2.3 — Pilot-Controller Communication;

To enhance preparation for a go-around, primary elements of • 5.1 — Approach Hazards Overview; the missed approach procedure and task-sharing under normal • 6.1 — Being Prepared to Go Around; and, conditions or abnormal conditions should be discussed during the approach briefing. • 7.1 — Stabilized Approach.◆

The briefing should include the following: Reference • go-around call (a loud and clear “go-around/flaps”); • PF/PNF task-sharing (flow of respective actions, 1. Flight Safety Foundation. “Killers in Aviation: FSF Task including desired guidance — mode selection — Force Presents Facts About Approach-and-landing and airspeed target, go-around altitude, excessive-parameter- Controlled-flight-into-terrain Accidents.”Flight Safety Digest deviation calls); Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts presented by • Intended use of automation (automatic or manual go- the FSF ALAR Task Force were based on analyses of 287 around, use of FMS LNAV or use of selected modes for fatal approach-and-landing accidents (ALAs) that occurred the missed approach); in 1980 through 1996 involving turbine aircraft weighing • Missed-approach lateral navigation and vertical more than 12,500 pounds/5,700 kilograms, detailed studies navigation (highlight obstacles and terrain features, as of 76 ALAs and serious incidents in 1984 through 1997 and

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 33 audits of about 3,300 flights. Regulatory Resources

International Civil Aviation Organization (ICAO). Interna- Related Reading from FSF Publications tional Standards and Recommended Practices, Annex 6 to the Convention of International Civil Aviation, Operation of Flight Safety Foundation (FSF). “Controlled Flight Into Ter- Aircraft. Part I, International Commercial Air Transport – rain: Korean Air Flight 801, Boeing 747-300, HL 7468 Nimitz Aeroplanes. Appendix 2, “Contents of an Operations Manual,” Hill, Guam, August 6, 1997.” Flight Safety Digest Volume 19 5.16. Seventh edition – July 1998, incorporating Amendments (May–July 2000). 1–25.

FSF Editorial Staff. “Preparing for Last-minute Runway ICAO. Procedures for Air Navigation Services. Aircraft Op- Change, Boeing 757 Flight Crew Loses Situational Aware- erations. Volume I, Flight Procedures. Fourth edition, 1993. ness, Resulting in Collision with Terrain.” Accident Prevention Reprinted May 2000, incorporating Amendments 1–10. Volume 54 (July–August 1997). ICAO. Preparation of an Operations Manual. Second edi- Sumwalt, Robert L. III. “Accident and Incident Reports Show tion – 1997. Importance of ‘Sterile Cockpit’ Compliance.” Flight Safety Digest Volume 13 (July 1994). U.S. Federal Aviation Administration. Federal Aviation Regu- lations. 121.315 “Instrument and Equipment Requirements.” Edwards, Mary. “Crew Coordination Problems Persist, De- January 1, 2000. mand New Training Challenges.” Cabin Crew Safety Volume Joint Aviation Authorities. Joint Aviation Requirements – Op- 27 (November–December 1992). erations 1. Commercial Air Transportation (Aeroplanes). 1.1045 “Operations Manual – structure and contents.” March 1, 1998.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

34 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 2.1 — Human Factors

Human factors identified in approach-and-landing accidents • Task saturation; (ALAs) should be used to assess a company’s risk exposure • Inadequate knowledge or failure to understand the rule, and develop corresponding company accident-prevention strat- procedure or action because of: egies, or to assess an individual’s risk exposure and develop corresponding personal lines of defense. – Inadequate training; – Printed information not easily understood; and/or, Whether involving crew, air traffic control (ATC), maintenance, organizational factors or aircraft design, each link of the error – Perception that a procedure is inappropriate; chain involves human beings and, therefore, human decisions • Insufficient emphasis on adherence to SOPs during and behaviors. transition training and recurrent training; • Inadequate vigilance (fatigue); Statistical Data • Interruptions (e.g., because of pilot-controller communication); There is general agreement that human error is involved in more than 70 percent of aviation accidents. • distractions (e.g., because of flight deck activities); • Incorrect management of priorities (lack of decision- making model for time-critical situations); Human Factors Issues • Reduced attention (tunnel vision) in abnormal conditions Standard Operating Procedures (SOPs) or high-workload conditions; • Incorrect crew resource management (CRM) techniques To ensure adherence to published standard operating proce- (for crew coordination, cross-check and backup); dures (SOPs) and associated normal checklists and standard • Company policies (e.g., schedules, costs, go-arounds calls, it is important to understand why pilots may deviate and diversions); from SOPs. • other policies (e.g., crew duty time); Pilots sometimes deviate intentionally from SOPs; some devia- • Personal desires or constraints (schedule, mission tions occur because the procedure that was followed in place of completion); the SOP seemed to be appropriate for the prevailing situation. Other deviations are usually unintentional. • Complacency; and/or, • overconfidence. The following factors often are cited in discussing deviations from SOPs:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 35 Automation not flying (PNF).

Errors in using automatic flight systems (AFSs) and insuf- The briefing should help the pilot flying (PF) and the PNF to ficient knowledge of AFS operation have been contributing know the sequence of events and actions, as well as the special factors in approach-and-landing accidents and incidents, hazards and circumstances of the approach. including those involving controlled flight into terrain. An interactive briefing style provides the PF and the PNF with The following are some of the more common errors in using an opportunity to fulfill two important goals of the briefing: AFSs: • Correct each other; and, • Inadvertent selection of an incorrect mode; • Share a common mental image of the approach. • Failure to verify the selected mode by reference to the flight-mode annunciator (FMA); Crew-ATC Communication • Failure to arm a mode (e.g., failure to arm the approach Effective communication is achieved when our intellectual mode) at the correct time; process for interpreting the information contained in a message • Inadvertent change of a target entry (e.g., changing the accommodates the message being received. target airspeed instead of entering a new heading); This process can be summarized as follows: • Failure to enter a required target (e.g., failure to enter the correct final approach course); • how do we perceive the message? • Incorrect altitude entry and failure to confirm the entry • how do we reconstruct the information contained in the on the primary flight display (PFD); message? • how do we link the information to an objective or to an • Entering a target altitude that is lower than the final expectation? approach intercept altitude during approach; • What amount of bias or error is introduced in this • Preoccupation with FMS programming during a process? critical flight phase, with consequent loss of situational awareness; and/or, CRM highlights the relevance of the context and the expecta- • Failure to monitor automation and cross-check parameters tions in communication. with raw data.1 The following factors may affect adversely the understanding of communications: Other frequent causal factors2 in ALAs include: • high workload; • Inadequate situational awareness; • Fatigue; • Incorrect interaction with automation; • Nonadherence to the “sterile cockpit rule”4; • overreliance on automation; and/or, • Interruptions; • Inadequate effective crew coordination, cross-check and backup.3 • distractions; and/or, • Conflicts and pressures. Briefing Techniques The results may include: The importance of briefing techniques often is underestimated, although effective briefings enhance crew standardization and • Incomplete communication; communication. • omission of the aircraft call sign or use of an incorrect call sign; Routine and formal repetition of the same information on each flight may become counterproductive; adapting and expanding • Use of nonstandard phraseology; and, the briefing by highlighting the special aspects of the approach • Failure to listen or to respond. or the actual weather conditions will result in more effective briefings. Crew Communication

In short, the briefing should attract the attention of the pilot Interruptions and distractions on the flight deck break the flow

36 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 pattern of ongoing activities, such as: • Fatigue in short-haul, medium-haul or long-haul operations (which highlights the need for developing • SOPs; countermeasures to restore vigilance and alertness for • Normal checklists; the descent, approach and landing); • Communication (listening, processing, responding); • Pressure of flight schedule (making up for delays); • Monitoring tasks; and, • Any crew-induced circumstance or ATC-induced • Problem-solving activities. circumstance resulting in insufficient time to plan, prepare and conduct a safe approach (including accepting The diverted attention resulting from the interruption or dis- requests from ATC to fly higher, to fly faster or to fly traction usually causes the flight crew to feel rushed and to be shorter routings than desired); confronted by competing tasks. • Inadequate ATC awareness of crew capability or aircraft Moreover, when confronted with concurrent task demands, the capability to accommodate a last-minute change; natural human tendency is to perform one task to the detri- • late takeover from automation (e.g., after the autopilot ment of another. fails to capture the localizer or glideslope, usually because the crew failed to arm the approach mode); Unless mitigated by adequate techniques to set priorities, inter- ruptions and distractions may result in the flight crew: • Inadequate awareness of adverse wind conditions; • Not monitoring the flight path (possibly resulting in an • Incorrect anticipation of aircraft deceleration altitude deviation, course deviation or controlled flight characteristics in level flight or on a three-degree glide into terrain); path; • Missing or misinterpreting an ATC instruction (possibly • Failure to recognize deviations or to remember the resulting in a traffic conflict or runway incursion); excessive-parameter-deviation limits; • omitting an action and failing to detect and correct • Belief that the aircraft will be stabilized at the minimum the resulting abnormal condition or configuration, if stabilization height (i.e., 1,000 feet above airport interrupted during a normal checklist; and, elevation in instrument meteorological conditions or 500 feet above airport elevation in visual meteorological • leaving uncertainties unresolved (e.g., an ATC conditions) or shortly thereafter; instruction or an abnormal condition). • PNF overconfidence in the PF to achieve timely stabilization; Altimeter-setting Error • PF/PNF overreliance on each other to call excessive An incorrect altimeter setting often is the result of one or more deviations or to call for a go-around; and/or, of the following factors: • Visual illusions during the acquisition of visual references • high workload; or during the visual segment. • Incorrect pilot-system interface; Runway Excursions and Runway Overruns • Incorrect pilot-controller communication; The following are human factors (involving ATC, flight crew • deviation from normal task-sharing; and/or maintenance personnel) in runway excursions and • Interruptions and distractions; and/or, runway overruns: • Insufficient backup between crewmembers. • No go-around decision when warranted; • Inaccurate information on surface wind, runway Adherence to the defined task-sharing (for normal conditions or condition or wind shear; abnormal conditions) and use of normal checklists are the most effective lines of defense against altimeter-setting errors. • Incorrect assessment of crosswind limit for prevailing runway conditions; Unstabilized Approaches • Incorrect assessment of landing distance for prevailing wind conditions and runway conditions, or for a The following often are cited when discussing unstabilized malfunction affecting aircraft configuration or braking approaches: capability;

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 37 • Captain taking over the controls and landing the aircraft • 2.3 — Pilot-Controller Communication; despite the announcement or initiation of a go-around • 2.4 — Interruptions/Distractions; by the first officer (the PF); • 3.1 — Barometric Altimeter and Radio Altimeter; • late takeover from automation, when required (e.g., late takeover from autobrakes because of system • 3.2 — Altitude Deviations; malfunction); • 7.1 — Stabilized Approach; and, • Inoperative equipment not noted per the minimum • 8.1 — Runway Excursions and Runway Overruns.◆ equipment list (e.g., one or more brakes being inoperative); and/or, References • Undetected thrust asymmetry (forward/reverse asymmetric thrust condition). 1. The FSF ALAR Task Force defines raw data as “data received directly (not via the flight director or flight Adverse Wind Conditions management computer) from basic navigation aids (e.g., ADF, VOR, DME, barometric altimeter).” The following human factors often are cited in discussing events 2. The FSF ALAR Task Force defines causal factor as involving adverse winds (e.g., crosswinds, tail winds): “an event or item judged to be directly instrumental in • Reluctance to recognize changes in landing data over the causal chain of events leading to the accident [or time (e.g., change in wind direction/velocity, increase incident].” in gusts); 3. Flight Safety Foundation. “Killers in Aviation: FSF Task • Failure to seek evidence to confirm landing data and Force Presents Facts About Approach-and-landing and established options (i.e., reluctance to change plans); Controlled-flight-into-terrain Accidents.” Flight Safety Digest Volume 17 (November–December 1998) and • Reluctance to divert to an airport with more favorable Volume 18 (January–February 1999): 1–121. The facts wind conditions; and/or, presented by the FSF ALAR Task Force were based on • Insufficient time to observe, evaluate and control the analyses of 287 fatal approach-and-landing accidents aircraft attitude and flight path in a dynamic situation. (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 Summary kilograms, detailed studies of 76 ALAs and serious incidents in 1984 through 1997 and audits of about 3,300 flights. Addressing human factors in ALAs must include: 4. The sterile cockpit rule refers to U.S. Federal Aviation • defined company safety culture; Regulations Part 121.542, which states: “No flight • defined company safety policies; crewmember may engage in, nor may any pilot-in-command permit, any activity during a critical phase of flight which • Company accident-prevention strategies; could distract any flight crewmember from the performance • SOPs; of his or her duties or which could interfere in any way with the proper conduct of those duties. Activities such as • CRM practices; and, eating meals, engaging in nonessential conversations within • Personal lines of defense. the cockpit and nonessential communications between the cabin and cockpit crews, and reading publications not The following FSF ALAR Briefing Notes provide information related to the proper conduct of the flight are not required to supplement this discussion for the safe operation of the aircraft. For the purposes of this section, critical phases of flight include all ground • 1.1 — Operating Philosophy; operations involving taxi, takeoff and landing, and all other • 1.3 — Golden Rules; flight operations below 10,000 feet, except cruise flight.” • 1.4 — Standard Calls; [The FSF ALAR Task Force says that “10,000 feet” should be height above ground level during flight operations over • 1.5 — Normal Checklists; high terrain.] • 1.6 — Approach Briefing; • 2.2 — Crew Resource Management;

38 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Related Reading from FSF Publications FSF Editorial Staff. “Spatial Disorientation Linked to Fatal DC-8 Freighter Crash.” Accident Prevention Volume 50 FSF. “Aviation Grapples with Human-factors Accidents.” (March 1993). Flight Safety Digest Volume 18 (May 1999). Antuñano, Melchor J.; Mohler, Stanley R. “Inflight Spatial FSF Editorial Staff. “B-757 Damaged by Ground Strike During Disorientation.” Human Factors & Aviation Medicine Volume Late Go-around from Visual Approach.” Accident Prevention 39 (January–February 1992). Volume 56 (May 1999). Wilson, Donald R. “The Overall Approach to Cockpit Safety.” FSF Editorial Staff. “Boeing 737 Pilot Flying Selects Incor- Accident Prevention Volume 46 (June 1989). rect Altitude in Holding Pattern, Causes Dangerous Loss of Separation with MD-81.” Accident Prevention Volume 55 (April 1998). Regulatory Resources

FSF Editorial Staff. “Inadequate Visual References in Flight International Civil Aviation Organization (ICAO). International Pose Threat of Spatial Disorientation.” Human Factors & Avia- Standards and Recommended Practices, Annex 6 to the Con- tion Medicine Volume 44 (November–December 1997). vention of International Civil Aviation, Operation of Aircraft. Part I, International Commercial Air Transport – Aeroplanes. FSF Editorial Staff. “Different Altimeter Displays and Crew Appendix 2, “Contents of an Operations Manual,” 15. Seventh Fatigue Likely Contributed to Canadian Controlled-flight-into- edition – July 1998, incorporating Amendments 1–25. terrain Accident.” Accident Prevention Volume 52 (December 1995). ICAO. Procedures for Air Navigation Services. Aircraft Op- erations. Volume I, Flight Procedures. Fourth edition, 1993. FSF Editorial Staff. “Poorly Flown Approach in Fog Results in Reprinted May 2000, incorporating Amendments 1–10. Collision With Terrain Short of Runway.” Accident Prevention Volume 52 (August 1995). ICAO. Accident Prevention Manual. 1984. Mohler, Stanley R. “The Human Balance System: A Refresher for Pilots.” Human Factors & Aviation Medicine Volume 42 ICAO. Human Factors Training Manual. First edition – 1998, (July–August 1995). incorporating Circular 216.

Lawton, Russell. “Steep Turn by Captain During Approach ICAO. Circular 241, Human Factors Digest No. 8, “Human Results in Stall and Crash of DC-8 Freighter.” Accident Pre- Factors in Air Traffic Control.” 1993. vention Volume 51 (October 1994). U.S. Federal Aviation Administration. U.S. Federal Aviation FSF Editorial Staff. “Cockpit Coordination, Training Issues Regulations. 121.406 “Reduction of CRM/DRM programmed Pivotal in Fatal Approach-to-Landing Accident.” Accident hours based on credit for previous CRM/DRM training,” Prevention Volume 51 (January 1994). 121.419 “Pilots and flight engineers: Initial, transition, and upgrade ground training,” 121.421 “Flight attendants: Initial FSF Editorial Staff. “Fatal Commuter Crash Blamed on Visual and transition ground training,” 121.422 “Aircraft dispatchers: Illusion, Lack of Cockpit Coordination.” Accident Prevention Initial and transition ground training.” January 1, 2000. Volume 50 (November 1993). Joint Aviation Authorities. Joint Aviation Requirements - Pope, John A. “Comparing Accident Reports: Looking Beyond Operations 1. Commercial Air Transportation (Aeroplanes). Causes to Identify Recurrent Factors.” Flight Safety Digest 1.945 “Conversion training and checking,” 1.955 “Nomination Volume 12 (June 1993). as commander,” 1.965 “Recurrent training and checking.” March 1, 1998.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 39 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

40 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 2.2 — Crew Resource Management

Minimum required crew resource management (CRM) train- cultural flight crews, cultural factors become an important part ing is defined by regulations, and companies should consider of customized CRM training. customized CRM training for company-specific operations, such as multi-cultural flight crews. Understanding differences among cultures and recognizing the importance of national sensitivities should be emphasized in CRM training. Statistical Data The importance of using standard phraseology as a common The Flight Safety Foundation Approach-and-landing Accident working language also should be emphasized. Reduction (ALAR) Task Force found that failure in CRM (i.e., flight crew coordination, cross-check and backup) was a causal factor1 in 63 percent of 76 approach-and-landing accidents and Leadership serious incidents worldwide in 1984 through 1997.2 The role of the pilot-in-command (PIC) in complex and de- manding situations (e.g., an approach with marginal weather Because CRM is a key factor in flight crew performance and conditions, abnormal conditions or emergency conditions) is in their interaction with automated systems, CRM has a role an integral part of CRM training. to some degree in most aircraft incidents and accidents. Teamwork Company Safety Culture and Policies The captain’s attitude in establishing communication with the Although the flight crew is the last line of defense — and usually first officer and flight attendants is essential to maintain open the last link in an error chain — many factors associated with ac- communication, thus ensuring effective: cidents are early links in the accident chain and can be forged far • human relations (e.g., effective crew communication); from the flight deck. The early links could be inadequate training, a design flaw in equipment or incorrect maintenance. • Teamwork (e.g., encouraging the first officer to voice any concern about the safety and the progress of the flight); Thus, company safety culture should support CRM throughout and, the organization, as well as among aircraft crewmembers. • Crew coordination, cross-check and backup.

International Cultural Factors Conducting a preflight briefing that includes the flight crew and the cabin crew is one method of establishing the basis for As more companies have international operations and multi- effective teamwork.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 41 Assertiveness Error Management

Incidents and accidents have revealed that when an option Error management should be practiced at the company level (such as conducting a go-around) has not been briefed, the and at the personal level. flight crew may lack the information to make the go-around decision or to conduct the missed approach correctly. To foster this practice, identifying and understanding the relevant factors that cause errors are necessary for the devel- Fatigue, overconfidence or reluctance to change a plan often opment of associated: result in inadequate assertiveness and decision making. • Company accident-prevention strategies; and,

Inquiry and Advocacy • Personal lines of defense. The most critical aspect in discussing error management is Flight crews often receive air traffic control (ATC) requests not the error (deviation), but the failure to detect the error by that are either: cross-checking. • Not understood (e.g., instructions to fly below the minimum safe altitude when the minimum vectoring Risk Management altitude is not known); or,

• Challenging (e.g., a request to fly higher and/or faster Risk management is the process of assessing potential safety than desired, or to fly a shorter route than desired). hazards and finding ways to avoid the hazards or to minimize their effects on safety. Flight crews should not accept instructions without asking for clarification or being sure that they can comply safely with Risk management should be seen as a balanced management the instructions. of priorities.

Procedures Decision Making

Deviations from standard operating procedures (SOPs) and SOPs sometimes are perceived as limiting the flight crew’s from other procedures usually are not deliberate; understanding judgment and decisions. the human factors involved in such deviations is essential for the development of company accident-prevention strategies. Without denying the captain’s emergency authority, SOPs are safeguards against biased decision making.

Briefings Effective flight crew decision making often requires a joint evaluation of options prior to proceeding with an agreed-upon Conducting effective and interactive briefings requires adher- decision and action. ence to SOPs to ensure crew coordination and preparation for planned or unexpected occurrences. The effect of pressures (such as delays or company poli- cies) that may affect how the flight crew conducts the flight and makes decisions should be recognized by the aviation Time Management industry.

Taking time to make time, task-sharing and ensuring task priori- Nevertheless, eliminating all pressures is not a realistic ob- tization are essential factors in staying ahead of the aircraft. jective. Thus, CRM — incorporated with company accident- prevention strategies and personal lines of defense — should Interruptions/Distractions be used to cope effectively with such pressures. For example, using a tactical-decision-making model for time- Coping with interruptions/distractions on the flight deck re- critical situations is an effective technique. quires the flight crew “to expect the unexpected,” which lessens the effects of any disruption in the flow pattern of ongoing Several tactical-decision-making models (usually based on flight deck activities. memory aids or on sequential models) are available for discus- sion during CRM training.

42 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 All tactical-decision-making models include the following • Reluctance to accept the influence of human factors and steps: CRM in ALAs. • Recognizing the prevailing condition; • Assessing short-term consequences and long-term Summary consequences for the flight; CRM alone is not the answer or universal remedy for prevent- • Evaluating available options and procedures; ing ALAs. Nevertheless, CRM is a powerful tool to optimize • deciding on a course of action; flight crew performance.

• Taking action in accordance with the defined procedures, Good CRM skills: as available, and task-sharing; • Relieve the effects of pressures, interruptions and • Evaluating and monitoring results; and, distractions; • Resuming standard flying duties. • Provide benchmarks for timely decision making; and,

Postponing a decision until a safe option is no longer available • Provide safeguards for effective error management. is a recurring pattern in ALAs. The following FSF ALAR Briefing Notes provide information to supplement this discussion: CRM Factors • 1.1 — Operating Philosophy; The following CRM factors have been identified as contribut- • 1.3 — Golden Rules; ing to approach-and-landing incidents and accidents, including • 1.4 — Standard Calls; controlled flight into terrain: • 1.5 — Normal Checklists; • Risks associated with complacency (e.g., when operating at a familiar airport) or with overconfidence (e.g., • 1.6 — Approach Briefing; resulting from a high level of experience with the • 2.1 — Human Factors; aircraft); • 2.3 — Pilot-Controller Communication; and, • Inadequate proactive flight management (i.e., not “staying ahead of the aircraft”); • 2.4 — Interruptions/Distractions.◆ • Inadequate preparedness to respond to changing situations or to an emergency (i.e., expecting the References unexpected) by precise planning and by using all the 1. The Flight Safety Foundation Approach-and-landing available flight deck technical and human resources; Accident Reduction (ALAR) Task Force defines causal • Crewmembers’ personal factors (e.g., fatigue, spatial factor as “an event or item judged to be directly instrumental disorientation); and/or, in the causal chain of events leading to the accident [or incident].” Each accident and incident in the study sample • Absence of specific training of instructors and check involved several causal factors. airmen to evaluate the CRM performance of trainees and line pilots. 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety Factors Affecting CRM Digest Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts The following factors may adversely affect implementation presented by the FSF ALAR Task Force were based on of effective CRM: analyses of 287 fatal approach-and-landing accidents • Company culture and policies; (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 • Belief that actions or decisions are the correct ones at kilograms, detailed studies of 76 ALAs and serious the time, although they deviate from SOPs; incidents in 1984 through 1997 and audits of about 3,300 • Effects of fatigue and inadequate countermeasures for flights. restoring vigilance and alertness; and/or,

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 43 Related Reading From FSF Publications Lawton, Russell. “Captain Stops First Officer’s Go-around, DC-9 Becomes Controlled-flight-into-terrain (CFIT) Acci- Flight Safety Foundation (FSF) Editorial Staff. “Learjet Strikes dent.” Accident Prevention Volume 51 (February 1994). Terrain When Crew Tracks False Glideslope Indication and Continues Descent Below Published Decision Height.” Ac- FSF Editorial Staff. “Cockpit Coordination, Training Issues cident Prevention Volume 56 (June 1999). Pivotal in Fatal Approach-to-Landing Accident.” Accident Prevention Volume 51 (January 1994). FSF Editorial Staff. “Flight Crew’s Failure to Perform Land- FSF Editorial Staff. “Fatal Commuter Crash Blamed on Visual ing Checklist Results in DC-9 Wheels-up Landing.” Accident Illusion, Lack of Cockpit Coordination.” Accident Prevention Prevention Volume 54 (May 1997). Volume 50 (November 1993).

Koenig, Robert L. “FAA Identifies CRM-related Issues and Pope, John A. “Faulty Angle-of-attack Sensor Provokes Go/ Training Needs in Flight-inspection Missions.” Human Factors No-go Decision with an Inadequately Coordinated Crew.” & Aviation Medicine Volume 44 (January–February 1997). Accident Prevention Volume 50 (August 1993).

FSF Editorial Staff. “Learjet MEDEVAC Flight Ends in FSF Editorial Staff. “Spatial Disorientation Linked to Fatal Controlled-flight-into-terrain (CFIT) Accident.” Accident DC-8 Freighter Crash.” Accident Prevention Volume 50 Prevention Volume 54 (January 1997). (March 1993).

FSF Editorial Staff. “Commuter Captain Fails to Follow Haynes, Alfred C. “United 232: Coping With the ‘One-in- Emergency Procedures After Suspected Engine Failure, Loses a-Billion’ Loss of All Flight Controls.” Accident Prevention Control of the Aircraft During Instrument Approach.” Accident Volume 48 (June 1991). Prevention Volume 53 (April 1996). Orlady, Harry W. “Today’s Professional Airline Pilot: All FSF Editorial Staff. “Captain’s Inadequate Use of Flight Con- the Old Skills — and More.” Flight Safety Digest Volume 9 trols During Single-engine Approach and Go-around Results in (June 1990). Loss of Control and Crash of Commuter.” Accident Prevention Volume 52 (November 1995). Helmreich, Robert L.; Chidester, Thomas R.; Foushee, H. Clayton; Gregorich, Steve; Wilhelm, John A. “How Effective Sumwalt, Robert L. III.; Watson, Alan W. “ASRS Incident Data Is Cockpit Resource Management Training?” Flight Safety Reveal Details of Flight-crew Performance During Aircraft Mal- Digest Volume 9 (May 1990). functions.” Flight Safety Digest Volume 14 (October 1995).

FSF Editorial Staff. “Captain’s Failure to Establish Stabilized Regulatory Resources Approach Results in Controlled-flight-into-terrain Commuter Accident.” Accident Prevention Volume 52 (July 1995). International Civil Aviation Organization (ICAO). Interna- tional Standards and Recommended Practices, Annex 6 to Duke, Thomas A.; FSF Editorial Staff. “Aircraft Descended the Convention of International Civil Aviation, Operation of Below Minimum Sector Altitude and Crew Failed to Respond Aircraft. Part I, International Commercial Air Transport – to GPWS as Chartered Boeing 707 Flew into Mountain in Aeroplanes. Appendix 2, “Contents of an Operations Manual,” Azores.” Accident Prevention Volume 52 (February 1995). 5.15, 5.21, 5.22. Seventh edition – July 1998, incorporating Lawton, Russell. “Steep Turn by Captain During Approach Amendments 1–25. Results in Stall and Crash of DC-8 Freighter.” Accident Pre- vention Volume 51 (October 1994). ICAO. Procedures for Air Navigation Services. Rules of the Air and Air Traffic Services. Thirteenth edition – 1996, incor- Lawton, Russell. “Breakdown in Coordination by Commuter porating Amendments 1–3. Crew During Unstabilized Approach Results in Controlled- flight-into-terrain Accident.” Accident Prevention Volume 51 ICAO. Procedures for Air Navigation Services. Aircraft (September 1994). Operations. Volume I, Flight Procedures. Fourth edition, 1993. Reprinted May 2000, incorporating Amendments U.S. National Transportation Safety Board. “A Review of 1–10. Flightcrew-involved, Major Accidents of U.S. Air Carriers, 1978 Through 1990.” Safety Study NTSB/SS-94/01. Flight ICAO. Accident Prevention Manual. 1984. Safety Digest Volume 12 (April 1994). ICAO. Human Factors Training Manual. First edition - 1998,

44 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 incorporating Circular 216. training,” 121.422 “Aircraft dispatchers: Initial and tran- sition ground training.” January 1, 2000. ICAO. Circular 241, Human Factors Digest No. 8, “Hu- man Factors in Air Traffic Control.” 1993. FAA. Advisory Circular 60-22, Aeronautical Decision Making. December 13, 1991. U.S. Federal Aviation Administration (FAA). U.S. Fed- eral Aviation Regulations. 121.406 “Reduction of CRM/ Joint Aviation Authorities. Joint Aviation Requirements DRM programmed hours based on credit for previous – Operations 1. Commercial Air Transportation (Aero- CRM/DRM training,” 121.419 “Pilots and flight engi- planes). 1.945 “Conversion training and checking,” 1.955 neers: Initial, transition, and upgrade ground training,” “Nomination as commander,” 1.965 “Recurrent training 121.421 “Flight attendants: Initial and transition ground and checking.” March 1, 1998.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 45 Flight Safety Foundation

Approach-and-landing Accident Reduction Tool Kit FSF ALAR Briefing Note 2.3 — Pilot-Controller Communication FSF ALAR Briefing Note 2.3 — Pilot-Controller Communication

UntilUntil data-link communicationcommunication comes comes into into widespread widespread use, use, air airtraffic traffic control control (ATC) (ATC) will will depend depend primarily primarily upon upon voice voice com- Pilot-Controller Communication Loop: communicationmunication that thatis affected is affected by various by various factors. factors. The Confirmation/Correction Process

CommunicationCommunication between pilot and controllercontroller can bebe improvedimproved ATC Clearance byby the mutualmutual understanding understanding of each of eachother’s other’s operating operating environ- Acknowledge Transmit or Correct environment.ment.

StatisticalStatistical DataData

TheThe FlightFlight SafetySafety FoundationFoundation Approach-and-landingApproach-and-landing AccidentAccident Listen Controller’s ReductionReduction (A(ALAR)LAR) Task Task Force Force found found that that incorrect incorrect or inad or- Hearback Pilot’s inadequateequate ATC ATC instruction/advice/service instruction/advice/service was was a causal a causal factor factor1 in1 Readback

in33 33 percent percent of of 76 76 approach-and-landing approach-and-landing accidentsaccidents and serious Listen Transmit incidentsincidents worldwideworldwide inin 19841984 throughthrough 1997.1997.22

TheseThese accidentsaccidents andand incidentsincidents involved incorrect or inadequate: •• ATCATC instructionsinstructions (e.g.,(e.g., radarradar vectors);vectors); ATC = Air traffic control Source: Flight Safety Foundation Approach-and-landing Accident •• WeatherWeather oror traffictraffic information; information; and/or, and/or, Reduction (ALAR) Task Force • Advice/service in an emergency. • Advice/service in an emergency. Figure 1

Pilot-ControllerPilot-Controller CommunicationCommunication Loop Loop Wheneveradherence adverseto the confirmation/correction factors are likely to affect process communication, is a line of adherencedefense against to the communication confirmation/correction errors. process is a line of TheThe responsibilitiesresponsibilities ofof thethe pilotpilot andand controllercontroller overlap in many defense against communication errors. areasareas andand provideprovide backup.backup. Effective Communication Effective Communication TheThe pilot-controllerpilot-controller confirmation/correctionconfirmation/correction process process is is a a“loop” “loop” Pilots and controllers are involved equally in the ATC system. thatthat ensuresensures effectiveeffective communicationcommunication (Figure(Figure 1).1). Pilots and controllers are involved equally in the ATC system. Achieving effective radio communication involves many fac- tors that should not be considered in isolation; more than one FLIGHTWhenever SAFETY adverse FOUNDATION factors are likely• FLIGHT to affect SAFETY communication, DIGEST • AUGUST–NOVEMBER 2000 47

46 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 factor usually is involved in a breakdown of the communica- heading (left, right), airspeed; and, tion loop. • Where — (at […] waypoint). Human Factors The construction of the initial message and subsequent message(s) should support this operational context by: Effective communication is achieved when the intellectual process for interpreting the information contained in a message • Following the chronological order of the actions; accommodates the message received. • grouping instructions and numbers related to each action; and, This process can be summarized as follows: • limiting the number of instructions in the transmission. • how do we perceive the message? • how do we reconstruct the information contained in the The intonation, the speed of speaking and the placement and message? duration of pauses may affect the understanding of a com- munication. • how do we link the information to an objective or to an expectation (e.g., route, altitude or time)? Mastering the Language • What bias or error is introduced in this process? CRM studies show that language differences on the flight Crew resource management (CRM) highlights the relevance deck are a greater obstacle to safety than cultural differences of the context and the expectation in communication. Never- on the flight deck. theless, expectation may introduce either a positive bias or a negative bias in the effectiveness of the communication. Because English has become a shared language in aviation, an effort has been initiated to improve the English-language High workload, fatigue, noncompliance with the “sterile cock- skills of pilots and controllers worldwide. pit rule,”3 distractions, interruptions and conflicts are among the factors that may affect pilot-controller communication Nevertheless, even pilots and controllers for whom English is and result in: the native language may not understand all words spoken in • Incomplete communication; English because of regional accents or dialects.

• omission of the aircraft call sign or use of an incorrect In many regions of the world, language differences generate call sign; other communication difficulties. • Use of nonstandard phraseology; For example, controllers using both English (for communi- • Failure to hear or to respond; and, cation with international flights) and the country’s official • Failure to effectively implement a confirmation or language (for communication with domestic flights) hinder correction. some flight crews from achieving the desired level of situ- ational awareness (loss of “party-line” communication). Language and Communication Nonstandard Phraseology Native speakers may not speak their own language correctly and consistently. Nonstandard phraseology is a major obstacle to effective communication. The language of pilot-controller communication is intended to overcome this basic shortcoming. Standard phraseology in pilot-controller communication is intended to be understood universally. The first priority of any communication is to establish an op- erational context that defines the following elements: Standard phraseology helps lessen the ambiguities of spoken language and, thus, facilitates a common understanding among • Purpose — clearance, instruction, conditional statement speakers: or proposal, question or request, confirmation; • of different native languages; or, • When — immediately, anticipate, expect; • of the same native language but who use, pronounce or • What and how — altitude (climb, descend, maintain), understand words differently.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 47 Nonstandard phraseology or the omission of key words may the result of frequency congestion and the need for the con- change completely the meaning of the intended message, troller to issue clearances and instructions to several aircraft resulting in potential traffic conflicts. in succession.

For example, any message containing a number should indicate An uncorrected erroneous readback (known as a hearback what the number refers to (e.g., an altitude, a heading or an error) may lead to a deviation from the assigned altitude or airspeed). Including key words prevents erroneous interpreta- noncompliance with an altitude restriction or with a radar tion and allows an effective readback/hearback. vector.

Pilots and controllers might use nonstandard phraseology, with A deviation from an intended clearance may not be detected good intentions, for simplicity; however, standard phraseology until the controller observes the deviation on his/her radar minimizes the potential for misunderstanding. display.

Building Situational Awareness Less-than-required vertical separation or horizontal separation (and near midair collisions) and runway incursions usually are Radio communication should contribute to the pilot’s and the the result of hearback errors. controller’s situational awareness, which may be enhanced if they provide each other with advance information. Expectations

Frequency Congestion Bias in understanding a communication can affect pilots and controllers. Frequency congestion affects significantly the flow of commu- nication during approach-and-landing phases at high-density The bias of expectation can lead to: airports, and demands enhanced vigilance by pilots and by • Transposing the numbers contained in a clearance (e.g., controllers. a flight level [FL]) to what was expected, based on experience or routine; and, Omission of Call Sign • Shifting a clearance or instruction from one parameter Omitting the call sign or using an incorrect call sign jeopardizes to another (e.g., perceiving a clearance to maintain a an effective readback/hearback. 280-degree heading as a clearance to climb/descend and maintain FL 280). Omission of Readback or Inadequate Readback Failure to Seek Confirmation The term “roger” often is misused, as in the following situ- ations: Misunderstandings may involve half-heard words or guessed- at numbers. • A pilot says “roger” (instead of providing a readback) to acknowledge a message containing numbers, thus The potential for misunderstanding numbers increases when preventing any effective hearback and correction of an ATC clearance contains more than two instructions. errors by the controller; or, • A controller says “roger” to acknowledge a message Failure to Request Clarification requiring a definite answer (e.g., a positive confirmation or correction, such as acknowledging a pilot’s statement Reluctance to seek confirmation may cause flight crews to that an altitude or airspeed restriction cannot be met), either: thus decreasing both the pilot’s and the controller’s • Accept an inadequate instruction (over-reliance on ATC); situational awareness. or, Failure to Correct Readback • determine for themselves the most probable interpretation. The absence of an acknowledgment or a correction following a clearance readback is perceived by most flight crews as an Failing to request clarification may cause a flight crew to -be implicit confirmation of the readback. lieve erroneously that they have received an expected clearance (e.g., clearance to cross an active runway). The absence of acknowledgment by the controller usually is

48 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Failure to Question Instructions Blocked Transmissions (Simultaneous Communication) Failing to question an instruction can cause a crew to accept an altitude clearance below the minimum safe altitude (MSA) Blocked transmissions often are the result of not immediately or a heading that places the aircraft near obstructions. releasing the push-to-talk switch after a communication.

Taking Another Aircraft’s Clearance or Instruction An excessive pause in a message (i.e., holding the push-to-talk switch while considering the next item of the transmission) This usually occurs when two aircraft with similar-sounding also may result in blocking part of the response or part of call signs are on the same frequency and are likely to receive another message. similar instructions, or when the call sign is blocked by another transmission. Simultaneous transmission by two stations (two aircraft or one aircraft and ATC) results in one of the two (or both) transmis- When pilots of different aircraft with similar-sounding call sions being blocked and unheard by the other stations (or being signs omit the call sign on readback, or when simultaneous heard as a buzzing sound or as a squeal). readbacks are made by both pilots, the error may go unnoticed by the pilots and the controller. The absence of a readback (from the pilot) or a hearback acknowledgment (from the controller) should be treated as a Filtering Communications blocked transmission and prompt a request to repeat or confirm the message. Because of other flight deck duties, pilots tend to filter com- munications, hearing primarily communications that begin Blocked transmissions can result in altitude deviations, missed with their aircraft call sign and not hearing most other com- turnoffs and takeoffs, landings without clearances and other munications. hazards.

For workload reasons, controllers also may filter communica- tions (e.g., not hearing and responding to a pilot readback while Communicating Specific Events engaged in issuing clearances/instructions to other aircraft or ensuring internal coordination). The following events should be reported as soon as practical to ATC, stating the nature of the event, the action(s) taken and To maintain situational awareness, this filtering process should the flight crew’s intention(s): be adapted, according to the flight phase, for more effective • Traffic-alert and collision avoidance system (TCAS) listening. resolution advisory (RA);

For example, when occupying an active runway (e.g., back- • Severe turbulence; taxiing or holding in position) or when conducting a final • Volcanic ash; approach to an assigned runway, the flight crew should listen and give attention to communications related to the landing • Wind shear or microburst; and, runway. • A terrain-avoidance maneuver prompted by a ground- proximity warning system (GPWS) warning or terrain Timeliness of Communication awareness and warning system (TAWS)4 warning.

Deviating from an ATC clearance may be required for opera- Emergency Communication tional reasons (e.g., a heading deviation or altitude deviation for weather avoidance, or an inability to meet a restriction). In an emergency, the pilot and the controller must communicate clearly and concisely, as suggested below. Both the pilot and the controller need time to accommodate this deviation; therefore, ATC should be notified as early as Pilot possible to obtain a timely acknowledgment. The standard International Civil Aviation Organization (ICAO) Similarly, when about to enter a known non-radar-controlled phraseology “Pan Pan”5 or “Mayday”6 must be used to alert a flight information region (FIR), the pilot should contact the controller and trigger an appropriate response. appropriate ATC facility approximately 10 minutes before reaching the FIR boundary to help prevent misunderstandings or less-than-required separation.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 49 Controllers and instructions (e.g., CRM).

Controllers should recognize that, when faced with an emer- Special emphasis should be placed on pilot-controller commu- gency situation, the flight crew’s most important needs are: nication and task management during emergency situations. • Time; • Airspace; and, Summary • Silence. The following should be emphasized in pilot-controller com- munication: The controller’s response to the emergency situation could be patterned after a memory aid such as ASSIST: • Recognize and understand respective pilot and controller working environments and constraints; • Acknowledge: • Use standard phraseology; – Ensure that the reported emergency is understood and acknowledged; • Adhere to the pilot-controller confirmation/correction process in the communication loop; • Separate: • Request clarification or confirmation when in doubt; – Establish and maintain separation with other traffic and/or terrain; • Question an incorrect clearance or inadequate instruction; • Silence: • Prevent simultaneous transmissions; – Impose silence on your control frequency, if necessary; and, • listen to party-line communications as a function of the flight phase; and, – do not delay or disturb urgent flight crew action by unnecessary transmissions; • Use clear and concise communication in an emergency. • Inform: – Inform your supervisor and other sectors, units and The following FSF ALAR Briefing Notes provide information airports as appropriate; to supplement this discussion: • Support: • 2.1 — Human Factors; – Provide maximum support to the flight crew; and, • 2.2 — Crew Resource Management; • Time: • 2.4 — Interruptions/Distractions; and, – Allow the flight crew sufficient time to handle the • 7.1 — Stabilized Approach.◆ emergency.

References Training Program 1. The Flight Safety Foundation Approach-and-landing A company training program on pilot-controller communica- Accident Reduction (ALAR) Task Force defines causal tion should involve flight crews and ATC personnel in joint factor as “an event or item judged to be directly instrumental meetings, to discuss operational issues and, in joint flight/ in the causal chain of events leading to the accident [or ATC simulator sessions, to promote a mutual understanding incident].” Each accident and incident in the study sample of each other’s working environment, including: involved several causal factors. • Modern flight decks (e.g., flight management system 2. Flight Safety Foundation. “Killers in Aviation: FSF Task reprogramming) and ATC equipment (e.g., absence Force Presents Facts About Approach-and-landing and of primary returns, such as weather, on modern radar Controlled-flight-into-terrain Accidents.” Flight Safety displays); Digest Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts • operational requirements (e.g., aircraft deceleration presented by the FSF ALAR Task Force were based on characteristics, performance, limitations); and, analyses of 287 fatal approach-and-landing accidents • Procedures (e.g., standard operating procedures [SOPs]) (ALAs) that occurred in 1980 through 1996 involving

50 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 turbine aircraft weighing more than 12,500 pounds/5,700 FSF Editorial Staff. “Use of Standard Phraseology by Flight kilograms, detailed studies of 76 ALAs and serious Crews and Air Traffic Controllers Clarifies Aircraft Emergen- incidents in 1984 through 1997 and audits of about 3,300 cies.” Airport Operations Volume 26 (March–April 2000). flights. FSF Editorial Staff. “Studies Investigate the Role of Memory 3. The sterile cockpit rule refers to U.S. Federal Aviation in the Interaction Between Pilots and Air Traffic Controllers.” Regulations Part 121.542, which states: “No flight Airport Operations Volume 24 (January–February 1998). crewmember may engage in, nor may any pilot-in- command permit, any activity during a critical phase Uplinger, Shannon. “English-language Training for Air Traffic of flight which could distract any flight crewmember Controllers Must Go Beyond Basic ATC Vocabulary.” Airport from the performance of his or her duties or which Operations Volume 23 (September–October 1997). could interfere in any way with the proper conduct of those duties. Activities such as eating meals, engaging FSF Editorial Staff. “Preparing for Last-minute Runway in nonessential conversations within the cockpit and Change, Boeing 757 Flight Crew Loses Situational Aware- nonessential communications between the cabin and ness, Resulting in Collision with Terrain.” Accident Prevention cockpit crews, and reading publications not related to the Volume 54 (July–August 1997). proper conduct of the flight are not required for the safe operation of the aircraft. For the purposes of this section, FSF Editorial Staff. “During Nonprecision Approach at Night, critical phases of flight include all ground operations MD-83 Descends Below Minimum Descent Altitude and Con- involving taxi, takeoff and landing, and all other flight tacts Trees, Resulting in Engine Flame-out and Touchdown operations below 10,000 feet, except cruise flight.” [The Short of Runway.” Accident Prevention Volume 54 (April FSF ALAR Task Force says that “10,000 feet” should be 1997). height above ground level during flight operations over high terrain.] Koenig, Robert L. “Excess Words, Partial Readbacks Score 4. Terrain awareness and warning system (TAWS) is the High in Analysis of Pilot-ATC Communication Errors.” Airport term used by the European Joint Aviation Authorities Operations Volume 23 (January–February 1997). and the U.S. Federal Aviation Administration to describe equipment meeting International Civil Aviation FSF Editorial Staff. “Flight Crew of DC-10 Encounters Mi- Organization (ICAO) standards and recommendations for croburst During Unstabilized Approach, Ending in Runway ground-proximity warning system (GPWS) equipment that Accident.” Accident Prevention Volume 53 (August 1996). provides predictive terrain-hazard warnings. “Enhanced GPWS” and “ground collision avoidance system” are FSF Editorial Staff. “Pilot of Cessna 441 Incorrectly Taxis other terms used to describe TAWS equipment. onto Active Runway and Aircraft Is Struck by McDonnell Douglas MD-82 on Takeoff Roll.” Accident Prevention Volume 5. ICAO says that the words “Pan Pan” at the beginning of 53 (March 1996). a communication identifies urgency — i.e., “a condition concerning the safety of an aircraft … or of some FSF Editorial Staff. “Unaware That They Have Encountered a person on board or within sight, but which does not Microburst, DC-9 Flight Crew Executes Standard Go-around; require immediate assistance.” ICAO says that “Pan Pan” Aircraft Flies Into Terrain.” Accident Prevention Volume 53 (pronounced “Pahn, Pahn”) should be spoken three times (February 1996). at the beginning of an urgency call. 6. ICAO says that the word “Mayday” at the beginning of Cushing, Steven. “Pilot–Air Traffic Control Communications: a communication identifies distress — i.e., “a condition It’s Not (Only) What You Say, It’s How You Say It.” Flight of being threatened by serious and/or imminent danger Safety Digest Volume 14 (July 1995). and of requiring immediate assistance.” ICAO says that “Mayday” should be spoken three times at the beginning Duke, Thomas A.; FSF Editorial Staff. “Aircraft Descended of a distress call. Below Minimum Sector Altitude and Crew Failed to Respond to GPWS as Chartered Boeing 707 Flew into Mountain in Azores.” Accident Prevention Volume 52 (February 1995). Related Reading from FSF Publications FSF Editorial Staff. “Cockpit Coordination, Training Issues Flight Safety Foundation (FSF) Editorial Staff. “ATR 42 Strikes Pivotal in Fatal Approach-to-Landing Accident.” Accident Mountain on Approach in Poor Visibility to Pristina, Kosovo.” Prevention Volume 51 (January 1994). Accident Prevention Volume 57 (October 2000).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 51 Gless, Richard D. “Communication Creates Essential Bond to Amendments 1–74. Allow Air Traffic Control System to Function Safely.”Accident Prevention Volume 49 (May 1992). ICAO. Manual of Radiotelephony. Second edition – 1990.

Wilson, Donald R. “My Own Mouth Shall Condemn Me.” ICAO. Human Factors Training Manual. First edition – 1998, Accident Prevention Volume 47 (June 1990). incorporating Circular 216.

ICAO. Circular 241, Human Factors Digest No. 8, “Human Regulatory Resources Factors in Air Traffic Control.” 1993.

International Civil Aviation Organization (ICAO). Interna- U.S. Federal Aviation Administration (FAA). Federal Aviation tional Standards and Recommended Practices, Annex 6 to Regulations. 121.406 “Reduction of CRM/DRM programmed the Convention of International Civil Aviation, Operation of hours based on credit for previous CRM/DRM training,” Aircraft. Part I, International Commercial Air Transport – 121.419 “Pilots and flight engineers: Initial, transition, and Aeroplanes. Appendix 2, “Contents of an Operations Manual,” upgrade ground training,” 121.421 “Flight attendants: Initial 5.15. Seventh edition – July 1998, incorporating Amendments and transition ground training,” 121.422 “Aircraft dispatchers: 1–25. Initial and transition ground training.” January 1, 2000.

ICAO. Procedures for Air Navigation Services. Rules of the FAA. Advisory Circular 60-22, Aeronautical Decision Making. Air and Air Traffic Services. Thirteenth edition – 1996, incor- December 13, 1991. porating Amendments 1–3. FAA. Aeronautical Information Manual: Official Guide to ICAO. Procedures for Air Navigation Services. Aircraft Op- Basic Flight Information and ATC Procedures. erations. Volume I, Flight Procedures. Fourth edition – 1993. Reprinted May 2000, incorporating Amendments 1–10. Joint Aviation Authorities. Joint Aviation Requirements – Operations 1. Commercial Air Transportation (Aeroplanes). ICAO. International Standards, Recommended Practices 1.945 “Conversion training and checking,” 1.955 “Nomination and Procedures for Air Navigation Services, Annex 10 to as commander,” 1.965 “Recurrent training and checking.” the Convention of International Civil Aviation, Aeronautical March 1, 1998. Telecommunications. Volume II, Communication Procedures Including Those With PANS Status. Chapter 5, “Aeronautical U.K. Civil Aviation Authority. Radiotelephony Manual. Mobile Service.” Fifth edition – July 1995, incorporating January 2000.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

52 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 2.4 — Interruptions/Distractions

Interruptions and distractions often result in omitting an ac- or resolution advisory [RA]). tion and/or deviating from standard operating procedures (SOPs). Distractions — even a minor equipment malfunction — can turn a routine flight into a challenging event. Interruptions (e.g., because of an air traffic control [ATC] communication) and distractions (e.g., because of a cabin Effect of Interruptions/Distractions crewmember entering the flight deck) occur frequently; some cannot be avoided, some can be minimized or eliminated. The primary effect of interruptions/distractions is to break the flow pattern of ongoing flight deck activities (actions or Statistical Data communications), such as: The Flight Safety Foundation Approach-and-landing Accident • SOPs; Reduction (ALAR) Task Force found that omission of action or • Normal checklists; inappropriate action (i.e., inadvertent deviation from SOPs) was a causal factor1 in 72 percent of 76 approach-and-landing acci- • Communications (listening, processing, responding); 2 dents and serious incidents worldwide in 1984 through 1997. • Monitoring tasks (systems monitoring, pilot flying/pilot not flying [PF/PNF] cross-checking); and, Types of Interruptions/Distractions • Problem-solving activities. Interruptions/distractions on the flight deck may be subtle or brief, but they can be disruptive to the flight crew. An interruption/distraction can cause the flight crew to feel rushed and to be confronted with competing tasks. Interruptions/distractions can be classified in three categories: When confronted with competing tasks, the crew must select • Communication (e.g., receiving the final weights while one task to perform before another task, which can result in taxiing or a flight attendant entering the flight deck); poor results in one or more of the completed tasks. Thus, the • head-down work (e.g., reading the approach chart or interruption/distraction can result in the crew: programming the flight management system [FMS]); • Not monitoring the flight path (possibly resulting in an and, altitude deviation, a course deviation or controlled flight • Responding to an abnormal condition or to an unexpected into terrain [CFIT]); situation (e.g., system malfunction or traffic-alert and • Not hearing or misinterpreting an ATC instruction collision avoidance system [TCAS] traffic advisory [TA] (possibly resulting in a traffic conflict or runway

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 53 incursion); tion to the flight crew.

• omitting an action and failing to detect and correct The following are suggested examples of occurrences that the resulting abnormal condition or configuration (if warrant breaking the sterile cockpit rule: interrupted during a normal checklist); and, • Fire, burning odor or smoke in the cabin; • leaving uncertainties unresolved (e.g., an ATC instruction or an abnormal condition). • Medical emergency; • Unusual noise or vibration (e.g., evidence of tail strike); Reducing Interruptions/Distractions • Engine fire (torching flame); Acknowledging that a flight crew may have control over some • Fuel or fluid leakage; interruptions/distractions and not over others is the first step in • Emergency-exit or door-unsafe condition (although this developing personal lines of defense for the crew. condition is annunciated to the flight crew); Actions that are under control (e.g., SOPs, initiation of normal • localized extreme cabin temperature changes; checklists) should be scheduled for usual periods of minimum • Evidence of a deicing problem; disruption, to help prevent interference with actions that are not under control (e.g., ATC or cabin crew). • Cart-stowage problem;

Complying with the U.S. Federal Aviation Administration’s • Suspicious, unclaimed bag or package; and, “sterile cockpit rule”3 also can reduce interruptions/distrac- • Any other condition deemed relevant by the senior cabin tions. crewmember (purser).

Complying with the sterile cockpit rule during taxi-out and These examples should be adjusted for local regulations or to taxi-in requires discipline because the taxi phases often provide suit company policy. relief between phases of high workload and concentration. Cabin crewmembers may hesitate (depending on national The sterile cockpit rule has been adopted by many non-U.S. culture and company policy) to report technical occurrences operators and is included (although in less explicit terms) in to the flight crew. To overcome this reluctance, implementa- Joint Aviation Requirements–Operations 1.085(d)(8). tion and interpretation of the sterile cockpit rule should be explained during cabin crew CRM training and cited by the The sterile cockpit rule should be implemented with good captain during the crew preflight briefing. common sense so that communication remains open among all aircraft crewmembers. Analysis of aviation safety reports indicates that the most frequent violations of the sterile cockpit rule are caused by Nevertheless, the application of efficient crew resource man- the following: agement (CRM) by the flight crew or the communication of emergency or safety-related information by cabin crew should • Non-flight-related conversations; not be prevented by a rigid interpretation of this rule. • distractions by cabin crew; The U.S. Federal Aviation Administration agrees that it is better • Non-flight-related radio calls; and/or, to break the sterile cockpit rule than to fail to communicate. • Nonessential public-address announcements. Adherence to the sterile cockpit rule by cabin crew creates two challenges: Building Lines of Defense • how to identify when the rule applies; and, A high level of interaction and communication between flight • how to identify occurrences that warrant breaking the crewmembers, and between cabin crewmembers and flight crew- sterile cockpit rule. members, constitutes the first line of defense to reduce errors.

Several methods of signaling to the cabin crew that a sterile Company policies, SOPs, CRM and leadership by the pilot- cockpit is being maintained have been evaluated (e.g., using in-command contribute to effective communication among all the all-cabin-crew call or a public-address announcement). aircraft crewmembers, thus enhancing their performance.

Whatever method is used, it should not create its own distrac-

54 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 The following personal lines of defense can be developed to – What decision or action shall I take to get “back on minimize flight deck interruptions/distractions: track”?

• Communication: In the ensuing decision-making process, the following strategy – Keep flight deck communication clear and concise; should be applied: and, • Prioritize: – Interrupt conversations when necessary to correct – Aviate (fly); a flight parameter or to comply with an altitude restriction; – Navigate; – Communicate; and, • head-down work (FMS programming or chart review): – Manage. – define task-sharing for FMS programming or • Plan: reprogramming depending on the level of automation Some actions may have to be postponed until time and being used and on the flight phase (SOPs); conditions permit. Requesting a delay (e.g., from ATC or – Plan long periods of head-down tasks for periods of from the other crewmember) will prevent being rushed lower workload; and, in the accomplishment of competing actions (take time to make time); and, – Announce that you are going “head-down.” • Verify: • Responding to an abnormal condition or to an unanticipated situation: Various SOP techniques (e.g., event triggers and normal – Keep the autopilot engaged to decrease workload, checklists) ensure that the action(s) that had been unless otherwise required; postponed have been accomplished. – Ensure that one pilot is primarily responsible for Finally, if the interruption or distraction disrupts a normal flying/monitoring the aircraft; checklist or abnormal checklist, an explicit hold should be an- – Adhere to PF/PNF task-sharing under abnormal nounced to mark the disruption of the checklist and an explicit conditions (with particular emphasis for the PNF to command should be used to resume the checklist at the last maintain situational awareness and back up the PF); item checked before the disruption of the checklist. and, – give particular attention to normal checklists, Summary because handling an abnormal condition may disrupt the normal flow of SOP actions (SOP actions or Interruptions/distractions usually result from the following normal checklists are initiated based on events — factors: usually referred to as triggers; such events may go • Flight crew-ATC, flight deck or flight crew-cabin crew unnoticed, and the absence of the trigger may be communication; interpreted incorrectly as action complete or checklist complete). • head-down work; and, • Response to an abnormal condition or unexpected Managing Interruptions/Distractions situation.

Because some interruptions/distractions may be subtle and in- Company accident-prevention strategies and personal lines sidious, the first priority is to recognize and to identify them. of defense should be developed to minimize interruptions/ distractions. The second priority is to re-establish situational awareness, as follows: The most effective company accident-prevention strategies and • Identify: personal lines of defense are adherence to the following: – What was I doing? • SOPs; • Ask: • golden rules; – Where was I interrupted or distracted? • Sterile cockpit rule (as applicable); and, • decide/act: • Recovery tips, such as:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 55 – Identify – ask – decide – act; and, operations involving taxi, takeoff and landing, and all other – Prioritize – plan – verify. flight operations below 10,000 feet, except cruise flight.” [The FSF ALAR Task Force says that “10,000 feet” should be height above ground level during flight operations over The following FSF ALAR Briefing Notes provide information high terrain.] to supplement this discussion: • 1.3 — Golden Rules; Related Reading from FSF Publications • 1.4 — Standard Calls; • 1.5 — Normal Checklists; Flight Safety Foundation (FSF) Editorial Staff. “B-757 Dam- • 2.1 — Human Factors; aged by Ground Strike During Late Go-around from Visual Approach.” Accident Prevention Volume 56 (May 1999). • 2.2 — Crew Resource Management; and, • 2.3 — Pilot-Controller Communication.◆ Rosenthal, Loren J.; Chamberlin, Roy W.; Matchette, Robert D. “Flight Deck Confusion Cited in Many Aviation Incident References Reports.” Human Factors & Aviation Medicine Volume 41 (July–August 1994). 1. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force defines causal Sumwalt, Robert L. III. “Accident and Incident Reports Show factor as “an event or item judged to be directly instrumental Importance of ‘Sterile Cockpit’ Compliance.” Flight Safety in the causal chain of events leading to the accident [or Digest Volume 13 (July 1994). incident].” Each accident and incident in the study sample involved several causal factors. 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Regulatory Resources Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety International Civil Aviation Organization (ICAO). Preparation Digest Volume 17 (November–December 1998) and Volume of an Operations Manual. Second edition – 1997. 18 (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on analyses of 287 ICAO. Human Factors Training Manual. First edition – 1998, fatal approach-and-landing accidents (ALAs) that occurred incorporating Circular 216. in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 kilograms, detailed studies ICAO. Circular 241, Human Factors Digest No. 8, “Human of 76 ALAs and serious incidents in 1984 through 1997 and Factors in Air Traffic Control.” 1993. audits of about 3,300 flights. U.S. Federal Aviation Administration. Federal Aviation Regu- 3. The sterile cockpit rule refers to U.S. Federal Aviation lations. 121.406 “Reduction of CRM/DRM programmed hours Regulations Part 121.542, which states: “No flight based on credit for previous CRM/DRM training,” 121.419 crewmember may engage in, nor may any pilot-in-command “Pilots and flight engineers: Initial, transition, and upgrade permit, any activity during a critical phase of flight which ground training,” 121.421 “Flight attendants: Initial and tran- could distract any flight crewmember from the performance sition ground training,” 121.422 “Aircraft dispatchers: Initial of his or her duties or which could interfere in any way and transition ground training,” 121.542 “Flight crewmember with the proper conduct of those duties. Activities such as duties.” January 1, 2000. eating meals, engaging in nonessential conversations within the cockpit and nonessential communications between Joint Aviation Authorities. Joint Aviation Requirements – the cabin and cockpit crews, and reading publications not Operations 1. Commercial Air Transportation (Aeroplanes). related to the proper conduct of the flight are not required 1.085 “Crew responsibilities,” 1.945 “Conversion training and for the safe operation of the aircraft. For the purposes of checking,” 1.955 “Nomination as commander,” 1.965 “Recur- this section, critical phases of flight include all ground rent training and checking.” March 1, 1998.

56 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 57 FSF ALAR Briefing Note 3.1 — Barometric Altimeter and Radio Altimeter

Flight crews on international routes encounter different units of altimeter-setting errors. measurement for setting barometric altimeters, thus requiring altimeter cross-check procedures. Units of Measurement

Statistical Data The most common units of measurement for setting altimeters are: The Flight Safety Foundation Approach-and-landing Accident • hectopascals (hPa) [previously referred to as millibars Reduction (ALAR) Task Force found that lack of positional (mb)]; and, awareness was a causal factor1 in 51 percent of 76 approach- and-landing accidents and serious incidents worldwide in 1984 • Inches of mercury (in. Hg). through 1997.2 The task force said that these accidents and incidents generally involved lack of vertical-position awareness When in. Hg is used for the altimeter setting, unusual baromet- and resulted in controlled flight into terrain (CFIT). ric pressures, such as a 28.XX in. Hg (low pressure) or a 30.XX in. Hg (high pressure), may go undetected when listening to the automatic terminal information service (ATIS) or ATC, QNH or QFE? resulting in a more usual 29.XX altimeter setting being set.

QNH (altimeter setting that causes the altimeter to indicate Figure 1 and Figure 2 show that a 1.00 in. Hg discrepancy height above mean sea level [i.e., field elevation at touchdown in the altimeter setting results in a 1,000-foot error in the on the runway]) has the advantage of eliminating the need indicated altitude. to change the altimeter setting during operations below the transition altitude/flight level (FL). In Figure 1, QNH is an unusually low 28.XX in. Hg, but the altimeter was set mistakenly to a more usual 29.XX in. Hg, QNH also eliminates the need to change the altimeter setting resulting in the true altitude (i.e., the aircraft’s actual height during a missed approach, whereas such a change usually above mean sea level) being 1,000 feet lower than indicated. would be required when QFE (altimeter setting that causes the altimeter to indicate height above the QFE reference datum In Figure 2, QNH is an unusually high 30.XX in. Hg, but the al- [i.e., zero at touchdown on the runway]) is used. timeter was set mistakenly to a more usual 29.XX in. Hg, resulting in the true altitude being 1,000 feet higher than indicated. Some operators set the altimeter to QFE in areas where air traffic control (ATC) uses QNH and the majority of operators Confusion about units of measurement (i.e., hPa vs. in. Hg) use QNH. Standard operating procedures (SOPs) can prevent leads to similar errors.

58 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Effect of a One-inch-high Altimeter Setting Actual Height 1,000 AFL

Indicated Altitude Actual Altitude 4,000 Feet 3,000 Feet MSL Field Elevation 2,000 Feet

Sea Level QNH: 28.XX Inches Hg Altimeter Error 1,000 Feet Altimeter Setting: 29.XX Inches Hg

AFL = Above field level MSL = Mean sea level Hg = Mercury QNH = Altimeter setting that causes altimeter to indicate height above mean sea level (thus, field elevation at touchdown) Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 1

Effect of a One-inch-low Altimeter Setting

Actual Height Indicated Altitude 3,000 AFL 4,000 Feet Actual Altitude 5,000 Feet MSL Field Elevation Altimeter Setting: 29.XX Inches Hg 2,000 Feet

Sea Level QNH: 30.XX Inches Hg Altimeter Error 1,000 Feet

AFL = Above field level MSL = Mean sea level Hg = Mercury QNH = Altimeter setting that causes altimeter to indicate height above mean sea level (thus, field elevation at touchdown) Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 2

In Figure 3,2, aQNH QNH is ofan 991 unusually hPa was high set 30.XXmistakenly in. Hg, on butthe theal- Setting• All digits, the asAltimeter well as the unit of measurement (e.g., inches timeteraltimeter as was29.91 set in. mistakenly Hg (equivalent to a more to 1012 usual hPa), 29.XX resulting in. Hg, in or hectopascals), should be announced. the true altitude being 640 feet lower than indicated. resulting in the true altitude being 1,000 feet higher than To helpA transmissionprevent errors such associated as “altimeter with setting different six seven” units can of indicated. measurementbe interpreted or with as 28.67unusual in. Hvaluesg, 29.67 (low in. orHg, high), 30.67 thein. Setting the Altimeter followingHg orSOPs 967 shouldhPa. be used when broadcasting (ATIS or Confusion about units of measurement (i.e., hPa vs. in. Hg) controllers) or reading back (pilots) an altimeter setting: Stating the complete altimeter setting prevents confusion Toleads help to preventsimilar errors.errors associated with different units of mea- •and All digits, allows as welldetection as the unitand ofcorrection measurement of (e.g.,a previous inches surement or with unusual values (low or high), the following error.or hectopascals), should be announced. SInO FigurePs should 3 (page be used 61), when a QNH broadcasting of 991 hPa (ATIS was setor controllers) mistakenly oron readingthe altimeter back (pilots) as 29.91 an altimeterin. Hg (equivalent setting: to 1012 hPa), • WhenA transmission using in. suchHg, “low”as “altimeter should settingprecede six an seven” altimeter can resulting in the true altitude being 640 feet lower than be interpreted as 28.67 in. Hg, 29.67 in. Hg, 30.67 in. indicated. Hg or 967 hPa.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 59 60 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Effect of an Altimeter Mis-set to Inches, Rather than Hectopascals

Actual Height 1,360 AFL

Indicated Altitude Actual Altitude 4,000 Feet 3,360 Feet MSL Field Elevation 2,000 Feet

Sea Level QNH: 991 hPa Altimeter Error 640 Feet Altimeter Setting: 29.91 Inches Hg (1012 hPa)

AFL = Above field level MSL = Mean sea level Hg = Mercury hPa = Hectopascals QNH = Altimeter setting that causes altimeter to indicate height above mean sea level (thus, field elevation at touchdown) Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 3

settingStating ofthe 28.XX complete in. altimeterHg and “high” setting shouldprevents precede confusion an • Fixed for a given airportairport (as(as indicatedindicated onon thethe approachapproach altimeterand allows setting detection of 30.XX and correction in. Hg. of a previous error. chart); or,or, • When using in. Hg, “low” should precede an altimeter • Variable, depending onon QNHQNH (as(as indicatedindicated inin thethe ATISATIS An incorrect altimeter setting often is the result of one or more setting of 28.XX in. Hg and “high” should precede an broadcast). of the followingaltimeter setting factors: of 30.XX in. Hg. • high workload; DependingDepending on the airline’s/flight crew’s crew’s usual usual area area of of operation, operation, An incorrect altimeter setting often is the result of one or more changing fromfrom a a fixed fixed transition transition altitude/flight altitude/flight level level to variable to vari- • A deviation from defined task-sharing; of the following factors: transitionable transition altitudes/flight altitudes/flight levels levels may mayresult result in ina prematurea premature resetting or a late resetting of the altimeter. •• An High interruption/distraction; workload; resetting or a late resetting of the altimeter. • Inadequate cross-checking by flight crewmembers; or, • A deviation from defined task-sharing; An altitudealtitude constraint constraint (expressed (expressed in altitudein altitude or flight or flight level) level)also •• Confusion An interruption/distraction; about units of measurement. mayalso delaymay delayor advance or advance the setting the ofsetting the standard of the altimeterstandard setting altim- (1013.2eter setting hPa or(1013.2 29.92 in. hPa Hg), or possibly 29.92 in. resulting Hg), possibly in crew confusion. resulting • Inadequate cross-checking by flight crewmembers; or, Adherence to the defined task-sharing (for normal conditions in crew confusion. or abnormal• Confusion conditions) about units and ofnormal measurement. checklists are effective Altimeter References defenses to help prevent altimeter-setting errors. Adherence to the defined task-sharing (for normal conditions Altimeter References The barometric-altimeter reference (“bug”) and the radio- or abnormal conditions) and normal checklists are effective altimeter decision height (RA DH) bug must be set according Metricdefenses Altimeterto help prevent altimeter-setting errors. The barometric-altimeter reference (“bug”) and the radio- to the aircraft manufacturer’s SOPs or the company’s SOPs. altimeter decision height (RA DH) bug must be set according Table 1 (page 62) shows some examples. Metric altitudes in certain countries (e.g., Russia and China) to the aircraft manufacturer’s SOPs or the company’s SOPs. alsoMetric require Altimeter SOPs for the use of metric altimeters (or conver- Table 1 shows some examples. sion tables). For all approaches, except Category (CAT) I instrument landing Metric altitudes in certain countries (e.g., the Commonwealth of system (ILS) approaches with RA DH, CAT II ILS approaches For all approaches, except Category (CAT) I instrument landing Independent States and the People’s Republic of China) also and CAT III ILS approaches, the standard call “minimum” system (ILS) approaches with RA DH, CAT II ILS approaches Crossingrequire SOPs forthe the Transition use of metric altimeters Altitude/Flight (or conversion tables). will be based on the barometric-altimeter bug set at the Level minimumand CAT III descent ILS approaches, altitude/height the standard [MDA(H)] call “minimum” or decision will altitude/heightbe based on the [DA(H)]. barometric-altimeter bug set at the minimum TheCrossing transition the altitude/flight Transition level Altitude/Flight can be either: Level descent altitude/height [MDA(H)] or decision altitude/height Radio-altimeter[DA(H)]. standard calls can be either: The• transitionFixed for altitude/flight the whole country level (e.g.,can be F Leither: 180 in the United States); Radio-altimeter• Announced standard by the PNFcalls (or can the be flighteither: engineer); or, • Fixed for the whole country (e.g., FL 180 in the United States); • Generated automatically by a synthesized voice.

60 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 61 • Conduct task-sharing for effective cross-check and – Radio-altimeter calls; and, backup, particularly mode selections and target entries – Setting the barometric-altimeter bug and RA DH bug; (e.g., airspeed, heading, altitude); and, and, • Adhere to the basic golden rule: aviate (fly), navigate, • Cross-check that the assigned altitude is above the MSA communicate and manage, in that order. (unless the crew is aware of the applicable minimum vectoring altitude for the sector). Navigate can be defined by the following “know where” statements: Table 1 shows examples of SOPs for setting the barometric- • Know where you are; altimeter bug and the RA DH bug. • Know where you should be; and, Nevertheless, unless the airport has high close-in terrain, the • Know where the terrain and obstacles are. Table 1 radio-altimeter indication should reasonably agree with the height above airport elevation (obtained by direct reading of Terrain-awareness elements of effective cross-check and Barometric-altimeter and the altimeter if using QFE or by computation if using QNH). backup include: Radio-altimeter Reference Settings Radio-altimeter indications below the following obstacle- • Assertive challenging; Barometric Radio Approach Altimeter Altimeter clearance values, should be cause for alarm: • Altitude calls; Visual MDA(H)/DA(H) of 200 feet* • Initial approach, 1,000 feet; • Excessive parameter-deviation calls; and, instrument approach or • Intermediate approach (or minimum radar vectoring • Task-sharing and standard calls for the acquisition of 200 feet above altitude), 500 feet; and, visual references. airport elevation Nonprecision MDA/(H) 200 feet* • Final approach (nonprecision approach), 250 feet. Terrain awareness can be improved by correct use of the radio ILS CAT I DA(H) 200 feet* altimeter. The barometric-altimeter bug and the radio- no RA ILS CAT I DA(H) RA DH Low Outside Air Temperature (OAT) altimeter decision height (RA DH) bug must be set according with RA to the aircraft manufacturer’s SOPs or the company’s SOPs. ILS CAT II DA(H) RA DH In a standard atmosphere, the indicated QNH altitude is ILS CAT III DA(H) RA DH the true altitude. Altimeter-setting Errors with DH ILS CAT III TDZE Alert height Whenever the temperature deviates significantly from the with no DH standard temperature, the indicated altitude deviates from the The following will minimize the potential for altimeter-setting MDA(H) = Minimum descent altitude/height true altitude, as follows: errors and provide for optimum use of the barometric-altimeter DA(H) = Decision altitude/height bug and RA DH bug: ILS = Instrument landing system • At extremely high temperatures, the true altitude is CAT = Category higher than the indicated altitude; and, • Awareness of altimeter-setting changes because of RA DH = Radio altimeter decision height prevailing weather conditions (temperature-extreme TDZE = Touchdown zone elevation • At extremely low temperatures, the true altitude is lower cold front or warm front, steep frontal surfaces, semi- * The RA DH should be set (e.g., at 200 feet) for terrain-awareness than the indicated altitude, resulting in reduced terrain permanent or seasonal low-pressure areas); purposes. The use of the radio altimeter should be discussed clearance. during the approach briefing. • Awareness of the altimeter-setting unit of measurement Note: For all approaches, except CAT II and CAT III ILS Flying into an area of low temperatures has the same effect in use at the destination airport; approaches, the approach “minimum” call will be based on the as flying into a low-pressure area; the aircraft is lower than barometric-altimeter bug set at MDA(H) or DA(H). • Awareness of the expected altimeter setting (using both the altimeter indicates. Source: Flight Safety Foundation Approach-and-landing Accident routine aviation weather reports [METARs] and Reduction (ALAR) Task Force automatic terminal information system [ATIS] for cross- The International Civil Aviation Organization (ICAO) pub- checking); lishes altitude corrections (based on the airport surface temperature and the height above the elevation of the altimeter- • Effective pilot flying-pilot not flying (PF-PNF) cross- • Announced by the PNF (or the flight engineer); or, setting source) to be made to the published minimum safe check and backup; altitudes.3 Use• of generated Radio automatically Altimeter by a synthesized voice. • Adherence to SOPs for: For example, Figure 4 shows that when conducting an ILS ap- Radio-altimeterStandard calls are calls tailored can be to either: the company SOPs and to the – Resetting altimeters at the transition altitude/flight proach with a published minimum glideslope intercept altitude type• of Announced approach. by the PNF (or the flight engineer); or, level; of 2,000 feet and an OAT of -40 degrees Celsius (-40 degrees Fahrenheit), the minimum glideslope intercept altitude should To• enhance Generated the flight automatically crew’s awareness by a synthesized of terrain, voice. the standard – Use of the standby altimeter to cross-check the be increased by 440 feet. primary altimeters; call “radio altimeter alive” should be announced by the first Thecrewmember calls should observing be tailored radio-altimeter to the company activation operating at 2,500 policy feet – Altitude calls; and to the type of approach. The pilot is responsible for conducting this correction, except above ground level (AGL). when under radar control in a radar-vectoring area (because the controller is responsible normally for terrain clearance, 94 FLIGHT SAFETY FOUNDATIONThe radio • FLIGHT altimeter SAFETY then should DIGEST be included• AUGUST–NOVEMBER in the instrument 2000 including accounting for the cold temperature correction). scan for the remainder of the approach. Nevertheless, the pilot should confirm this responsibility with The radio altimeter indicates the aircraft’s height above the the air traffic services of the country of operation. ground, not the aircraft’s height above airport elevation. The ra- dar altimeter does not indicate height above trees or towers. Flight crews must apply the ICAO corrections for low tem- peratures to the following published altitudes:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 61 Effects of Temperature on True Altitude True Altitude

Given Atmospheric Pressure (Pressure Altitude)

Indicated Altitude

3,000 Feet 2,000 Feet −440 Feet 1,560 Feet 2,000 Feet

1,000 Feet

High OAT Standard OAT Low OAT OAT = Outside air temperature Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 4

• Minimum Waypoint crossingen route altitudesaltitude (MEA)during aand global minimum positioning safe • Awareness– Using the of altimeter-settingstandby altimeter changes to cross-check demanded theby altitudesystem (GPS)(MSA); approach flown with barometric vertical prevailingprimary weatheraltimeters; conditions (extreme cold fronts, navigation. extreme warm fronts, steep frontal surfaces, semi- • Transition route altitude; permanent– Altitude lowcalls; pressure areas or seasonal low pressure ICAO• Proceduredoes not provide turn altitude altitude (as corrections applicable); for extremely high areas);– Radio-altimeter calls; and, temperatures; however, the temperature effect on true altitude • Awareness of the unit of measurement for setting the must• notFinal be approach ignored fix when (FAF) planning altitude; for a constant-angle – Setting the barometric-altimeter bug and RA DH bug. altimeter at the destination airport; nonprecision approach (CANPA) (i.e., to maintain the required • Step-down altitude(s) and MDA(H) during a nonprecision The following FSF ALAR Briefing Notes provide information flight path/verticalapproach; speed). • Awareness of the anticipated altimeter setting (based on to supplementaviation thisroutine discussion weather reports [METARs] and ATIS • outer marker (OM) crossing altitude during an ILS • broadcasts);1.1 — Operating Philosophy; Summaryapproach; and, • PF-PNF 2.3 — Pilot-Controller cross-checking; Communication and, ; • Waypoint crossing altitudes during a global positioning Altimeter-setting errors result in insufficient vertical-position • Adherence to SOPs for: awareness.system The (G followingPS) approach minimize flown the withpotential barometric for altimeter- vertical • 2.4 — Interruptions/Distractions; and, settingnavigation. errors and foster optimum use of the barometric- •– 3.2 Resetting — Altitude altimeters Deviations at .♦the transition altitude/flight altimeter bug and RA DH bug: level; ICAO does not provide altitude corrections for extremely high temperatures;• Awareness however, of altimeter-setting the temperature changes effect on demanded true altitude by References– Using the standby altimeter to cross-check the must notprevailing be ignored weather when conditions planning (extreme for a constant-angle cold fronts, extreme non- primary altimeters; warm fronts, steep frontal surfaces, semi-permanent 1. The Flight Safety Foundation Approach-and-landing precision approach (CANPA) (i.e., to maintain the required Accident– Altitude Reduction calls; (ALAR) Task Force defines causal flight lowpath/vertical pressure areasspeed). or seasonal low pressure areas); factor– Radio-altimeter as “an event calls; or itemand, judged to be directly • Awareness of the unit of measurement for setting the instrumental in the causal chain of events leading to the altimeter at the destination airport; Summary accident– Setting [or incident].”the barometric-altimeter Each accident andbug incident and RA in DH the • Awareness of the anticipated altimeter setting (based on studybug. sample involved several causal factors. Altimeter-settingaviation routine errors weather result in reports insufficient [METARs] vertical-position and ATIS 2. Flight Safety Foundation. “Killers in Aviation: FSF Task awareness.broadcasts); The following minimize the potential for altimeter- The following FSF ALAR Briefing Notes provide information to supplementForce Presents this discussion Facts About Approach-and-landing and setting• PF-PNF errors andcross-checking; foster optimum and, use of the barometric- Controlled-flight-into-terrain Accidents.” Flight Safety altimeter bug and RA DH bug: • Digest1.1 — VolumeOperating 17 Philosophy (November–December; 1998) and • Adherence to SOPs for: Volume 18 (January–February 1999): 1–121. The facts – Resetting altimeters at the transition altitude/flight level; presented by the FSF ALAR Task Force were based on

62 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 63 • 2.3 — Pilot-Controller Communication; FSF Editorial Staff. “Different Altimeter Displays and Crew Fatigue Likely Contributed to Canadian Controlled-flight-into- • 2.4 — Interruptions/Distractions; and, terrain Accident.” Accident Prevention Volume 52 (December • 3.2 — Altitude Deviations.◆ 1995).

Lawton, Russell. “DC-10 Destroyed, No Fatalities, After Air- References craft Veers Off Runway During Landing.” Accident Prevention 1. The Flight Safety Foundation Approach-and-landing Volume 51 (May 1994). Accident Reduction (ALAR) Task Force defines causal factor as “an event or item judged to be directly instrumental Regulatory Resources in the causal chain of events leading to the accident [or incident].” Each accident and incident in the study sample International Civil Aviation Organization (ICAO). Interna- involved several causal factors. tional Standards and Recommended Practices, Annex 3 to the Convention of International Civil Aviation, Meteorological 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Service for International Air Navigation. Chapter 4, “Meteo- Force Presents Facts About Approach-and-landing and rological Observations and Reports.” Thirteenth edition – July Controlled-flight-into-terrain Accidents.” Flight Safety 1998. Digest Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts ICAO. International Standards, Annex 5 to the Convention presented by the FSF ALAR Task Force were based on of International Civil Aviation, Units of Measurement to be analyses of 287 fatal approach-and-landing accidents Used in Air and Ground Operations. Chapter 3, “Standard (ALAs) that occurred in 1980 through 1996 involving Application of Units of Measurement,” Table 3-4, “Standard turbine aircraft weighing more than 12,500 pounds/5,700 application of specific units of measurement.” Fourth edition kilograms, detailed studies of 76 ALAs and serious – July 1979. incidents in 1984 through 1997 and audits of about 3,300 flights. ICAO. International Standards and Recommended Practices, Annex 6 to the Convention of International Civil Aviation, 3. International Civil Aviation Organization. Procedures Operation of Aircraft. Part I, International Commercial Air for Air Navigation Services. Aircraft Operations. Volume Transport - Aeroplanes. Chapter 6, “Aeroplane Instruments, I, Flight Procedures. Part III, Approach Procedures. Equipment and Flight Documents,” 6.9.1. Appendix 2, “Con- Fourth edition - 1993. Reprinted May 2000, incorporating tents of an Operations Manual,” 5.13. Seventh edition – July Amendments 1–10. 1998, incorporating Amendments 1–25.

Related Reading from FSF Publications ICAO. Procedures for Air Navigation Services. Rules of the Air and Air Traffic Services. Thirteenth edition – 1996, incor- Flight Safety Foundation (FSF) Editorial Staff. “Boeing 737 porating Amendments 1–3. Pilot Flying Selects Incorrect Altitude in Holding Pattern, Causes Dangerous Loss of Separation with MD-81. Accident ICAO. Preparation of an Operations Manual. Second edi- Prevention Volume 55 (April 1998). tion – 1997.

FSF Editorial Staff. “During Nonprecision Approach at Night, ICAO. Manual of Radiotelephony. Second edition – 1990. MD-83 Descends Below Minimum Descent Altitude and Contacts Trees, Resulting in Engine Flame-out and Touchdown Short of ICAO. Human Factors Training Manual. First edition – 1998, Runway.” Accident Prevention Volume 54 (April 1997). incorporating Circular 216.

FSF Editorial Staff. “Learjet MEDEVAC Flight Ends in ICAO. Circular 241, Human Factors Digest No. 8, “Human Controlled-flight-into-terrain (CFIT) Accident.” Accident Factors in Air Traffic Control.” 1993. Prevention Volume 54 (January 1997).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 63 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

64 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 3.2 — Altitude Deviations

Altitude deviations may result in substantial loss of aircraft • The pilot-system interface: vertical separation or horizontal separation, which could cause – Altimeter setting, use of autopilot, monitoring of a midair collision. instruments and displays; or, Maneuvers to avoid other aircraft often result in injuries to • The pilot-controller interface: passengers, flight crewmembers and, particularly, to cabin crewmembers. – Communication loop (i.e., the confirmation/correction process).

Statistical Data Altitude deviations occur usually as the result of one or more of the following conditions: An analysis by the U.S. Federal Aviation Administration (FAA) and by USAir (now US Airways) of altitude-deviation events1 • The controller assigns an incorrect altitude or reassigns showed that: a flight level after the pilot was cleared to an altitude; • Approximately 70 percent of altitude deviations were the • Pilot-controller communication breakdown — mainly result of a breakdown in pilot-controller communication; readback/hearback errors such as the following: and, – Controller transmits an incorrect altitude, the pilot • Nearly 40 percent of altitude deviations resulted when air does not read back the altitude and the controller does traffic control (ATC) assigned 10,000 feet and the flight not challenge the absence of a readback; crew set 11,000 feet in the selected-altitude window, or – Pilot reads back an incorrect altitude, but the controller when ATC assigned 11,000 feet and the flight crew set does not hear the erroneous readback and does not 10,000 feet in the selected-altitude window. correct the pilot’s readback; or,

Defining Altitude Deviations – Pilot accepts an altitude clearance intended for another aircraft (confusion of call signs); An altitude deviation is a deviation from the assigned altitude • Pilot receives, understands and reads back the correct (or flight level) equal to or greater than 300 feet. altitude or flight level but selects an incorrect altitude or flight level because of: Causes of Altitude Deviations – Confusion of numbers with another element of the message (e.g., airspeed, heading or flight number); Altitude deviations are usually the result of a breakdown in either: – Expectation of another altitude/flight level;

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 65 – Interruption/distraction; or, or when reading back the instruction (this bias is also termed wish-hearing) or may be confused by similar – Breakdown in crew cross-checking; call signs; and, • Autopilot fails to capture the selected altitude; – The controller may confuse similar call signs, be • The crew does not respond to altitude-alert aural distracted by other radio communications or by warnings and visual warnings when hand-flying; or, telephone communications, or be affected by blocked transmissions or by workload; • The crew conducts an incorrect go-around procedure. • Use standard phraseology for clear and unambiguous pilot- controller communication and crew communication. Altitude-awareness Program – Standard phraseology is a common language for pilots The development and implementation of altitude-awareness and controllers, and this common language increases programs by several airlines have reduced significantly the the likelihood of detecting and correcting errors; number of altitude deviations. • Use expanded phraseology, such as: To help prevent the primary causes of altitude deviations, an – Announcing when leaving an altitude (e.g., “Leaving altitude-awareness program should include the following: […] for […],” or, “leaving […] and climbing to […]”), thus increasing the controller’s situational General awareness; – The announcement “leaving [altitude or flight level]” An altitude-awareness program should enhance the monitoring should be made only when a vertical speed of 500 roles of the pilot flying (PF) and the pilot not flying (PNF) by feet per minute (fpm) has been established and emphasizing the importance of: the altimeter confirms departure from the previous • Announcing intentions and actions, particularly when altitude; they are different from expectations (e.g., delayed climb or descent, management of altitude or airspeed – Combining different expressions of specific altitudes restrictions); and, (“one one thousand feet — that is, eleven thousand feet”); and, • Cross-checking. – Preceding each number by the corresponding flight Communication parameter (flight level, heading, airspeed [e.g., “descend to flight level two four zero” instead of The FAA-USAir study showed that approximately 70 percent “descend to two four zero”]); and, of altitude deviations are the result of a breakdown in the pilot- • When in doubt about a clearance, request confirmation controller communication loop caused by: from the controller; do not guess about the clearance • Readback/hearback errors (this risk is greater when one based on crew discussion. pilot does not monitor radio communications because of other duties such as listening to the automatic terminal Task-prioritization and Task-sharing information service [ATIS], complying with company- communication requirements or making public-address The following recommendations enable optimum prioritization announcements); of tasks and task-sharing: • Blocked transmissions; or, • Reduce nonessential tasks during climb and descent (in addition to the “critical phases of flight” defined in • Confusion of call signs. the “sterile cockpit rule,”2 some operators consider the final 1,000 feet before reaching the assigned altitude as The following recommendations improve communication and a sterile-cockpit period); situational awareness: • Monitor/supervise the operation of the autopilot • Be aware that readback/hearback errors involve both the to confirm correct level-off at the cleared altitude pilot and the controller: and for compliance with altitude restrictions or time – The pilot may be interrupted or distracted when restrictions; listening to a clearance, be subject to forgetfulness or • Plan tasks that preclude listening to ATC be subject to the bias of expectation when listening to communications (e.g., ATIS, company calls, public-

66 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 address announcements) for periods of infrequent ATC When within 1,000 feet of the assigned altitude/flight level communication; and, or an altitude restriction in visual meteorological conditions (VMC), one pilot should concentrate on scanning instruments • When one pilot does not monitor the ATC frequency (one head down) and one pilot should concentrate on traffic while doing other duties (e.g., company calls) or when watch (one head up). leaving the flight deck, the other pilot should: – Acknowledge receiving responsibility for ATC radio communication and aircraft control, as applicable; Flight Level Confusion

– Check that the radio volume is adequate to hear an Confusion between 10,000 feet and 11,000 feet (FL 100 and ATC call; FL 110) is usually the result of the combination of two or more – give increased attention to listening/confirming/ of the following factors: reading back (because of the absence of cross- • Readback/hearback error because of similar-sounding checking); and, phrases; – Brief the other pilot when he/she completes other • lack of standard phraseology: duties or returns to the flight deck, and communicate – International Civil Aviation Organization (ICAO): relevant new information and any change in ATC “flight level one zero zero/flight level one one clearances or instructions. zero”; Altitude-setting Procedures – U.K. National Air Traffic Services (NATS): “flight level one hundred/flight level one one zero”; The following techniques enhance standard operating proce- • Mindset tending to focus only on “one zero” and thus dures (SOPs): to more easily understand “10,000 feet”; • When receiving an altitude clearance, set immediately • Failing to question the unusual (e.g., bias of expectation the assigned/cleared altitude in the altitude window; on a familiar standard terminal arrival [STAR]); and/ • Ensure that the selected altitude is cross-checked by or, both pilots (e.g., each pilot should announce what he/she • Interpreting subconsciously a request to slow to 250 heard and then point to the altitude window to confirm knots as a clearance to descend to FL 100 (or 10,000 that the correct altitude has been set); feet). • Ensure that the assigned altitude is above the minimum safe altitude (MSA); and, Transition Altitude/Flight Level • Positively confirm the altitude clearance, when receiving radar vectors. The transition altitude/flight level can be either: • Fixed for the whole country (e.g., FL 180 in the United Standard Calls States); Use the following calls to increase PF/PNF situational aware- • Fixed for a given airport (as indicated on the approach ness and to ensure effective backup and challenge (and to detect chart); or, a previous error in the assigned altitude/flight level): • Variable as a function of QNH (an altimeter setting that • Mode changes on the flight mode annunciator (FMA) causes the altimeter to indicate height above mean sea and changes of targets (e.g., airspeed, heading, altitude) level [i.e., field elevation at touchdown on the runway]) on the primary flight display (PFD) and navigation as indicated in the ATIS broadcast. display (ND); Depending on the airline’s/flight crew’s usual area of operation, • “Leaving [...] for […]” when a 500 fpm (minimum) changing from a fixed transition altitude/flight level to vari- vertical speed has been established; and, able transition altitudes/flight levels may result in a premature • “One to go,” “One thousand to go” or “[…] for […]” resetting or a late resetting of the altimeter. when within 1,000 feet of the assigned/cleared altitude/ flight level. An altitude restriction (expressed in altitude or flight level) also may delay or advance the setting of the standard altim-

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 67 eter setting (1013.2 hPa or 29.92 in. Hg), possibly resulting To be effective, a company altitude-awareness program should in crew confusion. be emphasized during transition training, recurrent training and line checks. In countries operating with QFE (altimeter setting that causes the altimeter to indicate height above the QFE reference datum Blame-free reporting of altitude-deviation events should be [i.e., zero at touchdown on the runway]), the readback should encouraged to broaden the company’s knowledge and the indicate the altimeter reference (i.e., QFE). industry’s knowledge of the causal factors of altitude devia- tions.

Altitude Deviations in Holding Patterns The following should be promoted: • Adhere to the pilot-controller confirmation/correction Controllers assume that the pilot will adhere to a clearance process (communication loop); that the pilot has read back correctly. • Practice flight crew cross-checking to ensure that the Two separate holding patterns may be under the control of the selected altitude is the assigned altitude; same controller, on the same frequency. • Cross-check that the assigned altitude is above the MSA With aircraft in holding patterns, controllers particularly rely (unless the flight crew is aware that the assigned altitude on pilots because the overlay of aircraft data tags on the con- is above the minimum vectoring altitude); troller’s radar display may not allow the immediate detection • Monitor instruments and automation when reaching the of an impending traffic conflict. assigned altitude/flight level; and,

Secondary surveillance radars provide conflict alert but not • In VMC, apply the practice of one head down and one resolution advisory; thus, accurate pilot-controller communica- head up when reaching the assigned altitude/flight tion is essential when descending in a holding pattern. level.

The following pilot actions are important when in a holding The following FSF ALAR Briefing Notes provide information pattern: to supplement this discussion: • do not take a communication intended for another • 1.1 — Operating Philosophy; aircraft (by confusion of similar call signs); • 1.3 — Golden Rules; • Prevent/minimize the risk of blocked transmission (e.g., • 1.4 — Standard Calls; simultaneous readback by two aircraft with similar call signs or simultaneous transmissions by the pilot and the • 2.3 — Pilot-Controller Communication; controller); and, • 2.4 — Interruptions/Distractions; and, • Announce “leaving [altitude or flight level]” only when • 3.1 — Barometric Altimeter and Radio Altimeter.◆ a vertical speed of 500 fpm has been established and the altimeter confirms departure from the previous References altitude. 1. Pope, John A. “Research Identifies Common Errors Behind Altitude Deviations.” Flight Safety Digest Volume TCAS (ACAS) 12 (June 1993): 1–13. The traffic-alert and collision avoidance system (airborne col- 2. The sterile cockpit rule refers to U.S. Federal Aviation lision avoidance system) is an effective tool to help prevent Regulations Part 121.542, which states: “No flight midair collisions, which can result from altitude deviations. crewmember may engage in, nor may any pilot-in- command permit, any activity during a critical phase Summary of flight which could distract any flight crewmember from the performance of his or her duties or which Altitude deviations can be prevented by adhering to SOPs could interfere in any way with the proper conduct of to: those duties. Activities such as eating meals, engaging in nonessential conversations within the cockpit and • Set the altimeter reference; and, nonessential communications between the cabin and • Select the assigned altitude/flight level. cockpit crews, and reading publications not related to the proper conduct of the flight are not required for the safe

68 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 operation of the aircraft. For the purposes of this section, Approach Results in Controlled-flight-into-terrain Commuter critical phases of flight include all ground operations Accident.” Accident Prevention Volume 52 (July 1995). involving taxi, takeoff and landing, and all other flight operations below 10,000 feet, except cruise flight.” [The Enders, John H. “Study Urges Application of Flight Opera- FSF ALAR Task Force says that “10,000 feet” should be tional Quality Assurance Methods in U.S. Air Carrier Opera- height above ground level during flight operations over tions.” Flight Safety Digest Volume 12 (April 1993). high terrain.] Regulatory Resources Related Reading from FSF Publications International Civil Aviation Organization (ICAO). Internation- Flight Safety Foundation (FSF) Editorial Staff. “ATR 42 Strikes al Standards and Recommended Practices, Annex 6 to the Con- Mountain on Approach in Poor Visibility to Pristina, Kosovo.” vention of International Civil Aviation, Operation of Aircraft. Accident Prevention Volume 57 (October 2000). Part I, International Commercial Air Transport – Aeroplanes. Chapter 4, “Flight Operations,” Chapter 6, “Aeroplane, Instru- Sumwalt, Robert L. III. “Enhancing Flight-crew Monitoring ments, Equipment and Flight Documents,” 6.9.1. Appendix Skills Can Increase Flight Safety.” Flight Safety Digest Volume 2, “Contents of an Operations Manual,” 5.13, 5.15. Seventh 18 (March 1999). edition – July 1998, incorporating Amendments 1–25. Flight Safety Foundation. “Killers in Aviation: FSF Task ICAO. International Standards and Recommended Practices, Force Presents Facts About Approach-and-landing and Annex 6 to the Convention of International Civil Aviation, Controlled-flight-into-terrain Accidents.” Flight Safety Di- Operation of Aircraft. Part II, International General Avia- gest Volume 17 (November–December 1998) and Volume 18 tion – Aeroplanes. Chapter 6, “Aeroplane Instruments and (January–February 1999): 1–121. The facts presented by the Equipment,” 6.6. Sixth edition – July 1998, incorporating FSF ALAR Task Force were based on analyses of 287 fatal Amendments 1–20. approach-and-landing accidents (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing more than ICAO. International Standards and Recommended Practices, 12,500 pounds/5,700 kilograms, detailed studies of 76 ALAs Annex 6 to the Convention of International Civil Aviation, and serious incidents in 1984 through 1997 and audits of about Operation of Aircraft. Part III, International Operations – 3,300 flights. Helicopters. Section III, “International General Aviation,” Chapter 4, “Helicopter instruments, equipment and flight FSF Editorial Staff. “Boeing 737 Pilot Flying Selects Incor- documents,” 4.6. Fourth edition – July 1998, incorporating rect Altitude in Holding Pattern, Causes Dangerous Loss of Amendments 1–7. Separation with MD-81.” Accident Prevention Volume 55 (April 1998). ICAO. Procedures for Air Navigation Services. Rules of the Air and Air Traffic Services. Thirteenth edition – 1996, incor- FSF Editorial Staff. “During Nonprecision Approach at Night, porating Amendments 1–3. MD-83 Descends Below Minimum Descent Altitude and Con- tacts Trees, Resulting in Engine Flame-out and Touchdown ICAO. Procedures for Air Navigation Services. Aircraft Op- Short of Runway.” Accident Prevention Volume 54 (April erations. Volume I, Flight Procedures. Fourth edition, 1993. 1997). Reprinted May 2000, incorporating Amendments 1–10.

FSF Editorial Staff. “Different Altimeter Displays and Crew U.S. Federal Aviation Administration. Federal Aviation Regu- Fatigue Likely Contributed to Canadian Controlled-flight-into- lations. 91.119, “Minimum safe altitudes: General,” 91.121 terrain Accident.” Accident Prevention Volume 52 (December “Altimeter settings,” 91.129 “Operations in Class D airspace,” 1995). 91.221 “Traffic alert and collision avoidance system equip- ment and use,” 121.356 “Traffic Alert and Collision Avoidance Sumwalt, Robert L. III. “Altitude Awareness Programs Can System.” January 1, 2000. Reduce Altitude Deviations.” Flight Safety Digest Volume 14 (December 1995). U.K. Civil Aviation Authority. Radiotelephony Manual. Chap- ter 3, “General Phraseology.” January 2000. FSF Editorial Staff. “Captain’s Failure to Establish Stabilized

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 69 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

70 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 4.1 — Descent-and-approach Profile Management Incorrect management of the descent-and-approach profile • “Overconfidence, lack of vigilance and ‘press-on- and/or aircraft energy condition may result in: itis’3; • A loss of situational awareness; and/or, • “Lack of crew coordination; and, • An unstabilized approach. • “Accepting demanding air traffic control (ATC) clearances, leading to high-workload conditions.” Either situation increases the risk of approach-and-landing accidents, including those involving controlled flight into Descent Preparation and Approach terrain (CFIT). Briefing

Statistical Data To help prevent delaying initiation of the descent and to ensure optimum management of the descent-and-approach profile, the The Flight Safety Foundation Approach-and-landing Accident following procedures are recommended: Reduction (ALAR) Task Force found that unstabilized ap- • descent preparation and the approach briefing should proaches (i.e., approaches conducted either low/slow or high/ be completed typically 10 minutes before the top-of- fast) were a causal factor1 in 66 percent of 76 approach-and- descent point (or when within very-high-frequency landing accidents and serious incidents worldwide in 1984 [VHF] communication range if automatic terminal through 1997.2 information system [ATIS] information cannot be obtained 10 minutes before the top-of-descent point); The task force said that factors associated with being low/slow • If a standard terminal arrival (STAR) is included in the on approach include: flight management system (FMS) flight plan but is not • “Inadequate awareness of automation/systems status; expected to be flown because of radar vectors, the STAR should be checked (track, distance, altitude and airspeed • “Lack of vigilance and crew coordination, including restrictions) against the expected routing to adjust the omission of standard airspeed-and-altitude calls; and, top-of-descent point; • “High workload and confusion during execution of • If descent initiation is delayed by ATC, airspeed should nonprecision approaches.” be reduced (as appropriate to the aircraft model) to minimize the effect of the delay on the descent profile; The task force said that factors associated with being high/fast on approach include: • Wind-forecast data should be programmed on the appropriate FMS page at waypoints near the top-of-

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 71 descent point and along the descent-profile path; • If a missed approach procedure is included in the FMS Table 1 flight plan, the FMS missed approach procedure should be checked against the approach chart; and, Recommended Elements Of a Stabilized Approach • If FMS navigation accuracy does not meet the applicable criteria for descent, terminal area navigation or approach, All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions no descent should be made below the minimum en route (IMC) or by 500 feet above airport elevation in visual altitude (MEA) or minimum safe altitude (MSA) without meteorological conditions (VMC). An approach is stabi- prior confirmation of the aircraft position using raw lized when all of the following criteria are met: data.4 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to Achieving Flight Parameters maintain the correct flight path; 3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than V ; The flight crew must “stay ahead of the aircraft” throughout REF 4. The aircraft is in the correct landing configuration; the flight. This includes achieving desired flight parameters (e.g., aircraft configuration, aircraft position, energy condition, 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 track, vertical speed, altitude, airspeed and attitude) during the feet per minute, a special briefing should be con- descent, approach and landing. Any indication that a desired ducted; flight parameter will not be achieved should prompt immediate 6. Power setting is appropriate for the aircraft configura- corrective action or the decision to go around. tion and is not below the minimum power for approach as defined by the aircraft operating manual; At the final approach fix (FAF) or the outer marker (OM), the 7. All briefings and checklists have been conducted; crew should decide whether to proceed with the approach, 8. Specific types of approaches are stabilized if they based on the following factors: also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of • Ceiling and visibility are better than or equal to applicable the glideslope and localizer; a Category II or Cat- minimums; egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, • Aircraft is ready (position, altitude, configuration, energy wings should be level on final when the aircraft condition); and, reaches 300 feet above airport elevation; and, • Crew is ready (briefing completed, agreement on the 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a approach). stabilized approach require a special briefing. An approach that becomes unstabilized below 1,000 If the required aircraft configuration and airspeed are not feet above airport elevation in IMC or below 500 feet attained, or if the flight path is not stabilized when reaching above airport elevation in VMC requires an immediate the minimum stabilization height (1,000 feet above airport go-around. elevation in instrument meteorological conditions or 500 feet Source: Flight Safety Foundation Approach-and-landing Accident above airport elevation in visual meteorological conditions), Reduction (ALAR) Task Force (V1.1 November 2000) a go-around should be initiated immediately.

The pilot not flying (PNF) should announce any flight -pa closely to anticipate any decrease in head wind component rameter that exceeds the criteria for any of the elements of a or increase in tail wind component, and the flight path profile stabilized approach (Table 1). should be adjusted appropriately. Descent Profile Monitoring The descent also may be monitored and adjusted based on a The descent profile should be monitored, using all available typical 3,000 feet per 10 nautical mile (nm) descent gradient instruments and chart references, including: (corrected for the prevailing head wind component or tail wind component), while adhering to the required altitude/airspeed • FMS vertical-deviation indication, as applicable; restrictions (deceleration management). • Raw data; and, Below 10,000 feet, flying at 250 knots, the following recom- • Charted descent-and-approach profile. mendations may be used to confirm the descent profile and to ensure a smooth transition between the various approach Wind conditions and wind changes should be monitored phases:

72 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • 9,000 feet above airport elevation at 30 nm from • Failure to effectively monitor descent progress using all touchdown; and, available instrument references; • 3,000 feet above airport elevation at 15 nm from • Failure to monitor wind conditions and wind changes; touchdown (to allow for deceleration and slats/flaps and/or, extension). • Inappropriate technique to establish the descent profile. Descent Profile Adjustment/Recovery

If the flight path is significantly above the desired descent Summary profile (e.g., because of ATC restrictions or a greater-than- anticipated tail wind), the desired flight path can be recovered The following should be emphasized during transition training, by: line training and line audits: • Reverting from FMS vertical navigation (VNAV) to a • Conduct timely descent-and-approach preparation; selected vertical mode, with an appropriate airspeed • Adhere to SOPs for FMS setup; target (e.g., airspeed, heading, altitude) or vertical-speed target; • Cross-check all target entries; • Use the primary flight display (PFD), navigation display • Maintaining a high airspeed (and a steep angle of (ND) and FMS to support and to illustrate the approach descent) as long as practical; briefing; • Using speed brakes (as allowed by applicable SOPs, depending on airspeed and configuration, keeping one • Confirm FMS navigation accuracy before selecting FMS hand on the speed-brake handle until the speed brakes modes for the descent and approach; are retracted); • Review terrain-awareness data and other approach • Extending the landing gear, as allowed by airspeed and hazards; and, configuration, if speed brakes are not sufficient; or, • Monitor the descent profile and adjust the descent profile • As a last resort, conducting a 360-degree turn (as as required. practical, and with ATC clearance). Maintain instrument references throughout the turn to monitor and control The following FSF ALAR Briefing Notes provide information the rate of descent, bank angle and aircraft position; to supplement this discussion: this will help avoid loss of aircraft control or CFIT, and • 1.1 — Operating Philosophy; prevent overshooting the localizer or extended runway centerline. • 1.3 — Golden Rules; • 4.2 — Energy Management; If the desired descent flight path cannot be established, ATC should be notified for timely coordination. • 5.2 — Terrain; • 6.1 — Being Prepared to Go Around; and, Adverse Factors and Typical Errors • 7.1 — Stabilized Approach.◆ The following factors and errors often are observed during transition training and line training: References • late descent, which results in rushing the descent, approach preparation and briefing, and increases the 1. The Flight Safety Foundation Approach-and-landing likelihood that important items will be omitted; Accident Reduction (ALAR) Task Force defines causal factor as “an event or item judged to be directly instrumental • Failure to cross-check target entry; in the causal chain of events leading to the accident [or • Failure to allow for a difference between the expected incident].” Each accident and incident in the study sample routing and the actual routing (e.g., STAR vs. radar involved several causal factors. vectors); 2. Flight Safety Foundation. “Killers in Aviation: FSF Task • distraction leading to or resulting from two heads down; Force Presents Facts About Approach-and-landing and • Failure to resolve ambiguities, doubts or Controlled-flight-into-terrain Accidents.” Flight Safety disagreements; Digest Volume 17 (November–December 1998) and

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 73 Volume 18 (January–February 1999): 1–121. The facts terrain Accident.” Accident Prevention Volume 52 (December presented by the FSF ALAR Task Force were based on 1995). analyses of 287 fatal approach-and-landing accidents (ALAs) that occurred in 1980 through 1996 involving FSF Editorial Staff. “Captain’s Failure to Establish Stabilized turbine aircraft weighing more than 12,500 pounds/5,700 Approach Results in Controlled-flight-into-terrain Commuter kilograms, detailed studies of 76 ALAs and serious Accident.” Accident Prevention Volume 52 (July 1995). incidents in 1984 through 1997 and audits of about 3,300 flights. FSF Editorial Staff. “Stall and Improper Recovery During ILS Approach Result in Commuter Airplane’s Uncontrolled Col- 3. The FSF ALAR Task Force defines press-on-itis as lision with Terrain.” Accident Prevention Volume 52 (January “continuing toward the destination despite a lack of 1995). readiness of the airplane or crew.” Lawton, Russell. “Moving Power Levers Below Flight Idle 4. The FSF ALAR Task Force defines raw data as “data During Descent Results in Dual Engine Flameout and Power- received directly (not via the flight director or flight off Emergency Landing of Commuter Airplane.” Accident management computer) from basic navigation aids (e.g., Prevention Volume 51 (December 1994). ADF, VOR, DME, barometric altimeter).” Lawton, Russell. “Steep Turn by Captain During Approach Related Reading from FSF Publications Results in Stall and Crash of DC-8 Freighter.” Accident Pre- vention Volume 51 (October 1994).

Flight Safety Foundation (FSF) Editorial Staff. “Pilot Loses Lawton, Russell. “Breakdown in Coordination by Commuter Control of Twin Turboprop During ILS Approach in Low Vis- Crew During Unstabilized Approach Results in Controlled- ibility.” Accident Prevention Volume 57 (July 2000). flight-into-terrain Accident.” Accident Prevention Volume 51 (September 1994). FSF Editorial Staff. “Learjet Strikes Terrain When Crew Tracks False Glideslope Indication and Continues Descent Below Published Decision Height.” Accident Prevention Volume 56 Regulatory Resources (June 1999). International Civil Aviation Organization (ICAO). Interna- FSF Editorial Staff. “Boeing 767 Descends Below Glide Path, tional Standards and Recommended Practices, Annex 6 to Strikes Tail on Landing.” Accident Prevention Volume 55 the Convention of International Civil Aviation, Operation (February 1998). of Aircraft. Part I, International Commercial Air Transport – Aeroplanes. Appendix 2, “Contents of an Operations FSF Editorial Staff. “Preparing for Last-minute Runway Manual,” 5.18, 5.19. Seventh edition - July 1998, incorpo- Change, Boeing 757 Flight Crew Loses Situational Aware- rating Amendments 1–25. ness, Resulting in Collision with Terrain.” Accident Prevention Volume 54 (July–August 1997). ICAO. Procedures for Air Navigation Services. Air- craft Operations. Volume I, Flight Procedures. Fourth FSF Editorial Staff. “Learjet MEDEVAC Flight Ends in edition, 1993. Reprinted May 2000, incorporating Controlled-flight-into-terrain (CFIT) Accident.” Accident Amendments 1–10. Prevention Volume 54 (January 1997). U.S. Federal Aviation Administration. Advisory Circular FSF Editorial Staff. “Commuter Captain Fails to Follow 120-71, Standard Operating Procedures for Flight Deck Emergency Procedures After Suspected Engine Failure, Loses Crewmembers. August 10, 2000. Control of the Aircraft During Instrument Approach.” Accident Prevention Volume 53 (April 1996). Joint Aviation Authorities. Joint Aviation Requirements – Operations 1, Commercial Air Transportation (Aeroplanes). FSF Editorial Staff. “Different Altimeter Displays and Crew 1.1045 “Operations Manual – structure and contents.” March Fatigue Likely Contributed to Canadian Controlled-flight-into- 1, 1998.

74 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 75 FSF ALAR Briefing Note 4.2 — Energy Management

The flight crew’s inability to assess or to manage the aircraft’s Aircraft Energy Condition energy condition during approach is cited often as a cause of unstabilized approaches. Aircraft energy condition is a function of the following primary flight parameters: Either a deficit of energy (low/slow) or an excess of energy • Airspeed and airspeed trend; (high/fast) may result in an approach-and-landing incident or accident involving: • Altitude (or vertical speed or flight path angle); • loss of control; • drag (caused by speed brakes, slats/flaps and landing gear); and, • landing before reaching the runway; • Thrust. • hard landing; • Tail strike; or, One of the primary tasks of the flight crew is to control and to monitor aircraft energy condition (using all available refer- • Runway overrun. ences) to: • Maintain the appropriate energy condition for the flight Statistical Data phase (i.e., configuration, flight path, airspeed and thrust); or, The Flight Safety Foundation Approach-and-landing Accident • Recover the aircraft from a low-energy condition or a Reduction (ALAR) Task Force found that unstabilized ap- high-energy condition. proaches (i.e., approaches conducted either low/slow or high/ 1 fast) were a causal factor in 66 percent of 76 approach-and- Controlling aircraft energy involves balancing airspeed, thrust landing accidents and serious incidents worldwide in 1984 (and drag) and flight path. through 1997.2 Autopilot modes, flight director modes, aircraft instruments, These accidents involved incorrect management of aircraft warnings and protections are designed to relieve or assist the energy condition, resulting in an excess or deficit of energy, flight crew in this task. as follows: • Aircraft were low/slow on approach in 36 percent of the Going Down and Slowing Down accidents/incidents; and, • Aircraft were high/fast on approach in 30 percent of the A study by the U.S. National Transportation Safety Board3 accidents/incidents. said that maintaining a high airspeed to the outer marker

76 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 (OM) may prevent capture of the glideslope by the autopilot and may prevent aircraft stabilization at the defined stabiliza- tion height. Table 1 Recommended Elements The study concluded that no airspeed restriction should be Of a Stabilized Approach imposed by air traffic control (ATC) when within three nauti- cal miles (nm) to four nm of the OM, especially in instrument All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions meteorological conditions (IMC). (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabi- ATC instructions to maintain a high airspeed to the OM (160 lized when all of the following criteria are met: knots to 200 knots, typically) are common at high-density 1. The aircraft is on the correct flight path; airports, to increase the landing rate. 2. Only small changes in heading/pitch are required to maintain the correct flight path; 3. The aircraft speed is not more than V + 20 knots Minimum Stabilization Height REF indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; Table 1 shows that the minimum stabilization height is: 5. Sink rate is no greater than 1,000 feet per minute; if • 1,000 feet above airport elevation in IMC; or, an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be con- • 500 feet above airport elevation in visual meteorological ducted; conditions (VMC). 6. Power setting is appropriate for the aircraft configura- tion and is not below the minimum power for approach Typical company policy is to cross the OM (usually between as defined by the aircraft operating manual; 1,500 feet and 2,000 feet above airport elevation) with the air- 7. All briefings and checklists have been conducted; craft in the landing configuration to allow time for stabilizing 8. Specific types of approaches are stabilized if they the final approach speed and completing the landing checklist also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of before reaching the minimum stabilization height. the glideslope and localizer; a Category II or Cat- egory III ILS approach must be flown within the ex- Aircraft Deceleration Characteristics panded localizer band; during a circling approach, wings should be level on final when the aircraft Although deceleration characteristics vary among aircraft reaches 300 feet above airport elevation; and, types and their gross weights, the following typical values 9. Unique approach procedures or abnormal conditions can be used: requiring a deviation from the above elements of a stabilized approach require a special briefing. • deceleration in level flight: An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet – With approach flaps extended: 10 knots to 15 knots above airport elevation in VMC requires an immediate per nm; or, go-around. – during extension of the landing gear and landing Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) flaps: 20 knots to 30 knots per nm; and, • deceleration on a three-degree glide path (for a typical 140-knot final approach groundspeed, a rule of thumb Speed brakes may be used to achieve a faster deceleration of is to maintain a descent gradient of 300 feet per nm/700 some aircraft (usually, the use of speed brakes is not recom- feet per minute [fpm]): mended or not permitted below 1,000 feet above airport eleva- – With approach flaps and landing gear down, during tion or with landing flaps extended). extension of landing flaps: 10 knots to 20 knots per nm; Typically, slats should be extended not later than three nm from the final approach fix (FAF). – decelerating on a three-degree glide path in a clean configuration is not possible usually; and, Figure 1 shows aircraft deceleration capability and the maxi- – When capturing the glideslope with slats extended and mum airspeed at the OM based on a conservative deceleration no flaps, typically a 1,000-foot descent and three nm are rate of 10 knots per nm on a three-degree glide path. flown while establishing the landing configuration and stabilizing the final approach speed. For example, in IMC (minimum stabilization height, 1,000 feet

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 77 • A point of minimum thrust required to fly; Typical Schedule for Deceleration on • A segment of the curve located right of this point; and, the •power A point curve of). minimum thrust required to fly; Three-degree Glide Path From Outer • A segment of the curve located left of this point, called Typical Schedule for Deceleration on • A segment of the curve located right of this point; and, Marker to Stabilization Height (1,000 Feet) The powerthe back curve side comprises of the power the following curve (i.e., elements: where induced Three-degree Glide Path From Outer •drag A segment requires of more the curve power located to fly atleft a slowerof this point,steady-state called • A point of minimum thrust required to fly; Marker toMM Stabilization HeightOM (1,000 Feet) airspeedthe back thanside theof thepower power required curve to(i.e., maintain where ainduced faster Deceleration airspeed on the front side of the power curve). Segment • Adrag segment requires of more the powercurve tolocated fly at aright slower of steady-statethis point; MM (10 Knots/ OM and,airspeed than the power required to maintain a faster Nautical Mile) Deceleration The differenceairspeed onbetween the front the side available of the powerthrust curve).and the thrust Segment • A segment of the curve located left of this point, called (10 Knots/ 1,000 Feet required to fly represents the climb or acceleration capability. Above Airport the back side of the power curve (i.e., where induced Nautical Mile) The difference between the available thrust and the thrust Elevation drag requires more power to fly at a slower steady-state 1,000 Feet Therequired right to segment fly represents of the thepower climb curve or acceleration is the normal capability. zone of Above Airport operation;airspeed the thrust than thebalance power (i.e., required the balance to maintain between a thrustfaster Elevation airspeed on the front side of the power curve). requiredThe right to segment fly and availableof the power thrust) curve is stable. is the normal zone of 0 3.0 6.0 V at V operation; the thrust balance (i.e., the balance between thrust APP MAX The difference between the available thrust and the thrust re- 1,000 Feet = at OM = Thus,required at toa givenfly and thrust available level, thrust) any istendency stable. to accelerate 130 Knots 160 Knots 0 3.0 6.0 increasesquired to flythe representsthrust required the climb to fly or and,acceleration hence, returnscapability. the NauticalVAPP at Miles VMAX 1,000 Feet = at OM = aircraftThus, atto athe given initial thrust airspeed. level, any tendency to accelerate MM = Middle marker OM 130= Outer Knots marker160 Knots Theincreases right segmentthe thrust of required the power to curvefly and, is the hence, normal returns zone theof V = Final approach speedNautical V =Miles Maximum airspeed operation; the thrust balance (i.e., the balance between thrust APP MAX Conversely,aircraft to the the initial back airspeed.side of the power curve is unstable: At a required to fly and available thrust) is stable. Source:MM = MiddleFlight Safety marker Foundation OM = Outer Approach-and-landing marker Accident given thrust level, any tendency to decelerate increases the Reduction (ALAR) Task Force VAPP = Final approach speed VMAX = Maximum airspeed thrustConversely, required the toback fly sideand, of hence, the power increases curve theis unstable: tendency At to a decelerate.Thus,given atthrust a given level, thrust any level,tendency any totendency decelerate to accelerateincreases inthe- Source: Flight Safety Foundation Approach-and-landing Accident creases the thrust required to fly and, hence, returns the aircraft Reduction (ALAR) Task ForceFigure 1 thrust required to fly and, hence, increases the tendency to Thetodecelerate. the final initial approach airspeed. speed usually is slightly on the back side of the power curve, while the minimum thrust speed is 1.35 approach speed,4 the maximumFigure deceleration1 achievable timesConversely, V (stall the backspeed side in landingof the power configuration) curve is unstable: to 1.4 times At a between the OM (six nm) and the stabilization point (1,000 The finalSO approach speed usually is slightly on the back side above airport elevation) and with a typical 130-knot final ap- given thrust level, any tendency to decelerate increases the thrust VofSO the. power curve, while the minimum thrust speed is 1.35 feetproachapproach above speed, airportspeed,4 the 4 elevation maximumthe maximum and deceleration three deceleration nm) achievable is: achievable between requiredtimes V to (stallfly and, speed hence, in landingincreases configuration) the tendency to to decelerate. 1.4 times thebetween OM (six the nm)OM and(six thenm) stabilization and the stabilization point (1,000 point feet (1,000 above SO V . airportfeet above10 elevation knots airport per and elevation nm three x (6 nm) and nm is: three– 3 nm) nm) = is: 30 knots. SO Thrust Required to Fly a Three-degree To be 10stabilized10 knotsknots per perat 130nmnm xxknots (6(6 nmnm at – –1,000 33 nm)nm) feet == 3030 above knots.knots. airport elevation, the maximum airspeed that can be accepted and Glide Path in Landing Configuration Thrust Required to Fly a Three-degree canTo be be stabilized maintainedstabilized at at 130down 130 knots toknots the at 1,000OM at 1,000 is, feet therefore: abovefeet above airport airport eleva- tion,elevation, the maximum the maximum airspeed airspeed that can that be can accepted be accepted and can and be 160%Glide Path in Landing Configuration maintainedcan be maintained down130 knots to down the + O 30toM theknots is, OMtherefore: = is,160 therefore: knots. 150% 160% Given Gross Weight Given Pressure Altitude Whenever a flight crew is requested to maintain a high Given Flight Path 130130 knotsknots ++ 3030 knotsknots == 160160 knots.knots. 140% airspeed down to the OM, a quick computation such as the 150% Given Gross Weight one shown above can help assess the ATC request. Given Pressure Altitude Whenever a aflight flight crew crew is requestedis requested to maintain to maintain a high aairspeed high 130% Given Flight Path 140% downairspeed to thedown OM, to athe quick OM, computation a quick computation such as the such one asshown the one shown above can help assess the ATC request. 120% Backabove can Side help of assess the the Power ATC request. Curve 130% Stable Thrust Required Unstable 110% 120% DuringBack anSide unstabilized of the approach, Power airspeed Curve or the thrust setting Stable Back Side of the Power Curve Thrust Required 100% Unstable Thrust for VAPP often deviates from recommended criteria as follows: 110% During an unstabilized approach, airspeed or the thrust setting During• Airspeed an unstabilized decreases approach, below V airspeedREF; and/or, or the thrust setting 90% often deviates from recommended criteria as follows: 100%90 100 110 120 130 140 150 160Thrust 170 for 180VAPP 190 200 • Thrust is reduced to idle and is maintained at idle. VAPP VMinimum Thrust • Airspeed decreases below VREF;; and/or,and/or, 90% Airspeed (Knots) REF 90 100 110 120 130 140 150 160 170 180 190 200 Thrust-required-to-fly Curve • Thrust is reduced to idle and is maintained at idle. VAPP VMinimum Thrust • Thrust is reduced to idle and is maintained at idle. VAPP = Final approach speed Airspeed (Knots) FigureThrust-required-to-fly 2 shows the thrust-required-to-fly Curve curve (also called Source: Flight Safety Foundation Approach-and-landing Accident Thrust-required-to-fly Curve ReductionV = Final (ALAR) approach Task Force speed the power curve). APP Figure 2 showsshows thethe thrust-required-to-flythrust-required-to-fly curve curve (also (also called called Source: Flight Safety Foundation Approach-and-landing Accident Thethe powerpower curvecurve). comprises the following elements: Reduction (ALAR) Task ForceFigure 2

The power curve comprises the following elements: Figure 2 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 77 78 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 77 If airspeed is allowed to decrease below the final approach The hazards are increased if thrust is set and maintained at idle. speed, more thrust is required to maintain the desired flight If airspeed is allowed to decrease below the final approach The hazards are increased if thrust is set and maintained at idle. path and/or to regain the final approach speed. If a go-around is required, the initial altitude loss and the time speed, more thrust is required to maintain the desired flight for recovering the lost altitude are increased if the airspeed is path and/or to regain the final approach speed. If a go-around is required, the initial altitude loss and the time If thrust is set to idle and maintained at idle, no energy is available lower than the final approach speed and/or if the thrust is set for recovering the lost altitude are increased if the airspeed is immediately to recover from a low-speed condition or to initiate at idle. If thrust is set to idle and maintained at idle, no energy is available lower than the final approach speed and/or if the thrust is set a go-around (as shown in Figure 3, Figure 4 and Figure 5). immediately to recover from a low-speed condition or to initiate at idle. a go-around (as shown in Figure 3, Figure 4 and Figure 5). U.S. Federal Aviation Regulations (FARs) Typical Engine Response From U.S.Requirements Federal Aviation for Engine Regulations Response (FARs) — Flight-idle Thrust to Go-around Thrust Approach-idleTypical Engine Thrust Response to Go-around From Thrust Requirements for Engine Response — 100% Approach-idle100% Thrust to Go-around Thrust Flight-idle Thrust to Go-around Thrust 88% 95% 100% 100% 80% 80% 88% 95% (Typical Engine-to-engine 80% 80% Scatter) 60% 5 seconds (FARs Part 33) 60% (Typical Engine-to-engine 60% 5 seconds (FARs Part 33) Scatter) 40% 60% 8 seconds (FARs Part 25) 40%

Go-around Thrust Go-around 40% 20%

Go-around Thrust Go-around 8 seconds (FARs Part 25) 40% 15%

20% Thrust Go-around 20% Go-around Thrust Go-around 0% Approach Idle 15% 20% 012345678910 0% Approach Idle 0% Time (Seconds) 012345678910 012345678910 0% Time (Seconds) Time (Seconds) 012345678910 FARs Part 25 = Airworthiness Standards: Transport Category Airplanes Source: Flight Safety FoundationTime Approach-and-landing (Seconds) Accident FARs Part 25 = Airworthiness Standards: Transport Category Reduction (ALAR) Task Force FARs Part 33 = Airworthiness Standards: Aircraft Engines Source: Flight Safety Foundation Approach-and-landing Accident Airplanes Reduction (ALAR) Task Force Source:FARs Part Flight 33 Safety = Airworthiness Foundation Approach-and-landing Standards: Aircraft AccidentEngines Figure 3 Reduction (ALAR) Task Force Source: Flight Safety Foundation Approach-and-landing Accident Figure 3 Reduction (ALAR) Task Force TheEngine final Acceleration approach speed usually is slightly on the back side of Figure 4 the power curve, while the minimum thrust speed is 1.35 times Engine Acceleration Figure 4 VWhenSO (stall flying speed the in landingfinal approach configuration) with theto 1.4thrust times set VS Oand. maintained at idle (approach idle), the pilot should be aware When flying the final approach with the thrust set and Typical Altitude Loss Ifof airspeedthe acceleration is allowed characteristics to decrease of below jet engines the final (Figure approach 3). maintained at idle (approach idle), the pilot should be aware After Initiation of a Go-around speed, more thrust is required to maintain the desired flight Typical Altitude Loss of the acceleration characteristics of jet engines (Figure 3). (Aircraft in Landing Configuration) pathBy design, and/or tothe regain acceleration the final capabilityapproach speed. of a jet engine is After Initiation of a Go-around controlled to protect the engine against a compressor stall or 30(Aircraft in Landing Configuration) By design, the acceleration capability of a jet engine is Ifflame-out thrust is and set to to comply idle and with maintained engine and at aircraft idle, no certification energy is Condition at initiation of go-around: controlled to protect the engine against a compressor stall or 2030 availablerequirements. immediately to recover from a low-speed condi- VAPP, Thrust Stabilized Condition at initiation of go-around: flame-out and to comply with engine and aircraft certification VAPP, Thrust Decreasing tion or to initiate a go-around (as shown in Figure 3, Figure 20 V , Thrust Stabilized requirements. 10 VAPPAPP, Idle Thrust V , Thrust Decreasing 4For and example, Figure 5). Figure 4 shows that U.S. Federal Aviation VAPPAPP –10 Knots, Idle Thrust Regulations (FARs) Part 33 requires a time of five seconds or 100 VAPP, Idle Thrust For example, Figure 4 shows that U.S. Federal Aviation VAPP –10 Knots, Idle Thrust less to accelerate from 15 percent to 95 percent of the go- Regulations (FARs) Part 33 requires a time of five seconds or 100 around thrust (15 percent of go-around thrust corresponds − less to accelerate from 15 percent to 95 percent of the go- typically to the thrust level required to maintain the final −10 Enginearound thrust Acceleration (15 percent of go-around thrust corresponds −20

approach speed on a stable three-degree approach path). Altitude Change (Feet) typically to the thrust level required to maintain the final When flying the final approach with the thrust set and main- −3020

approach speed on a stable three-degree approach path). Altitude Change (Feet) tainedFARs atPart idle 25 (approach requires idle),that athe transport pilot should airplane be aware achieve of the a 30 −40 minimum climb gradient of 3.2 percent with engine thrust accelerationFARs Part 25 characteristics requires that of a jet transport engines (Figureairplane 3). achieve a available eight seconds after the pilot begins moving the throttle −40 minimum climb gradient of 3.2 percent with engine thrust −50 Bylevers design, from thethe accelerationminimum flight-idle capability thrust of a jetsetting engine to theis con go-- 012345678 available eight seconds after the pilot begins moving the throttle −50 Time (Seconds) trolledaround thrustto protect setting. the engine against a compressor stall or 012345678 levers from the minimum flight-idle thrust setting to the go- V = Final approach speed flameoutaround thrust and setting.to comply with engine and aircraft certification APP Time (Seconds) Go-around From Low Airspeed/Low Thrust requirements. Source:VAPP = FinalFlight approachSafety Foundation speed Approach-and-landing Accident Reduction (ALAR) Task Force Go-around From Low Airspeed/Low Thrust Source: Flight Safety Foundation Approach-and-landing Accident ForFigure example, 5 shows Figure the hazards 4 shows of flying that atU.S. an airspeedFederal belowAviation the Reduction (ALAR) Task Force final approach speed. RegulationsFigure 5 shows (FARs) the hazards Part 33 of requires flying at a an time airspeed of five below seconds the Figure 5 orfinal less approach to accelerate speed. from 15 percent to 95 percent of the go- Figure 5 78around thrust (15 percent of go-around FLIGHTthrust corresponds SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 typically to the thrust level required to maintain the final FARs Part 25 requires that a transport airplane achieve a mini- 78approach speed on a stable three-degreeFLIGHT approach SAFETY path). FOUNDATIONmum climb • FLIGHT gradient SAFETY of 3.2 percent DIGEST with • AUGUST–NOVEMBER engine thrust available 2000 eight seconds after the pilot begins moving the throttle levers

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 79 from the minimum flight-idle thrust setting to the go-around of 76 ALAs and serious incidents in 1984 through 1997 and thrust setting. audits of about 3,300 flights. 3. U.S. National Transportation Safety Board. Special Study: Go-around From Low Airspeed/Low Thrust Flightcrew Coordination Procedures in Air Carrier Instrument Landing System Approach Accidents. Report Figure 5 shows the hazards of flying at an airspeed below the No. NTSB-AAS-76-5. August 18, 1976. final approach speed.

4. Final approach speed is VREF (reference landing speed The hazards are increased if thrust is set and maintained at [typically 1.3 times stall speed in landing configuration]) idle. plus a correction factor for wind conditions, aircraft configuration or other conditions. If a go-around is required, the initial altitude loss and the time for recovering the lost altitude are increased if the airspeed is lower Related Reading from FSF Publications than the final approach speed and/or if the thrust is set at idle. Flight Safety Foundation (FSF) Editorial Staff. “Business Jet Summary Overruns Wet Runway After Landing Past Touchdown Zone.” Accident Prevention Volume 56 (December 1999). Deceleration below the final approach speed should be allowed only during the following maneuvers: Sallee, G. P.; Gibbons, D. M. “Propulsion System Malfunction Plus Inappropriate Crew Response (PSM+ICR).” Flight Safety • Terrain-avoidance maneuver; Digest Volume 18 (November–December 1999). • Collision-avoidance maneuver; or, • Wind shear recovery maneuver. FSF Editorial Staff. “Airplane’s Low-energy Condition and Degraded Wing Performance Cited in Unsuccessful Go-around Nevertheless, during all three maneuvers, the throttle levers Attempt.” Accident Prevention Volume 56 (July 1999). must be advanced to maximum thrust (i.e., go-around thrust) while initiating the maneuver. FSF Editorial Staff. “Boeing 767 Descends Below Glide Path, Strikes Tail on Landing.” Accident Prevention Volume The following FSF ALAR Briefing Notes provide information 55 (February 1998). to supplement this discussion: FSF Editorial Staff. “Commuter Captain Fails to Follow • 6.1 — Being Prepared to Go Around; Emergency Procedures After Suspected Engine Failure, Loses • 7.1 — Stabilized Approach; and, Control of the Aircraft During Instrument Approach.” Accident Prevention Volume 53 (April 1996). • 7.2 — Constant-angle Nonprecision Approach.◆ FSF Editorial Staff. “Unaware That They Have Encountered a References Microburst, DC-9 Flight Crew Executes Standard Go-around; Aircraft Flies Into Terrain.” Accident Prevention Volume 53 1. The Flight Safety Foundation Approach-and-landing (February 1996). Accident Reduction Task Force defined causal factor as “an event or item judged to be directly instrumental in the causal chain of events leading to the accident [or FSF Editorial Staff. “Captain’s Inadequate Use of Flight Con- incident].” Each accident and incident in the study sample trols During Single-engine Approach and Go-around Results in involved several causal factors. Loss of Control and Crash of Commuter.” Accident Prevention Volume 52 (November 1995). 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and FSF Editorial Staff. “Stall and Improper Recovery During ILS Controlled-flight-into-terrain Accidents.”Flight Safety Digest Approach Result in Commuter Airplane’s Uncontrolled Collision Volume 17 (November–December 1998) and Volume 18 with Terrain.” Accident Prevention Volume 52 (January 1995). (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on analyses of 287 Lawton, Russell. “Moving Power Levers Below Flight Idle fatal approach-and-landing accidents (ALAs) that occurred During Descent Results in Dual Engine Flameout and Power- in 1980 through 1996 involving turbine aircraft weighing off Emergency Landing of Commuter Airplane.” Accident more than 12,500 pounds/5,700 kilograms, detailed studies Prevention Volume 51 (December 1994).

80 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Lawton, Russell. “Steep Turn by Captain During Approach tion of International Civil Aviation, Operation of Aircraft. Part I, Results in Stall and Crash of DC-8 Freighter.” Accident Pre- International Commercial Air Transport – Aeroplanes. Appendix vention Volume 51 (October 1994). 2, “Contents of an Operations Manual,” 5.18, 5.19. Seventh edi- tion – July 1998, incorporating Amendments 1–25.

Regulatory Resources ICAO. Procedures for Air Navigation Services. Aircraft Op- erations. Volume I, Flight Procedures. Fourth edition, 1993. International Civil Aviation Organization (ICAO). International Reprinted May 2000, incorporating Amendments 1–10. Standards and Recommended Practices, Annex 6 to the Conven-

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 81 FSF ALAR Briefing Note 5.1 — Approach Hazards Overview

Few air transport accidents occur on calm sunny days; risk or visual illusions; increases during flight over hilly terrain, with reduced visibility, • Twenty-nine percent involved nonfitment of available adverse winds, contaminated runways and limited approach safety equipment (e.g., ground-proximity warning aids. Visual illusions also can contribute to approach-and- system [GPWS] or radio altimeter); landing accidents. • Eighteen percent involved runway conditions (e.g., wet or contaminated by standing water, slush, snow or ice); Statistical Data and,

The Flight Safety Foundation Approach-and-landing Accident • Twenty-one percent involved inadequate ground aids Reduction Task Force, in an analysis of 76 approach-and- (e.g., navigation aids, approach/runway lights or visual landing accidents and serious incidents, including controlled- approach-slope guidance). flight-into-terrain (CFIT) accidents, worldwide in 1984 through 1 1997, found that: Awareness Program • Fifty-three percent of the accidents and incidents occurred during nonprecision instrument approaches or A company awareness program on approach-and-landing visual approaches (42 percent of the visual approaches hazards should emphasize the following elements that lead to were conducted where an instrument landing system good crew decisions: [ILS] approach was available); • Use the FSF Approach-and-landing Risk Awareness Tool • Fifty percent occurred where no radar service was to heighten crew awareness of the specific hazards to available; the approach; • Sixty-seven percent of the CFIT accidents occurred in • Use the FSF Approach-and-landing Risk Reduction hilly terrain or mountainous terrain; Guide; • Fifty-nine percent of the accidents and incidents occurred • Anticipate by asking, “What if?” and prepare; in instrument meteorological conditions (IMC); • Identify threats during approach briefings; • Fifty percent occurred in precipitation (snow, rain); • Adhere to standard operating procedures (SOPs) and • Fifty-three percent occurred in darkness or twilight; published limitations; and, • Prepare options, such as: • Thirty-three percent involved adverse wind conditions (i.e., strong crosswinds, tail winds or wind shear); – Request a precision approach into the wind; • Twenty-one percent involved flight crew disorientation – Select an approach gate2 for a stabilized approach

82 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 (Table 1); • Unknown and thus discovered as the approach and landing progresses. – Wait for better conditions; or, – divert to an airport with better conditions. The following FSF ALAR Briefing Notes provide information to supplement this discussion: The company awareness program should include review and • 5.2 — Terrain; discussion of factors that may contribute to approach-and- landing accidents. • 5.3 — Visual Illusions; • 5.4 — Wind Shear; Approach briefings should include factors that are: • 6.1 — Being Prepared to Go Around; and, • Known to the crew (e.g., by means of notices to airmen [NOTAMs], dispatcher’s briefing, automatic terminal • 6.3 — Terrain-avoidance (Pull-up) Maneuver.◆ information system [ATIS], etc.; or, References 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Table 1 Force Presents Facts About Approach-and-landing and Recommended Elements Controlled-flight-into-terrain Accidents.” Flight Safety Of a Stabilized Approach Digest Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts All flights must be stabilized by 1,000 feet above presented by the FSF ALAR Task Force were based on airport elevation in instrument meteorological conditions analyses of 287 fatal approach-and-landing accidents (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabi- (ALAs) that occurred in 1980 through 1996 involving lized when all of the following criteria are met: turbine aircraft weighing more than 12,500 pounds/5,700 1. The aircraft is on the correct flight path; kilograms, detailed studies of 76 ALAs and serious 2. Only small changes in heading/pitch are required to incidents in 1984 through 1997 and audits of about 3,300 maintain the correct flight path; flights.

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than V ; 2. The FSF Approach-and-landing Accident Reduction REF (ALAR) Task Force definesapproach gate as “a point in 4. The aircraft is in the correct landing configuration; space (1,000 feet above airport elevation in instrument 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 meteorological conditions or 500 feet above airport feet per minute, a special briefing should be con- elevation in visual meteorological conditions) at which a ducted; go-around is required if the aircraft does not meet defined 6. Power setting is appropriate for the aircraft configura- stabilized approach criteria.” tion and is not below the minimum power for approach as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; Related Reading from FSF Publications 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system FSF Editorial Staff. “During Nonprecision Approach at Night, (ILS) approaches must be flown within one dot of MD-83 Descends Below Minimum Descent Altitude and Con- the glideslope and localizer; a Category II or Cat- tacts Trees, Resulting in Engine Flame-out and Touchdown egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, Short of Runway.” Accident Prevention Volume 54 (April wings should be level on final when the aircraft 1997). reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions FSF Editorial Staff. “Dubrovnik-bound Flight Crew’s Im- requiring a deviation from the above elements of a properly Flown Nonprecision Instrument Approach Results in stabilized approach require a special briefing. Controlled-Flight-into-Terrain Accident.” Flight Safety Digest An approach that becomes unstabilized below 1,000 Volume 15 (July–August 1996). feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate go-around. FSF Editorial Staff. “Captain’s Failure to Establish Stabilized Approach Results in Controlled-flight-into-terrain Commuter Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) Accident.” Accident Prevention Volume 52 (July 1995).

Duke, Thomas A.; FSF Editorial Staff. “Aircraft Descended

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 83 Below Minimum Sector Altitude and Crew Failed to Respond Lawton, Russell. “Captain Stops First Officer’s Go-around, to GPWS as Chartered Boeing 707 Flew into Mountain in DC-9 Becomes Controlled-flight-into-terrain (CFIT) Acci- Azores.” Accident Prevention Volume 52 (February 1995). dent.” Accident Prevention Volume 51 (February 1994).

Lawton, Russell. “Breakdown in Coordination by Commuter FSF Editorial Staff. “Cockpit Coordination, Training Issues Crew During Unstabilized Approach Results in Controlled- Pivotal in Fatal Approach-to-Landing Accident.” Accident flight-into-terrain Accident.” Accident Prevention Volume 51 Prevention Volume 51 (January 1994). (September 1994).

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

84 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Approach-and-Landing Risk Awareness Tool Elements of this tool should be integrated, as appropriate, with the standard approach briefing prior to top of descent to improve awareness of factors that can increase the risk of an accident during approach and landing. The number of warning symbols ( ) that accompany each factor indicates a relative measure of risk. Generally, the greater the number of warning symbols that accompany a factor, the greater the risk presented by that factor. Flight crews should consider carefully the effects of multiple risk factors, exercise appropriate vigilance and be prepared to conduct a go-around or a missed approach.

Failure to recognize the need for a missed approach and to execute a missed approach, is a major cause of approach-and-landing accidents.

Flight Crew

Long duty period — reduced alertness......

Single-pilot operation......

Airport Services and Equipment

No approach radar service or airport tower service......

No current local weather report......

Unfamiliar airport or unfamiliar procedures......

Minimal or no approach lights or runway lights......

No visual approach-slope guidance — e.g., VASI/PAPI......

Foreign destination — possible communication/language problems......

Expected Approach

Nonprecision approach — especially with step-down procedure or circling procedure......

Visual approach in darkness......

Late runway change......

No published STAR......

Environment

Hilly terrain or mountainous terrain......

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 85 Visibility restrictions — e.g., darkness, fog, haze, IMC, low light, mist, smoke......

Visual illusions – e.g., sloping terrain, wet runway, whiteout/snow ......

Wind conditions — e.g., crosswind, gusts, tail wind, wind shear......

Runway conditions — e.g., ice, slush, snow, water......

Cold-temperature effects — true altitude (actual height above mean sea level) lower than indicated altitude......

Aircraft Equipment

No GPWS/EGPWS/GCAS/TAWS......

No radio altimeter......

No wind shear warning system......

No TCAS ......

• greater risk is associated with conducting a nonprecision approach (rather than a precision approach) and with conduct- ing an approach in darkness and in IMC (rather than in daylight and in VMC). The combined effects of two or more of these risk factors must be considered carefully.

• Crews can reduce risk with planning and vigilance. If necessary, plans should be made to hold for better conditions or to divert to an alternate airport. Plan to abandon the approach if company standards for a stabilized approach are not met.

• After commencement of the approach, a go-around or a missed approach should be conducted when:

– Confusion exists or crew coordination breaks down;

– There is uncertainty about situational awareness;

– Checklists are being conducted late or the crew is task overloaded;

– Any malfunction threatens the successful completion of the approach;

Table 1 Recommended Elements of a Stabilized Approach All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabilized when all of the following criteria are met: 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be conducted; 6. Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Category III ILS approach must be flown within the expanded localizer band; during a circling approach, wings should be level on final when the aircraft reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a stabilized approach require a special briefing. An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate go-around. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1, November 2000)

86 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 – The approach becomes unstabilized in altitude, airspeed, glide path, course or configuration;

– Unexpected wind shear is encountered — proceed per company SOP;

– gPWS/EGPWS/GCAS/TAWS alert — proceed per company SOP;

– ATC changes will result in an unstabilized approach; or,

– Adequate visual references are absent at DH or MDA.

Notes:

1. All information in the FSF Approach-and-landing Risk Awareness Tool is based on data published in “Killers in Aviation: FSF Task Force Presents Facts about Approach-and-landing and Controlled-flight-into-terrain Accidents,” Flight Safety Digest Volume 17 (November–December 1998) and Volume 18 (January–February 1999).

2. ATC = Air traffic control DH = Decision height EGPWS = Enhanced ground-proximity warning system GCAS = Ground-collision avoidance system GPWS = Ground-proximity warning system IMC = Instrument meteorological conditions MDA = Minimum descent altitude PAPI = Precision approach path indicator SOP = Standard operating procedure STAR = Standard terminal arrival route TAWS = Terrain awareness and warning system TCAS = Traffic-alert and collision avoidance system VASI = Visual approach slope indicator VMC = Visual meteorological conditions

Copyright © 2000 Flight Safety Foundation Suite 300, 601 Madison Street • Alexandria, VA 22314 U.S. • Telephone +1 (703) 739-6700, Fax: +1 (703) 739-6708 www.flightsafety.org In the interest of aviation safety, this publication may be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially without the express written permission of Flight Safety Foundation’s director of publications. All uses must credit Flight Safety Foundation.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 87 Approach-and-Landing Risk Reduction Guide

The Flight Safety Foundation (FSF) Approach-and-landing Accident Reduction (ALAR) Task Force designed this guide as part of the FSF ALAR Tool Kit, which is designed to help prevent ALAs, including those involving controlled flight into terrain. This guide should be used to evaluate specific flight operations and to improve crew awareness of associated risks. This guide is intended for use as a strategic tool (i.e., for long-term planning). Part 1 of this guide should be used by the chief pilot to review flight operations policies and training. Part 2 should be used by dispatchers and schedulers. The chief pilot should provide Part 3 to flight crews for evaluating pilot understand- ing of company training objectives and policies. Part 4 should be used by the chief pilot and line pilots. This guide is presented as a “check-the-box” questionnaire; boxes that are not checked may represent shortcomings and should prompt further assessment.

Part 1 — Operations: Policies and Training Check the boxes below that apply to your specific flight operations.

Approach Crew Resource Management ❑ Is risk management taught in initial training and recurrent training? ❑ Are crew resource management (CRM) roles defined for each crewmember? ❑ Are CRM roles defined for each crewmember for emergencies and/or system malfunctions? ❑ Are standard operating procedures (SOPs) provided for “sterile-cockpit”1 operations? ❑ Are differences between domestic operations and international operations explained in CRM training? ❑ Is decision making taught in CRM training? Approach Procedures ❑ do detailed and mandatory approach-briefing requirements exist? (See Part 4 below.) ❑ Are approach risks among the required briefing items? ❑ Are standard calls defined for approach deviations? ❑ Are limits defined for approach gate2 at 1,000 feet in instrument meteorological conditions (IMC) or at 500 feet in visual meteorological conditions (VMC). ❑ Is a missed approach/go-around recommended when stabilized approach criteria (Table 1) are exceeded? ❑ Is a “no fault” go-around policy established? If so, is it emphasized during training?

88 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Table 1 Recommended Elements of a Stabilized Approach All flights must be stabilized by 1,000 feet above airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabilized when all of the following criteria are met: 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be conducted; 6. Power setting is appropriate for the aircraft configuration and is not below the minimum power for approach as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Category III ILS approach must be flown within the expanded localizer band; during a circling approach, wings should be level on final when the aircraft reaches 300 feet above airport elevation; and, 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a stabilized approach require a special briefing. An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate go-around. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1, November 2000)

❑ does the checklist policy require challenge-and-response for specified items? ❑ does the checklist policy provide for interruptions/distractions? ❑ Is a go-around recommended when the appropriate checklist is not completed before reaching the approach gate? ❑ Are captain/first officer weather limits provided for approach (e.g., visibility, winds and runway conditions)? ❑ Are crewmember roles defined for approach (e.g., crewmember assigned pilot flying duties, crewmember monitoring and conducting checklist, crewmember who decides to land or go around, crewmember landing aircraft, exchange of aircraft control)? Fuel ❑ Are fuel minimums defined for proceeding to the alternate airport, contingency fuel, dump-fuel limits? ❑ Are crews aware of when to declare “minimum fuel” or an emergency? ❑ When declaring an emergency for low fuel, is International Civil Aviation Organization (ICAO) phraseology required (e.g., “Mayday, Mayday, Mayday for low fuel”)? Approach Type ❑ Is your risk exposure greatest during precision, nonprecision, circling or visual approaches? Is the training provided appropriate for the risk? ❑ Are SOPs provided for constant-angle nonprecision approaches (CANPAs) using rate of descent or angle? Environment ❑ Is training provided for visual illusions on approach (e.g., “black hole effect,”3 sloping terrain, etc.)? ❑ Is training provided for minimum-safe-altitude awareness? ❑ does a policy exist to use the radio altimeter as a terrain-awareness tool? ❑ Are crews required to adjust altitudes during approach for lower than international standard atmosphere (ISA) standard temperatures?

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 89 ❑ Are crews aware that most approach-and-landing accidents occur with multiple conditions present (e.g., rain and darkness, rain and crosswind)? Airport and Air Traffic Control (ATC) Services ❑ Are crews aware of the increased risk at airports without radar service, approach control service or tower service? ❑ Is training provided for unfamiliar airports using a route check or a video? ❑ Is potential complacency at very familiar airports discussed? ❑ Are crews provided current weather at destination airfields via automatic terminal information service (ATIS), airborne communications addressing and reporting system (ACARS) and/or routine weather broadcasts for aircraft in flight (VOLMET)? Aircraft Equipment ❑ Are procedures established to evaluate the accuracy and reliability of navigation/terrain databases? ❑ Are mechanical checklists or electronic checklists installed? ❑ Is a radio altimeter installed in the pilot’s normal scan pattern? ❑ does the radio altimeter provide visual/audio alerting? ❑ Is a wind shear alert system (either predictive or reactive) installed? ❑ Is a ground-proximity warning system (GPWS) or a terrain awareness and warning system (TAWS)4 installed? ❑ Is a traffic-alert and collision avoidance system (TCAS) installed? ❑ Are head-up displays (HUDs) installed with a velocity-vector indicators? ❑ Are angle-of-attack indicators installed? ❑ For aircraft with a flight management system (FMS), are lateral navigation/vertical navigation (LNAV/VNAV) approach procedures database-selected? ❑ Are pilots prevented from modifying specified FMS data points on approach? ❑ Is the FMS system “sole-means-of-navigation” capable? ❑ Is there a policy for appropriate automation use (e.g., “full up for Category III instrument landing system, okay to turn automation off for a daylight visual approach”)? ❑ Is there a policy requiring standard calls by the pilot not flying for mode changes and annunciations on the mode control panel? ❑ Is training provided and are policies established for the use of all the equipment installed on all aircraft? ❑ Are current and regulator-approved navigation charts provided for each flight crewmember? Flight Crew ❑ Is there a crew-pairing policy established for new captain/new first officer based on flight time or a minimum number of trip segments? ❑ Is the check airmen/training captain program monitored for feedback from pilots? Are additional training needs, failure rates and complaints about pilots from line operations tracked? Is it possible to trace these issues to the check airmen/training captain who trained specific pilots? ❑ Is there a hazard reporting system such as a captain’s report? Are policies established to identify and to correct problems? Is a system set up to provide feedback to the person who reports a hazard? Safety Programs ❑ Is a nonpunitive safety reporting system established? ❑ Is a proactive safety monitoring program such as a flight operational quality assurance (FOQA) program or an aviation safety action program (ASAP) established?

90 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Landing ❑ Is training provided and are policies established for the use of visual landing aids? ❑ Is it recommended that crews use all available vertical guidance for approaches, especially at night? ❑ Is training provided and are policies established for landing on contaminated runways with adverse winds? ❑ Are crews knowledgeable of the differences in braking deceleration on contaminated runways and dry runways? ❑ does training include performance considerations for items such as critical touchdown area, braking required, land-and-hold-short operation (LAHSO), engine-out go-around, and full-flaps/gear-extended go-around? ❑ does the aircraft operating manual (AOM)/quick reference handbook (QRH) provide crosswind limitations? ❑ Is a policy in effect to ensure speed brake deployment and autobrake awareness? ❑ does policy prohibit a go-around after reverse thrust is selected?

Part 2 — Dispatcher/Scheduler Check the boxes below that apply to your specific flight operations. ❑ does the company have a dispatch system to provide information to assist flight crews in evaluating approach- and-landing risks? Approach and Landing ❑ Are dispatchers and captains familiar with each other’s authority, accountability and responsibility? ❑ Are crews monitored for route qualifications and appropriate crew pairing? ❑ Are crew rest requirements defined adequately? ❑ does the company monitor and provide suitable crew rest as defined by requirements? ❑ Are crews provided with timely and accurate aircraft performance data? ❑ Are crews assisted in dealing with minimum equipment list(MEL)/dispatch deviation guide (DDG)/configuration deviation list (CDL) items? ❑ do dispatch-pilot communications exist for monitoring and advising crews en route about changing conditions? ❑ Are updates provided on weather conditions (e.g., icing, turbulence, wind shear, severe weather)? ❑ Are updates provided on field conditions (e.g., runway/taxiway conditions, braking-action reports)? ❑ Is there coordination with the captain to determine appropriate loads and fuel required for the effects of ATC flow control, weather and alternates? ❑ Are all the appropriate charts provided for routing and approaches to destinations and alternates? ❑ Is a current notice to airmen (NOTAM) file maintained for all of your operations and is the appropriate information provided to crews?

Part 3 — Flight Crew Check the boxes below that apply to your specific flight operations. ❑ do you believe that you have appropriate written guidance, training and procedures to evaluate and reduce approach-and-landing risks? Approach ❑ Is the Flight Safety Foundation Approach-and-landing Risk Awareness Tool (RAT) provided to flight crews, and is its use required before every approach?

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 91 ❑ does the approach briefing consist of more than the “briefing strip” minimum? (See Part 4 below.) ❑ do briefings include information about visual illusions during approach and methods to counteract them? ❑ Are the following briefed: setup of the FMS, autopilot, HUD, navigation radios and missed approach procedures? ❑ Is a discussion of missed approach/go-around details required during every approach briefing? ❑ Are performance minimums briefed for the approach gate? ❑ Are standard calls required for deviations from a stabilized approach? ❑ does the briefing include execution of a missed approach/go-around if criteria for the approach gate are not met? ❑ Are stabilized approach criteria defined? Is a go-around recommended in the event that these criteria are not met? ❑ does your company practice a no-fault go-around policy? ❑ Are you required to write a report to the chief pilot if you conduct a missed approach/go-around? ❑ do you back up the flight plan top-of-descent point with your own calculation to monitor descent profile? ❑ Are approach charts current and readily available for reference during approach? ❑ Are policies established to determine which crewmember is assigned pilot flying duties, which crewmember is assigned checklist duties, which crewmember will land the aircraft and how to exchange aircraft control? Do these policies change based on prevailing weather? ❑ do terrain-awareness procedures exist (e.g., calling “radio altimeter alive,” checking radio altimeter altitudes during approach to confirm that the aircraft is above required obstacle clearance heights)? ❑ do altitude-deviation-prevention policies exist (e.g., assigned altitude, minimum descent altitude/height [MDA(H)], decision altitude/height [DA(H)])? ❑ Are you familiar with the required obstacle clearance criteria for charting design? ❑ do altimeter-setting procedures and cross-check procedures exist? ❑ do temperature-compensation procedures exist for temperatures lower than ISA at the destination airport? ❑ Are you aware of the increased risk during night/low-visibility approaches when approach lighting/visual approach slope indicator/precision approach path indicator aids are not available? How do you compensate for these deficiencies? For example, are runways with vertical guidance requested in those conditions? ❑ Are you aware of the increased risk associated with nonprecision approaches compared with precision approaches? ❑ Is a CANPA policy established at your company? Are you aware of the increased risk associated with step- down approaches compared with constant-angle approaches? ❑ Is a policy established for maintaining visual look-out, and is there a requirement to call “head-down”? ❑ does a look-out policy exist for approach and landing in visual flight rules (VFR) conditions?

Part 4 — Recommended Approach-and-landing Briefing Items For the approach-risk briefing, refer to top-of-descent use of theFSF Approach-and-landing RAT. In addition to the briefing strip items (e.g., chart date, runway, approach type, glideslope angle, check altitudes), which of following items are briefed, as appropriate? ❑ Automation setup and usage ❑ Navigation equipment setup and monitoring ❑ Rate of descent/angle of descent

92 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 ❑ Intermediate altitudes and standard calls ❑ Altitude-alert setting and acknowledgment ❑ MDA(H)/DA(H) calls (e.g., “landing, continue, go-around”); runway environment expected to see (offsets); lighting ❑ Radio-altimeter setting in the DH window, calls required (e.g., “radio altimeter alive” and “below 1,000 feet” prior to an intermediate approach fix; “below 500 feet” prior to the final approach fix [FAF]; “go around” after the FAF if “minimums” is called [with radio altimeter at 200 feet] and if visual contact with the required references is not acquired or the aircraft is not in position for a normal landing) ❑ Aircraft configuration ❑ Airspeeds ❑ Checklists complete ❑ ATC clearance ❑ Uncontrolled airport procedures ❑ Manual landing or autoland ❑ Missed approach procedure/go-around ❑ Performance data ❑ Contaminated runway/braking action and autobrakes ❑ Illusions/hazards or other airport-specific items ❑ Abnormals (e.g., aircraft equipment/ground facilities unserviceable, MEL/DDG items, glideslope out) ❑ Runway (e.g., length, width, lighting, LAHSO, planned taxiway exit) ❑ Procedure for simultaneous approaches (as applicable)

References 1. The sterile cockpit rule refers to U.S. Federal Aviation Regulations Part 121.542, which states: “No flight crewmember may engage in, nor may any pilot-in-command permit, any activity during a critical phase of flight which could distract any flight crewmember from the performance of his or her duties or which could interfere in any way with the proper conduct of those duties. Activities such as eating meals, engaging in nonessential conversations within the cockpit and nonessential communications between the cabin and cockpit crews, and reading publications not related to the proper conduct of the flight are not required for the safe operation of the aircraft. For the purposes of this section, critical phases of flight include all ground operations involving taxi, takeoff and landing, and all other flight operations below 10,000 feet, except cruise flight.” [The FSF ALAR Task Force says that “10,000 feet” should be height above ground level during flight operations over high terrain.] 2. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force defines approach gate as “a point in space (1,000 feet above airport elevation in instrument meteorological conditions or 500 feet above airport elevation in visual meteorological conditions) at which a go-around is required if the aircraft does not meet defined stabilized approach criteria.” 3. The black-hole effect typically occurs during a visual approach conducted on a moonless or overcast night, over water or over dark, feature- less terrain where the only visual stimuli are lights on and/or near the airport. The absence of visual references in the pilot’s near vision affect depth perception and cause the illusion that the airport is closer than it actually is and, thus, that the aircraft is too high. The pilot may respond to this illusion by conducting an approach below the correct flight path (i.e., a low approach). 4. Terrain awareness and warning system (TAWS) is the term used by the European Joint Aviation Authorities and the U.S. Federal Aviation Administration to describe equipment meeting International Civil Aviation Organization standards and recommendations for ground- proximity warning system (GPWS) equipment that provides predictive terrain-hazard warnings. “Enhanced GPWS” and “ground collision avoidance system” are other terms used to describe TAWS equipment.

Copyright © 2009 Flight Safety Foundation Suite 300, 601 Madison Street, Alexandria, VA 22314-1756 U.S. • Telephone: +1 (703) 739-6700, Fax: +1 (703) 739-6708 www.flightsafety.org In the interest of aviation safety, this publication may be reproduced, in whole or in part, in all media, but may not be offered for sale or used commerciallywithout the express written permission of Flight Safety Foundation’s director of publications. All uses must credit Flight Safety Foundation.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 93 FSF ALAR Briefing Note 5.2 — Terrain

Terrain awareness can be defined as the combined awareness • descending below the minimum descent altitude/height and knowledge of the following: (MDA[H]) or decision altitude/height (DA[H]) without adequate visual references or having acquired incorrect • Aircraft position; visual references (e.g., a lighted area in the airport • Aircraft altitude; vicinity, a taxiway or another runway); and, • Applicable minimum safe altitude (MSA); • Continuing the approach after the loss of visual references (e.g., because of a fast-moving rain shower • Terrain location and features; and, or fog patch). • other hazards. Navigation Deviations and Inadequate Ter- Statistical Data rain Separation

The Flight Safety Foundation Approach-and-landing Accident A navigation (course) deviation occurs when an aircraft is oper- Reduction Task Force found that controlled flight into terrain ated beyond the course clearance issued by air traffic control (CFIT) was involved in 37 percent of 76 approach-and-landing (ATC) or beyond the defined airway system. accidents (ALAs) and serious incidents worldwide in 1984 through 1997.1 Inadequate terrain separation occurs when terrain separation of 2,000 feet in designated mountainous areas or 1,000 feet in all The task force said that among these CFIT accidents/inci- other areas is not maintained (unless authorized and properly dents: assigned by ATC in terminal areas). • Sixty-seven percent occurred in hilly terrain or Navigation deviations and inadequate terrain separation are mountainous terrain, and 29 percent occurred in areas of usually the results of monitoring errors. flat terrain (the type of terrain in which the remainder of the CFIT accidents/incidents occurred was unknown); Monitoring errors involve the crew’s failure to adequately • Fifty-seven percent occurred during nonprecision monitor the aircraft trajectory and instruments while program- approaches; and, ming the autopilot or flight management system (FMS), or while being interrupted or distracted. • Seventy percent occurred in poor visibility or fog.

The absence or the loss of visual references is the most com- Standard Operating Procedures mon primary causal factor2 in ALAs involving CFIT. These accidents result from: Standard operating procedures (SOPs) should emphasize the

94 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 following terrain-awareness items: level; • Conduct task-sharing for effective cross-check and – Use of the standby altimeter to cross-check the backup, particularly mode selections and target entries primary altimeters; (e.g., airspeed, heading, altitude); and, – Altitude calls; • Adhere to the basic golden rule: aviate (fly), navigate, • Conduct task-sharing for effective cross-check and – Radio-altimeter calls; and, communicate and manage, in that order. backup, particularly mode selections and target entries – Setting the barometric-altimeter bug and RA DH bug; (e.g., airspeed, heading, altitude); and, Navigate can be defined by the following “know where” and, statements:• Adhere to the basic golden rule: aviate (fly), navigate, • Cross-check that the assigned altitude is above thethe MSAMSA communicate and manage, in that order. • Know where you are; (unless the crew is aware of thethe applicableapplicable minimumminimum vectoring altitude for the sector). Navigate• Know can where be defined you should by the be; followingand, “know where” statements: • Know where the terrain and obstacles are. Table 1 shows examples of SSOPsOPs for setting the barometric- • Know where you are; altimeter bug and the RA DH bug. Terrain-awareness elements of effective cross-check and • Know where you should be; and, backup include: • Know where the terrain and obstacles are. • Assertive challenging; Table 1 Terrain-awareness• Altitude calls; elements of effective cross-check and Barometric-altimeter and backup include: Radio-altimeter Reference Settings • Excessive parameter-deviation calls; and, • Assertive challenging; Barometric Radio • Task-sharing and standard calls for the acquisition of Approach Altimeter Altimeter • Altitudevisual references. calls; Visual MDA(H)/DA(H) of 200 feet* • Excessive parameter-deviation calls; and, instrument approach Terrain awareness can be improved by correct use of the radio or altimeter.• Task-sharing The barometric-altimeter and standard calls bug andfor thethe radio-altimeteracquisition of 200 feet above airport elevation decisionvisual height references. (RA DH) bug must be set according to the Nonprecision MDA/(H) 200 feet* aircraft manufacturer’s SOPs or the company’s SOPs. Terrain awareness can be improved by correct use of the radio ILS CAT I DA(H) 200 feet* altimeter. The barometric-altimeter bug and the radio- no RA ILS CAT I DA(H) RA DH altimeterAltimeter-setting decision height Errors (RA DH) bug must be set according with RA to the aircraft manufacturer’s SOPs or the company’s SOPs. ILS CAT II DA(H) RA DH The following will minimize the potential for altimeter-setting ILS CAT III DA(H) RA DH errors and provide for optimum use of the barometric-altimeter Altimeter-setting Errors with DH bug and RA DH bug: ILS CAT III TDZE Alert height with no DH The• followingAwareness will ofminimize altimeter-setting the potential changes for altimeter-setting because of MDA(H) = Minimum descent altitude/height errors prevailingand provide weather for optimum conditions use of the (temperature-extreme barometric-altimeter DA(H) = Decision altitude/height bug andcold RA front DH orbug: warm front, steep frontal surfaces, semi- ILS = Instrument landing system permanent or seasonal low-pressure areas); CAT = Category • Awareness of altimeter-setting changes because of RA DH = Radio altimeter decision height • prevailingAwareness ofweather the altimeter-setting conditions (temperature-extreme unit of measurement TDZE = Touchdown zone elevation coldin use front at the or destination warm front, airport; steep frontal surfaces, semi- * The RA DH should be set (e.g., at 200 feet) for terrain-awareness permanent or seasonal low-pressure areas); purposes. The use of the radio altimeter should be discussed • Awareness of the expected altimeter setting (using during the approach briefing. • Awarenessboth routine of aviationthe altimeter-setting weather reports unit of[METARs] measurement and Note: For all approaches, except CAT II and CAT III ILS inautomatic use at the terminal destination information airport; system [ATIS] for cross- approaches, the approach “minimum” call will be based on the checking); barometric-altimeter bug set at MDA(H) or DA(H). • Awareness of the expected altimeter setting (using both Source: Flight Safety Foundation Approach-and-landing Accident • routineEffective aviationpilot flying-pilot weather not reports flying [METARs] (PF-PNF) cross- and Reduction (ALAR) Task Force automaticcheck and terminalbackup; information system [ATIS] for cross- checking); • Adherence to SOPs for: • Effective pilot flying-pilot not flying (PF-PNF) cross- – Resetting altimeters at the transition altitude/flight check and backup; Use of Radio Altimeter • Adherence to SOPs for: Radio-altimeter calls can be either: – Resetting altimeters at the transition altitude/flight • Announced by the PNF (or the flight engineer); or, MAY 2009 • Fllevel;ight Safety Foundation • RUNWAY SAFETY INITIATIVE 95 • Generated automatically by a synthesized voice. – Use of the standby altimeter to cross-check the primary altimeters; The calls should be tailored to the company operating policy – Altitude calls; and to the type of approach.

94 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Use of Radio Altimeter – 29.XX inches of mercury (in. Hg) vs. 28.XX in. Hg or 30.XX in. Hg (with typical errors of approximately Radio-altimeter calls can be either: 1,000 feet); or, • Announced by the PNF (or the flight engineer); or, – 29.XX in. Hg vs. 9XX hectopascals (hPa) (true altitude [actual height above mean sea level] 600 feet • generated automatically by a synthesized voice. lower than indicated); and,

The calls should be tailored to the company operating policy • Awareness of altitude corrections for low outside and to the type of approach. air temperature (OAT) operations and awareness of pilot’s/controller’s responsibilities in applying these To enhance the flight crew’s terrain awareness, the call “radio corrections. altimeter alive” should be made by the first crewmember ob- serving the radio-altimeter activation at 2,500 feet. Pilot-Controller Communication

The radio-altimeter indication then should be included in the The company should develop and implement an awareness instrument scan for the remainder of the approach. and training program to improve pilot-controller communi- cation. Flight crews should call radio-altimeter indications that are below obstacle-clearance requirements during the approach. Route Familiarization Program The radio altimeter indications should not be below the fol- lowing minimum heights: A training program should be implemented for departure, route, approach and airport familiarization, using: • 1,000 feet during arrival until past the intermediate fix, except when being radar-vectored; • high-resolution paper material; • 500 feet when being radar-vectored by ATC or until past • Video display; and/or, the final approach fix (FAF); and, • Visual simulator. • 250 feet from the FAF to a point on final approach to the landing runway where the aircraft is in visual conditions Whenever warranted, a route familiarization check for a new and in position for a normal landing, except during pilot should be conducted by a check airman or with the new Category (CAT) II instrument landing system (ILS) and pilot as an observer of a qualified flight crew. CAT III ILS approaches. CFIT Training The following cross-check procedures should be used to con- firm the barometric-altimeter setting: CFIT training should include the following: • When receiving an altitude clearance, immediately set • ground-proximity warning system (GPWS) modes or the assigned altitude in the altitude window (even before terrain awareness and warning system (TAWS)3 modes readback, if appropriate because of workload); (the detection limits of each mode, such as inhibitions • Ensure that the selected altitude is cross-checked by and protection envelopes, should be emphasized clearly); the captain and the first officer (e.g., each pilot should and, announce what he or she heard and then point to the • Terrain-avoidance (pull-up) maneuver. altitude window to confirm that the correct altitude has been selected); and, • Ensure that the assigned altitude is above the applicable Departure Strategies MSA. Briefing

Training Standard instrument departure (SID) charts and en route charts should be used to cross-check the flight plan and the ATC Altitude Awareness Program route clearance. The FMS control display unit (CDU) and the navigation display (ND) should be used for illustration during The altitude awareness program should emphasize the fol- the cross-check. lowing: • Awareness of altimeter-setting errors: The takeoff-and-departure briefing should include the fol-

96 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 lowing terrain-awareness items, using all available charts and Descent Strategies cockpit displays to support and illustrate the briefing: • Significant terrain or obstacles along the intended Management and Monitoring departure course; and, When entering the terminal area, FMS navigation accuracy • SID routing and MSAs. should be checked against raw data.

If available, SID charts featuring terrain depictions with color- If the accuracy criteria for FMS lateral navigation in a terminal shaded contours should be used during the briefing. area and/or for approach are not met, revert to selected lateral navigation with associated horizontal situation indicator (HSI)- Standard Instrument Departure type navigation display.

When conducting a SID, the flight crew should: Standard Terminal Arrival • Be aware of whether the departure is radar-monitored When conducting a STAR, the flight crew should: by ATC; • Be aware of whether the arrival is radar-monitored by • Maintain a “sterile cockpit”4 below 10,000 feet or ATC; below the MSA, particularly at night or in instrument meteorological conditions (IMC); • Maintain a sterile cockpit; • Monitor the sequencing of each waypoint and the • Monitor the sequencing of each waypoint and the guidance after waypoint sequencing (i.e., correct direction guidance after waypoint sequencing (i.e., correct direction of turn and correct “TO” waypoint, in accordance with of turn and correct “TO” waypoint, in accordance with the SID), particularly after a flight plan revision or after the STAR), particularly after a flight plan revision or conducting a “DIR TO”; and, after conducting a “DIR TO”; and, • In the event of incorrect sequencing/lateral guidance, • In the event of incorrect sequencing/lateral guidance, the crew should be alert to conduct a “DIR TO” [an the crew should be prepared to conduct a “DIR TO” appropriate waypoint] or to revert to selected lateral (an appropriate waypoint) or to revert to selected lateral navigation. navigation.

Changes in ATC clearances should be understood before they En Route Strategies are accepted and are implemented.

Navigation For example, an ATC clearance to descend to a lower altitude should never be understood as a clearance to descend (pre- The en route charts should be accessible if a total loss of maturely) below the MSA or an approach-segment minimum FMS navigation occurs or any doubt arises about FMS lateral altitude. guidance. When receiving ATC radar vectors, ensure that: Flight Progress Monitoring • The controller has identified your radar return by stating The flight crew should: “radar contact”; • Monitor and cross-check FMS guidance and navigation • The pilot-controller confirmation/correction process accuracy; (communication loop) remains effective at all times; • Monitor instruments and raw data5; • The flight crew maintains situational awareness; and, • Use all information available (flight deck displays, • The pilot requests confirmation or clarification from charts); and, the controller without delay if there is any doubt about a clearance. • Request confirmation or clarification from ATC if any doubt exists about terrain clearance, particularly when During the final approach segment, the attention of both receiving radar vectors. pilots should be directed to any required altitude restriction or altitude/distance check prior to reaching the MDA(H) or DA(H).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 97 Unless the airport is near high terrain, the radio-altimeter • MSAs; indication should reasonably agree with the height above • Terrain and man-made obstacles; airport elevation (obtained by direct reading of the barometric altimeter if using QFE — an altimeter setting that causes the • Applicable minimums (ceiling, visibility or runway altimeter to indicate height above the QFE reference datum visual range [RVR]); [i.e., zero at touchdown on the runway] — or by computation • Applicable minimum stabilization height (approach if using QNH — an altimeter setting that causes the altimeter gate); to indicate height above mean sea level [i.e., field elevation at touchdown on the runway]). • Final approach descent gradient (and vertical speed); and, In IMC or at night, flight crews should respond immediately • go-around altitude and missed approach initial steps. to any GPWS/TAWS warning. The following is an expanded review of the terrain-awareness Approach Strategies

Briefing Table 2 The approach briefing should include information about: Recommended Elements • descent profile management; Of a Stabilized Approach All flights must be stabilized by 1,000 feet above • Energy management; airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual • Terrain awareness; meteorological conditions (VMC). An approach is stabi- • Approach hazards awareness; lized when all of the following criteria are met: 1. The aircraft is on the correct flight path; • Elements of a stabilized approach (Table 2) and approach 2. Only small changes in heading/pitch are required to gate6; maintain the correct flight path;

3. The aircraft speed is not more than VREF + 20 knots • Readiness and commitment to respond to a GPWS/ indicated airspeed and not less than V ; TAWS warning; and, REF 4. The aircraft is in the correct landing configuration; • Missed approach procedures. 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 If available, approach charts featuring terrain depictions with feet per minute, a special briefing should be con- ducted; color-shaded contours should be used during the approach 6. Power setting is appropriate for the aircraft configura- briefing to enhance terrain awareness. tion and is not below the minimum power for approach as defined by the aircraft operating manual; A thorough briefing should be conducted, regardless of: 7. All briefings and checklists have been conducted; • how familiar the destination airport and the approach 8. Specific types of approaches are stabilized if they may be; or, also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of • how often the pilots have flown together. the glideslope and localizer; a Category II or Cat- egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, The briefing should help the pilot flying (conducting the wings should be level on final when the aircraft briefing) and the pilot not flying (acknowledging the brief- reaches 300 feet above airport elevation; and, ing) know: 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a • The main features of the descent, approach and missed stabilized approach require a special briefing. approach; An approach that becomes unstabilized below 1,000 • The sequence of events and actions; and, feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate • Any special hazards. go-around. Source: Flight Safety Foundation Approach-and-landing Accident The flight crew should include the following terrain-awareness Reduction (ALAR) Task Force (V1.1 November 2000) items in the approach briefing:

98 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 items to be included in the approach briefing — as practical When OAT is below zero degrees Celsius (32 degrees Fahr- and as appropriate for the conditions of the flight. enheit), low-temperature correction should be applied to the following published altitudes: ATIS • Minimum en route altitude (MEA) and MSA; Review and discuss the following items: • Transition route altitude; • Runway in use (type of approach); • Procedure turn altitude (as applicable); • Expected arrival route (standard terminal arrival [STAR] • FAF altitude; or radar vectors); • Step-down altitude(s) and MDA(H) during a nonprecision • Altimeter setting (QNH or QFE, as required); and, approach; • Transition altitude/level (unless standard for the country • outer marker (OM) crossing altitude during an ILS or for the airport). approach; and, • Waypoint-crossing altitudes during a global positioning Approach Chart system (GPS) approach flown with barometric vertical navigation. Review and discuss the following terrain-awareness items us- ing the approach chart and the FMS/ND (as applicable): In a standard atmosphere, indicated altitude is the true altitude • designated runway and approach type; above mean sea level (MSL) and, therefore, provides a reliable indication of terrain clearance. • Chart index number and date; Whenever the temperature is significantly different from the • MSA reference point, sectors and altitudes; standard temperature, indicated altitude is significantly differ- • let-down navaid frequency and identification (confirm ent from true altitude. the navaid setup); In low temperature, true altitude is lower than indicated alti- • Airport elevation; tude, thus creating a lower than anticipated terrain clearance • Approach transitions (fixes, holding pattern, altitude and and a potential terrain-separation hazard. airspeed restrictions, required navaids setup); Flying into a low-temperature area has the same effect as • Initial approach fix (IAF) and intermediate approach fix flying into a low-pressure area; the aircraft is lower than the (IF), as applicable (positions and crossing altitudes); altimeter indicates. • Final approach course (and lead-in radial); For example, Figure 1, which is based on low-temperature • Terrain features (location and elevation of hazardous altimeter corrections published by the International Civil terrain or man-made obstacles); Aviation Organization (ICAO), shows that indicated altitude • Approach profile view: and true altitude are the same for an aircraft flying at 2,000 – FAF; feet in an area of standard temperature (15 degrees Celsius [59 degrees Fahrenheit] at the surface); however, for an aircraft – Final descent point (if different from FAF); flying at 2,000 feet in an area where the surface temperature – Visual descent point (VDP); is –40 degrees Celsius (–40 degrees Fahrenheit), true altitude would be 440 feet lower than indicated altitude. – Missed approach point (MAP); – Typical vertical speed at expected final approach Airport Charts groundspeed; and, Review and discuss the following terrain-awareness items – Touchdown zone elevation (TDZE); and, using the airport charts: • Missed approach: • Approach lighting and runway lighting, and other – lateral navigation and vertical navigation; and, expected visual references; and, – Significant terrain or obstacles. • Specific hazards (such as man-made obstacles, as applicable). Low-OAT Operation

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 99 • Final approach course (and lead-in radial); • Outer marker (OM) crossing altitude during an ILS approach; and, • Terrain features (location and elevation of hazardous terrain or man-made obstacles); • Waypoint-crossing altitudes during a global positioning • Approach profile view: system (GPS) approach flown with barometric vertical navigation. – FAF; – Final descent point (if different from FAF); In a standard atmosphere, indicated altitude is the true altitude above mean sea level (MSL) and, therefore, provides a reliable – Visual descent point (VDP); indication of terrain clearance. – Missed approach point (MAP); Whenever the temperature is significantly different from the – Typical vertical speed at expected final approach standard temperature, indicated altitude is significantly groundspeed; and, different from true altitude. – Touchdown zone elevation (TDZE); and, • Missed approach: In low temperature, true altitude is lower than indicated altitude, thus creating a lower-than-anticipated – Lateral navigation and vertical navigation; and, terrain clearance and a potential terrain-separation – Significant terrain or obstacles. hazard.

Low-OAT Operation Flying into a low-temperature area has the same effect as flying into a low-pressure area; the aircraft is lower than the altimeter When OAT is below zero degrees Celsius (32 degrees indicates. Fahrenheit), low-temperature correction should be applied to the following published altitudes: For example, Figure 1, which is based on low-temperature • Minimum en route altitude (MEA) and MSA; altimeter corrections published by the International Civil Aviation Organization (ICAO), shows that indicated altitude • Transition route altitude; and true altitude are the same for an aircraft flying at 2,000 • Procedure turn altitude (as applicable); feet in an area of standard temperature (15 degrees Celsius [59 degrees Fahrenheit] at the surface); however, for an aircraft • FAF altitude; flying at 2,000 feet in an area where the surface temperature • Step-down altitude(s) and MDA(H) during a is –40 degrees Celsius (–40 degrees Fahrenheit), true altitude nonprecision approach; would be 440 feet lower than indicated altitude.

Effects of Temperature on True Altitude

True Altitude

Given Atmospheric Pressure (Pressure Altitude)

Indicated Altitude

3,000 Feet 2,000 Feet −440 Feet 1,560 Feet 2,000 Feet

1,000 Feet

High OAT Standard OAT Low OAT OAT = Outside air temperature Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 1

If another airport is located near the destination airport, relevant fore, terrain awareness. 98details or procedures of that airport shouldFLIGHT be discussed. SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Company accident-prevention strategies and personal lines Automation of defense should be developed to cope with these factors (as practical). Discuss the intended use of automation for vertical navigation • Aircraft equipment: and lateral navigation: – lack of navigation display/terrain display/radar • FMS or selected modes; and, display with mapping function; • Precision approach, constant-angle nonprecision – lack of area navigation (RNAV) capability; approach (CANPA) or step-down approach, as required. – lack of radio altimeter or lack of (automatic) calls; and/or, Preparation for a Go-around – lack of GPWS or TAWS; Company policy should stress the importance of: • Airport environment: • Being prepared and committed for an immediate – Night “black-hole effect”7 and/or rising or sloping response to a GPWS/TAWS warning; and, terrain along the approach path; • Being prepared to go around. • Airport equipment: – lack of or restricted radar coverage; Circling Approaches – lack of a precision approach, a visual approach slope When conducting a circling approach, the crew should be indicator (VASI) or precision approach path indicator aware of and remain within the applicable obstruction clear- (PAPI); and, ance protected area. – limited approach lighting and runway lighting;

Factors Affecting Terrain Awareness • Navigation charts: – lack of published approach procedure; The following factors affect situational awareness and, there-

100 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 – lack of color-shaded terrain contours on approach Summary chart; and, – lack of published minimum radar vectoring Terrain awareness is enhanced by the following: altitudes; • SOPs defining crew task-sharing for effective cross- check and backup; • Training: • Correct use of the barometric altimeter and radio – lack of area familiarization and/or airport altimeter; familiarization; and, • Thorough approach briefings; and, – Inadequate knowledge of applicable obstacle clearance and/or minimum vectoring altitude; • Use of GPWS/TAWS.

• SOPs: The following FSF ALAR Briefing Notes provide information – Inadequate briefings; to supplement this discussion: • 1.1 — Operating Philosophy; – Monitoring errors (i.e., inability to monitor the aircraft trajectory and instruments while conducting FMS • 1.2 — Automation; entries or because of an interruption/distraction); • 1.3 — Golden Rules; – Inadequate monitoring of flight progress (being • 1.4 — Standard Calls; “behind the aircraft”); • 1.5 — Normal Checklists; – Incorrect use of automation; • 1.6 — Approach Briefing; – omission of a normal checklist or part of a normal • 2.3 — Pilot-Controller Communication; checklist (usually because of an interruption/ distraction); and/or, • 2.4 — Interruptions/Distractions; – deliberate or inadvertent deviation from SOPs. • 3.1 — Barometric Altimeter and Radar Altimeter; • Pilot-controller communication: • 3.2 — Altitude Deviations; – omission of a position report upon first radio contact • 6.1 — Being Prepared to Go Around; and, in an area without radar coverage (i.e., reducing the • 6.3 — Terrain Avoidance (Pull-up) Maneuver.◆ controller’s situational awareness of the aircraft); – Breakdown in pilot-controller or crew communication References (e.g., readback/hearback errors, failure to resolve doubts or ambiguities, use of nonstandard 1. Flight Safety Foundation. “Killers in Aviation: FSF Task phraseology); and/or, Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety – Accepting an amended clearance without prior Digest Volume 17 (November–December 1998) and evaluation. Volume 18 (January–February 1999): 1–121. The facts • human factors and crew resource management presented by the FSF ALAR Task Force were based on (CRM): analyses of 287 fatal approach-and-landing accidents (ALAs) that occurred in 1980 through 1996 involving – Incorrect CRM practices (e.g., lack of cross-check turbine aircraft weighing more than 12,500 pounds/5,700 and backup for mode selections and target entries, kilograms, detailed studies of 76 ALAs and serious late recognition of monitoring errors); incidents in 1984 through 1997 and audits of about 3,300 – Incorrect decision making; flights. – Failure to resolve a doubt or confusion; 2. The FSF ALAR Task Force defines causal factor as “an event or item judged to be directly instrumental in – Fatigue; the causal chain of events leading to the accident [or – Complacency; incident].” Each accident and incident in the study sample involved several causal factors. – Spatial disorientation; and/or, 3. Terrain awareness and warning system (TAWS) is the – Visual illusions. term used by the European Joint Aviation Authorities

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 101 and the U.S. Federal Aviation Administration to FSF Editorial Staff. “B-757 Damaged by Ground Strike During describe equipment meeting International Civil Aviation Late Go-around from Visual Approach.” Accident Prevention Organization standards and recommendations for ground- Volume 56 (May 1999). proximity warning system (GPWS) equipment that provides predictive terrain-hazard warnings. “Enhanced FSF Editorial Staff. “Preparing for Last-minute Runway GPWS” and “ground collision avoidance system” are Change, Boeing 757 Flight Crew Loses Situational Aware- other terms used to describe TAWS equipment. ness, Resulting in Collision with Terrain.” Accident Prevention Volume 54 (July–August 1997). 4. The sterile cockpit rule refers to U.S. Federal Aviation Regulations Part 121.542, which states: “No flight FSF Editorial Staff. “During Nonprecision Approach at Night, crewmember may engage in, nor may any pilot-in- MD-83 Descends Below Minimum Descent Altitude and Con- command permit, any activity during a critical phase tacts Trees, Resulting in Engine Flame-out and Touchdown of flight which could distract any flight crewmember Short of Runway.” Accident Prevention Volume 54 (April from the performance of his or her duties or which 1997). could interfere in any way with the proper conduct of those duties. Activities such as eating meals, engaging FSF Editorial Staff. “Learjet MEDEVAC Flight Ends in in nonessential conversations within the cockpit and Controlled-flight-into-terrain (CFIT) Accident.” Accident nonessential communications between the cabin and Prevention Volume 54 (January 1997). cockpit crews, and reading publications not related to the proper conduct of the flight are not required for the safe FSF Editorial Staff. “Dubrovnik-bound Flight Crew’s Im- operation of the aircraft.” properly Flown Nonprecision Instrument Approach Results in Controlled-flight-into-terrain Accident.” Flight Safety Digest 5. The FSF ALAR Task Force defines raw data as “data Volume 15 (July–August 1996). received directly (not via the flight director or flight management computer) from basic navigation aids (e.g., Enders, John H.; Dodd, Robert; Tarrel, Rick; Khatwa, Ratan; ADF, VOR, DME, barometric altimeter).” Roelen, Alfred L.C.; Karwal, Arun K. “Airport Safety: A study of Accidents and Available Approach-and-landing Aids.” Flight 6. The FSF ALAR Task Force defines approach gate as Safety Digest Volume 15 (March 1996). “a point in space (1,000 feet above airport elevation in instrument meteorological conditions or 500 feet above FSF Editorial Staff. “Different Altimeter Displays and Crew airport elevation in visual meteorological conditions) at Fatigue Likely Contributed to Canadian Controlled-flight-into- which a go-around is required if the aircraft does not meet terrain Accident.” Accident Prevention Volume 52 (December defined stabilized approach criteria.” 1995).

7. The black-hole effect typically occurs during a visual FSF Editorial Staff. “Poorly Flown Approach in Fog Results in approach conducted on a moonless or overcast night, Collision With Terrain Short of Runway.” Accident Prevention over water or over dark, featureless terrain where the only Volume 52 (August 1995). visual stimuli are lights on and/or near the airport. The absence of visual references in the pilot’s near vision affect Duke, Thomas A.; FSF Editorial Staff. “Aircraft Descended depth perception and cause the illusion that the airport is Below Minimum Sector Altitude and Crew Failed to Respond closer than it actually is and, thus, that the aircraft is too to GPWS as Chartered Boeing 707 Flew into Mountain in high. The pilot may respond to this illusion by conducting Azores.” Accident Prevention Volume 52 (February 1995). an approach below the correct flight path (i.e., a low approach). Lawton, Russell. “Captain Stops First Officer’s Go-around, DC-9 Becomes Controlled-flight-into-terrain (CFIT) Acci- Related Reading from FSF Publications dent.” Accident Prevention Volume 51 (February 1994).

Wilson, Dale R. “Darkness Increases Risks of Flight.” Hu- man Factors & Aviation Medicine Volume 46 (November– Regulatory Resources December 1999). International Civil Aviation Organization. Procedures for Air FSF Editorial Staff. “Learjet Strikes Terrain When Crew Tracks Navigation Services. Aircraft Operations. Volume I, Flight False Glideslope Indication and Continues Descent Below Procedures. Part VI, Altimeter Setting Procedures. Fourth Published Decision Height.” Accident Prevention Volume 56 edition – 1993. Reprinted May 2000, incorporating Amend- (June 1999). ments 1–10.

102 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 U.S. Federal Aviation Administration (FAA). Federal Aviation dures,” 121.97 “Airports: Required data,” 121.117 “Airports: Regulations (FARs). 91.3 “Responsibility and authority of the Required data,” 121.135 “Contents,” 121.315 “Cockpit check pilot in command,” 91.119 “Minimum safe altitudes: General,” procedure,” 121.443 “Pilot in command qualification: Routes 91.121 “Altimeter settings,” 91.123 “Compliance with ATC and airports,” 121.445 “Pilot in command airport qualification: clearances and instructions,” 91.155 “Basic VFR weather Special areas and airports,” 121.542 “Flight crewmember du- minimums,” 91.157 “Special VFR weather minimums,” ties.” January 1, 2000. 91.175 “Takeoff and landing under IFR,” 91.185 “IFR opera- tions: Two-way radio communications failure,” 97 “Standard FAA. FARs. 121.360 “Ground proximity warning-glide slope Instrument Approach Procedures, Subpart C – TERPS Proce- deviation alerting system.” March 29, 2000.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 103 FSF ALAR Briefing Note 5.3 —Visual Illusions

Visual illusions result from many factors and appear in many • ground texture and features; different forms. • off-airport light patterns, such as brightly lighted parking lots or streets; Illusions occur when conditions modify the pilot’s perception of the environment relative to his or her expectations, possibly • “Black-hole effect”4 along the final approach flight path; resulting in spatial disorientation or landing errors (e.g., land- and/or, ing short or landing long). • Uphill-sloping terrain or downhill-sloping terrain in the airport vicinity. Statistical Data Runway environment: The Flight Safety Foundation Approach-and-landing Accident • Runway dimensions; Reduction Task Force found that visual approaches were being conducted in 28 percent of the 76 approach-and-landing accidents • Runway slope (uphill gradient or downhill gradient); (ALAs) and serious incidents worldwide in 1984 through 1997.1 • Terrain drop-off at the approach end of the runway; Visual approaches at night typically present a greater risk • Approach lighting and runway lighting; and/or, because of fewer visual references, and because of visual il- • Runway condition. lusions and spatial disorientation. Weather conditions: The task force found that disorientation or visual illusion was a causal factor2 in 21 percent of the 76 ALAs and serious • Ceiling; incidents, and that poor visibility was a circumstantial factor3 • Visibility; and/or, in 59 percent of the accidents and incidents. • obstructions to vision. Visual Illusions Pilot’s Perception The following factors and conditions affect the flight crew’s ability to perceive accurately the environment, resulting in Visual illusions result from the absence of visual references visual illusions. or the alteration of visual references, which modify the pilot’s perception of his or her position (in terms of height, distance Airport environment: and/or intercept angle) relative to the runway threshold.

104 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Visual illusions are most critical when transitioning from • Possibly inducing a correction (e.g., increasing the instrument meteorological conditions (IMC) and instrument rate of descent) that places the aircraft below the references to visual meteorological conditions (VMC) and intended glide path; or, visual references. • Preventing the flight crew from detecting a too- shallow flight path; and, Visual illusions affect the flight crew’s situational awareness, particularly while on base leg and during the final approach. – A downhill slope in the approach zone creates an illusion of being too low (impression of a shallow Visual illusions usually induce crew inputs (corrections) that glide path [Figure 2]), thus: cause the aircraft to deviate from the vertical flight path or • Possibly inducing a correction that places the horizontal flight path. aircraft above the intended glide path; or, Visual illusions can affect the decision process of when and • Preventing the flight crew from detecting a too- Visualhow rapidly illusions to descend are most from critical the minimum when transitioning descent altitude/ from • Possiblysteep flight inducing path. a correction (e.g., increasing the instrumentheight (MDA[H]). meteorological conditions (IMC) and instrument rate of descent) that places the aircraft below the referencesVisual illusions to visualare most meteorological critical when transitioning conditions from (VMC) instrument and intended glide path; or, The following are factors and conditions that create visual visualmeteorological references. conditions (IMC) and instrument references to visual illusions that can affect the pilot’s perception of: • PreventingDownhill the flightSlope crew Creates from detecting a too- meteorological conditions (VMC) and visual references. shallow flight path; and, Visual illusions affect the flight crew’s situational awareness, Illusion That Aircraft Is on • The airport and runway environment; Shallower-than-actual Glide Path particularlyVisual illusions while affect on base the flight leg and crew’s during situational the final approach.awareness, – A downhill slope in the approach zone creates an • Terrain separation; and, illusion of being too low (impression of a shallow particularly while on base leg and during the final approach. Visual• Deviationillusions usuallyfrom the induce horizontal crew flight inputs path (corrections) or vertical flight that glide path [Figure 2]), thus: cause the aircraft to deviate from the vertical flight path or Visualpath. illusions usually induce crew inputs (corrections) that • Possibly inducing a correction that places the horizontal flight path. cause the aircraft to deviate from the vertical flight path or aircraft above the intended glide path; or, Perceived Glide Path Usually,horizontal more flight than path. one factor is involved in a given approach. Actual Glide Path Visual illusions can affect the decision process of when and • Preventing the flight crew from detecting a too- how rapidly to descend from the minimum descent altitude/ steep flight path. AirportVisual illusions environment can affect the decision process of when and height (MDA[H]). how rapidly to descend from the minimum descent altitude/ Conditionsheight (MD thatA[H create]). visual illusions include: The following are factors and conditions that create visual illusions• Black-hole that can affecteffect thealong pilot’s the finalperception approach of: flight path; Source: Flight SafetyDownhill Foundation Slope Approach-and-landing Creates Accident The following are factors and conditions that create visual Reduction (ALAR)Illusion Task Force That Aircraft Is on • Uphill-sloping terrain or downhill-sloping terrain: illusions• The that airport can affectand runway the pilot’s environment; perception of: Shallower-than-actual Glide Path •• Terrain–The An airport uphill separation; and slope runway inand, the environment;approach zone or a drop-off of Figure 2 terrain at the approach end of the runway creates an •• DeviationTerrainillusion separation; from of being the horizontal tooand, high (impression flight path or of vertical a steep flight glide an illusion of being too high (impression of a steep path. • deviationpath [Figure from 1]), the thus: horizontal flight path or vertical Runwayglide environment path [Figure 1]), thus: flight path. Perceived• PossiblyGlide Path inducing a correction (e.g., increasing the Usually, more than one factor is involved in a given approach. Conditions that createActual visual Glide Path illusions include: rate of descent) that places the aircraft below the AirportUsually, environmentmore than one factor is involved in a given ap- • Runwayintended dimensions: glide path; or, proach. Uphill Slope Creates Illusion That Aircraft – The• Preventing runway aspect the flight ratio (i.e., crew its from length detecting relative ato too- its ConditionsIs on that Steeper-than-actual create visual illusions include: Glide Path width) affects the crew’s visual perception of the Airport environment shallow flight path; and, runway (Figure 3, page 105, middle panel, shows the • Black-hole effect along the final approach flight path; Source:– FlightA downhill Safety Foundation slope Approach-and-landingin the approach zone Accident creates an Reductionexpected (ALAR) Task image Force of the runway); Conditions• Uphill-sloping that create terrain visual or illusions downhill-sloping include: terrain: illusion of being too low (impression of a shallow – A wide or short runway (low aspect ratio) creates an • Black-hole effect along the final approach flight path; glide path [Figure 2]), thus: – An uphillPerceived slope in Actualthe approach zone or a drop-off of impression of beingFigure too low 2 (Figure 3, left panel); and, Glide Path Glide Path • Uphill-slopingterrain at the terrainapproach or downhill-slopingend of the runway terrain: creates an • Possibly inducing a correction that places the illusion of being too high (impression of a steep glide – A narrowaircraft orabove long the runway intended (high glide aspect path; ratio) or, creates – pathAn uphill [Figure slope 1]), inthus: the approach zone or a drop-off Runwayan environment impression of being too high (Figure 3, right of terrain at the approach end of the runway creates panel);• Preventing the flight crew from detecting a too- steep flight path. Conditions• Runway that uphill create slope visual or illusions downhill include: slope: Runway• Runway– An environment uphill dimensions: slope creates an illusion of being too high UphillSource: Flight Slope Safety FoundationCreates Approach-and-landing Illusion That Accident Aircraft – The(impression runway aspectof a steep ratio glide (i.e., path); its length and, relative to its ReductionIs on (ALAR) Steeper-than-actual Task Force Glide Path Conditions that create visual illusions include: –width) A downhill affects slope the creates crew’s an visual illusion perception of being tooof lowthe Figure 1 • Runwayrunway(impression dimensions: (Figure of a3, shallow page 105, glide middle path); panel, shows the expected image of the runway); – The runway aspect ratio (i.e., its length relative to 104 FLIGHT SAFETY FOUNDATION– • Aits FLIGHT wide width) or SAFETY affectsshort runway theDIGEST crew’s (low • AUGUST–NOVEMBERvisual aspect perception ratio) creates of the an2000 Perceived Actual impressionrunway (Figure of being 3, middle too low panel, (Figure shows 3, left the panel); expected and, Glide Path Glide Path image of the runway); – A narrow or long runway (high aspect ratio) creates – anA wideimpression or short ofrunway being (low too aspecthigh (Figure ratio) creates 3, right an panel);impression of being too low (Figure 3, left panel); • Runwayand, uphill slope or downhill slope: – AnA narrow uphill slopeor long creates runway an (highillusion aspect of being ratio) too creates high Source: Flight Safety Foundation Approach-and-landing Accident (impressionan impression of aof steep being glide too path); high and,(Figure 3, right Reduction (ALAR) Task Force panel); – A downhill slope creates an illusion of being too low Figure 1 • Runway(impression uphill ofslope a shallow or downhill glide slope:path);

104 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 105 • Offsetat a differentlocalizer anglecourse; (e.g., and, intercept angle is perceived as smaller than actual). Effects of Runway Dimensions on • Two-bar visual approach slope indicator (VASI), if used Perception of Height below (typically) 300 feet height above touchdown The following runway approach-aid conditions may increase (HAT) for glide-path corrections. the crew’s exposure to visual illusions: Weather• A glideslope conditions that is unusable beyond a certain point because of terrain or below a certain altitude because The followingof water; weather conditions can create visual illusions: • oCeilingffset localizer and visibility course; (vertical,and, slant and horizontal visibility): • Two-bar visual approach slope indicator (VASI), if used below– Flying (typically) in light rain, 300 fog, feet haze, height mist, above smoke, touchdown dust, glare (HAT)or darkness for glide-path usually corrections. creates an illusion of being too high; Weather conditions B AC – Shallow fog (i.e., a fog layer not exceeding 300 feet thickness) results in a low obscuration and in low Note: All three panels show a pilot’s sight picture from an aircraft The followinghorizontal weather visibility: conditions can create visual illu- at 200 feet and on a three-degree glide path. The runway in panel sions: A is 150 feet (45 meters) wide and 11,500 feet (3,500 meters) • When on top of a shallow fog layer, the ground long. The runway in panel B is wider/shorter than the runway in • Ceiling(or andairport visibility and runway, (vertical, if flying slant overhead) and horizontal can be panel A; the crew may believe that the aircraft is on shallower- visibility): than-actual glide path. The runway in panel C is narrower/longer seen; but when entering the fog layer, forward than the runway in panel A; the crew may believe that the aircraft – Flyingvisibility in light and rain, slant fog, visibility haze, mist, are smoke, lost; and, dust, glare is on steeper-than-actual flight path. or• Enteringdarkness ausually fog layer creates also creates an illusion the perception of being oftoo a Source: Flight Safety Foundation Approach-and-landing Accident high;pitch-up, which causes the pilot to respond with a Reduction (ALAR) Task Force – Shallownose-down fog (i.e., correction a fog thatlayer steepens not exceeding the approach 300 path; feet Figure 3 –thickness) Flying in haze results creates in athe low impression obscuration that andthe runwayin low horizontalis farther away, visibility: inducing a tendency to shallow the • Lighting: – An uphill slope creates an illusion of being too high glide• When path on and top land of a long;shallow fog layer, the ground (or – Approach(impression lighting of a steep and glide runway path); lighting and, (including – In lightairport rain and or runway, moderate if flyingrain, the overhead) runway maycan beappear seen; touchdown-zone lighting) affect depth perception, indistinctbut when because entering of thethe “rain fog layer, halo effect,”forward increasing visibility – dependingA downhill on: slope creates an illusion of being too low (impression of a shallow glide path); theand risk slant of misperception visibility are oflost; the and, vertical deviation or • Lighting intensity; horizontal• Entering deviation a fog layer during also creates the visual the perceptionsegment (the of • lighting: segment flown after transition from instrument • Daytime conditions or nighttime conditions; and a pitch-up, which causes the pilot to respond with – Approach lighting and runway lighting (including referencesa nose-down to visual correction references); that steepens the approach • Weather conditions; touchdown-zone lighting) affect depth perception, – Heavypath; rain affects depth perception and distance depending on: – Bright runway lights create the impression of being – Flyingperception: in haze creates the impression that the runway closer to the runway (thus, on a steeper glide path); • lighting intensity; is• farther Rain on away, a windshield inducing creates a tendency refraction to shallow effects thatthe – Low-intensity• daytime conditions lights create or nighttime the impression conditions; of being and glidecause path the and crew land to long; believe that the aircraft is too farther away (thus, on a shallower glide path); – In lighthigh, rain resulting or moderate in an rain, unwarranted the runway maynose-down appear • Weather conditions; correction and flight below the desired flight path; – Nonstandard spacing of runway lights modifies the indistinct because of the “rain halo effect,” increasing – pilot’sBright perceptionrunway lights of distance create the to theimpression runway andof being glide the• In risk daylight of misperception conditions, rain of diminishesthe vertical the deviation apparent path;closer and, to the runway (thus, on a steeper glide path); or intensityhorizontal of deviation the approach during light the visualsystem segment (ALS), (theresulting segment in flown the runway after transition appearing from to instrumentbe farther – Iflow-intensity the runway lighting lights create is partially the impression visible (e.g., of beingwhile referencesaway. As to a visual result references); of this illusion, the flight crew onfarther base away leg (thus,during on a avisual shallower approach glide path);or circling tends to shallow the flight path, resulting in a long approach), the runway may appear farther away or at – heavy rain affects depth perception and distance – Nonstandard spacing of runway lights modifies the landing; and, apilot’s different perception angle (e.g., of distance intercept to theangle runway is perceived and glide as perception: smaller than actual). • In nighttime conditions, rain increases the apparent path; and, • Rain on a windshield creates refraction effects that brilliance of the ALS, making the runway appear cause the crew to believe that the aircraft is too high, The following– If the runway lightingapproach-aid is partially conditions visible may (e.g., increase while to be closer, inducing a pitch-down input and the resulting in an unwarranted nose-down correction the crew’son exposure base leg to during visual illusions:a visual approach or circling risk of landing short of the runway threshold; approach), the runway may appear farther away or and flight below the desired flight path; • A glideslope that is unusable beyond a certain point – When breaking out at both ceiling minimums and because of terrain or below a certain altitude because of visibility minimums, the slant visibility may not be water; sufficient for the crew to see the farther bar(s) of the 106 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 105 VASI or precision approach path indicator (PAPI), Lessening the Effects thus reducing the available visual clues for the visual segment in reduced visibility; • In daylight conditions, rain diminishes the apparent To •lessen Crosswind: the effects of visual illusions, company accident- • Crosswind:intensity of the approach light system (ALS), prevention strategies and personal lines of defense should be – In crosswind conditions, the runway lights and resulting in the runway appearing to be farther developed and implemented based on the following – In crosswind conditions, the runway lights and environment will appear at an angle to the aircraft away. As a result of this illusion, the flight crew recommendations. environment will appear at an angle to the aircraft heading; the flight crew should maintain the drift tends to shallow the flight path, resulting in a long heading; the flight crew should maintain the drift correction and resist the tendency to align the aircraft landing; and, Hazard Awareness correction and resist the tendency to align the aircraft with the runway centerline; and, with• In the nighttime runway conditions, centerline; rain and, increases the apparent Companies should assess their exposure to visual illusions on • Runway surface condition: • Runwaybrilliance surface of condition: the ALS, making the runway appear their route network and in their operating environment(s). to be closer, inducing a pitch-down input and the – A wet runway reflects very little light; this can affect – A wetrisk runway of landing reflects short very of thelittle runway light; thisthreshold; can affect Flight crewsdepth should perception be trained and causeto recognize the flight and crew to understand to perceive depth perception and cause the flight crew to perceive incorrectly that the aircraft is farther away from the – When breaking out at both ceiling minimums and the factors and conditions that cause visual illusions and their incorrectly that the aircraft is farther away from the runway. This effect usually results in a late flare and visibility minimums, the slant visibility may not effects, including: runway. This effect usually results in a late flare and hard landing. hardbe sufficient landing. for the crew to see the farther bar(s) • Perception of height/depth, distances and angles; and, of the VASI or precision approach path indicator Table• Assessment1 provides ofa summarythe aircraft’s of horizontalvisual illusions position factors and glide and (PAPI), thus reducing the available visual cues for Table 1 provides a summary of visual illusions factors and their effectspath. on the pilot’s perception and actions. their effectsthe onvisual the pilot’ssegment perception in reduced and visibility; actions. Hazard Assessment Lessening the Effects Table 1 Approach hazards should be assessed during the approach Factors That Cause Visual Illusions and briefingTo lessen by the reviewing effects ofthe visual following illusions, elements: company accident- Result in Incorrect Pilot Responses prevention strategies and personal lines of defense should be developed• Ceiling and conditions implemented and visibilitybased on conditions;the following recom- Factor Perception Action Result mendations.• Weather: Narrow or long runway Hazard– Wind,Awareness and turbulence; Runway or Too high Push Land – Rain showers; and/or, terrain short/hard Companies should assess their exposure to visual illusions uphill slope on their– route Fog or network smoke andpatches; in their operating environment(s). Wide or • Crew experience at the airport and in the airport short runway Flightenvironment: crews should be trained to recognize and to understand Runway or Too low Pull Land long/ the factors and conditions that cause visual illusions and their terrain overrun – Surrounding terrain; and/or, downhill slope effects, including: – Specific airport hazards and runway hazards Bright runway Too close Land • Perception of height/depth, distances and angles; and, lighting (too steep) Push short/hard (obstructions, black-hole effect, off-airport light • Assessmentpatterns); ofand, the aircraft’s horizontal position and glide Low-intensity Farther away Pull Land long/ path. lighting (too shallow) overrun • Runway approach aids and visual aids: Light rain, fog, Too high Push Land Hazard– TypeAssessment of approach (let-down navaid restriction, such haze, mist, short/hard smoke, dust as a glideslope that is unusable beyond a specific point Approachor hazardsbelow a shouldspecific be altitude); assessed during the approach Entering fog Steepen briefing by reviewing the following elements: (shallow layer) Pitch-up Push over glide path/ – Type of approach lights; and, (CFIT) • Ceiling conditions and visibility conditions; – VASI or PAPI availability. Flying in Farther away Pull Land long/ haze (too shallow) overrun • Weather: Terrain Awareness Wet runway Farther away Late flare Hard – Wind, and turbulence; (too high) landing When –requesting Rain showers; or accepting and/or, a visual approach, the flight Crosswind Angled with Cancel drift Drifting crew should be aware of the surrounding terrain features and runway correction off track – Fog or smoke patches; man-made obstacles. CFIT = Controlled flight into terrain • Crew experience at the airport and in the airport Source: Flight Safety Foundation Approach-and-landing At night,environment: an unlighted hillside between a lighted area and the Accident Reduction (ALAR) Task Force runway may prevent the flight crew from correctly perceiving – Surrounding terrain; and/or, the rising terrain.

106 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 107 – Specific airport hazards and runway hazards • Pitching down toward the approach lights in an attempt (obstructions, black-hole effect, off-airport light to see the runway during a precision approach; or, patterns); and, • descending prematurely because of the incorrect • Runway approach aids and visual aids: perception of being too high. – Type of approach (let-down navaid restriction, such as The pilot not flying (PNF) must maintain instrument refer- a glideslope that is unusable beyond a specific point ences, including glideslope deviation, during the visual portion or below a specific altitude); of an ILS approach. – Type of approach lights; and, Monitoring the VASI or PAPI, whenever available, provides – VASI or PAPI availability. additional visual references to resist the tendency to increase or to decrease the rate of descent. Terrain Awareness On runways with an ALS with sequenced flashing lights II When requesting or accepting a visual approach, the flight (ALSF-II), flight crews should be aware that two rows of red crew should be aware of the surrounding terrain features and lights are aligned with the touchdown zone lights; this will man-made obstacles. provide an additional guard against descending prematurely. At night, an unlighted hillside between a lighted area and the The following can counter visual illusions (and prevent a flight runway may prevent the flight crew from correctly perceiving crew from descending prematurely): the rising terrain. • Maintain an instrument scan down to touchdown; Type of Approach • Cross-check instrument indications against outside At night, whenever an instrument approach is available (par- visual references to confirm glide path; ticularly an instrument landing system [ILS] approach) the • Use an ILS approach whenever available; instrument approach should be preferred to a visual approach, to reduce the risk of accidents caused by visual illusions. • Use a VASI or PAPI, if available, down to runway threshold; and, If an ILS approach is available, fly the ILS and use VASI or • Use other available tools, such as an extended runway PAPI for the visual portion of the approach. centerline shown on the flight management system (FMS) navigation display, ILS-DME (distance- If an ILS approach is not available, a nonprecision approach measuring equipment) or VOR (very-high-frequency supported by a VASI or PAPI should be the preferred option. omnidirectional radio)-DME distance, altitude above airport elevation to confirm the glide path (based on a On a nonprecision approach, do not descend below the typical 300-feet/one-nautical-mile approach gradient). MDA(H) before reaching the visual descent point (VDP), even if visual references have been acquired. Crew Resource Management (CRM)

To help prevent transitioning too early to visual references and CRM should ensure continuous monitoring of visual refer- descending prematurely, the pilot flying (PF) should maintain ences and instrument references throughout the transition to instrument references until reaching the VDP. the visual segment of an instrument approach. During a visual or circling approach, when on the base leg, In demanding conditions, the PNF should reinforce his or her if the VASI or PAPI indicates that the aircraft is below glide monitoring of instrument references and of the flight progress path, level off or climb until the VASI or PAPI indicates on- for effective cross-check and backup of the PF. glide-path. Altitude calls and excessive-parameter-deviation calls should Flight Path Monitoring be the same for instrument approaches and for visual ap- proaches, and should be continued during the visual portion Resisting the tendency to pitch down or to descend intention- of the approach (including glideslope deviation during an ILS ally below the appropriate altitude is the greatest challenge approach or vertical-speed deviation during a nonprecision during the visual segment of the approach. This includes: approach).

108 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Consequences References

The following are cited often in the analysis of approach- 1. Flight Safety Foundation. “Killers in Aviation: FSF Task and-landing incidents and accidents resulting from visual Force Presents Facts About Approach-and-landing and illusions: Controlled-flight-into-terrain Accidents.” Flight Safety Digest Volume 17 (November–December 1998) and Volume • Unconscious modification of the aircraft trajectory to 18 (January–February 1999): 1–121. The facts presented by maintain a constant perception of visual references; the FSF ALAR Task Force were based on analyses of 287 • Natural tendency to descend below the glideslope or the fatal approach-and-landing accidents (ALAs) that occurred initial glide path; in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 kilograms, detailed studies • The preceding tendencies combined with the inability to of 76 ALAs and serious incidents in 1984 through 1997 and judge the proper flare point because of restricted visual audits of about 3,300 flights. references (often resulting in a hard landing before reaching the desired touchdown point); 2. The Flight Safety Foundation (FSF) Approach-and- landing Accident Reduction (ALAR) Task Force defined • Inadequate reference to instruments to support the visual causal factor as “an event or item judged to be directly segment; instrumental in the causal chain of events leading to the • Failure to detect the deterioration of visual references; accident [or incident].” Each accident and incident in the and, study sample involved several causal factors.

• Failure to monitor the instruments and the flight path 3. The FSF ALAR Task Force definedcircumstantial factor because both pilots are involved in the identification of as “an event or item that was judged not to be directly in visual references. the causal chain of events but could have contributed to the accident [or incident].” Summary 4. The black-hole effect typically occurs during a visual approach conducted on a moonless or overcast night, over To guard against the adverse effects of visual illusions, flight water or over dark, featureless terrain where the only visual crews should: stimuli are lights on and/or near the airport. The absence of visual references in the pilot’s near vision affect depth • Be aware of all weather factors; perception and cause the illusion that the airport is closer • Be aware of surrounding terrain and obstacles; than it actually is and, thus, that the aircraft is too high. The pilot may respond to this illusion by conducting an approach • Assess the airport environment, airport and runway below the correct flight path (i.e., a low approach). hazards; and, • Adhere to defined PF-PNF task-sharing after the transition to visual flying, including: Related Reading from FSF Publications – Monitoring by the PF of outside visual references Wilson, Dale R. “Darkness Increases Risks of Flight.” Hu- while referring to instrument references to support man Factors & Aviation Medicine Volume 46 (November– and monitor the flight path during the visual portion December 1999). of the approach; and, Enders, John H.; Dodd, Robert; Tarrel, Rick; Khatwa, Ratan; – Monitoring by the PNF of head-down references Roelen, Alfred L.C.; Karwal, Arun K. “Airport Safety: A study while the PF flies and looks outside, for effective of Accidents and Available Approach-and-landing Aids.” Flight cross-check and backup. Safety Digest Volume 15 (March 1996).

The following FSF ALAR Briefing Notes provide information FSF Editorial Staff. “Fatal Commuter Crash Blamed on Visual to supplement this discussion: Illusion, Lack of Cockpit Coordination.” Accident Prevention • 1.6 — Approach Briefing; Volume 50 (November 1993). • 5.2 — Terrain; FSF Editorial Staff. “Spatial Disorientation Linked to Fatal DC-8 Freighter Crash.” Accident Prevention Volume 50 • 7.3 — Visual References; and, (March 1993). • 7.4 — Visual Approaches.◆

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 109 Regulatory Resources Joint Aviation Authorities. Joint Aviation Requirements – Operations 1. Commercial Air Transport (Aeroplanes). 1.430 International Civil Aviation Organization. Preparation of an “Aerodrome Operating Minima – General,” 1.435 – Terminol- Operations Manual. Second edition – 1997. ogy. July 1, 2000.

U.S. Federal Aviation Administration. Federal Aviation Regulations. 91.175 “Takeoff and landing under IFR.” July 1, 2000.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

110 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 5.4 — Wind Shear

Flight crew awareness and alertness are key factors in the suc- • Mountain waves; cessful application of wind shear avoidance techniques and • Frontal surfaces; recovery techniques. • Thunderstorms and convective clouds; and, Statistical Data • Microbursts.

The Flight Safety Foundation Approach-and-landing Acci- Microbursts present two distinct threats to aviation safety: dent Reduction (ALAR) Task Force found that adverse wind • A downburst that results in strong downdrafts (reaching conditions (i.e., strong crosswinds, tail winds or wind shear) 40 knots vertical velocity); and, were involved in about 33 percent of 76 approach-and-landing accidents and serious incidents worldwide in 1984 through • An outburst that results in strong horizontal wind shear 1997.1 and wind-component reversal (with horizontal winds reaching 100 knots). Definition Avoidance Wind shear is a sudden change of wind velocity/direction. The following information can be used to avoid areas of po- The following types of wind shear exist: tential wind shear or observed wind shear: • Vertical wind shear (vertical variations of the horizontal • Weather reports and forecasts: wind component, resulting in turbulence and affecting – The low-level wind shear alert system (LLWAS) aircraft airspeed when climbing or descending through is used by controllers to warn pilots of existing or the shear layer); and, impending wind shear conditions: • horizontal wind shear (horizontal variations of the wind • llWAS consists of a central wind sensor (sensing component [e.g., decreasing head wind or increasing wind velocity and direction) and peripheral wind tail wind, or a shift from a head wind to a tail wind], sensors located approximately two nautical miles affecting the aircraft in level flight, climb or descent). (nm) from the center. Central wind sensor data are averaged over a rolling two-minute period and Wind shear is associated usually with the following weather compared every 10 seconds with the data from the conditions: peripheral wind sensors. • Jet streams; • An alert is generated whenever a difference in

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 111 excess of 15 knots is detected. The LLWAS may • heading variations of 10 degrees or more; and, not detect downbursts with a diameter of two nm • Unusual autothrottle activity or throttle lever position. or less: – Terminal doppler weather radar (TDWR) detects approaching wind shear areas and, thus, provides Reactive/Predictive Warnings pilots with an advance warning of wind shear hazard; In addition to flight director (FD) wind shear recovery guid- ance, some aircraft provide a “wind shear” warning. • Pilot reports: – Pilot reports (PIREPs) of wind shear causing airspeed The wind shear warning and FD recovery guidance are referred fluctuations in excess of 20 knots or vertical-speed to as a reactive wind shear system, which does not incorporate changes in excess of 500 feet per minute (fpm) below any forward-looking (anticipation) capability. 1,000 feet above airport elevation should be cause for caution; To complement the reactive wind shear system and provide an early warning of wind shear activity, some weather radars • Visual observation: detect wind shear areas ahead of the aircraft (typically provid- – Blowing dust, rings of dust, dust devils (i.e., ing a one-minute advance warning) and generate a wind shear whirlwinds containing dust or sand) and any other warning (red “WIND SHEAR AHEAD”), caution (amber evidence of strong local air outflow near the surface “WIND SHEAR AHEAD”) or advisory alert messages. often are indications of wind shear; This equipment is referred to as a predictive wind shear sys- • on-board wind component and groundspeed tem. monitoring: – on approach, a comparison of the head wind Operating Procedures component or tail wind component aloft (as available) and the surface head wind component or tail wind The following opportunities are available to enhance wind component indicates the likely degree of vertical shear awareness and operating procedures. wind shear; • on-board weather radar; and, Standard Operating Procedures

• on-board predictive wind shear system. Standard operating procedures (SOPs) should emphasize the following wind shear awareness items: Recognition • Wind shear awareness and avoidance:

Timely recognition of wind shear is vital for successful imple- – Approach briefing; and, mentation of a wind shear recovery procedure. – Approach hazards awareness;

Some flight guidance systems can detect a wind shear condition • Wind shear recognition: during approach and during go-around, based on analysis of – Task-sharing for effective cross-check and backup, aircraft flight parameters. particularly for excessive parameter deviations;

The following are indications of a suspected wind shear – Energy management during approach; and, condition: – Elements of a stabilized approach (Table 1) and 2 • Indicated airspeed variations in excess of 15 knots; approach gate ; and, • groundspeed variations (decreasing head wind or • Wind shear recovery procedure: increasing tail wind, or a shift from head wind to tail – Readiness and commitment to respond to a wind shear wind); warning. • Vertical-speed excursions of 500 fpm or more; Training • Pitch attitude excursions of five degrees or more; • glideslope deviation of one dot or more; A wind shear awareness program should be developed and implemented, based on the industry-developed Windshear

112 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 – Most recent weather reports and forecasts; Table 1 – Visual observations; and, Recommended Elements – Crew experience with the airport environment and Of a Stabilized Approach the prevailing weather conditions; and, All flights must be stabilized by 1,000 feet above • Consideration to delaying the takeoff until conditions airport elevation in instrument meteorological conditions improve. (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabi- lized when all of the following criteria are met: Takeoff and Initial Climb 1. The aircraft is on the correct flight path; If wind shear conditions are expected, the crew should: 2. Only small changes in heading/pitch are required to maintain the correct flight path; • Select the most favorable runway, considering the

3. The aircraft speed is not more than VREF + 20 knots location of the likely wind shear/downburst condition; indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; • Select the minimum flaps configuration compatible 5. Sink rate is no greater than 1,000 feet per minute; if with takeoff requirements, to maximize climb-gradient an approach requires a sink rate greater than 1,000 capability; feet per minute, a special briefing should be con- ducted; • Use the weather radar (or the predictive wind shear system, if available) before beginning the takeoff to 6. Power setting is appropriate for the aircraft configura- tion and is not below the minimum power for approach ensure that the flight path is clear of hazards; as defined by the aircraft operating manual; • Select maximum takeoff thrust; 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they • After selecting the takeoff/go-around (TOGA) mode, also fulfill the following: instrument landing system select the flight-path-vector display for the pilot not (ILS) approaches must be flown within one dot of flying (PNF), as available, to obtain a visual reference the glideslope and localizer; a Category II or Cat- of the climb flight path angle; and, egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, • Closely monitor the airspeed and airspeed trend during wings should be level on final when the aircraft the takeoff roll to detect any evidence of impending wind reaches 300 feet above airport elevation; and, shear. 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a stabilized approach require a special briefing. Wind Shear Recovery An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet If wind shear is encountered during the takeoff roll or during above airport elevation in VMC requires an immediate initial climb, the following actions should be taken without go-around. delay: Source: Flight Safety Foundation Approach-and-landing Accident • Before V : Reduction (ALAR) Task Force (V1.1 November 2000) 1 – The takeoff should be rejected if unacceptable airspeed variations occur (not exceeding the target V ) and if there is sufficient runway remaining to Training Aid or the Flight Safety Foundation-developed Wind- 1 stop the airplane; shear Training Aid Package.3

• After V1: Training on the wind shear recovery procedure should be – disconnect the autothrottles (A/THR), if available, conducted in a full-flight simulator, using wind shear profiles and maintain or set the throttle levers to maximum recorded during actual wind shear encounters. takeoff thrust; – Rotate normally at V ; and, Departure Briefing R – Follow the FD pitch command if the FD provides The takeoff-and-departure briefing should include the follow- wind shear recovery guidance, or set the required pitch ing wind shear awareness items: attitude (as recommended in the aircraft operating • Assessment of the conditions for a safe takeoff based manual [AOM]/quick reference handbook [QRH]); on: • during initial climb:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 113 – disconnect the A/THR, if available, and maintain or – Crew experience with the airport environment and set the throttle levers to maximum takeoff thrust; the prevailing weather conditions; – If the autopilot (AP) is engaged and if the FD provides • Consider delaying the approach and landing until wind shear recovery guidance, keep the AP engaged; conditions improve, or consider diverting to a suitable or, airport; Follow the FD pitch command, if the FD provides • Whenever downburst/wind shear conditions are wind shear recovery guidance; or, anticipated, based on pilot reports from preceding Set the required pitch attitude (as recommended in aircraft or based on an alert by the airport LLWAS, the the AOM/QRH); landing should be delayed or the aircraft should be flown to the destination alternate airport; – level the wings to maximize the climb gradient, unless a turn is required for obstacle clearance; • Select the most favorable runway, considering: – Closely monitor the airspeed, airspeed trend and flight – The location of the likely wind shear/downburst path angle (as available); condition; and, – Allow airspeed to decrease to stick shaker onset – The available runway approach aids; (intermittent stick shaker activation) while monitoring • Use the weather radar (or the predictive wind shear the airspeed trend; system, if available) during the approach to ensure that – do not change the flaps or landing-gear configurations the flight path is clear of potential hazards; until out of the wind shear condition; and, • Select the flight path vector display for the PNF, as – When out of the wind shear condition, increase available, to obtain a visual reference of the flight path airspeed when a positive climb rate is confirmed, angle; retract the landing gear, flaps and slats, then establish a normal climb profile. • Select less than full flaps for landing (to maximize climb- gradient capability), if authorized by the AOM/QRH, Approach Briefing and adjust the final approach speed accordingly; • If an instrument landing system (ILS) approach is The approach briefing should include the following: available, engage the AP for more accurate approach • Based on the automatic terminal information service tracking and for warnings of excessive glideslope (ATIS) broadcast, review and discuss the following deviations; items: • Select a final approach speed based on the reported – Runway in use (type of approach); surface wind — an airspeed correction (usually a – Expected arrival route (standard terminal arrival maximum of 15 knots to 20 knots, based on the expected [STAR] or radar vectors); wind shear value) is recommended; – Prevailing weather; and, • Compare the head wind component aloft or the tail wind component aloft with the surface head wind component – Reports of potential low-level wind shear (LLWAS or surface tail wind component to assess the likely degree warnings, TDWR data); and, of vertical wind shear; • discuss the intended use of automation for vertical • Closely monitor the airspeed, airspeed trend and navigation and lateral navigation as a function of the groundspeed during the approach to detect any evidence suspected or forecast wind shear conditions. of impending wind shear; Descent and Approach – Be alert for microbursts, which are characterized by a significant increase of the head wind component Before conducting an approach that may be affected by wind followed by a sudden change to a tail wind; and, shear conditions, the crew should: • Be alert to respond without delay to a predictive wind • Assess the conditions for a safe approach and landing shear warning or to a reactive wind shear warning, as based on: applicable. The response should adhere to procedures – Most recent weather reports and forecasts; in the AOM/QRH.

– Visual observations; and, Recovery During Approach and Landing

114 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 If wind shear is encountered during the approach or landing, the – Inadequate monitoring of flight progress; and/or, following recovery actions should be taken without delay: – Incorrect use of automation; and, • Select the takeoff/go-around (TOGA) mode and set and • human factors and crew resource management maintain maximum go-around thrust; (CRM): • Follow the FD pitch command (if the FD provides wind – Absence of cross-checking (for excessive parameter shear recovery guidance) or set the pitch-attitude target deviations); recommended in the AOM/QRH; – Absence of backup (standard calls); and/or, • If the AP is engaged and if the FD provides wind shear – Fatigue. recovery guidance, keep the AP engaged; otherwise, disconnect the AP and set and maintain the recommended pitch attitude; Summary

• do not change the flap configuration or landing-gear Avoidance configuration until out of the wind shear; • Assess the conditions for a safe approach and landing, • level the wings to maximize climb gradient, unless a based on all available meteorological data, visual turn is required for obstacle clearance; observations and on-board equipment; • Allow airspeed to decrease to stick-shaker onset • As warranted, consider delaying the approach, or (intermittent stick-shaker activation) while monitoring consider diverting to a more suitable airport; and, airspeed trend; • Be prepared and committed to respond immediately to • Closely monitor airspeed, airspeed trend and flight path a wind shear warning. angle (if flight-path vector is available and displayed for the PNF); and, Recognition • When out of the wind shear, retract the landing gear, • Be alert for wind shear conditions, based on all available flaps and slats, then increase the airspeed when a positive weather data, on-board equipment and aircraft flight climb rate is confirmed and establish a normal climb parameters and flight path; and, profile. • Monitor the instruments for evidence of impending wind shear. Awareness Recovery Company accident-prevention strategies and personal lines • Avoid large thrust variations or trim changes in response of defense should be developed to address the following fac- to sudden airspeed variations; tors: • Aircraft equipment: • If a wind shear warning occurs, follow the FD wind shear recovery pitch guidance or apply the recommended – Absence of reactive/predictive wind shear system(s); escape procedure; and, and, • Make maximum use of aircraft equipment, such as the – Absence of glideslope excessive-deviation warning; flight path vector (as available). • Airport equipment: The following FSF ALAR Briefing Notes provide information – Absence of an LLWAS; and, to supplement this discussion: – Absence of TDWR; • 1.1 — Operating Philosophy; • Training: • 1.2 — Automation; – Absence of a wind shear awareness program; and/ or, • 1.3 — Golden Rules; – Absence of wind shear recovery (escape) simulator • 1.4 — Standard Calls; training; • 1.6 — Approach Briefing; • SOPs: • 5.1 — Approach Hazards Overview; and, – Inadequate briefings; • 6.1 — Being Prepared to Go Around.◆

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 115 References croburst During Unstabilized Approach, Ending in Runway Accident.” Accident Prevention Volume 53 (August 1996). 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and FSF Editorial Staff. “Unaware That They Have Encountered a Controlled-flight-into-terrain Accidents.” Flight Safety Microburst, DC-9 Flight Crew Executes Standard Go-around; Digest Volume 17 (November–December 1998) and Aircraft Flies Into Terrain.” Accident Prevention Volume 53 Volume 18 (January–February 1999): 1–121. The facts (February 1996). presented by the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents FSF Editorial Staff. “Wind Shear Sends Commuter Aircraft (ALAs) that occurred in 1980 through 1996 involving Plunging Out of Control.” Accident Prevention Volume 49 turbine aircraft weighing more than 12,500 pounds/5,700 (September 1992). kilograms, detailed studies of 76 ALAs and serious incidents in 1984 through 1997 and audits of about 3,300 U.S National Center for Atmospheric Research. “Improved flights. Microburst Warnings Aim for Safer Terminal Operations.” Accident Prevention Volume 47 (July 1990). 2. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force definesapproach FSF. “Summer Hazards.” Accident Prevention Volume 44 gate as “a point in space (1,000 feet above airport elevation (July 1988). in instrument meteorological conditions or 500 feet above airport elevation in visual meteorological conditions) at which a go-around is required if the aircraft does not meet Regulatory Resources defined stabilized approach criteria.” International Civil Aviation Organization (ICAO). Preparation 3. The two-volume Windshear Training Aid, developed of an Operations Manual. Second edition – 1997. primarily for operators of air carrier aircraft, is available for purchase from the U.S. National Technical Information ICAO. Circular 186, “Wind Shear.” 1987. Service (NTIS), 5285 Port Royal Road, Springfield, VA 22161 U.S.A. Telephone: (800) 553-6847 (U.S.) or +1 ICAO. International Standards and Recommended Practices, (703) 605-6000. Fax: +1 (703) 605-6900. Internet site: Annex 6 to the Convention of International Civil Aviation, www.ntis.gov. Each volume costs US$123 plus shipping- Operation of Aircraft. Part I, International Commercial Air and-handling charges. Transport – Aeroplanes. Chapter 6, “Aeroplane Instruments, Equipment and Flight Documents,” 6.21 Seventh edition – July The multimedia Windshear Training Aid Package, 1998, incorporating Amendments 1-25. developed by Flight Safety Foundation for operators of regional, on-demand, business and other general aviation U.S. Federal Aviation Administration. Federal Aviation aircraft, is available for purchase from NTIS for $330, plus Regulations. 121.135 “Contents,” 121.315 “Cockpit check pro- shipping-and-handling charges. cedure,” 121.357 “Airborne weather radar equipment require- ments,” 121.358 “Low-altitude windshear system equipment requirements,” 121.424 “Pilots: Initial, transition, and up-grade Related Reading from FSF Publications flight training,” 121.542 “Flight crewmember duties,” 121.599 “Familiarity with weather conditions.” January 1, 2000. FSF Editorial Staff. “During Nonprecision Approach at Night, MD-83 Descends Below Minimum Descent Altitude and Con- FAA. FARs. 121.360 “Ground proximity warning-glide slope tacts Trees, Resulting in Engine Flame-out and Touchdown deviation alerting system.” March 29, 2000. Short of Runway.” Accident Prevention Volume 54 (April 1997). FAA. Advisory Circular 00-54, Pilot Windshear Guide. No- vember 25, 1988. FSF Editorial Staff. “Flight Crew of DC-10 Encounters Mi-

116 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 117 FSF ALAR Briefing Note 6.1 — Being Prepared to Go Around

The importance of being go-around-prepared and being go- descent altitude/height (MDA[H]) or decision altitude/height around-minded must be emphasized, because a go-around is (DA[H]); confusion regarding aircraft position; and automa- not a frequent occurrence. This requires having a clear mental tion-interaction problems. image of applicable briefings, standard calls, sequences of actions, task-sharing and cross-checking, and being prepared The task force found that only 17 percent of the accident/ to abandon the approach if requirements are not met in terms incident flight crews initiated go-arounds when conditions of: indicated that go-arounds should have been conducted. • Weather minimums; or, General • Criteria for a stabilized approach (Table 1). Being go-around-prepared and go-around-minded implies The sequence of events leading to a go-around can begin at the following: the top of descent, so the following recommendations begin with descent preparation. • Knowledge of applicable briefings, standard calls, sequences of actions, task-sharing and cross-checking; Statistical Data • Being ready to abandon the approach if the weather minimums or the criteria for a stabilized approach are The Flight Safety Foundation Approach-and-landing Accident not met, or if doubt exists about the aircraft’s position Reduction (ALAR) Task Force found that failure to recognize or about aircraft guidance; and, the need for and to execute a missed approach when appro- priate is a primary cause of approach-and-landing accidents • After the go-around is initiated, the flight crew must fly (ALAs), including those involving controlled flight into ter- the published missed approach procedure. rain (CFIT).1

The task force found that inadequate professional judgment/ Operational Recommendations airmanship was a causal factor2 in 74 percent of 76 approach- and-landing accidents and serious incidents worldwide in Task-sharing 1984 through 1997. Adherence to the defined pilot flying-pilot not flying (PF-PNF) Among the flight crew errors committed in these occurrences task-sharing procedures for normal operations and abnormal was failure to conduct a go-around when required by: an operations is a major part of preparing for a go-around and of unstabilized approach; excessive glideslope/localizer devia- conducting a safe go-around. tions; absence of adequate visual references at the minimum

118 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Descent Preparation

Descent preparation and the approach briefing should be Table 1 planned and should be conducted to prevent delaying the Recommended Elements initiation of the descent and to prevent rushed management Of a Stabilized Approach of the descent profile. All flights must be stabilized by 1,000 feet above Approach Briefing airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabi- To be go-around-prepared, the approach briefing should in- lized when all of the following criteria are met: clude a discussion of the primary elements of the go-around 1. The aircraft is on the correct flight path; maneuver and the published missed approach procedure. The 2. Only small changes in heading/pitch are required to discussion should include the following: maintain the correct flight path; 3. The aircraft speed is not more than V + 20 knots • Approach gate3; REF indicated airspeed and not less than VREF; • go-around call (e.g., a loud and clear “go around/ 4. The aircraft is in the correct landing configuration; flaps”); 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 • PF-PNF task-sharing (flow of respective actions, feet per minute, a special briefing should be con- including desired guidance, mode selection, airspeed ducted; target, go-around altitude, deviations calls); and, 6. Power setting is appropriate for the aircraft configura- tion and is not below the minimum power for approach • Missed approach vertical navigation and lateral navigation as defined by the aircraft operating manual; (including airspeed and altitude restrictions). 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they Achieving Flight Parameters also fulfill the following: instrument landing system (ILS) approaches must be flown within one dot of The flight crew must “stay ahead of the aircraft” throughout the glideslope and localizer; a Category II or Cat- the flight. This includes achieving desired flight parameters egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, (e.g., aircraft configuration, aircraft position, energy condition, wings should be level on final when the aircraft track, altitude, vertical speed, airspeed and attitude) during the reaches 300 feet above airport elevation; and, descent, approach and landing. Any indication that a desired 9. Unique approach procedures or abnormal conditions flight parameter will not be achieved should prompt immediate requiring a deviation from the above elements of a corrective action or the decision to go around. stabilized approach require a special briefing. An approach that becomes unstabilized below 1,000 Descent Profile Monitoring feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate go-around. The descent profile should be monitored, using all available instrument references (including flight management system Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) [FMS] vertical navigation [VNAV]).

The descent profile also may be monitored or may be adjusted based on a typical 10 nautical mile per 3,000 feet descent • Maintaining a high airspeed and a high descent rate as gradient (corrected for the prevailing head wind component or long as practical; tail wind component) while adhering to the required altitude/ • Using speed brakes; airspeed restrictions (deceleration management). • Extending the landing gear, if the use of speed brakes If the flight path is significantly above the desired descent is not sufficient; or, profile (e.g., because of an air traffic control [ATC] restriction • As a last resort, conducting a 360-degree turn (as or greater-than-expected tail wind), the desired flight path can practical, and with ATC clearance). be recovered by: • Reverting from FMS VNAV to a selected vertical mode, If the desired descent flight path cannot be established, ATC with an appropriate airspeed target or vertical-speed should be notified for timely coordination. target; \

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 119 Final Approach The following FSF ALAR Briefing Notes provide information to supplement this discussion: Because the approach briefing was conducted at the end of the cruise phase, the crew should review primary elements of • 1.1 — Operating Philosophy; the go-around maneuver and the missed approach procedure • 1.3 — Golden Rules; at an appropriate time during final approach. • 1.4 — Standard Calls; To be prepared to take over manually when flying with the • 1.6 — Approach Briefing; autopilot (AP) engaged, the following should be considered: • 4.1 — Descent-and-approach Profile Management; • Seat adjustment and armrest adjustment (this is of primary importance for effective aircraft handling in a • 4.2 — Energy Management; dynamic phase of flight); and, • 6.2 — Manual Go-around; • Flying with one hand on the control column and one • 7.1 — Stabilized Approach; and, hand on the throttle levers. • 7.3 — Visual References.◆ Transitioning Back to Instrument Flying References One of the most frequent reasons for conducting a go-around is weather. 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and When approaching the minimum descent altitude/height Controlled-flight-into-terrain Accidents.” Flight Safety (MDA[H]) or the decision altitude/height (DA[H]), one pilot Digest Volume 17 (November–December 1998) and attempts to acquire the required visual references. During this Volume 18 (January–February 1999): 1–121. The facts time, the pilot is in almost-visual flying conditions. presented by the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents If a go-around is initiated, an immediate transition to instru- (ALAs) that occurred in 1980 through 1996 involving ment flying should occur. turbine aircraft weighing more than 12,500 pounds/5,700 kilograms, detailed studies of 76 ALAs and serious It is, therefore, of primary importance that the other pilot incidents in 1984 through 1997 and audits of about 3,300 maintain instrument references and be ready to make appropri- flights. ate calls if any flight parameter (airspeed, pitch attitude, bank angle, thrust) deviates from the normal value. 2. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force defines causal To ease this transition back to instrument flying, all efforts factor as “an event or item judged to be directly instrumental should be made to initiate the go-around with wings level and in the causal chain of events leading to the accident [or with no roll rate. incident].” Each accident and incident in the study sample involved several causal factors. The above discussion does not apply when captain/first officer task-sharing is accomplished in accordance with an operating 3. The FSF ALAR Task Force defines approach gate as policy known as the shared approach, monitored approach or “a point in space (1,000 feet above airport elevation in delegated handling approach. [See FSF ALAR Briefing Note instrument meteorological conditions or 500 feet above 7.3 — Visual References.] airport elevation in visual meteorological conditions) at which a go-around is required if the aircraft does not meet defined stabilized approach criteria.” Summary

Because a go-around is not a frequent occurrence, the impor- Related Reading From FSF Publications tance of being go-around-prepared and go-around-minded should be emphasized. FSF Editorial Staff. “Business Jet Overruns Wet Runway After Landing Past Touchdown Zone.” Accident Prevention Volume If the criteria for safe continuation of the approach are not 56 (December 1999). met, the crew should initiate a go-around and fly the published missed approach. FSF Editorial Staff. “Airplane’s Low-energy Condition and Degraded Wing Performance Cited in Unsuccessful Go-around

120 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Attempt.” Accident Prevention Volume 56 (July 1999). Pope, John A. “Faulty Angle-of-attack Sensor Provokes Go/ No-go Decision with an Inadequately Coordinated Crew.” FSF Editorial Staff. “B-757 Damaged by Ground Strike During Accident Prevention Volume 50 (August 1993). Late Go-around from Visual Approach.” Accident Prevention Volume 56 (May 1999). Regulatory Resources FSF Editorial Staff. “Attempted Go-around with Deployed Thrust Reversers Leads to Learjet Accident.” Accident Preven- International Civil Aviation Organization (ICAO). Interna- tion Volume 56 (January 1999). tional Standards and Recommended Practices, Annex 6 to the Convention of International Civil Aviation, Operation of FSF Editorial Staff. “Unaware That They Have Encountered a Aircraft. Part I, International Commercial Air Transport – Microburst, DC-9 Flight Crew Executes Standard Go-around; Aeroplanes. Appendix 2, “Contents of an Operations Manual,” Aircraft Flies Into Terrain.” Accident Prevention Volume 53 5.16, 5.18, 5.19. Seventh edition – July 1998, incorporating (February 1996). Amendments 1–25.

FSF Editorial Staff. “Captain’s Inadequate Use of Flight Con- ICAO. Procedures for Air Navigation Services. Aircraft Op- trols During Single-engine Approach and Go-around Results in erations. Volume I, Flight Procedures. Fourth edition, 1993. Loss of Control and Crash of Commuter.” Accident Prevention Reprinted May 2000, incorporating Amendments 1–10. Volume 52 (November 1995). ICAO. Manual of All-Weather Operations. Second edition – Lawton, Russell. “DC-10 Destroyed, No Fatalities, After Air- 1991. craft Veers Off Runway During Landing.” Accident Prevention Volume 51 (May 1994). U.S. Federal Aviation Administration (FAA). Federal Aviation Regulations. 91.175 “Takeoff and landing under IFR,” 91.189 Lawton, Russell. “Captain Stops First Officer’s Go-around, “Category II and III operations: General operating rules.” DC-9 Becomes Controlled-flight-into-terrain (CFIT) Acci- January 1, 2000. dent.” Accident Prevention Volume 51 (February 1994). FAA. Advisory Circular 60-A, Pilot’s Spatial Disorientation. February 8, 1983.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 121 FSF ALAR Briefing Note 6.2 — Manual Go-around

The importance of being go-around-prepared and being go- • Flying manually, with flight director (FD) guidance and around-minded must be emphasized, because a go-around is an adapted (e.g., horizontal situation indicator [HSI]- not a frequent occurrence. type) navigation display (ND) mode.

This requires that the pilots have a clear mental image of ap- If manual thrust is selected, the pilot not flying (PNF) should plicable briefings, standard calls, sequences of actions, task- monitor closely the airspeed, airspeed trend and thrust, and sharing and cross-checking, and that the pilots are prepared call any excessive deviation (e.g., airspeed decreasing below

to abandon the approach if requirements are not met in terms VREF [reference landing speed]). of: The PNF is responsible for monitoring tasks and for conducting • Weather minimums; or, actions requested by the PF, including: • Criteria for a stabilized approach (Table 1). • Conducting the standard PNF tasks: After the go-around is initiated, the flight crew must fly the – Performing standard operating procedures (SOPs); missed approach procedure as published (i.e., following the – Conducting selections on the automatic flight system published vertical navigation and lateral navigation). (AFS) control panel when in manual flight; and, – Reading abnormal checklists or emergency checklists Recommendations (electronic and/or paper checklists) and conducting required actions in case of failure; Task-sharing • Monitoring the thrust setting; The following task-sharing principles are important in the very • Monitoring vertical speed and radio-altimeter altitude; dynamic phase of initiating a go-around. and, • Monitoring pitch attitude, bank angle, airspeed The pilot flying (PF) is responsible for controlling vertical and airspeed trend, and calling out any excessive navigation and lateral navigation, and for energy manage- deviation. ment, by either: • Supervising autopilot vertical guidance and lateral Understanding the Flight Dynamics of the Go- guidance, and autothrottle (A/THR) operation; and around maintaining awareness of flight-mode annunciator (FMA) status and FMA changes; or, Unlike the takeoff rotation, in which the aircraft is pre-trimmed and the thrust is already set, the initiation of a go-around re-

122 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 inoperative go-around.

Table 1 The pitch effects of underwing-mounted engines are discussed Recommended Elements in this briefing note. Of a Stabilized Approach When initiating a go-around at decision altitude/height All flights must be stabilized by 1,000 feet above (DA[H]), the PF is expected to minimize the altitude loss: airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual The PF must apply simultaneously nose-up pitch pressure on meteorological conditions (VMC). An approach is stabi- the control column, advance the throttle levers and select the lized when all of the following criteria are met: takeoff/go-around (TOGA) mode. 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to Pitch is affected by the following factors: maintain the correct flight path; • The nose-up elevator input initiates a pitch-attitude 3. The aircraft speed is not more than V + 20 knots REF change that minimizes altitude loss; indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; • Within a few seconds, thrust increases (resulting in an 5. Sink rate is no greater than 1,000 feet per minute; if additional nose-up pitch effect); and, an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be con- • Retracting one step of flaps results usually in a slight ducted; nose-up pitch effect. 6. Power setting is appropriate for the aircraft configura- tion and is not below the minimum power for approach As a result of these three nose-up pitch effects: as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; • The pitch-attitude rate increases; and, 8. Specific types of approaches are stabilized if they • The nose-up pitch force required to maintain the also fulfill the following: instrument landing system pitch-attitude target decreases until a nose-down pitch (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Cat- force is required to prevent an excessive nose-up pitch egory III ILS approach must be flown within the ex- attitude. panded localizer band; during a circling approach, wings should be level on final when the aircraft To maintain the desired pitch-attitude target (and prevent reaches 300 feet above airport elevation; and, overshooting this target), the PF must: 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a • Release back (nose-up) pressure on the control stabilized approach require a special briefing. column; An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet • Apply progressively, as thrust increases, forward (nose- above airport elevation in VMC requires an immediate down) pressure on the control column; and, go-around. • Re-trim the aircraft (nose-down), as necessary. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) Stated simply, the PF should aviate (fly the aircraft) while closely monitoring the primary flight display (PFD).

quires a very dynamic sequence of actions and changes (thrust, If the pitch attitude is not controlled positively, pitch will configuration) affecting the pitch balance. continue to increase and will reach values at which airspeed will decrease despite the go-around thrust. Pitch effects depend largely on the location of engines (i.e., mounted under the wings or on the tail) and other aircraft or Flying a Manual Go-around systems features. For a safe go-around, the following “three Ps” constitute a Pitch effects are amplified: golden rule: • At low gross weight, low altitude and low outside air • Pitch: temperature (hence, at a high thrust-to-weight ratio); and/or, – Set and maintain the pitch-attitude target; • With all engines operative, as compared to a one-engine- • Power:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 123 – Set and check the go-around thrust; and, delay: • Performance: – Set flaps as appropriate; – Check aircraft performance: positive rate of climb, – Announce “positive climb” and retract the landing

airspeed at or above VREF, speed brakes retracted, gear on PF command; radio-altimeter indications and barometric-altimeter – Monitor: indications increasing, wings level, gear up, flaps as required. • Airspeed and airspeed trend; • Pitch attitude and bank angle; and, The operational recommendations and task-sharing for the safe conduct of a manual go-around can be expanded as follows: • Thrust increase (confirm the thrust-limit mode, as

applicable, and actual thrust on fan-speed [N1] or For the PF: engine-pressure-ratio [EPR] indicators); • When calling “go-around/flaps,” without delay: – Check the FMA: – Select the TOGA mode and follow through the A/ • Announce in a loud and clear voice the FMA-thrust THR operation; mode, vertical-mode and lateral-mode selection; – Rotate (at the same rate as for takeoff, typically three • Check the autopilot (AP) status; call “AP engaged” degrees per second); or “hand flying”); and, – Follow the FD pitch command (but do not exceed • Check FD engagement status; and, the maximum pitch attitude applicable to the aircraft type); – Continue monitoring the flight parameters and call any excessive deviation: – Check go-around power (thrust); and, • “Speed,” if dropping below V ; – Check go-around performance: REF • “Speed trend,” if negative; • Positive rate of climb; • “Pitch attitude,” if approaching the ultimate value • Airspeed at or above VREF; (e.g., at 20 degrees if the ultimate value is 25 • Speed brakes retracted; degrees); • Radio-altimeter indication and barometric- • “Bank angle,” if in excess of 15 degrees (30 altimeter indication increasing; degrees if the missed approach procedure requires a turn); and/or, • Wings level; • “Thrust,” if a significant thrust reduction is • gear up; and, observed. • Flaps as required; • As thrust increases, be prepared to counteract the nose- Summary up pitch effect (i.e., apply increasing forward pressure — nose-down input — on the control column); and, To manually fly a safe go-around, adhere to the three-Ps golden rule: • Trim the aircraft nose-down, as required. • Pitch: The pitch attitude should not be allowed to exceed an ultimate – Set and maintain the pitch-attitude target; value (e.g., 25 degrees), because such a pitch attitude would result in a significant airspeed reduction. • Power: – Set and check go-around thrust; and, Immediate and firm elevator nose-down input (together with a nose-down pitch trim adjustment), however, may allow • Performance: recovering the pitch-attitude target. – Check the aircraft performance: positive rate of climb,

airspeed at or above VREF, speed brakes retracted, radio- For the PNF: altimeter indication and barometric-altimeter indication • When hearing the “go-around/flaps” call, without increasing, wings level, gear up, flaps as required.

124 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 While conducting the go-around, adherence to the defined Related Reading from FSF Publications PF-PNF task-sharing and the optimum use of crew resource management (e.g., for monitoring flight parameters and calling Flight Safety Foundation (FSF). “Killers in Aviation: FSF any excessive flight-parameter deviation) are of paramount Task Force Presents Facts about Approach-and-landing and importance. Controlled-flight-into-terrain Accidents.” Flight Safety Digest Volume 17–18 (November–December 1998, January–February The manual go-around technique must: 1999). • Minimize the initial altitude loss; and, FSF Editorial Staff. “Spatial Disorientation Linked to Fatal • Prevent an excessive nose-up pitch attitude by following DC-8 Freighter Crash.” Accident Prevention Volume 50 FD pitch commands, not exceeding the ultimate pitch (March 1993). attitude applicable to the aircraft type. FSF Editorial Staff. “Unstabilized Approach, Icing Conditions Should any warning be triggered or any other abnormal condi- Lead To Commuter Tragedy.” Accident Prevention Volume 49 tion occur during the go-around, the PF must concentrate his (December 1992). or her attention on flying the aircraft (controlling the vertical flight path and the lateral flight path). Regulatory Resources

The following FSF ALAR Briefing Notes provide information International Civil Aviation Organization (ICAO). Interna- to supplement this discussion: tional Standards and Recommended Practices, Annex 6 to • 1.1 — Operating Philosophy; the Convention of International Civil Aviation, Operation of Aircraft. Part I, International Commercial Air Transport – • 1.3 — Golden Rules; Aeroplanes. Appendix 2, “Contents of an Operations Manual,” • 1.4 — Standard Calls; 5.14, 5.16, 5.18, 5.21, 5.22. Seventh edition – July 1998, incorporating Amendments 1–25. • 6.1 — Being Prepared to Go Around; and, • 7.1 — Stabilized Approach.◆ ICAO. Preparation of an Operations Manual. Second edi- tion – 1997.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 125 FSF ALAR Briefing Note 6.3 — Terrain-avoidance (Pull-up) Maneuver

A typical training program to reduce approach-and-landing (SOPs) to reinforce situational awareness and the optimum use accidents (ALAs), including those involving controlled flight of automated systems and displays during approach procedures into terrain (CFIT), includes the following: should be incorporated in transition training and recurrent training programs developed by the aircraft manufacturer or • Alert flight crews to the factors that may cause ALAs by the company’s training department. and CFIT; • Ensure that situational awareness is maintained at all A training program should include: times; • An instructor-led classroom briefing or a self-briefing • Ensure that crews attain proficiency in conducting based on the FSF ALAR Tool Kit; approach procedures for their aircraft type; • A complete discussion about the operation of the GPWS/ • Provide crews with adequate knowledge of the capabilities TAWS; and limitations of the ground-proximity warning system (GPWS) or terrain awareness and warning system • The FSF Controlled Flight Into Terrain: An Encounter (TAWS)1 installed on their aircraft; and, Avoided video; • Ensure that crews are proficient in conducting the • Exercises to be incorporated in simulator training terrain-avoidance maneuver required in response to a sessions during transition training/recurrent training GPWS warning or a TAWS warning (as published in (three typical sample exercises are described later); the aircraft operating manual [AOM]/quick reference and, handbook [QRH]). • A simulator briefing for nonprecision approaches to emphasize CFIT risks and the advantages of using a Statistical Data constant-angle nonprecision approach (CANPA).

The Flight Safety Foundation Approach-and-landing Accident Simulator Requirements Reduction (ALAR) Task Force found that CFIT was involved in 37 percent of 76 approach-and-landing accidents and serious • The flight simulator database should include terrain in incidents worldwide in 1984 through 1997.2 the vicinity of the airports selected for training. The terrain database should extend to an area with a radius (centered on the airfield reference point) of 25 nautical GPWS/TAWS Training miles (nm) to 30 nm (45 kilometers to 55 kilometers). This terrain also should be displayed by the visual The rigorous application of standard operating procedures system;

126 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • The capability should be available to insert an “electronic Procedure. The instructor inserts an electronic mountain ahead mountain” from the instructor’s panel at a selected point of the aircraft and talks to the flight crew throughout the ma- on the aircraft’s projected flight path. neuver, insisting on an immediate and aggressive response. Inserting an electronic mountain at an airport that does Ensure proper crew coordination, with the pilot not flying not have such terrain, however, may result in the trainee (PNF) calling radio altitudes and trend (e.g., “300 feet de- dismissing the GPWS/TAWS warning as a spurious creasing”). warning, thus resulting in negative training. The slope and height of the mountain should be Continue the maneuver at maximum performance until the tailored to a particular aircraft at a representative gross mountain is cleared. The duration of the maneuver should be weight (e.g., maximum landing weight [MLW]), so that sufficient for the crew to demonstrate proficiency in maintain- maximum performance is required to avoid striking the ing maximum climb performance. mountain. Repeat the exercise, as needed, until crew proficiency is The slope of the mountain therefore should be adjustable achieved. to match the climb gradients that can be achieved in the pull-up maneuver; and, Debriefing. Review the exercise, as appropriate. • To prevent negative training, the simulator must represent realistically the handling qualities and performance as Pull-up in IMC Exercise airspeed reduces to stick-shaker speed or minimum airspeed. Objective. Reinforce and confirm correct response to aG PWS/ TAWS warning in instrument meteorological conditions (IMC), including pilot technique and crew coordination. Simulator Exercises Briefing. Explain the objective. Although the trainees will All GPWS/TAWS modes should be demonstrated. The objec- know that the exercise is to be conducted, explain that it is tive should be to ensure an understanding of the capabilities intended to simulate an inadvertent descent below minimum and limitations of the GPWS/TAWS installed on the aircraft safe altitude (MSA) because of a loss of situational awareness type. (e.g., because of a lateral navigation error, an incorrect altitude selection or an incorrect nonprecision approach procedure). These exercises can be conducted in either a fixed-base simula- tor (FBS) or a full-flight simulator (FFS). Initial Conditions. Either of the following two scenarios can be used: The following scenarios, to be conducted in an FFS, are designed to increase CFIT awareness and to allow the pilot • Establish initial approach configuration and airspeed, at to practice the correct response to GPWS/TAWS warnings or near the MLW, in a shallow descent or in level flight; without significantly increasing the training time. The scenarios or, should be modified in accordance with the company’s training • Establish landing configuration and approach speed, at requirements or operating environment. or near MLW, on a typical three-degree descent. Pull-up in VMC Exercise Procedure. The instructor inserts an electronic mountain ahead of the aircraft and talks to the flight crew throughout the ma- Objectives. Demonstrate GPWS/TAWS warnings, that a neuver, insisting on an immediate and aggressive response. pull-up maneuver must be immediate, the pull-up technique (with special emphasis on pitch force and attitude) and crew Ensure proper crew coordination, with the PNF calling radio coordination. altitudes and trend (e.g., “300 feet decreasing”). Briefing. Explain the objectives and emphasize that this is a Continue the maneuver at maximum performance until the training exercise. Describe the pull-up technique required for terrain is cleared. The duration of the maneuver should be suf- the particular aircraft type. ficient for the crew to demonstrate proficiency in maintaining the maximum climb performance. Initial Conditions. Establish initial approach configuration and airspeed, at or near the MLW, in a shallow descent or in Repeat the exercise, as needed, until crew proficiency is level flight. achieved.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 127 Debriefing. Review the exercise, as appropriate. • 1.2 — Automation; • 2.3 — Pilot-Controller Communication; Unexpected GPWS/TAWS Warning • 3.1 — Barometric Altimeter and Radio Altimeter; This scenario should be included during a line-oriented flight training (LOFT) session, which normally is programmed at • 3.2 — Altitude Deviations; the end of transition training and during periodic recurrent • 5.2 — Terrain; training LOFT sessions. • 7.1 — Stabilized Approach; Objective. To maintain crew awareness of the CFIT hazard • 7.2 — Constant-angle Nonprecision Approach; and to confirm crew proficiency in responding to a GPWS/ TAWS warning. • 7.3 — Visual References; and, • 7.4 — Visual Approaches.◆ Briefing. None.

Initial Conditions. Establish either initial-approach configu- References ration and airspeed, or clean configuration and maneuvering 1. Terrain awareness and warning system (TAWS) is the speed, at MLW, descending or in level flight. term used by the European Joint Aviation Authorities and the U.S. Federal Aviation Administration to Procedure. The instructor clears the crew to descend to an describe equipment meeting International Civil Aviation altitude below the MSA or provides radar vectors toward Organization standards and recommendations for ground- high terrain. proximity warning system (GPWS) equipment that provides predictive terrain-hazard warnings. “Enhanced If the flight crew takes corrective action before any GPWS/ GPWS” and “ground collision avoidance system” are TAWS warning (as expected), an electronic mountain can be other terms used to describe TAWS equipment. inserted at a later stage in the session. 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Verify crew response to GPWS/TAWS and crew coordination Force Presents Facts About Approach-and-landing and during the pull-up maneuver. Controlled-flight-into-terrain Accidents.” Flight Safety Digest Volume 17 (November–December 1998) and Debriefing. Review the exercise, as appropriate. Volume 18 (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents Summary (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 The following should be emphasized when discussing CFIT kilograms, detailed studies of 76 ALAs and serious awareness and response to a GPWS/TAWS warning: incidents in 1984 through 1997 and audits of about 3,300 flights. • Situational awareness must be maintained at all times; • Preventive actions (ideally) must be taken before a GPWS/TAWS warning; Related Reading from FSF Publications

• Response to a GPWS/TAWS warning by the pilot flying Flight Safety Foundation (FSF) Editorial Staff. “Preparing for (PF) must be immediate; Last-minute Runway Change, Boeing 757 Flight Crew Loses • The PNF must monitor and call the radio altitude and its Situational Awareness, Resulting in Collision with Terrain.” trend throughout the terrain-avoidance maneuver; and, Accident Prevention Volume 54 (July–August 1997).

• The pull-up maneuver must be continued at maximum FSF Editorial Staff. “Unaware That They Have Encountered a climb performance until the warning has ceased and Microburst, DC-9 Flight Crew Executes Standard Go-around; terrain is cleared (radio altimeter). Aircraft Flies Into Terrain.” Accident Prevention Volume 53 (February 1996). The following FSF ALAR Briefing Notes provide information to supplement this discussion: Duke, Thomas A.; FSF Editorial Staff. “Aircraft Descended Below Minimum Sector Altitude and Crew Failed to Respond • 1.1 — Operating Philosophy;

128 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 to GPWS as Chartered Boeing 707 Flew into Mountain in Amendments 1–25. Azores.” Accident Prevention Volume 52 (February 1995). U.S. Federal Aviation Administration. Federal Aviation Regulations. 91.223 “Terrain awareness and warning system,” Regulatory Resources 121.360 “Ground proximity warning-glide slope deviation alerting system,” 121.354 “Terrain awareness and warning International Civil Aviation Organization. International system,” 135.154 “Terrain awareness and warning system. Standards and Recommended Practices, Annex 6 to the Con- March 29, 2000. vention of International Civil Aviation, Operation of Aircraft. Part I, International Commercial Air Transport – Aeroplanes. Joint Aviation Authorities. Joint Aviation Requirements – Chapter 6, “Aeroplane Instruments, Equipment and Flight Operations 1. Commercial Air Transport (Aeroplanes). 1.665 Documents,” 6.15. Appendix 2, “Contents of an Operations “Ground proximity warning system. July 1, 2000. Manual,” 5.23. Seventh edition – July 1998, incorporating

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 129 FSF ALAR Briefing Note 6.4 — Bounce Recovery – Rejected Landing

A rejected landing (also called an aborted landing) is a Preconditions go-around maneuver initiated after touchdown of the main landing gear. A rejected landing is a challenging maneuver Four preconditions (usually referred to as the “four-no rule”) and typically is recommended only when an aircraft bounces must be observed before initiating a touch-and-go: more than approximately five feet (1.5 meters) off the runway after touchdown. • No ground spoilers: – ground spoilers must not be armed or manually No global statistical data are available on rejected-landing selected after touchdown; incidents or accidents. Nevertheless, the following are possible consequences of an incorrect decision to conduct a rejected • No autobrake system: landing: – Autobrakes must not be armed; • Tail strike following a go-around initiated because • No reverse: of directional control difficulties after thrust reverser selection; – Thrust reversers must not be selected upon touchdown; and, • Aircraft performance limitation following the inappropriate selection of reverse thrust during a touch- • No pedal braking: and-go landing and failure of one reverser to stow; – Pedal braking must not be used after touchdown. and, • loss of control following a go-around initiated after The above preconditions show that conducting a rejected thrust reverser selection and failure of one reverser to landing during a nontraining flight (i.e., with ground spoilers stow. and autobrakes armed, and being ready to select reverse thrust upon touchdown) involves an added challenge.

Touch-and-go Training Aircraft Reconfiguration

A touch-and-go landing is a training exercise. Nevertheless, After touchdown during a planned touch-and-go, the aircraft the conditions required for the safe conduct of this maneuver must be reconfigured for the takeoff configuration: provide a valuable introduction to the discussion of bounce • Flaps reset; recovery/rejected landing. • Pitch trim reset; • Rudder trim reset; and,

130 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Throttle-lever “stand-up” (i.e., initial movement of the not increase pitch attitude, because this could lead to a throttle levers to a straight-up position) for symmetric tail strike); engine acceleration. • Continue the landing; Task-sharing • Use power as required to soften the second touchdown; and, Conducting a touch-and-go also is dynamic and demanding • Be aware of the increased landing distance. in terms of task-sharing: • The pilot flying (PF) is responsible for: Recovery From a High Bounce (More Than Five Feet) – Tracking the runway centerline; and, – Advancing initially the throttle levers slightly above When a more severe bounce occurs, do not attempt to land, idle; because the remaining runway may be insufficient for a safe landing. • The pilot not flying (PNF) is responsible for: – Reconfiguring the aircraft for takeoff; The following go-around technique can be applied: – Resetting systems, as required; • Maintain or establish a normal landing pitch attitude; – Monitoring engine parameters and flight-mode • Initiate a go-around by activating the go-around levers/ annunciations; switches and advancing the throttle levers to the go- around thrust position; – Conducting the takeoff calls; • Maintain the landing flaps configuration or set a different – deciding to reject the takeoff, if required; and, flaps configuration, as required by the aircraft operating – Ensuring backup of the PF during rotation and initial manual (AOM)/quick reference handbook (QRH). climb. • Be prepared for a second touchdown; Conducting a rejected landing further amplifies the importance • Be alert to apply forward pressure on the control of adherence to defined task-sharing by the PF and the PNF. column and reset the pitch trim as the engines spool up (particularly with underwing-mounted engines); Bouncing and Bounce Recovery • When safely established in the go-around and when no risk remains of touchdown (steady positive rate of Bouncing during a landing usually is the result of one or more climb), follow normal go-around procedures; and, of the following factors: • Re-engage automation, as desired, to reduce • loss of visual references; workload. • Excessive sink rate; Commitment to a Full-stop Landing • late flare initiation; • Incorrect flare technique; Landing incidents and accidents have demonstrated that after the thrust reversers have been deployed (even at reverse idle), • Excessive airspeed; and/or, the landing must be completed to a full stop because a suc- • Power-on touchdown (preventing the automatic extension cessful go-around may not be possible. of ground spoilers, as applicable). The following occurrences have resulted in a significantly The bounce-recovery technique varies with each aircraft type reduced rate of climb or in departure from controlled flight: and with the height reached during the bounce. • Thrust asymmetry resulting from asymmetric engine spool-up (i.e., asymmetric engine acceleration Recovery From a Light Bounce (Five Feet or Less) characteristics as thrust increases from a ground-idle level); When a light bounce occurs, a typical recovery technique can be applied: • Thrust asymmetry resulting from asymmetric stowing of thrust reversers (i.e., one reverser going to the stowed • Maintain or regain a normal landing pitch attitude (do position faster than the other); and,

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 131 • Severe thrust asymmetry resulting from one thrust be incorporated in the standard operating procedures (SOPs)/ reverser failing to stow. supplementary techniques of each AOM/QRH.

The following FSF ALAR Briefing Notes provide information Commitment to Go Around to supplement this discussion:

If a go-around is elected, the flight crew must be committed • 6.1 — Being Prepared to Go Around; to conduct the go-around. The crew must not change the go- around decision and must not retard the throttle levers in an • 7.1 —Stabilized Approach; and, attempt to complete the landing. • 8.1 — Runway Excursions and Runway Overruns.◆

Such a change of decision usually is observed when the deci- sion to reject the landing and the go-around are initiated by the Related Reading From FSF Publications first officer (as PF) but are overridden by the captain. FSF Editorial Staff. “Airplane’s Low-energy Condition and Runway overruns, collisions with obstructions and major air- Degraded Wing Performance Cited in Unsuccessful Go–around craft damage (or postimpact fire) often are the consequences Attempt.” Accident Prevention Volume 56 (July 1999). of landing after a go-around is initiated. FSF Editorial Staff. “Attempted Go-around with Deployed Thrust Reversers Leads to Learjet Accident.” Accident Preven- Summary tion Volume 56 (January 1999).

The flight crew should adhere to decision criteria for: Flight Safety Foundation (FSF). “Killers in Aviation: FSF • Committing to a full-stop landing; or, Task Force Presents Facts about Approach-and-landing and Controlled-flight-into-terrain Accidents.”Flight Safety Digest • Committing to a rejected landing and a go-around. Volume 17–18 (November–December 1998, January–February 1999). These criteria (adapted for each individual aircraft type) should

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

132 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 7.1 — Stabilized Approach

Unstabilized approaches are frequent factors in approach-and- causal factor in 45 percent of the 76 approach-and-landing landing accidents (ALAs), including those involving controlled accidents and serious incidents. flight into terrain (CFIT). The task force said that flight-handling difficulties occurred in Unstabilized approaches are often the result of a flight crew situations that included rushing approaches, attempts to comply who conducted the approach without sufficient time to: with demanding ATC clearances, adverse wind conditions and improper use of automation. • Plan; • Prepare; and, Definition • Conduct a stabilized approach. An approach is stabilized only if all the criteria in company standard operating procedures (SOPs) are met before or when Statistical Data reaching the applicable minimum stabilization height.

The Flight Safety Foundation Approach-and-landing Accident Table 1 shows stabilized approach criteria recommended by Reduction (ALAR) Task Force found that unstabilized ap- the FSF ALAR Task Force. proaches (i.e., approaches conducted either low/slow or high/ fast) were a causal factor1 in 66 percent of 76 approach-and- Note: Flying a stabilized approach that meets the recom- landing accidents and serious incidents worldwide in 1984 mended criteria discussed below does not preclude flying a through 1997.2 delayed-flaps approach (also referred to as a decelerated ap- proach) to comply with air traffic control (ATC) instructions. The task force said that although some low-energy approaches (i.e., low/slow) resulted in loss of aircraft control, most involved The following minimum stabilization heights are recom- CFIT because of inadequate vertical-position awareness. mended to achieve a stabilized approach: • 1,000 feet above airport elevation in instrument The task force said that the high-energy approaches (i.e., high/ meteorological conditions (IMC); or, fast) resulted in loss of aircraft control, runway overruns and runway excursions, and contributed to inadequate situational • 500 feet above airport elevation in visual meteorological awareness in some CFIT accidents. conditions (VMC).

The task force also found that flight-handling difficulties (i.e., At the minimum stabilization height and below, a call should the crew’s inability to control the aircraft to the desired flight be made by the pilot not flying (PNF) if any flight parameter parameters [e.g., airspeed, altitude, rate of descent]) were a exceeds criteria shown in Table 1.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 133 • Airspeed awareness, by monitoring airspeed trends; and, Table 1 Recommended Elements • Energy-condition awareness, by maintaining the engine thrust at the level required to fly a three-degree approach Of a Stabilized Approach path at the target final approach speed (or at the minimum All flights must be stabilized by 1,000 feet above groundspeed, as applicable). This also enhances go- airport elevation in instrument meteorological conditions around capability. (IMC) or by 500 feet above airport elevation in visual meteorological conditions (VMC). An approach is stabi- lized when all of the following criteria are met: In addition, a stabilized approach provides: 1. The aircraft is on the correct flight path; • More time and attention for monitoring ATC 2. Only small changes in heading/pitch are required to communications, weather conditions and systems maintain the correct flight path; operation; 3. The aircraft speed is not more than V + 20 knots REF • More time for monitoring and backup by the PNF; indicated airspeed and not less than VREF; 4. The aircraft is in the correct landing configuration; • defined flight-parameter-deviation limits and minimum 5. Sink rate is no greater than 1,000 feet per minute; if stabilization heights to support the decision to land or an approach requires a sink rate greater than 1,000 to go around; and, feet per minute, a special briefing should be con- ducted; • landing performance consistent with published 6. Power setting is appropriate for the aircraft configura- performance. tion and is not below the minimum power for approach as defined by the aircraft operating manual; 7. All briefings and checklists have been conducted; Factors in Unstabilized Approaches 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system Unstabilized approaches are attributed to: (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Cat- • Fatigue; egory III ILS approach must be flown within the ex- • Pressure of flight schedule (making up for delays); panded localizer band; during a circling approach, wings should be level on final when the aircraft • Any crew-induced or ATC-induced circumstances reaches 300 feet above airport elevation; and, resulting in insufficient time to plan, prepare and conduct 9. Unique approach procedures or abnormal conditions a safe approach. This includes accepting requests from requiring a deviation from the above elements of a stabilized approach require a special briefing. ATC to fly higher/faster or to fly shorter routings than desired; An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet • ATC instructions that result in flying too high/too fast above airport elevation in VMC requires an immediate during the initial approach; go-around. Source: Flight Safety Foundation Approach-and-landing Accident • Excessive altitude or excessive airspeed (e.g., inadequate Reduction (ALAR) Task Force (V1.1 November 2000) energy management) early in the approach; • late runway change (lack of ATC awareness of the time required by the flight crew to reconfigure the aircraft for Any time an approach is not stabilized at the minimum stabi- a new approach); lization height or becomes unstabilized below the minimum stabilization height, a go-around should be conducted. • Excessive head-down work (e.g., flight management system [FMS] reprogramming);

Benefits of a Stabilized Approach • Short outbound leg or short downwind leg (e.g., because of traffic in the area); Conducting a stabilized approach increases the flight crew’s • late takeover from automation (e.g., because the overall situational awareness, including: autopilot [AP] fails to capture the glideslope); • horizontal awareness, by closely monitoring the • Premature descent or late descent caused by failure to horizontal flight path; positively identify the final approach fix (FAF); • Vertical awareness, by monitoring the vertical flight path • Inadequate awareness of wind conditions, including: and the rate of descent;

134 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 – Tail wind component; minimum stabilization height: – low-altitude wind shear; – Excessive airspeed; – local wind gradient and turbulence (because of – Not aligned with runway; terrain or buildings); or, – Excessive bank angle; – Recent weather along the final approach path (e.g., – Excessive vertical speed; or, wind shift or downdrafts caused by a descending cold air mass following a rain shower); – Flight path above glideslope; • Incorrect anticipation of aircraft deceleration • Excessive bank angle, excessive sink rate or excessive characteristics in level flight or on a three-degree glide maneuvering while conducting a side-step maneuver; path; • Speed brakes remain extended on short-final • Failure to recognize deviations or failure to adhere to approach; the excessive-parameter-deviation limits; • Excessive flight-parameter deviation down to runway • Belief that the aircraft will be stabilized at the minimum threshold; stabilization height or shortly thereafter; • high at runway threshold crossing (i.e., more than 50 • Excessive confidence by the PNF that the pilot flying feet above threshold); and, (PF) will achieve a timely stabilization; • Extended flare and extended touchdown. • PF-PNF too reliant on each other to call excessive deviations or to call for a go-around; and, Company Accident-prevention Strategies • Visual illusions. and Personal Lines of Defense

Deviations in Unstabilized Approaches Preventing unstabilized approaches can be achieved by devel- oping recommendations for the early detection and correction One or more of the following deviations often are involved in of factors that contribute to an unstabilized approach. unstabilized approaches: The following strategy is recommended: • Entire approach flown at idle thrust down to touchdown, because of excessive airspeed and/or excessive altitude • Anticipate; from early in the approach; • detect; • Steep approach (above desired flight path with excessive • Correct; and, vertical speed). Steep approaches are conducted typically twice as often as shallow approaches; • decide.

• Shallow approach (below desired glide path); Anticipate • low-airspeed maneuvering (energy deficit); Some factors likely to result in an unstabilized approach can be • Excessive bank angle when capturing the final approach anticipated. For example, pilots and controllers should avoid course; situations that result in rushing approaches.

• Activation of the ground-proximity warning system The approach briefing provides opportunities to identify and (GPWS) or the terrain awareness and warning system discuss factors such as nonstandard altitude, airspeed restric- 3 (TAWS) : tions and energy management. The flight crew should agree – Mode 1: “sink rate”; on the management of the descent, deceleration and stabiliza- tion. This agreement will constitute a common objective for – Mode 2A: “terrain” (not full flaps); or, the PF and PNF. – Mode 2B: “terrain” (full flaps); Detect • late extension of flaps, or flaps-load-relief-system activation resulting in the late extension of flaps; The purpose of defined excessive-parameter-deviation limits • Excessive flight-parameter deviation when crossing the and minimum stabilization heights is to provide the PF and

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 135 PNF with a common reference for effective monitoring (early • Inadequate preparation or lack of commitment to detection of deviations) and backup (timely and precise calls conduct a go-around. A change of mindset should take for effective corrections). place from “we will land unless …” to “let’s be prepared for a go-around, and we will land if the approach is To ensure monitoring and backup, the following should be stabilized and if we have sufficient visual references to avoided: make a safe approach and landing”; and, • late briefings; • Absence of decision making (failure to remember the applicable excessive-deviation limits) because of fatigue • Unnecessary radio calls (e.g., company calls); or workload. • Unnecessary actions (e.g., use of airborne communications addressing and reporting system [ACARS]); and, Achieving Flight Parameters • Nonpertinent conversations on the flight deck (i.e., breaking the “sterile cockpit rule”4). The flight crew must “stay ahead of the aircraft” throughout the flight. This includes achieving desired flight parameters Reducing workload and flight deck interruptions/distractions (e.g., aircraft configuration, aircraft position, energy condition, also allows the flight crew to: track, vertical speed, altitude, airspeed and attitude) during the • Better cope with fatigue; descent, approach and landing. Any indication that a desired flight parameter will not be achieved should prompt immediate • Comply with an unexpected ATC request (e.g., runway corrective action or the decision to go around. change); 5 • Adapt to changing weather conditions; and, The minimum stabilization height constitutes an approach gate on the final approach; a go-around must be initiated if: • Manage a system malfunction (e.g., flaps jamming or landing gear failing to extend). • The required configuration and airspeed are not established, or the flight path is not stabilized when Correct reaching the minimum stabilization height; or,

Positive corrective actions should be taken before deviations • The aircraft becomes unstabilized below the minimum develop into a challenging situation or a hazardous situation stabilization height. in which the only safe action is a go-around. Transition to Visual Flying Corrective actions may include: • The timely use of speed brakes or landing gear to correct When transitioning from instrument flight to visual flight, excessive height or excessive airspeed; and, the pilot’s perception of the runway and outside environment should be kept constant by maintaining: • Extending the outbound leg or downwind leg. • drift correction, to continue tracking the runway Decide centerline (i.e., resisting the tendency to align the aircraft with the runway centerline); If the approach is not stabilized before reaching the minimum stabilization height, or if any flight parameter exceeds deviation • The aiming point, to remain on the correct glide path limits (other than transiently) when below the minimum stabi- until flare height (resisting the tendency to advance the lization height, a go-around must be conducted immediately. aiming point and, thus, descend below the correct glide path); and, The following behaviors often are involved when unstabilized • The final approach speed to maintain the energy approaches are continued: condition. • Excessive confidence in a quick recovery (postponing the go-around decision when flight parameters are Summary converging toward excessive-deviation limits); Three essential parameters must be stabilized for a safe ap- • Excessive confidence because of a long-and-dry runway proach: and a low gross weight, although airspeed or vertical speed may be excessive; • Aircraft track;

136 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Flight path angle; and, command permit, any activity during a critical phase of flight which could distract any flight crewmember • Airspeed. from the performance of his or her duties or which could interfere in any way with the proper conduct of Depending on the type of approach and aircraft equipment, those duties. Activities such as eating meals, engaging the most appropriate level of automation, as well as available in nonessential conversations within the cockpit and visual references, should be used to establish and to monitor nonessential communications between the cabin and the stabilization of the aircraft. cockpit crews, and reading publications not related to the proper conduct of the flight are not required for the safe The following FSF ALAR Briefing Notes provide information operation of the aircraft. For the purposes of this section, to supplement this discussion: critical phases of flight include all ground operations • 4.1 — Descent-and-approach Profile Management; involving taxi, takeoff and landing, and all other flight • 4.2 — Energy Management; operations below 10,000 feet, except cruise flight.” [The FSF ALAR Task Force says that “10,000 feet” should be • 6.1 — Being Prepared to Go Around; height above ground level during flight operations over • 7.2 —Constant-angle Nonprecision Approach; high terrain.] • 8.2 — The Final Approach Speed; and, 5. The FSF ALAR Task Force defines approach gate as “a point in space (1,000 feet above airport elevation in • 8.3 — Landing Distances.◆ instrument meteorological conditions or 500 feet above airport elevation in visual meteorological conditions) at References which a go-around is required if the aircraft does not meet defined stabilized approach criteria.” 1. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force defines causal Related Reading From FSF Publications factor as “an event or item judged to be directly instrumental in the causal chain of events leading to the accident [or Flight Safety Foundation (FSF) Editorial Staff. “ATR 42 Strikes incident].” Each accident and incident in the study sample Mountain on Approach in Poor Visibility to Pristina, Kosovo.” involved several causal factors. Accident Prevention Volume 57 (October 2000). 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and FSF Editorial Staff. “Learjet Strikes Terrain When Crew Tracks Controlled-flight-into-terrain Accidents.” Flight Safety False Glideslope Indication and Continues Descent Below Digest Volume 17 (November–December 1998) and Published Decision Height.” Accident Prevention Volume 56 Volume 18 (January–February 1999): 1–121. The facts (June 1999). presented by the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents FSF Editorial Staff. “Boeing 767 Descends Below Glide Path, (ALAs) that occurred in 1980 through 1996 involving Strikes Tail on Landing.” Accident Prevention Volume 55 turbine aircraft weighing more than 12,500 pounds/5,700 (February 1998). kilograms, detailed studies of 76 ALAs and serious incidents in 1984 through 1997 and audits of about 3,300 FSF Editorial Staff. “MD-88 Strikes Approach Light Struc- flights. ture in Nonfatal Accident.” Accident Prevention Volume 54 (December 1997). 3. Terrain awareness and warning system (TAWS) is the term used by the European Joint Aviation Authorities FSF Editorial Staff. “During Nonprecision Approach at Night, and the U.S. Federal Aviation Administration to MD-83 Descends Below Minimum Descent Altitude and Con- describe equipment meeting International Civil Aviation tacts Trees, Resulting in Engine Flame-out and Touchdown Organization standards and recommendations for ground- Short of Runway.” Accident Prevention Volume 54 (April proximity warning system (GPWS) equipment that 1997). provides predictive terrain-hazard warnings. “Enhanced GPWS” and “ground collision avoidance system” are FSF Editorial Staff. “Commuter Captain Fails to Follow other terms used to describe TAWS equipment. Emergency Procedures After Suspected Engine Failure, Loses Control of the Aircraft During Instrument Approach.” Accident 4. The sterile cockpit rule refers to U.S. Federal Aviation Prevention Volume 53 (April 1996). Regulations Part 121.542, which states: “No flight crewmember may engage in, nor may any pilot-in-

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 137 FSF Editorial Staff. “Captain’s Inadequate Use of Flight Con- (December 1992). trols During Single-engine Approach and Go-around Results in Loss of Control and Crash of Commuter.” Accident Prevention FSF. ”Head-up Guidance System Technology (HGST) — A Volume 52 (November 1995). Powerful Tool for Accident Prevention.” Flight Safety Digest Volume 10 (September 1991). FSF Editorial Staff. “Poorly Flown Approach in Fog Results in Collision With Terrain Short of Runway.” Accident Prevention Volume 52 (August 1995). Regulatory Resources

FSF Editorial Staff. “Captain’s Failure to Establish Stabilized International Civil Aviation Organization (ICAO). International Approach Results in Controlled-flight-into-terrain Commuter Standards and Recommended Practices, Annex 6 to the Conven- Accident.” Accident Prevention Volume 52 (July 1995). tion of International Civil Aviation, Operation of Aircraft. Part I, International Commercial Air Transport – Aeroplanes. Appendix Lawton, Russell. “Steep Turn by Captain During Approach 2, “Contents of an Operations Manual,” 5.18, 5.19. Seventh Results in Stall and Crash of DC-8 Freighter.” Accident Pre- edition – July 1998, incorporating Amendments 1–25. vention Volume 51 (October 1994). ICAO. Preparation of an Operations Manual. Second edi- tion – 1997. Lawton, Russell. “Breakdown in Coordination by Commuter Crew During Unstabilized Approach Results in Controlled- U.S. Federal Aviation Administration. Air Transportation flight-into-terrain Accident.”Accident Prevention Volume 51 Operations Inspector’s Handbook. Volume 4, “Aircraft Equip- (September 1994). ment and Operational Authorizations.” Chapter 2, “All-weather Terminal Area Operations,” Section 3, “Factors Affecting FSF Editorial Staff. “Unstabilized Approach, Icing Conditions All-Weather Terminal Area Operations.” August 26, 1998, Lead to Commuter Tragedy.” Accident Prevention Volume 49 incorporating changes 1–12.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

138 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 7.2 — Constant-angle Nonprecision Approach Planning and conducting a nonprecision approach are chal- Statistical Data lenging tasks that involve: • decision making on strategies and options; The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force found that CFIT was involved • Task-sharing; in 37 percent of 76 approach-and-landing accidents and seri- • Crew resource management (e.g., crew coordination, ous incidents worldwide in 1984 through 1997, and that 57 cross-check and backup); and, percent of the CFIT accidents and incidents occurred during step-down nonprecision approaches.3 • Controlled-flight-into-terrain (CFIT) risk awareness (e.g., awareness of the requirement for immediate The task force recommended expedited implementation response to a ground-proximity warning system [GPWS] worldwide of constant-angle nonprecision approach (CANPA) warning or a terrain awareness and warning system procedures and training flight crews to properly use such [TAWS]1 warning). procedures.

Nonprecision approaches have common features but require approach-specific techniques, depending on the navaids being Definition used or on the strategy being used for: A nonprecision approach is an instrument approach that does • lateral navigation and vertical navigation; not incorporate vertical guidance (i.e., no glideslope). • descent from the final approach fix (FAF) to the minimum descent altitude/height (MDA[H]); and, This discussion will include nonprecision instrument ap- proaches that use the following navaids: nondirectional beacon • decision making before or upon reaching the (NDB), very-high-frequency omnidirectional radio (VOR), MDA(H). localizer (LOC), VOR-DME (distance-measuring equipment), LOC-DME and LOC back course (BC). Note: The charted MDA(H) is referenced either to the touch- down zone elevation (TDZE) or to the airport elevation, which Instrument approaches normally include three approach seg- is the highest point in the landing area. The International Civil ments: Aviation Organization (ICAO) defines MDA(H) as: obstacle clearance altitude/height (OCA[H]) plus 30 feet.2 • Initial approach: – Beginning at an initial approach fix (IAF) and ending at the intermediate fix (IF), if defined; and,

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 139 – Beginning at an initial approach fix (IAF) and ending The VDP location is defined by: at the intermediate fix (IF), if defined; and, • Distance from a VOR-DME or LOC-DME; or, – With obstacle clearance of 1,000 feet; The VDP location is defined by: – With obstacle clearance of 1,000 feet; • Time from the FAF. • Intermediate approach: • distance from a VOR-DME or LOC-DME; or, • Intermediate approach: The VDP should be considered the last point from which a – From the IF to the final approach fix (FAF); and, • Time from the FAF. – From the IF to the final approach fix (FAF); and, stabilized approach can be conducted (Table 1). – With obstacle clearance of 500 feet; and, – With obstacle clearance of 500 feet; and, The VDP should be considered the last point from which a stabilizedCANPA approach Benefits can be conducted (Table 1). • Final approach: – From the FAF to the MMDA(H),DA(H), visual descent point CANPATraditional Benefitsstep-down approaches are based on an obstacle- (VDP)(VDP) or missed approach point (MAP); and, clearance profile; such approaches are not optimum for modern Traditionalturbine aircraft step-down and turboprop approaches aircraft. are based on an obstacle- – With obstacle clearance of 250 feet. clearance profile; such approaches are not optimum for modern turbine aircraft and turboprop aircraft. DDuringuring the intermediate approach, the aircraft is configured for the final approach as follows: Table 1 for the final approach as follows: Recommended Elements • Configuration establishedestablished (landing(landing flapsflaps and and landing landing Of a Stabilized Approach gear extended); All flights must be stabilized by 1,000 feet above • Airspeed stabilized at the final approachapproach speed;speed; Table 1 airport elevationRecommended in instrument meteorologicalElements • Aircraft aligned with the final approach course; and, conditions (IMC) and by 500 feet above airport • Aircraft aligned with the final approach course; and, elevationOf in visuala Stabilized meteorological Approach conditions (VMC). • Landinglanding checklist and briefings completed.completed. An approach is stabilized when all of the following Allcriteria flights are must met :be stabilized by 1,000 feet above a1.irport The elevation aircraft isin oninstrument the correct meteorological flight path; conditions The CANPA final approach approach features features a aconstant-angle constant-angle descentdescent (IMC) or by 500 feet above airport elevation in visual using the vertical-speed mode or the flightflight-path path vectorvector (as(as meteorological2. Only small conditionschanges in (VMC). heading/pitch An approach are required is stabi to- maintain the correct flight path; available), with altitude-distance checks. lized when all of the following criteria are met: 1.3. The The aircraft aircraft is speed on the is correct not more flight than path; VREF + 20 knots 2. Onlyindicated small airspeedchanges andin heading/pitch not less than are VREF required; to VDP Concept 4.maintain The aircraft the correctis in the flight correct path; landing configuration;

3.5. The Sink aircraft rate is speed no greater is not than more 1,000 than feetVREF per + 20 minute; knots if The VDPVDP isis the the location location at atthe the MDA(H) MDA(H where) where the theaircraft aircraft can indicatedan approach airspeed requires and anot sink less rate than greater VREF; than 1,000 canbe flown be flown on approximately on approximately a three-degree a three-degree glide glidepath pathto the to 4. Thefeet aircraft per minute, is in thea special correct briefing landing should configuration; be therunway runway (Figure (Figure 1). 1). 5. Sinkconducted; rate is no greater than 1,000 feet per minute; if 6.an Power approach setting requires is appropriate a sink rate for thegreater aircraft than 1,000 feetconfiguration per minute, and a special is not below briefing the shouldminimum be powercon- ducted;for approach as defined by the aircraft operating Visual Descent Point Provides 6. Powermanual; setting is appropriate for the aircraft configura- 7.tion All briefingsand is not and below checklists the minimum have powerbeen conducted;for approach Normal Descent to Runway as defined by the aircraft operating manual; 8. Specific types of approaches are stabilized if they 7. Allalso briefings fulfill the and following: checklists instrument have been landing conducted; system 8. Specific(ILS) approaches types of approachesmust be flown are withinstabilized one ifdot they of alsothe glideslopefulfill the following: and localizer; instrument a Category landing II orsystem Category III ILS approach must be flown within the Decision Go-around (ILS) approaches must be flown within one dot of theexpanded glideslope localizer and localizer; band; during a Category a circling II or Cat- egoryapproach, III ILS wings approach should must be belevel flown on final within when the theex- V M pandedaircraft localizerreaches band;300 feet during above a circlingairport approach,elevation; MDA(H) wingsand, should be level on final when the aircraft Land 9.reaches Unique approach300 feet above procedures airport or elevation; abnormal and, FAF VDP MAP 9. Uniqueconditions approach requiring procedures a deviation or abnormalfrom the aboveconditions requiringelements a ofdeviation a stabilized from approach the above require elements a special of a stabilizedbriefing. approach require a special briefing. FAF = Final approach fix An approach that becomes unstabilized below 1,000 MDA(H) = Minimum descent altitude/height An approach that becomes unstabilized below 1,000 feet above airport elevation in IMC or below 500 feet VDP = Visual descent point feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate MAP = Missed approach point above airport elevation in VMC requires an immediate go-around.go-around. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force Source:Source: Flight Flight Safety Safety Foundation Foundation Approach-and-landing Approach-and-landing Accident Accident ReductionReduction (ALAR) (ALAR) Task Task Force Force (V1.1 (V1.1 November November 2000) 2000) Figure 1

140 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 140 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Flying a constant-angle approach profile: The autothrottle system should remain in the “speed” mode. • Provides a more stabilized flight path; • Reduces workload; and, CFIT Awareness

• Reduces the risk of error. During the final descent to the MDA(H), both pilots must monitor the flight path to ensure that descent is not continued Strategies and Options through a charted step-down altitude before reaching the as- sociated charted fix (DME distance or other reference). Planning for a nonprecision approach requires several decisions A GPWS/TAWS warning in instrument meteorological condi- on the following strategies and options: tions (IMC) or night conditions demands an immediate pull-up • lateral navigation: maneuver. – Use of selected modes (heading or localizer); or, Descending Below MDA(H) – Use of the flight management system (FMS) lateral- navigation (LNAV) mode down to MDA(H) or until During a nonprecision approach, the pilot flying (PF) is either LOC interception; hand flying the aircraft or supervising AP operation; the pilot • Vertical navigation: not flying (PNF) is responsible for acquiring and calling out the visual references. – Use of selected modes (altitude hold and vertical speed); or, Continuing the approach below the MDA(H) is permitted only – Use of the FMS vertical-navigation (VNAV) if at least one of the required visual references is distinctly mode down to the FAF (or beyond, as applicable visible and identifiable by the PF. in accordance with the aircraft operating manual [AOM]/quick reference handbook [QRH]), and use of A nonprecision approach is completed visually with a hand the vertical-speed mode down to the MDA(H); and, flown landing, or a go-around is conducted. • Final descent from the FAF: SOPs and Standard Calls – Constant-angle descent with the decision made before or upon reaching MDA(H). Task-sharing, standard calls and altitude-deviation and The requirement to make the final-descent decision parameter-deviation calls are especially important during a before or upon reaching the MDA(H) depends upon nonprecision approach. applicable operating regulations about descent below the MDA(H) during a go-around maneuver. The The following overview outlines the actions and standard CANPA MDA(H) may be considered a DA(H) only calls required by standard operating procedures (SOPs) and if the approach has been surveyed and approved by illustrates the typical phases of the approach and the sequence the appropriate regulatory authorities. of decisions involved in a nonprecision approach.

A nonprecision approach may be conducted using either: Descent/Approach Preparation • lateral-navigation guidance, with monitoring of raw • Anticipate and confirm the runway in use and the type data4; of approach to be conducted; • Raw data only; • define the approach strategy for lateral navigation: • Flight path director, with or without the autopilot (AP) – Select heading mode and raw data (or VOR mode, if engaged; or, allowed for navigation in terminal areas); or, • Raw data supported by the flight path vector (as available – Select FMS LNAV mode with monitoring of raw on the primary flight display [PFD] or head-up display data, provided that the approach is defined in the [HUD]). FMS navigation database and that FMS navigation accuracy meets the criteria for approach; A nonprecision approach may be conducted with the AP • define the approach strategy for vertical navigation: engaged.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 141 – Vertical-speed mode; or, Before Reaching the IAF/Holding Fix – FMS VNAV mode down to the FAF (or beyond, as • Keep the AP engaged with FMS or selected lateral- applicable, in accordance with the AOM/QRH), then navigation mode and vertical-navigation mode, as vertical-speed mode down to the MDA(H); desired; • Insert the desired standard terminal arrival (STAR) and • Keep both navigation displays (NDs) in “MAP” mode approach (from the database) in the FMS flight plan; (unless FMS navigation accuracy is greater than one nautical mile [nm], or per applicable SOPs); • Enter the descent winds and surface winds on the appropriate FMS page, as applicable; • If the FMS LNAV mode is used: • Enter the landing configuration and wind correction on – Check the FMS navigation accuracy level (e.g., “R/I” the appropriate FMS page, as applicable; or “HIGH” or […], depending on the FMS type and standard); • If the VNAV mode is authorized after the FAF, enter the MDA(H) on the appropriate FMS page, as applicable; – Check the NDs for correct flight plan and for correct “TO WPT”; • Set up navaids (identify, as required); and, – Confirm that the FMS LNAV mode is shown on the • Plan the descent to reach the IAF at the prescribed flight-mode annunciator (FMA); and, altitude and planned airspeed. – Maintain both NDs in “MAP” mode (in accordance Approach Briefing with the AOM/QRH); • Check FMS navigation accuracy (usually by ensuring • Adjust the descent rate to reach the IAF at the charted/ that the FMS bearing/distance to a tuned VOR-DME prescribed altitude and target airspeed; and the radio magnetic indicator [RMI] raw data agree • Establish the desired configuration (clean or slats according to criteria defined in SOPs) and confirm extended) and airspeed; and, strategies for lateral navigation and vertical navigation (i.e., FMS or selected guidance); • Adjust weather radar gain and tilt, as applicable, for optimum use of the system for weather avoidance or • Review terrain features, location of obstacles and enhanced horizontal situational awareness. obstacle clearances; • Confirm the minimum safe altitude (MSA); Upon Reaching the IAF or Holding Fix • Review the approach procedure (altitudes, bearings and • If the FMS LNAV mode will be used beyond the IAF or headings); holding fix, keep both NDs in “MAP” mode if the FMS is certified as “sole means of navigation for approach” — • Review the approach vertical profile (step-down otherwise, one ND must be used to monitor raw data; altitudes) and MDA(H); • If selected heading mode or localizer mode will be used • Set and check the MDA(H) on the barometric-altimeter to capture and to track the final approach course, set bug; the PF’s ND to the arc or horizontal situation indicator • Review the expected visual references (approach (HSI)-type display; and, lighting and runway lighting); • The PNF may keep the ND in “MAP” mode (with display • Review the missed approach procedure; of airspeed and altitude restrictions) for situational awareness. • Confirm the timing from the FAF to the MAP or to the VDP, or confirm the DME reading for the VDP; While Holding or When Appropriate • Confirm the navaids (frequencies, courses and identifications); Configure the aircraft (slats extended only or approach flaps) and establish the associated maneuvering speed. • Compute the expected groundspeed; Exiting the Holding Pattern • Confirm the published vertical speed or computed vertical speed for the final descent; and, Select the holding “EXIT” prompt to allow the correct sequenc- • Confirm use of the flight director (FD) or the flight path ing of the FMS flight plan. director (as applicable).

142 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 After Leaving the Holding Pattern • Enter the published (or computed) vertical speed, as a function of the groundspeed; • If the FMS LNAV mode is not used, use the selected heading mode (or the VOR mode, if allowed for terminal • Select the flight path vector display (as available); area navigation; or the track mode, as available) to • Start timing (as required); and, intercept the final approach course, as follows: • Cross-check and call the next fix (or DME distance, as – For an NDB approach, set the final approach course applicable) and crossing altitude. on the ILS course selector; this will set the ILS course pointer on the ND and provide a course reference; During the Descent to the MDA(H) – For a VOR or VOR-DME approach, set the final • Monitor the raw data (vertical speed, flight path vector approach course on the VOR course selector, but do [as available], course, distances, altitudes) and call the not arm the VOR mode. Capture and track the VOR vertical profile for correct slope and track (i.e., at each course using the selected heading/track mode; or, altitude/distance check): – For a LOC or LOC-DME approach, set the final – Cross-check and call the altitude deviation; approach course on the ILS course selector and arm the localizer mode; and, – Adjust vertical speed, as required; and, • To prepare for re-engaging the LNAV mode for a go- – Call the next fix (or DME distance) and crossing around, check the correct FMS flight plan sequencing altitude; and, (the “TO WPT” must be the FAF; if not, program a “DIR • Set the altitude selector per applicable SOPs (usually, TO” the FAF). the go-around altitude). Before Reaching the FAF Approaching the MDA(H) • Align the aircraft within five degrees of the final approach course; At an altitude corresponding to the MDA(H) plus 1/10 the rate of descent (typically MDA[H] plus 50 feet to 100 feet), • Extend the landing gear; anticipate a go-around decision to avoid descent below the • Arm the ground spoilers; MDA(H), as required by applicable regulations. • Set landing flaps; At the MDA(H) • Enter the target final approach speed; If adequate visual references are acquired: • Set the go-around altitude (if the go-around altitude is the same as the FAF crossing altitude, set the go-around • disconnect the AP and continue the approach visually altitude only after beginning the final descent); (the autothrottles may remain engaged in speed mode down to the retard point, as applicable). • Conduct the “LANDING” checklist; • If the FMS VNAV mode will be used after the FAF, enter If adequate visual references are not acquired: the published or computed vertical speed and course; • Initiate a go-around climb; and, • If the flight path vector will be used after the FAF (as • overfly the MAP (to guarantee obstacle clearance during available on the PFD or HUD), enter the published or the go-around) and fly the published missed approach computed flight path angle and track; and, procedure. • If the VNAV mode is not authorized beyond the FAF, deselect the VNAV mode by selecting the altitude-hold (ICAO says that although the flight crew should overfly the mode or the vertical-speed mode, as required. MAP before conducting the published missed approach pro- cedure, “this does not preclude flying over the [MAP] at an Approaching the FAF altitude/height greater than that required by the procedure” [as shown in Figure 1].) 5 Typically 0.3 nautical mile (nm) to 0.2 nm before reaching the FAF, to begin descent at the FAF on profile: Nonprecision Approach Factors • Engage the VNAV mode and check mode engagement on the FMA; Training feedback and line-operations experience have shown

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 143 that the nonprecision approach is affected by: final descent; • Incorrect or outdated instrument approach chart; • Beginning the descent at the correct point; • late descent preparation; • Maintaining the correct flight path angle (vertical speed) during the final descent; • FMS navigation accuracy not checked; • Acquiring visual references and making the decision to • FMS flight plan not correctly programmed; land; and, • Failure to monitor raw data; • Preparing for a go-around. • Navaids not tuned correctly (frequency or course); The following FSF ALAR Briefing Notes provide information • Incomplete briefing; to supplement this discussion: • Incorrect choice of autopilot modes; • 1.1 — Operating Philosophy; • Incorrect entry of autopilot targets (e.g., airspeed, • 1.4 — Standard Calls; heading, altitude) or autothrottle targets; • 1.6 — Approach Briefing; • Inadequate cross-check and backup by the PF/PNF; • 4.2 — Energy Management; • Inaccurate tracking of the final approach course, using the selected heading (or track) mode; • 7.1 —Stabilized Approach; and, • late configuration of aircraft; • 7.3 — Visual References.◆ • Final approach speed not stabilized at FAF; • Failure to include prevailing head wind component in References computing the vertical speed for the final constant-angle 1. Terrain awareness and warning system (TAWS) is the descent; term used by the European Joint Aviation Authorities • No timing or positive identification of the VDP or and the U.S. Federal Aviation Administration to MAP; describe equipment meeting International Civil Aviation Organization standards and recommendations for ground- • Inadequate monitoring of raw data; proximity warning system (GPWS) equipment that • Incorrect identification of the FAF; provides predictive terrain-hazard warnings. “Enhanced GPWS” and “ground collision avoidance system” are • go-around altitude not entered; and, other terms used to describe TAWS equipment. • Premature descent to the next step-down altitude (if 2. International Civil Aviation Organization (ICAO). multiple step-downs) or below the MDA(H). Procedures for Air Navigation Services. Aircraft Operations. Volume I, Flight Procedures. Fourth edition, Summary 1993. Reprinted May 2000, incorporating Amendments 1–10. Successful nonprecision approaches include: 3. Flight Safety Foundation. “Killers in Aviation: FSF Task • determining the type of guidance to be used; Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety • Preparing the FMS, as applicable; Digest Volume 17 (November–December 1998) and • Completing an approach briefing; Volume 18 (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on • Planning aircraft configuration setup; analyses of 287 fatal approach-and-landing accidents • Monitoring descent; (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing more than 12,500 pounds/5,700 • Managing aircraft energy condition during intermediate kilograms, detailed studies of 76 ALAs and serious approach and final approach; incidents in 1984 through 1997 and audits of about 3,300 • Not descending below an altitude before reaching the flights. associated fix; 4. The Flight Safety Foundation Approach-and-landing • determining the correct angle (vertical speed) for the Accident Reduction (ALAR) Task Force definesraw data

144 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 as “data received directly (not via the flight director or Enders, John H.; Dodd, Robert; Tarrel, Rick; Khatwa, Ratan; flight management computer) from basic navigation aids Roelen, Alfred L.C.; Karwal, Arun K. “Airport Safety: A study (e.g., ADF, VOR, DME, barometric altimeter).” of Accidents and Available Approach-and-landing Aids.” Flight Safety Digest Volume 15 (March 1996). 5. ICAO. Manual of All-Weather Operations. Second edition – 1991. FSF Editorial Staff. “Different Altimeter Displays and Crew Fatigue Likely Contributed to Canadian Controlled-flight-into- Related Reading From FSF Publications terrain Accident.” Accident Prevention Volume 52 (December 1995). FSF Editorial Staff. “Collision with Antenna Guy Wire Severs Lawton, Russell. “Breakdown in Coordination by Commuter Jet’s Wing During Nonprecision Approach.” Accident Preven- Crew During Unstabilized Approach Results in Controlled- tion Volume 54 (October 1997). flight-into-terrain Accident.”Accident Prevention Volume 51 (September 1994). FSF Editorial Staff. “During Nonprecision Approach at Night, MD-83 Descends Below Minimum Descent Altitude and Con- tacts Trees, Resulting in Engine Flame-out and Touchdown Regulatory Resource Short of Runway.” Accident Prevention Volume 54 (April U.S. Federal Aviation Administration. Special Notice to Air- 1997). men AFS-420 (11/26/99).

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 145 FSF ALAR Briefing Note 7.3 — Visual References

The transition from instrument references to external visual Statistical Data references is an important element of any type of instrument approach. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force found that flight crew omission Some variations exist in company operating philosophies about of action/inappropriate action was a causal factor1 in 25 percent flight crew task-sharing for: of 287 fatal approach-and-landing accidents worldwide in • Acquiring visual references; 1980 through 1996 involving jet aircraft and turboprop aircraft with maximum takeoff weights above 12,500 pounds/5,700 • Conducting the landing; and, kilograms.2 The task force said that these accidents typically • Conducting the go-around. involved the following errors: • descending below the minimum descent altitude/height For task-sharing during approach, two operating philosophies (MDA[H]) or decision altitude/height (DA[H]) without are common: adequate visual references or having acquired incorrect • Pilot flying-pilot not flying (PF-PNF) task-sharing with visual references (e.g., a lighted area in the airport differences about the acquisition of visual references, vicinity, a taxiway or another runway); and, depending on the type of approach and on the use of automation: • Continuing the approach after the loss of visual references (e.g., because of a fast-moving rain shower – Nonprecision and Category (CAT) I instrument or fog patch). landing system (ILS) approaches; or, – CAT II/CAT III ILS approaches (the captain usually Altitude-deviation and Terrain Avoidance is the PF, and only an automatic approach and landing is considered); and, During the final-approach segment, the primary attention of • Captain-first officer (CAPT-FO) task-sharing, which both pilots should be directed to published minimum approach usually is referred to as a shared approach, monitored altitudes and altitude-distance checks prior to reaching the approach or delegated-handling approach. MDA(H) or DA(H).

Differences in the philosophies include: An immediate pull-up is required in response to a ground- proximity warning system (GPWS) warning or a terrain • The transition to flying by visual references; and, awareness and warning system (TAWS)3 warning in instrument • Using and monitoring the autopilot. meteorological conditions (IMC) or at night.

146 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Definition Visual References

Whenever a low-visibility approach is anticipated, the approach The task-sharing for the acquisition of visual references and briefing must include a thorough review of the approach light for the monitoring of the flight path and aircraft systems var- system (ALS) by using the instrument approach chart and the ies, depending on: airport chart. • The type of approach; and, Depending on the type of approach and prevailing ceiling • The level of automation being used: and visibility conditions, the crew should discuss the lighting – hand flying (using the flight director [FD]); or, system(s) expected to be observed upon first visual contact. – Autopilot (AP) monitoring (single or dual AP). For example, U.S. Federal Aviation Regulations (FARs) Part 91.175 says that at least one of the following references must Nonprecision and CAT I ILS Approaches be distinctly visible and identifiable before the pilot descends below DA(H) on a CAT I ILS approach or MDA(H) on a Nonprecision approaches and CAT I ILS approaches can be nonprecision approach: flown by hand with reference to raw data4 or to the FD com- mands, or with the AP engaged. • “The approach light system, except that the pilot may not descend below 100 feet above the touchdown zone The PF is engaged directly in either: elevation using the approach lights as a reference unless the red terminating bars or the red side-row bars are also • hand flying the airplane, by actively following the DF distinctly visible and identifiable; commands and monitoring the raw data; or, • “The [runway] threshold; • Supervising AP operation and being ready to take manual control of the aircraft, if required. • “The threshold markings; • “The threshold lights; The PNF is responsible for progressively acquiring and call- ing the visual references while monitoring flight progress and • “The runway end identifier lights; backing up the PF. • “The visual approach slope indicator; The PNF scans alternately inside and outside, calls flight- • “The touchdown zone or touchdown zone markings; parameter deviations and calls: • “The touchdown zone lights; • “One hundred above” then “minimum” (if no automatic • “The runway or runway markings; [or,] call) if adequate visual references are not acquired; or, • “The runway lights.” • “Visual” (or whatever visual reference is in sight) if adequate visual references are acquired. The International Civil Aviation Organization says that re- quired visual reference “means that section of the visual aids The PNF should not lean forward while attempting to or of the approach area which should have been in view for acquire visual references. If the PNF calls “visual” sufficient time for the pilot to have made an assessment of the while leaning forward, the PF might not acquire the aircraft position and rate of change of position in relation to visual reference because his/her viewing angle will be the desired flight path.” different.

When using external references, the visual references must The PF then confirms the acquisition of visual references and be adequate for the pilot to assess horizontal flight path and calls “landing” (or “go around” if visual references are not vertical flight path. adequate).

After adequate visual references have been acquired to allow If “landing” is called, the PF progressively transitions from descent below the MDA(H) or DA(H), the different elements instrument references to external visual references. of the various ALSs provide references for position, drift angle, distance and rates of change for the final phase of the CAT II/CAT III ILS Approaches approach. CAT II/CAT III ILS approaches are flown using the automatic landing system (as applicable for the aircraft type).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 147 CAT II automatic approaches can be completed with a hand • Regardless of who was the PF for the sector, the FO is flown landing (although the standard operating procedure is always the PF for the approach; to use the automatic landing capability). • The CAPT is PNF and monitors the approach and the acquisition of visual references; In CAT III weather conditions, automatic landing is manda- tory usually. • Before or upon reaching the DA(H), depending on the company’s policy: Consequently, visual reference does not have the same meaning – If visual references are acquired, the CAPT calls for CAT II and CAT III approaches. “landing,” takes over the controls and lands; or, For CAT II approaches, visual reference means being able – If visual references are not acquired, the CAPT calls to see to land (i.e., being able to conduct a hand-flown land- “go-around,” and the FO initiates the go-around and ing). flies the missed approach.

For CAT III approaches, visual references means being able Whatever the decision, landing or go-around, the FO maintains to see to verify aircraft position. instrument references for the complete approach and landing (or go-around and missed approach). FARs Part 91.189 and Joint Aviation Requirements–Operations 1.430 consider these meanings in specifying minimum visual Depending on the FO’s experience, the above roles can be references that must be available at the DA(H). reversed.

For a CAT III approach with no DA(H), no visual reference This operating policy minimizes the problem of transitioning is specified, but recommended practice is for the PF to look from instrument flying to visual flying and, in a go-around, for visual references before touchdown, because visual ref- the problem of resuming instrument flying. Nevertheless, this erences are useful for monitoring AP guidance during the operating policy involves a change of controls (i.e., PF/PNF roll-out phase. change) and requires the development of appropriate standard operating procedures (SOPs) and standard calls. During an automatic approach and landing, the flight path is monitored by the AP (autoland warning) and supervised by Depending on the company’s operating philosophy, this tech- the PNF (excessive-deviation calls). nique is applicable to: • CAT II/CAT III approaches only (for all other approaches, Thus, the PF can concentrate his or her attention on the acqui- the PF is also the pilot landing); or, sition of visual references, progressively increasing external scanning as the DH is approached. • All types of approaches (except automatic landings where the CAPT resumes control earlier, typically from When an approach is conducted near minimums, the time 1,000 feet radio altitude to 200 feet radio altitude). available for making the transition from instrument references to visual references is extremely short; the PF therefore must Implementation concentrate on the acquisition of visual references. Implementation of the shared approach/monitored approach/ The PNF maintains instrument references throughout the ap- delegated-handling approach requires the development of cor- proach and landing (or go-around) to monitor the flight path responding SOPs and standard calls. and the instruments, and to be ready to call any flight-parameter excessive deviation or warning. Of particular importance is that the sequence of planned actions or conditional actions and calls must be briefed accurately Shared Approach/Monitored Approach/ during the approach briefing. Delegated-handling Approach Such actions and calls usually include the following: Shared approach/monitored approach/delegated-handling For the CAPT: approach provides an alternative definition of the PF and PNF functions, based on CAPT-FO task-sharing. • If adequate visual references are acquired before or at DA(H): This operating policy can be summarized as follows: – Call “landing”; and,

148 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 – Take over flight controls and thrust levers, and call “I The PNF is responsible for monitoring the instruments and for have control” or “my controls,” per company SOPs; calling any excessive deviation. • If adequate visual references are not acquired at Vertical Deviation DA(H): – Call “go-around,” cross-check and back up the A high sink rate with low thrust when too high may result in FO during the go-around initiation and missed a hard landing or in a landing short of the runway. approach. The crew should establish the correct flight path, not exceed- For the FO: ing the maximum permissible sink rate (usually 1,000 feet per minute). • If CAPT calls “landing, I have controls” or “landing, my controls”: A shallow approach with high thrust when too low may result – Call “you have control” or “your controls,” per in an extended flare and a long landing. company SOPs; and, The crew should establish level flight until the correct flight – Continue monitoring instrument references; path is established. • If CAPT calls “go-around”: Lateral Deviation – Initiate immediately the go-around and fly the missed approach; Establish an aiming point on the extended runway centerline, • If CAPT does not make any call or does not take over approximately half the distance to the touchdown point, and the flight controls and throttle levers (e.g., because of aim toward the point while maintaining the correct flight path, subtle incapacitation): airspeed and thrust setting.

– Call “go-around” and initiate immediately the go- To avoid overshooting the runway centerline, anticipate the around. alignment by beginning the final turn shortly before crossing the extended runway-inner-edge line. Standard Calls Loss of Visual References Below MDA(H) The importance of task-sharing and standard calls during the or DA(H) final portion of the approach cannot be overemphasized. If loss of adequate visual references occurs below the MDA(H) Standard calls for confirming the acquisition of visual refer- or DA(H), a go-around must be initiated immediately. ences vary from company to company. For example, FARs Part 91.189 requires that “each pilot op- “Visual” or the acquired visual reference (e.g., “runway in erating an aircraft shall immediately execute an appropriate sight”) usually is called if adequate visual references are missed approach whenever [the conditions for operating below acquired and the aircraft is correctly aligned and on the ap- the authorized DA(H)] are not met.” proach glide path; otherwise, the call “visual” or “[acquired visual reference]” is followed by an assessment of the lateral deviation or vertical deviation (offset). Summary

The CAPT determines whether the lateral deviation or verti- • during nonprecision approaches and CAT I ILS cal deviation can be corrected safely and calls “continue” (or approaches, ensure that both the PF and PNF have “landing”) or “go-around.” acquired the same — and the correct — visual references; and,

Recovery From a Deviation • during CAT II/CAT III ILS approaches and during all shared/monitored/delegated-handling approaches, the FO must remain head-down, monitoring flight Recovering from a lateral deviation or vertical deviation when instruments, for approach and landing or go-around. transitioning to visual references requires careful control of the pitch attitude, bank angle and power with reference to raw data The following FSF ALAR Briefing Notes provide information to help prevent crew disorientation by visual illusions. to supplement this discussion:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 149 • 1.1 — Operating Philosophy; Collision With Terrain Short of Runway.” Accident Prevention Volume 52 (August 1995). • 1.2 — Automation; • 1.4 — Standard Calls; and, Mohler, Stanley R. “The Human Balance System: A Refresher for Pilots.” Human Factors & Aviation Medicine Volume 42 • 5.3 — Visual Illusions.◆ (July–August 1995).

References FSF Editorial Staff. “Spatial Disorientation Linked to Fatal DC-8 Freighter Crash.” Accident Prevention Volume 50 (March 1. The Flight Safety Foundation Approach-and-landing Accident 1993). Reduction (ALAR) Task Force definescausal factor as “an event or item judged to be directly instrumental in the causal Antuñano, Melchor J.; Mohler, Stanley R. “Inflight Spatial chain of events leading to the accident.” Each accident in the Disorientation.” Human Factors & Aviation Medicine Volume study sample involved several causal factors. 39 (January–February 1992). 2. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and Regulatory Resources Controlled-flight-into-terrain Accidents.” Flight Safety Digest Volume 17 (November–December 1998) and International Civil Aviation Organization (ICAO). Interna- Volume 18 (January–February 1999): 1–121. The facts tional Standards and Recommended Practices, Annex 6 to the presented by the FSF ALAR Task Force were based on Convention of International Civil Aviation, Operation of Air- analyses of 287 fatal approach-and-landing accidents craft. Part I, International Commercial Air Transport – Aero- (ALAs) that occurred in 1980 through 1996 involving planes. Chapter 4, “Flight Operations,” 4.2.7, 4.4.1. Seventh turbine aircraft weighing more than 12,500 pounds/5,700 edition – July 1998, incorporating Amendments 1–25. kilograms, detailed studies of 76 ALAs and serious incidents in 1984 through 1997 and audits of about 3,300 ICAO. Manual of All-Weather Operations. Second edition – flights. 1991. 3. Terrain awareness and warning system (TAWS) is the term used by the European Joint Aviation Authorities U.S. Federal Aviation Administration (FAA). Federal Aviation and the U.S. Federal Aviation Administration to describe Regulations. 91.175 “Takeoff and landing under IFR,” 91.189 equipment meeting International Civil Aviation Organization “Category II and III operations: General operating rules,” standards and recommendations for ground-proximity 121.567 “Instrument approach procedures and IFR landing warning system (GPWS) equipment that provides predictive minimums.” January 1, 2000. terrain-hazard warnings. “Enhanced GPWS” and “ground collision avoidance system” are other terms used to describe FAA. Advisory Circular (AC) 60-A, Pilot’s Spatial Disorienta- TAWS equipment. tion. February 8, 1983.

4. The FSF ALAR Task Force defines raw data as “data FAA. AC 120-29, Criteria for Approving Category I and Cat- received directly (not via the flight director or flight egory II Landing Minima for FAR 121 Operators. September management computer) from basic navigation aids (e.g., 25, 1970, incorporating Change 1, December 15, 1971; Change ADF, VOR, DME, barometric altimeter).” 2, July 27, 1972; Change 3, December 3, 1974.

Related Reading From FSF Publications FAA. AC 120-28D, Criteria for Approval of Category III Landing Weather Minima for Takeoff, Landing, and Rollout. Flight Safety Foundation (FSF) Editorial Staff. “Learjet Strikes July 13, 1999. Terrain When Crew Tracks False Glideslope Indication and Continues Descent Below Published Decision Height.” Ac- Joint Aviation Authorities. Joint Aviation Requirements – cident Prevention Volume 56 (June 1999). Operations 1. Commercial Air Transport (Aeroplanes). 1.430 “Aerodrome Operating Minima – General.” July 1, 2000. FSF Editorial Staff. “Inadequate Visual References in Flight Pose Threat of Spatial Disorientation.” Human Factors & Avia- JAA. Joint Aviation Requirements – All Weather Operations. tion Medicine Volume 44 (November–December 1997). August 1, 1996.

FSF Editorial Staff. “Poorly Flown Approach in Fog Results in

150 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 151 FSF ALAR Briefing Note 7.4 — Visual Approaches

Accepting an air traffic control (ATC) clearance for a visual Definition approach or requesting a visual approach should be balanced carefully against the following: Although slightly different definitions are provided by the • Ceiling and visibility conditions; International Civil Aviation Organization (ICAO), the Euro- pean Joint Aviation Authorities and the U.S. Federal Aviation • darkness; Administration (FAA), the following definition, from the • Weather: FAA Aeronautical Information Manual, will be used in this discussion: – Wind, turbulence; • “[A visual approach is] an approach conducted on an – Rain or snow; and/or, instrument flight rules (IFR) flight plan which authorizes – Fog or smoke; the pilot to proceed visually and clear of clouds to the airport; • Crew experience with airport and airport environment: • “The pilot must, at all times, have either the airport or – Surrounding terrain; and/or, the preceding aircraft in sight; – Specific airport and runway hazards (obstructions, • “[The visual] approach must be authorized and under etc.); and, the control of the appropriate air traffic control facility; • Runway visual aids: [and], – Type of approach light system (ALS); and, • “Reported weather at the airport must be ceiling at or above 1,000 feet and visibility three miles or greater.” – Availability of visual approach slope indicator (VASI) or precision approach path indicator (PAPI). Visual Approach at Night

Statistical Data During a visual approach at night, fewer visual references are usable, and visual illusions and spatial disorientation occur The Flight Safety Foundation Approach-and-landing Accident more frequently. Reduction (ALAR) Task Force found that visual approaches were being conducted in 41 percent of 118 fatal approach-and- Visual illusions (such as the “black-hole effect”2) affect the landing accidents worldwide in 1980 through 1996 involving flight crew’s vertical situational awareness and horizontal jet aircraft and turboprop aircraft with maximum takeoff situational awareness, particularly on the base leg and when weights above 12,500 pounds/5,700 kilograms, and in which turning final. the type of approach being conducted was known.1

152 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 A visual approach at night should be considered only if: • Weather is suitable for flight under visual flight rules Table 1 (VFR); Recommended Elements • A close-in pattern is used (or a published visual approach Of a Stabilized Approach is available); All flights must be stabilized by 1,000 feet above • A pattern altitude is defined; and, airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual • The flight crew is familiar with airport hazards and meteorological conditions (VMC). An approach is stabi- obstructions. (This includes the availability of current lized when all of the following criteria are met: notices to airmen [NOTAMs].) 1. The aircraft is on the correct flight path; 2. Only small changes in heading/pitch are required to maintain the correct flight path; At night, whenever an instrument approach is available (par- 3. The aircraft speed is not more than V + 20 knots ticularly an instrument landing system [ILS] approach), an in- REF indicated airspeed and not less than V ; strument approach should be preferred to a visual approach. REF 4. The aircraft is in the correct landing configuration; If a precision approach is not available, select an approach 5. Sink rate is no greater than 1,000 feet per minute; if an approach requires a sink rate greater than 1,000 supported by VASI or PAPI. feet per minute, a special briefing should be con- ducted; 6. Power setting is appropriate for the aircraft configura- Overview tion and is not below the minimum power for approach as defined by the aircraft operating manual; The following overview provides a description of the various 7. All briefings and checklists have been conducted; phases and techniques associated with visual approaches. 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system References (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Cat- Visual approaches should be conducted with reference to egory III ILS approach must be flown within the ex- panded localizer band; during a circling approach, either: wings should be level on final when the aircraft • A published visual approach chart for the intended reaches 300 feet above airport elevation; and, runway; or, 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a • The visual approach procedure (altitude, aircraft stabilized approach require a special briefing. configuration and airspeed) published in the aircraft An approach that becomes unstabilized below 1,000 operating manual (AOM)/quick reference handbook feet above airport elevation in IMC or below 500 feet (QRH) or the pattern published in the AOM/QRH. above airport elevation in VMC requires an immediate go-around. Source: Flight Safety Foundation Approach-and-landing Accident Terrain Awareness Reduction (ALAR) Task Force (V1.1 November 2000)

When selecting or accepting a visual approach, the flight crew should be aware of the surrounding terrain and man-made obstacles. according to company standard operating procedures (SOPs). (See Table 1.) For example, at night, with an unlighted hillside between a lighted area and the runway, the flight crew may not see the If the aircraft is not stabilized by 500 feet above airport eleva- rising terrain. tion or if the approach becomes unstabilized below 500 feet above airport elevation, go around. Objective Automated Systems The objective of a visual approach is to conduct an ap- proach: Automated systems (autopilot, flight director, autothrottles) should be adapted to the type of visual approach (i.e., visual • Using visual references; and, approach chart or AOM/QRH visual approach procedure/ • Being stabilized by 500 feet above airport elevation pattern) and to the ATC environment (radar vectors or crew navigation).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 153 During the final phase of the approach, the crew should dis- way threshold), extend landing flaps and begin reducing to the connect the autopilot, clear the flight director command bars, target final approach speed. maintain the autothrottles in speed mode and select the flight path vector symbol (as available on the primary flight display Estimate the glide path angle to the runway threshold based [PFD] or head-up display [HUD]). on available visual references (e.g., VASI) or raw data3 (ILS glideslope or altitude/distance). (Glideslope indications and Initial/Intermediate Approach VASI indications are reliable only within 30 degrees of the final approach course.) The flight management system (FMS) may be used to build the teardrop outbound leg or the downwind leg, for enhanced Do not exceed a 30-degree bank angle when tuning final. situational awareness. This should be done when programming the FMS before reaching the top-of-descent point. Anticipate the crosswind effect (as applicable) to complete the turn correctly established on the extended runway centerline As applicable, set navaids for the instrument approach associ- with the required drift correction. ated with the landing runway (for monitoring and in case of loss of visual references). Final Approach

Review the primary elements of the visual approach and the Plan to be aligned with the runway (wings level) and stabi- primary elements of the associated instrument approach. lized at the final approach speed by 500 feet above airport elevation. Review the appropriate missed approach procedure. Monitor groundspeed variations (for wind shear awareness) Extend slats and fly at the corresponding maneuvering and call altitudes and excessive flight-parameter deviations as speed. for instrument approaches.

Barometric-altimeter and radio-altimeter bugs may be set (per Maintain visual scanning toward the aiming point (typically company SOPs) for enhanced terrain awareness. 1,000 feet from the runway threshold) to avoid any tendency to inadvertently descend below the final approach path (use raw Outbound/Downwind Leg data or the VASI/PAPI, as available, for a cross-check).

To be aligned on the final approach course and stabilized at 500 feet above airport elevation, the crew should intercept Visual Approach Factors typically the final approach course at three nautical miles from the runway threshold (time the outbound leg or downwind leg The following factors often are cited when discussing unsta- accordingly, as a function of the prevailing airspeed and wind bilized visual approaches: component). • Pressure of flight schedule (making up for delays);

Maintain typically 1,500 feet above airport elevation (or the • Crew-induced circumstances or ATC-induced charted altitude) until beginning the final descent or turning circumstances resulting in insufficient time to plan, base leg. prepare and conduct a safe approach; • Excessive altitude or excessive airspeed (e.g., inadequate Configure the aircraft per SOPs, typically turning base leg energy management) early in the approach; with approach flaps, landing gear extended and ground spoil- ers armed. • downwind leg too short (visual pattern) or interception too close (direct base-leg interception); Do not exceed a 30-degree bank angle when turning onto • Inadequate awareness of tail wind component and/or base leg. crosswind component;

Base Leg • Incorrect anticipation of aircraft deceleration characteristics in level flight or on a three-degree glide Resist the tendency to fly a continuous closing-in turn toward path; the runway threshold. • Failure to recognize deviations or failure to adhere to excessive-parameter-deviation criteria; Before turning final (depending on the distance from the run-

154 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Belief that the aircraft will be stabilized at the minimum • Awareness of surrounding terrain and obstacles; stabilization height or shortly thereafter; • Awareness of airport environment, airport and runway • Excessive confidence by the pilot not flying (PNF) that hazards; the pilot flying (PF) will achieve a timely stabilization, • Use of a visual approach chart or AOM/QRH procedures/ or reluctance by the PNF to challenge the PF; pattern; • PF and PNF too reliant on each other to call excessive • Tuning and monitoring all available navaids; deviations or to call for a go-around; • optimizing use of automation with timely reversion to • Visual illusions; hand flying; • Inadvertent modification of the aircraft trajectory to • Adhering to defined PF/PNF task-sharing (monitoring maintain a constant view of visual references; and, by PNF of head-down references [i.e., instrument • loss of ground visual references, airport visual references references] while PF flies and looks outside); or runway visual references, with the PF and the PNF • Maintaining visual contact with the runway and other both looking outside to reacquire visual references. traffic at all times; and, • Announcing altitudes and excessive flight-parameter Unstabilized Visual Approaches deviations, and adhering to the go-around policy for instrument approaches. The following deviations are typical of unstabilized visual approaches: The following FSF ALAR Briefing Notes provide information • Steep approach (high and fast, with excessive rate of to supplement this discussion: descent); • 1.1 — Operating Philosophy; • Shallow approach (below desired glide path); • 1.2 — Automation; • ground-proximity warning system (GPWS)/terrain awareness warning system (TAWS)4 activation: • 1.3 — Golden Rules;

– Mode 1: “sink rate”; • 1.4 — Standard Calls; – Mode 2A: “terrain” (less than full flaps); • 1.5 — Normal Checklists; – Mode 2B: “terrain” (full flaps); • 1.6 — Approach Briefing; • Final-approach-course interception too close to the runway threshold because of an inadequate outbound • 3.1 — Barometric Altimeter and Radio Altimeter; teardrop leg or downwind leg; • 4.2 — Energy Management; • laterally unstabilized final approach because of failure to correct for crosswind; • 5.2 — Terrain;

• Excessive bank angle and maneuvering to capture the • 5.3 — Visual Illusions; and, extended runway centerline or to conduct a side-step maneuver; • 7.1 — Stabilized Approach.◆ • Unstabilized approach with late go-around decision or no go-around decision; and, References • Inadvertent descent below the three-degree glide path. 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and Summary Controlled-flight-into-terrain Accidents.” Flight Safety Digest Volume 17 (November–December 1998) and The following should be discussed and understood for safe Volume 18 (January–February 1999): 1–121. The facts visual approaches: presented by the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents • Weighing the time saved against the risk; (ALAs) that occurred in 1980 through 1996 involving • Awareness of all weather factors; turbine aircraft weighing more than 12,500 pounds/5,700

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 155 kilograms, detailed studies of 76 ALAs and serious Related Reading From FSF Publications incidents in 1984 through 1997 and audits of about 3,300 flights. Flight Safety Foundation (FSF) Editorial Staff. “B-757 Dam- aged by Ground Strike During Late Go-around from Visual 2. The black-hole effect typically occurs during a visual Approach.” Accident Prevention Volume 56 (May 1999). approach conducted on a moonless or overcast night, over water or over dark, featureless terrain where the FSF Editorial Staff. “MD-88 Strikes Approach Light Struc- only visual stimuli are lights on and/or near the airport. ture in Nonfatal Accident.” Accident Prevention Volume 54 The absence of visual references in the pilot’s near (December 1997). vision affect depth perception and cause the illusion that the airport is closer than it actually is and, thus, that Lawton, Russell. “Steep Turn by Captain During Approach the aircraft is too high. The pilot may respond to this Results in Stall and Crash of DC-8 Freighter.” Accident Pre- illusion by conducting an approach below the correct vention Volume 51 (October 1994). flight path (i.e., a low approach). 3. The Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force definesraw data Regulatory Resources as “data received directly (not via the flight director or flight management computer) from basic navigation aids U.S. Federal Aviation Administration (FAA). Federal Avia- (e.g., ADF, VOR, DME, barometric altimeter).” tion Regulations. 91.175 “Takeoff and landing under IFR.” January 1, 2000. 4. Terrain awareness and warning system (TAWS) is the term used by the European Joint Aviation Authorities FAA. Advisory Circular 60-A, Pilot’s Spatial Disorientation. and the U.S. Federal Aviation Administration to February 8, 1983. describe equipment meeting International Civil Aviation Organization standards and recommendations for ground- Joint Aviation Authorities. Joint Aviation Requirements – proximity warning system (GPWS) equipment that Operations 1. Commercial Air Transport (Aeroplanes). 1.435 provides predictive terrain-hazard warnings. “Enhanced “Terminology.” July 1, 2000. GPWS” and “ground collision avoidance system” are other terms used to describe TAWS equipment.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

156 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 8.1 — Runway Excursions and Runway Overruns

Runway excursions occur when: • Wind shear; • Aircraft veer off the runway during the landing roll; • Crosswind; and, • Inaccurate information on wind conditions and/or • Aircraft veer off the runway or taxiway when exiting runway conditions; and, the runway. • Reverse-thrust effect in a crosswind and on a wet runway Runway overruns occur when the aircraft roll-out extends or a contaminated runway. beyond the end of the landing runway. Crew Technique/Decision Factors Runway excursions and runway overruns can occur after • Incorrect crosswind landing technique (e.g., drifting any type of approach in any light condition or environmental during the transition from a wings-level crosswind condition. approach [“crabbed” approach] to a steady-sideslip crosswind approach, or failing to transition from a wings- level approach to a steady-sideslip approach [“decrab”] Statistical Data when landing in strong crosswind conditions); The Flight Safety Foundation Approach-and-landing Ac- • Inappropriate differential braking by the crew; cident Reduction (ALAR) Task Force found that runway • Use of the nosewheel-steering tiller at airspeeds that are excursions and runway overruns were involved in 20 percent too fast; and, of 76 approach-and-landing accidents and serious incidents worldwide in 1984 through 1997.1 • Airspeed too fast on the runway to exit safely.

Systems Factors Factors Involved in Runway Excursions • Asymmetric thrust (i.e., forward thrust on one side, Runway excursions are usually the result of one or more of reverse thrust on the opposite side); the following factors: • Speed brakes fail to deploy; or,

Weather Factors • Uncommanded differential braking. • Runway condition (wet or contaminated by standing Factors Involved in Runway Overruns water, snow, slush or ice);

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 157 Runway overruns are usually the result of one or more of the Accident-prevention Strategies and Lines following factors: of Defense

Weather Factors The following company accident-prevention strategies and • Unanticipated runway condition (i.e., worse than personal lines of defense are recommended: anticipated); Policies • Inaccurate surface wind information; and, • define policy to promote readiness and commitment to go • Unanticipated wind shear or tail wind. around (discouraging any attempt to “rescue” a situation that is likely to result in a hazardous landing); Performance Factors • define policy to ensure that inoperative brakes (“cold • Incorrect assessment of landing distance following a brakes”) are reported in the aircraft logbook and that they malfunction or minimum equipment list (MEL)/dispatch receive attention in accordance with the MEL/DDG; deviation guide (DDG) condition affecting aircraft configuration or braking capability; and, • define policy for a rejected landing (bounce recovery); • Incorrect assessment of landing distance for prevailing wind and runway conditions. • define policy prohibiting landing beyond the touchdown zone; and, Crew Technique/Decision Factors • define policy encouraging a firm touchdown when • Unstable approach path (steep and fast): operating on a contaminated runway. – landing fast; and, – Excessive height over threshold, resulting in landing Standard Operating Procedures (SOPs) long; • define criteria and standard calls for a stabilized • No go-around decision when warranted; approach, and define minimum stabilization heights in • decision by captain (pilot not flying) to land, SOPs (Table 1); countermanding first officer’s decision to go around; • define task-sharing and standard calls for final approach • Extended flare (allowing the aircraft to float and to and roll-out phases in SOPs; and, decelerate [bleed excess airspeed] in the air uses • Incorporate in SOPs a standard call for “… [feet or typically three times more runway than decelerating on meters] runway remaining” or “… [feet or meters] to the ground); go” in low-visibility conditions, based on: • Failure to arm ground spoilers (usually associated with – Runway-lighting color change; thrust reversers being inoperative); – Runway-distance-to-go markers (as available); or, • Power-on touchdown (i.e., preventing the auto-extension of ground spoilers, as applicable); – other available visual references (such as runway/ • Failure to detect nondeployment of ground spoilers (e.g., taxiway intersections). absence of related standard call); • Bouncing and incorrect bounce recovery; Performance Data • late braking (or late takeover from autobrake system, • Publish data and define procedures for adverse runway if required); and, conditions; and, • Increased landing distance resulting from the use of • Provide flight crews with specific landing-distance data differential braking or the discontinued use of reverse for runways with a downhill slope/high elevation. thrust to maintain directional control in crosswind conditions. Procedures

Systems Factors • Publish SOPs and provide training for crosswind-landing techniques; • loss of pedal braking; • Publish SOPs and provide training for flare • Anti-skid system malfunction; or, techniques; • hydroplaning. • Publish SOPs for the optimum use of autobrakes and

158 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Ensure flight crew awareness and understanding of conditions conducive to hydroplaning; Table 1 Recommended Elements • Ensure flight crew awareness and understanding of crosswind and wheel-cornering issues; Of a Stabilized Approach • Ensure flight crew awareness of wind shear and develop All flights must be stabilized by 1,000 feet above corresponding procedures (particularly for the monitoring airport elevation in instrument meteorological conditions (IMC) or by 500 feet above airport elevation in visual of groundspeed variations during approach); meteorological conditions (VMC). An approach is stabi- • Ensure flight crew awareness of the relationships lized when all of the following criteria are met: among braking action, friction coefficient and runway- 1. The aircraft is on the correct flight path; condition index, and maximum crosswind components 2. Only small changes in heading/pitch are required to recommended for runway conditions; and, maintain the correct flight path; • Ensure flight crew awareness of runway lighting changes 3. The aircraft speed is not more than VREF + 20 knots

indicated airspeed and not less than VREF; when approaching the runway end: 4. The aircraft is in the correct landing configuration; – Standard centerline lighting: white lights changing to 5. Sink rate is no greater than 1,000 feet per minute; if alternating red and white lights between 3,000 feet an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be con- and 1,000 feet from runway end, and to red lights for ducted; the last 1,000 feet; and, 6. Power setting is appropriate for the aircraft configura- – Runway edge lighting (high-intensity runway light tion and is not below the minimum power for approach system): white lights changing to yellow lights on as defined by the aircraft operating manual; the last 2,000 feet of the runway. 7. All briefings and checklists have been conducted; 8. Specific types of approaches are stabilized if they also fulfill the following: instrument landing system Summary (ILS) approaches must be flown within one dot of the glideslope and localizer; a Category II or Cat- Runway excursions and runway overruns can be categorized egory III ILS approach must be flown within the ex- into six families of events, depending on their primary causal panded localizer band; during a circling approach, factor: wings should be level on final when the aircraft reaches 300 feet above airport elevation; and, • Events resulting from unstabilized approaches; 9. Unique approach procedures or abnormal conditions requiring a deviation from the above elements of a • Events resulting from incorrect flare technique; stabilized approach require a special briefing. • Events resulting from unanticipated or more-severe- An approach that becomes unstabilized below 1,000 than-expected adverse weather conditions; feet above airport elevation in IMC or below 500 feet above airport elevation in VMC requires an immediate • Events resulting from reduced braking or loss of go-around. braking; Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force (V1.1 November 2000) • Events resulting from an abnormal configuration (e.g., because the aircraft was dispatched under MEL conditions or DDG conditions, or because of an in-flight malfunction); and, thrust reversers on contaminated runways; • Events resulting from incorrect crew action and • Provide recommendations for the use of rudder and coordination, under adverse conditions. differential braking/nosewheel steering for directional control, depending on airspeed and runway condition; Corresponding company accident-prevention strategies and and, personal lines of defense can be developed to help prevent • Publish specific recommendations for aircraft lateral runway excursions and runway overruns by: control and directional control after a crosswind • Adherence to SOPs; landing. • Enhanced awareness of environmental factors; Crew Awareness • Enhanced understanding of aircraft performance and handling techniques; and, • Ensure flight crew awareness and understanding of all factors affecting landing distances; • Enhanced alertness for flight-parameter monitoring,

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 159 deviation calls and crew cross-check. Stop Demands More from Crew and Aircraft.” Flight Safety Digest Volume 12 (March 1993). The following FSF ALAR Briefing Notes provide information to supplement this discussion: Regulatory Resources • 1.1 — Operating Philosophy; International Civil Aviation Organization (ICAO). Interna- • 1.4 — Standard Calls; tional Standards and Recommended Practices, Annex 6 to • 6.4 — Bounce Recovery — Rejected Landing; the Convention of International Civil Aviation, Operation of • 7.1 — Stabilized Approach; Aircraft. Part I, International Commercial Air Transport – • 8.2 — The Final Approach Speed; Aeroplanes. Appendix 2, “Contents of an Operations Manual,” 5.9. Seventh edition – July 1998, incorporating Amendments • 8.3 — Landing Distances; 1–25. • 8.4 — Braking Devices; ICAO. Procedures for Air Navigation Services. Aircraft Op- • 8.5 — Wet or Contaminated Runways; and, erations. Volume I, Flight Procedures. Fourth edition, 1993. • 8.7 — Crosswind Landings.◆ Reprinted May 2000, incorporating Amendments 1–10. ICAO. Manual of All-Weather Operations. Second edition – Reference 1991. 1. Flight Safety Foundation. “Killers in Aviation: FSF Task ICAO. Preparation of an Operations Manual. Second edi- Force Presents Facts About Approach-and-landing and tion – 1997. Controlled-flight-into-terrain Accidents.” Flight Safety Federal Avia- Digest Volume 17 (November–December 1998) and U.S. Federal Aviation Administration (FAA). tion Regulations Volume 18 (January–February 1999): 1–121. The facts . 121.97 “Airports: Required data,” 121.117 presented by the FSF ALAR Task Force were based on “Airports: Required data,” 121.133 “Preparation,” 121.141 analyses of 287 fatal approach-and-landing accidents “Airplane Flight Manual,” 121.401 “Training program: Gen- (ALAs) that occurred in 1980 through 1996 involving eral,” 121.195 “Airplanes: Turbine-engine-powered: Landing turbine aircraft weighing more than 12,500 pounds/5,700 limitations: Destination airports,” 121.197 “Airplanes: Turbine- kilograms, detailed studies of 76 ALAs and serious engine-powered: Landing limitations: Alternate airports,” incidents in 1984 through 1997 and audits of about 3,300 125.287 “Initial and recurrent pilot testing requirements,” flights. 135.293 “Initial and recurrent pilot testing requirements.” January 1, 2000. Related Reading From FSF Publications FAA. Advisory Circular 120-51C, Crew Resource Management Training. October 30, 1998. Flight Safety Foundation (FSF) Editorial Staff. “Business Jet FAA. Air Transportation Operations Inspector’s Handbook. Overruns Wet Runway After Landing Past Touchdown Zone.” Volume 4, “Aircraft Equipment and Operational Authoriza- Accident Prevention Volume 56 (December 1999). tions.” Chapter 2, “All-weather Terminal Area Operations,” FSF Editorial Staff. “Attempted Go-around with Deployed August 26, 1998, incorporating changes 1–12. Accident Preven- Thrust Reversers Leads to Learjet Accident.” Joint Aviation Authorities. Joint Aviation Requirements – tion Volume 56 (January 1999). Operations 1. Commercial Air Transportation (Aeroplanes). Enders, John H.; Dodd, Robert; Tarrel, Rick; Khatwa, Ratan; 1.515 “Landing – Dry Runways,” 1.520 “Landing – Wet and Roelen, Alfred L.C.; Karwal, Arun K. “Airport Safety: A study contaminated runways.” March 3, 1998. of Accidents and Available Approach-and-landing Aids.” Flight U.K. Civil Aviation Authority (CAA). Aeronautical Informa- Safety Digest Volume 15 (March 1996). tion Circular (AIC) 11/98, Landing Performance of Large Lawton, Russell. “DC-10 Destroyed, No Fatalities, After Air- Transport Aeroplanes. January 27, 1998. craft Veers Off Runway During Landing.” Accident Prevention U.K. CAA. AIC 61/1999, Risks and Factors Associated with Volume 51 (May 1994). Operations on Runways Affected by Snow, Slush or Water. King, Jack L. “During Adverse Conditions, Decelerating to June 3, 1999.

160 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 161 FSF ALAR Briefing Note 8.2 — The Final Approach Speed

Assuring a safe landing requires achieving a balanced distribu- • Flap configuration (when several flap configurations are tion of safety margins between: certified for landing); • The computed final approach speed (also called the • Aircraft systems status (airspeed corrections for abnormal target threshold speed); and, configurations); • The resulting landing distance. • Icing conditions; and, • Use of autothrottle speed mode or autoland. Statistical Data The final approach speed is based on the reference landing

Computation of the final approach speed rarely is a factor in speed, VREF. runway overrun events, but an approach conducted signifi-

cantly faster than the computed target final approach speed is VREF usually is defined by the aircraft operating manual (AOM) cited often as a causal factor. and/or the quick reference handbook (QRH) as:

The Flight Safety Foundation Approach-and-landing Accident 1.3 x stall speed with full landing flaps Reduction (ALAR) Task Force found that “high-energy” ap- or with selected landing flaps. proaches were a causal factor1 in 30 percent of 76 approach- and-landing accidents and serious incidents worldwide in 1984 Final approach speed is defined as: through 1997.2

VREF + corrections. Defining the Final Approach Speed Airspeed corrections are based on operational factors (e.g., The final approach speed is the airspeed to be maintained down wind, wind shear or icing) and on landing configuration (e.g., to 50 feet over the runway threshold. less than full flaps or abnormal configuration).

The final approach speed computation is the result of a deci- The resulting final approach speed provides the best compro- sion made by the flight crew to ensure the safest approach and mise between handling qualities (stall margin or controllability/ landing for the following: maneuverability) and landing distance. • gross weight; • Wind;

162 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Factors Affecting the Final Approach on the appropriate flight management system (FMS) page. Speed Flap Configuration The following airspeed corrections usually are not cumulative; When several flap configurations are certified for landing, V only the highest airspeed correction should be added to V REF REF (for the selected configuration) is defined by manufacturers (unless otherwise stated in the AOM/QRH): as either: • Airspeed correction for wind; • VREF full flaps plus a correction for the selected flap setting; or, • Airspeed correction for ice accretion; • V selected flaps. • Airspeed correction for autothrottle speed mode or REF autoland; or, In calm wind conditions or light-and-variable wind conditions, V (or V corrected for the selected landing flap setting) • Airspeed correction for forecast turbulence/wind shear REF REF plus five knots is a typical target final approach speed. conditions.

Abnormal Configuration Gross Weight System malfunctions (e.g., the failure of a hydraulic system Because V is derived from the stall speed, the V value REF REF or the jamming of slats/flaps) require an airspeed correction depends directly on aircraft gross weight. to restore:

The AOM/QRH usually provides VREF values as a function of • The stall margin; or, gross weight in a table or graphical format for normal landings and for overweight landings. • Controllability/maneuverability.

For a given primary malfunction, the airspeed correction pro- Wind Conditions vided in the AOM/QRH usually considers all the consequential effects of the malfunction (i.e., no combination of airspeed The wind correction provides an additional stall margin for corrections is required normally). airspeed excursions caused by turbulence and wind shear. In the unlikely event of two unrelated malfunctions — both Depending on aircraft manufacturers and aircraft models, the affecting controllability/maneuverability or stall margin — the wind correction is defined using different methods, such as following recommendations are applied usually: the following: • If both malfunctions affect the stall margin, the airspeed • half of the steady head wind component plus the entire corrections must be added; gust value, limited to a maximum value (usually 20 knots); • If both malfunctions affect controllability/ maneuverability, only the higher airspeed correction • one-third of the tower-reported average wind velocity must be considered; and, or the gust velocity, whichever is higher, limited to a maximum value (usually 15 knots); or, • If one malfunction affects the stall margin and the other malfunction affects controllability/maneuverability, only • A graphical assessment based on the tower-reported the higher airspeed correction must be considered. wind velocity and wind angle, limited to a maximum value (usually 15 knots). Use of Autothrottle Speed Mode The gust velocity is not used in this graphical assessment, but the resulting wind correction usually is very close to the Whenever the autothrottle system is used for maintaining the second method. target final approach speed, the crew should consider an air-

speed correction (typically five knots) to REFV to allow for the Usually, no wind correction is applied for tail winds. accuracy of the autothrottle system in maintaining the target final approach speed. On some aircraft models, the wind correction can be entered

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 163 This airspeed correction ensures that an airspeed equal to When a system malfunction results in a configuration correc-

or greater than VREF is maintained down to 50 feet over the tion to VREF, the final approach speed becomes: runway threshold.

VREF + configuration correction + wind correction. CAT II/CAT III Autoland The wind correction is limited usually to a maximum value For Category (CAT) II instrument landing system (ILS) ap- (typically 15 knots to 20 knots). proaches using the autothrottles, CAT III ILS approaches and autoland approaches (regardless of weather minimums), the The configuration correction is determined by referring to the AOM/QRH. five-knot airspeed correction to VREF — to allow for the accu- racy of the autothrottle system — is required by certification regulations. The configuration correction and wind correction are combined usually according to the following rules (as applicable, based Ice Accretion on the AOM/QRH): • If the configuration correction is equal to or greater When severe icing conditions are encountered, an airspeed than a specific limit (e.g., 20 knots), no wind correction correction (typically five knots) must be considered for the is added; or, possible accretion of ice on the unheated surfaces of the aircraft and on the wing surfaces above and below fuel tanks contain- • If the configuration correction is lower than a given ing cold-soaked fuel. value (e.g., 20 knots), then the configuration correction and wind correction are combined but limited to a Wind Shear maximum value (e.g., 20 knots).

Whenever wind shear is anticipated based on pilot reports from The five-knot airspeed correction for the use of autothrottles preceding aircraft or on an alert issued by the airport low-level and the five-knot airspeed correction for ice accretion (as ap- wind shear alert system (LLWAS), the landing should be de- plicable) may be disregarded if the other airspeed corrections layed or the crew should divert to the alternate airport. exceed five knots.

If neither a delayed landing nor a diversion is suitable, an Some manufacturers recommend combining the configuration airspeed correction (usually up to 15 knots to 20 knots, based correction and the wind correction in all cases. (When a system on the expected wind shear value) is recommended. malfunction requires a configuration correction, autoland is not permitted usually.) Landing with less than full flaps should be considered to maximize the climb gradient capability (as applicable, in compliance with the AOM/QRH), and the final approach speed Summary should be adjusted accordingly. Data provided by the manufacturer in the AOM/QRH are Wind shear is characterized usually by a significant increase designed to achieve a balanced distribution of safety margins of the head wind component preceding a sudden change to between: a tail wind component. Whenever wind shear is expected, • The target final approach speed; and, groundspeed should be monitored closely to enhance wind shear awareness. • The resulting landing distance. The following FSF ALAR Briefing Notes provide information Combine Airspeed Corrections to supplement this discussion:

The various airspeed corrections either are combined or not • 7.1 — Stabilized Approach; combined to distribute equally the safety margins of the fol- • 8.1 — Runway Excursions and Runway Overruns; lowing objectives: • 8.3 — Landing Distances; and, • Stall margin; • 8.4 — Braking Devices.◆ • Controllability/maneuverability; and,

• landing distance.

164 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 References Related Reading From FSF Publications

1. The Flight Safety Foundation Approach-and-landing Flight Safety Foundation (FSF) Editorial Staff. “Business Jet Accident Reduction (ALAR) Task Force defines causal Overruns Wet Runway After Landing Past Touchdown Zone.” factor as “an event or item judged to be directly instrumental Accident Prevention Volume 56 (December 1999). in the causal chain of events leading to the accident [or incident].” Lawton, Russell. “Moving Power Levers Below Flight Idle During Descent Results in Dual Engine Flameout and Power- 2. Flight Safety Foundation. “Killers in Aviation: FSF Task off Emergency Landing of Commuter Airplane.” Accident Force Presents Facts About Approach-and-landing and Prevention Volume 51 (December 1994). Controlled-flight-into-terrain Accidents.”Flight Safety Digest Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts presented by Regulatory Resources the FSF ALAR Task Force were based on analyses of 287 fatal approach-and-landing accidents (ALAs) that occurred U.S. Federal Aviation Administration (FAA). Advisory Circular in 1980 through 1996 involving turbine aircraft weighing (AC) 120-29, Criteria for Approving Category I and Category more than 12,500 pounds/5,700 kilograms, detailed studies II Landing Minima for FAR 121 Operators. September 25, of 76 ALAs and serious incidents in 1984 through 1997 and 1970. [Incorporating Change 1, December 15, 1971; Change audits of about 3,300 flights. 2, July 27, 1972; Change 3, December 3, 1974.]

FAA. AC 120-28D, Criteria for Approval of Category III Landing Weather Minima for Takeoff, Landing, and Rollout. July 13, 1999.

Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 165 Flight Safety Foundation

Approach-and-landing Accident Reduction Tool Kit

FSFFSF ALAR ALAR Briefing Briefing NoteNote 8.38.3 — — Landing Landing Distances Distances

WhenWhen discussing discussing landinglanding distance,distance, twotwo categoriescategories mustmust bebe considered:considered: Required Runway Length — JAA/FAA

•• ActualActual landing landing distance distance is is the the distance distance usedused inin landinglanding andand braking braking to to a a complete complete stop stop (on (on aa drydry runway)runway) afterafter Dry Runway crossingcrossing the the runway runway threshold threshold at at 50 50 feet; feet; and,and, Wet Runway

• Required landing distance is the distance derived by Actual Landing Regulatory • Required landing distance is the distance derived by Distance (Dry) Factor = 1.67 +15 applying a factor to the actual landing distance. Percent applying a factor to the actual landing distance. If Wet

ActualActual landing landing distances distances are are determined determined duringduring certificationcertification 50 Feet at Threshold flightflight tests tests without without the the use use of of thrust thrust reversers. reversers.

RequiredRequired landing distancesdistances are are used used for for dispatch dispatch purposes purposes (i.e., Required runway length (dry) = Actual landing distance (dry) x 1.67 (i.e.,for selecting for selecting the destination the destination airport and airport alternate and airports). alternate Required runway length (wet) = Actual landing distance (dry) x 1.92 airports). JAA = (European) Joint Aviation Authorities FAA = (U.S.) Federal Aviation Administration Statistical Data Source: Flight Safety Foundation Approach-and-landing Accident Statistical Data Reduction (ALAR) Task Force The Flight Safety Foundation Approach-and-landing Accident TheReduction Flight Safety (ALAR) Foundation Task Force Approach-and-landing found that runway Accidentoverruns Figure 1 Reductionwere involved (ALAR) in 12Task percent Force offound 76 approach-and-landingthat runway overruns wereaccidents involved and seriousin 12 percent incidents of worldwide 76 approach-and-landing in 1984 through Factors Affecting Landing Distance 1 accidents1997. and serious incidents worldwide in 1984 through Factors Affecting Landing Distance 1997.1 Actual landing distance is affected by various operational Actualfactors, landingincluding: distance is affected by various operational Defining Landing Distances factors, including: Defining Landing Distances • high airport elevation or high density altitude, resulting Figure 1 shows the definitions of actual landing distances and • Highin increased airport elevationgroundspeed; or high density altitude, resulting in increased groundspeed; Figurerequired 1 landingshows thedistances definitions used by of the actual European landing Joint distances Aviation • Runway gradient (i.e., slope); andAuthorities required (JAA) landing and distances by the U.S. used Federal by the Aviation European Adminis Joint- • Runway gradient (i.e., slope); • Runway condition (dry, wet or contaminated by standing Aviationtration (FAA). Authorities Figure (JAA) 2 shows and the by definitions the U.S. Federal of actual Aviation landing • Runwaywater, slush, condition snow (dry, or ice); wet or contaminated by standing Administrationdistance and required (FAA). landing Figure distance 2 (page used 168)by the shows U.K. Civil the water, slush, snow or ice); definitionsAviation Authority of actual (CAA). landing distance and required landing • Wind conditions; distance used by the U.K. Civil Aviation Authority (CAA). • Wind conditions;

166 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 167 Runwayaccounted Slope for in performance computations only if the runway Required Runway Length — U.K. CAA downhill slope exceeds 2 percent. Runway slope (gradient) has a direct effect on landing dis- tance. Dry or Wet Runway Runway Conditions

Actual Landing Regulatory ForAlthough example, runway a 1 percentcontamination downhill increases slope increases rolling resistance landing Distance (Dry) Factor = 1.92 distanceand spray-impingement by 10 percent (factor drag of(i.e., 1.1). drag However, caused this by effectwater isor accountedslush sprayed for in by performance tires onto the computations aircraft), it also only affects if the runway braking 50 Feet at Threshold downhillefficiency. slope exceeds 2 percent.

Required runway length (dry or wet) = Actual landing distance (dry) x 1.92 RunwayThe following Conditions landing distance factors are typical: • Wet runway: 1.3 to 1.4; CAA = Civil Aviation Authority Although runway contamination increases rolling resistance Source: Flight Safety Foundation Approach-and-landing Accident and• spray-impingement Standing-water or drag slush-contaminated (i.e., drag caused runway: by water 2.0 or to Reduction (ALAR) Task Force slush sprayed2.3; by tires onto the aircraft), it also affects brak- ing efficiency. Figure 2 • Compacted-snow-covered runway: 1.6 to 1.7; and, The• following Icy runway: landing 3.5 distanceto 4.5. factors are typical: • Type of braking (pedal braking or autobrakes, use of • Type of braking (pedal braking or autobrakes, use of • Wet runway: 1.3 to 1.4; thrust reversers); Wind Conditions thrust reversers); • Standing-water or slush-contaminated runway: 2.0 to • Anti-skid system failure; • Anti-skid system failure; Certification2.3; regulations and operating regulations require • Final approach speed; correction factors to be applied to actual landing distances to • Final approach speed; • Compacted-snow-covered runway: 1.6 to 1.7; and, compensate for: • landing technique (e.g., height and airspeed over the • Landing technique (e.g., height and airspeed over the • Icy runway: 3.5 to 4.5. threshold, thrust reduction and flare); • Fifty percent of the head-wind component; and, threshold, thrust reduction and flare); • Standard operating procedures (SOPs) deviations (e.g., Wind• OneConditions hundred fifty percent of the tail-wind component. • Standard operating procedures (SOPs) deviations (e.g., failure to arm ground spoilers/speed brakes); failure to arm ground spoilers); CertificationType of Braking regulations and operating regulations require • Minimum equipment list (MEL)/dispatch deviation guide • Minimum equipment list (MEL)/dispatch deviation correction factors to be applied to actual landing distances to (DDG) conditions (e.g., thrust reversers, brake unit, guide (DDG) conditions (e.g., thrust reversers, brake compensateActual landing for: distances are determined during certification anti-skid or ground spoilers/speed brakes inoperative); unit, anti-skid or ground spoilers inoperative); and, flight testing under the following conditions: and, • Fifty percent of the head wind component; and, • System malfunctions (e.g., increasing final approach • Flying an optimum flight segment from 50 feet over the • System malfunctions (e.g., increasing final approach • one hundred fifty percent of the tail wind component. speed and/or affecting lift-dumping capability and/or runway threshold to the flare; speed and/or affecting lift-dumping capability and/or braking capability). braking capability). Type• of Achieving Braking a firm touchdown (i.e., not extending the flare); and, The approximate effects of these factors on landing distance The approximate effects of these factors on landing distance Actual landing distances are determined during certification are shown in Figure 3 (page 169). • Using maximum pedal braking, beginning at main- are shown in Figure 3. flight testing under the following conditions: landing-gear touchdown. Airport Elevation • Flying an optimum flight segment from 50 feet over the Airport Elevation Publishedrunway actual threshold landing to distances the flare; seldom can be achieved in High airport elevation or high density altitude results in a higher line operations. High airport elevation or high density altitude results in a higher • Achieving a firm touchdown (i.e., not extending the true airspeed (TAS) and groundspeed, and a corresponding true airspeed (TAS) and groundspeed, and a corresponding flare); and, longer landing distance, compared to low airport elevation or Landing distances published for automatic landings with longer landing distance, compared to low airport elevation or low density altitude. autobrakes• Using are maximum more achievable pedal braking, in line operations.beginning at main- low density altitude. landing-gear touchdown. For example, at 1,000 feet airport elevation, a landing distance Airspeed Over Runway Threshold For example, at 1,000 feet airport elevation, a landing distance factor of 1.05 to 1.10 (depending on runway condition) must Published actual landing distances seldom can be achieved in factor of 1.05 to 1.10 (depending on runway condition) must be applied to the landing distance achieved at sea-level airport lineA 10 operations. percent increase in final approach speed results in a 20 be applied to the landing distance achieved at sea-level airport elevation. percent increase in landing distance. This assumes a normal elevation. Lflareanding and distances touchdown published (i.e., not for allowingautomatic the landings aircraft with to floatau- Runway Slope tobrakesand bleed are excess more airspeed).achievable in line operations.

Runway slope (gradient) has a direct effect on landing distance. Height Over Threshold

For example, a 1 percent downhill slope increases landing Crossing the runway threshold at 100 feet (50 feet higher than distance by 10 percent (factor of 1.1). However, this effect is recommended) results in an increase in landing distance of MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 167

168 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Landing Distance Factors

Reference (No Reverse Thrust)

1,000 Feet Elevation

10-knot Tail Wind

Final Approach Speed + 10 Knots

100 Feet at Threshold

Long Flare

No Ground Spoilers

Wet Runway

Compacted Snow

Water and Slush

Icy Runway

1.0 1.2 1.4 1.6 2.0 3.0 3.5

Required Landing Distance (Wet Runway) 1.92

Landing Distance Factor

Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 3

aboutAirspeed 1,000 Over feet (305 Runway meters), Threshold regardless of runway condition flareFor example, and touchdown a 5 percent (i.e., notincrease allowing in thefinal aircraft approach to float speed and and aircraft model (Figure 4, page 170). bleedincreases excess landing airspeed). distance by: A 10 percent increase in final approach speed results in a 20 • Ten percent, if a normal flare and touchdown are Flarepercent Technique increase in landing distance. This assumes a normal conducted (deceleration on the ground); or, Extending the flare (i.e., allowing the aircraft to float and bleed • Thirty percent, if touchdown is delayed (deceleration excess airspeed) increases the landing distance. during an extended flare). 168 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009

FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 169 brakes• Increasedto deploy automaticallylanding speed should because be called; of inoperative the crew then roll Effect of Threshold-crossing Height shouldspoilers manually (maneuverability); activate the ground spoilers/speed brakes. On Landing Distance • Increased landing distance because of inoperative ground Delay in lowering the nose landing gear to the runway main- spoilers (lift-dumping capability); and, tains lift, resulting in less load on the main landing gear and, 1,000 Feet (300 Meters) hence,• Increased less braking landing capability. distance becauseDepending of inoperative on the aircraft normal

100 Feet at Threshold design,braking this also system delays (braking the nosewheel capability). spin-up signal, which is required for optimum operation of the anti-skid system on 50 Feet at Threshold someThe aircraft aircraft. operating manual (AOM) and the quick reference handbook (QRH) provide the applicable landing speed MEL/DDGcorrections Conditions and landing distance corrections for many malfunctions (including their effects).

Source: Flight Safety Foundation Approach-and-landing Accident When operating with an MEL/DDG condition affecting land- Reduction (ALAR) Task Force ing speed or braking capability, the applicable landing speed correctionLanding and Distance landing distance Factors factor must be included in Figure 4 landing-distance computation. Landing distance factors result from either:

HeightGround Over Spoilers Threshold Not Armed System• A landingMalfunctions speed correction (e.g., because of a failure affecting stall margin or maneuverability); or, Crossing the runway threshold at 100 feet (50 feet higher than System malfunctions, such as hydraulic system low pressure, Several runway-overrun events have been caused by ground • Reduced lift-dumping capability or reduced braking recommended) results in an increase in landing distance of may result in multiple adjustments to landing speed and land- spoilers not being armed while the aircraft were being operated capability (e.g., because of a failure affecting ground aboutwith thrust 1,000 reversers feet (305 inoperative.meters), regardless of runway condition ing distance, such as: and aircraft model (Figure 4). spoilers or brakes). • Increased landing speed because of inoperative slats/ On most transport category aircraft, the ground spoilers extend Flare Technique Whetherflaps published (stall margin);in the AOM/QRH or computed by the pilot, when reverse thrust is selected (regardless of whether the the combination of landing distance factors for multiple failures • Increased landing speed because of inoperative roll ground spoilers are armed or not); this design feature must not usually complies with the following: Extendingbe relied upon the flare. The (i.e.,ground allowing spoilers the must aircraft be armedto float per and SOPs. bleed spoilers (maneuverability); excess airspeed) increases the landing distance. • If landing speed corrections are added, the corresponding • Increased landing distance because of inoperative ground Failure to arm the spoilers results in a typical landing distance landing distance factors must be multiplied; For example, a 5 percent increase in final approach speed spoilers/speed brakes (lift-dumping capability); and, factor of 1.3 (1.4 if combined with inoperative thrust reversers). • If only the highest airspeed correction is considered, then increases landing distance by: • Increased landing distance because of inoperative normal only the greatest landing distance factor must be braking system (braking capability). The• automaticTen percent, extension if a normal of ground flare and spoilers touchdown should are be considered; or, monitored.conducted Failure (deceleration of the on ground the ground); spoilers or, to deploy automatically should be called; the crew then should manually The• aircraft If two operating landing distance manual (AfactorsOM) areand considered, the quick reference and one activate• Thirty the ground percent, spoilers. if touchdown is delayed (deceleration handbook(or (QRboth)H )are provide related the toapplicable lift-dumping landing or speed braking, correc the- during an extended flare). tions andlanding landing distance distance factors corrections must be for multiplied. many malfunctions Delay in lowering the nose landing gear to the runway (including their effects). Groundmaintains Spoilers/Speed lift, resulting in less Brakes load on Not the Armed main landing gear Figure 3 shows typical landing distance factors for various and, hence, less braking capability. This also delays the runway conditions and operational factors. Severalnosewheel runway-overrun spin-up signal, events which have is beenrequired caused for by optimum ground Landing Distance Factors spoilers/speedoperation of the brakes anti-skid not beingsystem armed on some while aircraft. the aircraft were being operated with thrust reversers inoperative. LSummaryanding distance factors result from either: MEL/DDG Conditions • A landing speed correction (e.g., because of a failure On most transport category aircraft, the ground spoilers/speed When assessing the landing distance for a given landing, all the followingaffecting factorsstall margin should or maneuverability);be considered and or, should be brakesWhen extendoperating when with reverse an MEL/DDG thrust is selected condition (regardless affecting of combined as specified in the applicable AOM/QRH: whetherlanding speedthe ground or braking spoilers/speed capability, brakes the applicableare armed orlanding not); • Reduced lift-dumping capability or reduced braking thisspeed design correction feature and must landing not be distance relied upon factor. The must ground be included spoil- •capability MEL/DDG (e.g., dispatch because conditions, of a failure as applicable; affecting ground ers/speedin landing-distance brakes must computation. be armed per SOPs. spoilers/speed brakes or brakes). • In-flight failures, as applicable; FailureSystem to Malfunctionsarm the spoilers results in a typical landing distance Whether• Weather published conditions in the A (e.g.,OM/QR windH andor computed gusts, suspected by the pilot, wind factor of 1.3 (1.4 if combined with inoperative thrust reversers). the combinationshear, icing of conditions/icelanding distance accretion); factors for multiple failures System malfunctions, such as hydraulic system low pressure, usually complies with the following: • Runway condition; Themay resultautomatic in multiple extension adjustments of ground to landing spoilers/speed speed and landingbrakes • If landing speed corrections are added, the corresponding shoulddistance, be such monitored. as: Failure of the ground spoilers/speed •landing Use of distance braking factors devices must (e.g.,be multiplied; thrust reversers, autobrakes); and, • Increased landing speed because of inoperative slats/ flaps (stall margin); • Airport elevation and runway slope.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 169 170 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 • If only the highest airspeed correction is considered, more than 12,500 pounds/5,700 kilograms, detailed studies then only the greatest landing distance factor must be of 76 ALAs and serious incidents in 1984 through 1997 and considered; or, audits of about 3,300 flights. • If two landing distance factors are considered, and one (or both) are related to lift-dumping or braking, the Related Reading From FSF Publications landing distance factors must be multiplied. Flight Safety Foundation (FSF) Editorial Staff. “Business Jet Figure 3 shows typical landing distance factors for various Overruns Wet Runway After Landing Past Touchdown Zone.” runway conditions and operational factors. Accident Prevention Volume 56 (December 1999).

FSF Editorial Staff. “Unaware of Strong Crosswind, Fokker Summary Crew Loses Control of Aircraft on Landing.” Accident Preven- tion Volume 56 (November 1999). When assessing the landing distance for a given landing, all the following factors should be considered and should be combined Yager, Thomas J. “The Joint FAA/NASA Aircraft/Ground Ve- as specified in the applicable OA M/QRH: hicle Runway Friction Program.” Flight Safety Digest Volume • MEL/DDG dispatch conditions, as applicable; 8 (March 1989). • In-flight failures, as applicable; • Weather conditions (e.g., wind and gusts, suspected wind Regulatory Resources shear, icing conditions/ice accretion); International Civil Aviation Organization (ICAO). Preparation • Runway condition; of an Operations Manual. Second edition – 1997. • Use of braking devices (e.g., thrust reversers, autobrakes); U.S. Federal Aviation Administration (FAA). Federal Avia- and, tion Regulations. 121.97 “Airports: Required data,” 121.117 • Airport elevation and runway slope. “Airports: Required data,” 121.171 “Applicability,” 121.195 “Airplanes: Turbine-engine-powered: Landing limitations: The following FSF ALAR Briefing Notes provide information Destination airports.” 121.197 “Airplanes: Turbine-engine- to supplement this discussion: powered: Landing limitations: Alternate airports.” January 1, 2000. • 1.4 — Standard Calls; • 8.2 — The Final Approach Speed; FAA. Advisory Circular 91-6A, Water, Slush, and Snow on the Runway. May 24, 1978. • 8.4 — Braking Devices; and, • 8.5 — Wet or Contaminated Runways.◆ Joint Aviation Authorities. Joint Aviation Requirements – Operations 1. Commercial Air Transportation (Aeroplanes). Reference 1.515 “Landing – Dry Runways,” 1.520 “Landing – Wet and contaminated runways.” March 3, 1998. 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and U.K. Civil Aviation Authority (CAA). Aeronautical Informa- Controlled-flight-into-terrain Accidents.”Flight Safety Digest tion Circular (AIC) 11/98, Landing Performance of Large Volume 17 (November–December 1998) and Volume 18 Transport Aeroplanes. January 27, 1998. (January–February 1999): 1–121. The facts presented by the FSF ALAR Task Force were based on analyses of 287 U.K. CAA. AIC 61/1999, Risks and Factors Associated with fatal approach-and-landing accidents (ALAs) that occurred Operations on Runways Affected by Snow, Slush or Water. in 1980 through 1996 involving turbine aircraft weighing June 3, 1999.

170 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 171 FSF ALAR Briefing Note 8.4 — Braking Devices

The following braking devices are used to decelerate the air- • Increased aerodynamic drag, which contributes to air- craft until it stops: craft deceleration; and, • Lift-dumping, which increases the load on the • ground spoilers/speed brakes; wheels and, thus, increases wheel-brake efficiency (Figure • Wheel brakes (including anti-skid systems and auto- 1). brake systems); and, Wheel Brakes • Thrust-reverser systems. Braking action results from the friction force between the Statistical Data tires and the runway surface.

The Flight Safety Foundation Approach-and-landing Acci- The friction force is affected by: dent Reduction (ALAR) Task Force found that runway ex- • Aircraft speed; cursions and runway overruns were involved in 20 percent of 76 approach-and-landing accidents and serious incidents • Wheel speed (i.e., free-rolling, skidding or locked); 1 worldwide in 1984 through 1997. • Tire condition and pressure (i.e., friction surface); The task force also found that delayed braking action during • Runway condition (i.e., runway friction coefficient); the landing roll-out was involved in some of the accidents • The load applied on the wheel; and, and serious incidents in which slow/delayed crew action was a causal factor.2 Slow/delayed crew action was a causal factor • The number of operative brakes (as shown by the mini- in 45 percent of the 76 accidents and serious incidents. mum equipment list [MEL]/dispatch deviation guide [DDG]).

Braking Devices Braking force is equal to the load applied on the wheel multi- plied by the runway friction coefficient. Ground Spoilers/Speed Brakes Anti-skid systems are designed to maintain the wheel-skid- Ground spoilers/speed brakes usually deploy automatically ding factor (also called the slip ratio) near the point providing (if armed) upon main-landing-gear touchdown or upon acti- the maximum friction force, which is approximately 10 per- vation of thrust reversers. cent on a scale from zero percent (free-rolling) to 100 percent (locked wheel), as shown by Figure 2. Ground spoilers/speed brakes provide two aerodynamic ef- fects: With anti-skid operative, maximum pedal braking results

172 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Effects of Nosewheel Contact and Ground Spoilers On Weight-on-wheels and Aerodynamic Drag Effects of Nosewheel Contact andand GroundGround SpoilersSpoilers On Weight-on-wheels and Aerodynamic Drag85 Percent Weight on On Weight-on-wheels and Aerodynamic DragMain Wheels 85 Percent Weight on 85 PercentPlus Weight on Negligible Weight on 60 Percent Weight on 130MainMain Percent Wheels Wheels Drag Main Wheels Main Wheels Increase FromPlusPlus Spoilers NegligibleNegligible WeightWeight on 60 Percent Weight onon 130130 PercentPercent DragDrag MainMain WheelsWheels Main Wheels IncreaseIncrease FromFrom SpoilersSpoilers

Touchdown Nosewheel Down Ground Spoilers (VREF) Extended TouchdownTouchdown Nosewheel Down GroundGround SpoilersSpoilers VREF = Reference landing(V speed) Extended (VREFREF) Extended Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

VREF = Reference landing speed VREF = Reference landing speed Source:Source: FlightFlight SafetySafety FoundationFoundation Approach-and-landing Accident ReductionFigure (ALAR) 1 Task ForceForce

Figure 1 Thrust Reversers Effect of Anti-skid on Friction Force And Slip Ratio ThrustreverserThrust reversersdeceleration ReversersReversers provide force at ahigh deceleration airspeed. force that is EffectEffect ofof Anti-skidAnti-skid on Friction Force independent of runway condition. Anti-skid Activation 100 Thrust reversers provide a deceleration force that is AndAnd Slip Ratio ThrustThrust Reversers reversers provide a deceleration force that is 90 Thrust-reverserindependentindependent ofof runwayefficiencyrunway condition.condition. is higher at high airspeed (Figure Anti-skidAnti-skid ActivationActivation 80100 100 3);Thrust therefore, reversers thrust provide reversers a deceleration must be force selected that isas indepen early as- 709090 Thrust-reverser efficiency is higher at high airspeed (Figure possibledentThrust-reverser of runway after condition.touchdownefficiency is (in higher accordance at high airspeed with standard (Figure 608080 operating3); therefore, procedures thrustthrust reversers[SOPs]).reversers mustmust bebe selectedselected asas earlyearly asas 507070 possible afterafter touchdowntouchdown (in(in accordanceaccordance withwith standardstandard 4060 Thrust-reverser efficiency is higher at high airspeed (Figure 60 operating proceduresprocedures [SOPs]).[SOPs]). 305050 204040 Friction Force (Percent) Friction Force 103030 Typical Decelerating Forces 02020 During Landing Roll

Friction Force (Percent) Friction Force 0 5 10 15 20 30 40 50 60 70 80 90 100 Friction Force (Percent) Friction Force Free-rolling1010 Wheel Locked Wheel TypicalTypical DeceleratingDecelerating ForcesForces 00 Slip Ratio (Percent) Autobrake Low Mode 00 5 5 10 10 15 15 20 20 30 30 40 40 50 60 70 80 90 100 DuringDuring LandingLanding RollRoll Free-rollingFree-rolling Wheel Wheel Locked Wheel Source: Flight Safety Foundation Approach-and-landing Accident AutobrakeAutobrake Low Low Mode Mode Reduction (ALAR) Task ForceSlipSlip Ratio (Percent) Source:Source: FlightFlight SafetySafety FoundationFoundation Approach-and-landing Accident ReductionReduction (ALAR)(ALAR) TaskTask ForceForceFigure 2 Autobrake Demand FigureFigure 2 AutobrakeAutobrake Demand Demand

With anti-skid operative, maximum pedal braking results Force Stopping typically in a deceleration rate of eight knots to 10 knots per Stopping Force Stopping second.WithtypicallyWith anti-skidanti-skid in a deceleration operative,operative, ratemaximum of eight pedal knots brakingto 10 knots results per Force Stopping typicallysecond.typically inin aa decelerationdeceleration raterate ofof eighteight knots to 10 knots per 140 120 100 80 60 40 20 Autobrakesecond.second. systems are designed to provide a selectable Airspeed (Knots) decelerationAutobrake systemsrate, typically are designed between to three provide knots a per selectable second andde- 140140 120 120 100 100 80 80 60 60 40 40 20 20 sixAutobrakecelerationAutobrake knots per rate, systemssystemssecond. typically areare betweendesigneddesigned three to provideknots per a second selectable and Total Stopping ForceAirspeedAirspeed (Knots) (Knots)Reverse Thrust decelerationsixdeceleration knots per rate, rate,second. typicallytypically between three knots per second and Aerodynamic Drag Braking and Rolling Drag sixsix knotsknots perper second.second. TotalTotal StoppingStopping ForceForce ReverseReverse Thrust Thrust When a low autobrake deceleration rate (referred to hereafter Source: Flight Safety Foundation Approach-and-landing Accident AerodynamicAerodynamic Drag Drag BrakingBraking and and Rolling Rolling Drag Drag asWhen a “LOW” a low mode) autobrake is selected, deceleration brake pressure rate (referred is applied to hereafter usually Reduction (ALAR) Task Force When a low autobrake deceleration rate (referred to hereafter afterWhenas a a“ LOspecific a lowW” autobrakemode) time delay is selected, deceleration to give brake priority rate pressure to(referred the thrust-reverseris applied to hereafter usu- Source: FlightFlight SafetySafety FoundationFoundation Approach-and-landing Approach-and-landing Accident Accident decelerationasallyas a a “LOW”“LOW”after a specificforce mode)mode) at isis high selected,timeselected, airspeed. delay brake to givepressure priority is applied to the usually thrust- Reduction (ALAR)(ALAR) TaskTask ForceForceFigure 3 afterafter a a specific specific timetime delaydelay toto givegive priority to the thrust-reverser decelerationdeceleration forceforce atat highhigh airspeed. FigureFigure 33 174 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 173 174174 FLIGHT SAFETY FOUNDATION •• FLIGHTFLIGHT SAFETYSAFETY DIGESTDIGEST •• AUGUST–NOVEMBER AUGUST–NOVEMBER 2000 2000 3); therefore, thrust reversers must be selected as early as pos- • Rolling drag. sible after touchdown (in accordance with standard operating procedures [SOPs]). Autobrake activation is inhibited because the total stopping force exceeds the selected rate of the autobrakes or because Thrust reversers should be returned to reverse idle at low air- of the autobrake time delay. speed (to prevent engine stall or foreign object damage) and stowed at taxi speed. As airspeed decreases, total stopping force decreases because of a corresponding decrease in: Nevertheless, maximum reverse thrust can be maintained to a • Aerodynamic drag; and, complete stop in an emergency. • Reverse thrust efficiency.

Runway Conditions When the total stopping force becomes lower than the auto- brake setting or when the autobrake time delay has elapsed, Runway contamination increases impingement drag (i.e., the wheel brakes begin contributing to the total deceleration drag caused by water or slush sprayed by the tires onto the and stopping force. aircraft) and displacement drag (i.e., drag created as the tires move through a fluid contaminant [water, slush, loose snow] Typically, at 60 knots indicated airspeed (KIAS) to 80 KIAS, on the runway), and affects braking efficiency. the thrust-reverser levers are returned to the reverse-idle posi- tion (then to the stow position at taxi speed). The following landing distance factors are typical: • Wet runway, 1.3 to 1.4; As a result, the wheel brakes’ contribution to stopping force increases to maintain the desired deceleration rate (autobrake • Water-contaminated or slush-contaminated runway, demand) to a complete stop or until the pilot takes over with 2.0 to 2.3; pedal braking. • Compacted-snow-covered runway, 1.6 to 1.7; and, • Icy runway, 3.5 to 4.5. Ground Spoilers/Speed Brakes, Thrust Reversers and Brakes Stop the Aircraft Typical Landing Roll Figure 4 shows the respective contributions of the different Figure 3 shows a typical landing roll and the relation of the braking devices to total stopping energy, as a function of the different deceleration forces to the total stopping force as a achieved or desired stopping distance. function of decelerating airspeed (from touchdown speed to taxi speed). Figure 4 shows the following: • For a given braking procedure (maximum pedal brak- The ground spoilers are armed and the autobrakes are select- ing or autobrake mode), the stopping distance; and, ed to the “LOW” mode (for time-delayed brake application). • For a desired or required stopping distance, the nec- The autobrake demand in “LOW” mode (typically, three essary braking procedure (maximum pedal braking or knots per second constant deceleration rate) is equivalent, at autobrake mode). a given gross weight, to a constant deceleration force.

At touchdown, the ground spoilers automatically extend and Factors Affecting Braking maximum reverse thrust is applied. The following factors have affected braking in runway excur- The resulting total stopping force is the combined result of: sions or runway overruns: • Aerodynamic drag (the normal drag of the airplane • Failure to arm ground spoilers/speed brakes, with thrust during the roll-out, not the drag produced by the in- reversers deactivated (e.g., reliance on a thrust-reverser correct technique of keeping the nose high during an signal for ground-spoilers extension, as applicable); extended landing flare); • Failure to use any braking devices (i.e., reliance on the • Reverse thrust; and, incorrect technique of maintaining a nose-high attitude after touchdown to achieve aerodynamic braking);

174 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Effect of Braking Devices on Stopping Energy and Stopping Distance

Maximum Pedal Braking (Typically, 8 to 10 Knots per Second) No Braking

80 Autobrake Medium Mode (Typically, 6 Knots per Second) 70

60 Autobrake Low Mode (Typically, 3 Knots per Second) 50 Aerodynamic Drag

40 Maximum Reverse Thrust

30

20 Percent of Total Stopping Energy Total of Percent 10 Braking and Rolling Drag

1,000 2,000 3,000 4,000 Stopping Distance (Meters) on Dry Runway

Note: Examples assume that airplane touches down at maximum landing weight and at landing reference speed (VREF) on a dry runway at sea level and standard pressure and temperature. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 4

(The nosewheel should be lowered onto the runway as soon alternate braking or to emergency braking in response • Spongy pedals (air in the hydraulic wheel-braking • Select thrust reversers as soon as appropriate with as possible to increase weight-on-wheels and activate aircraft to abnormal braking; or, system); maximum reverse thrust (this increases safety on dry systems associated with the nose-landing-gear squat switch- • Crosswindrunways and landing wet runways, and incorrect and is mandatory braking technique. on runways • Anti-skid tachometer malfunction; es.) contaminated by standing water, snow, slush or ice); •• Asymmetric Failure to adequately thrust (i.e., recover one engine from lossabove of idlethe normalin for- • Monitor and call “spoilers” extension; wardbraking thrust system; or one engine failing to go into reverse Summary •thrust); Late selection of thrust reversers; • Be ready to take over from the autobrakes, if required; The following can ensure optimum braking during the land- • Brake unit inoperative (e.g., reported as a “cold brake” • No takeover or late takeover from autobrakes, when ing• roll: Monitor engine operation in reverse thrust (exhaust gas [i.e.,required; a brake whose temperature is lower, by a speci- temperature [EGT], evidence of surge); fied amount, than the other brakes on the same landing • Arm ground spoilers/speed brakes; •gear]); No switching or late switching from normal braking to • Monitor airspeed indication (or fluctuations) and return alternate braking or to emergency braking in response • Armengines autobrakes to reverse with idle the at most the appropriatepublished indicated mode for • Spongyto abnormal pedals braking; (air in theor, hydraulic wheel-braking sys- prevailingairspeed; conditions (short runway, low visibility, tem); contaminated runway); • Crosswind landing and incorrect braking technique. • If required, use maximum pedal braking; and, • Anti-skid tachometer malfunction; • Select thrust reversers as soon as appropriate with •maximum As a general reverse rule, thrustdo not (this stop increases braking safetyuntil assured on dry • Failure to adequately recover from loss of the normal runwaysthat the aircraft and wet will runways, stop within and theis mandatory remaining runwayon run- Summarybraking system; wayslength. contaminated by standing water, snow, slush or The• following late selection can ensure of thrust optimum reversers; braking during the landing ice); The following FSF ALAR Briefing Notes provide information roll: • No takeover or late takeover from autobrakes, when to supplement• Monitor thisand discussion:call “spoilers” extension; •required; Arm ground spoilers; • Be8.3 ready— Landing to take Distances over from; the autobrakes, if required; •• No Arm switching autobrakes or late with switching the most from appropriate normal brakingmode for to • 8.5 — Wet or Contaminated Runways; and, prevailing conditions (short runway, low visibility, contaminated runway); • 8.7 — Crosswind Landings.♦

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 175 176 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 • Monitor engine operation in reverse thrust (exhaust gas chanics Bulletin Volume 47 (May–June 1999). temperature [EGT], evidence of surge); FSF Editorial Staff. “Monitoring Aircraft-tire Pressure Helps • Monitor airspeed indication (or fluctuations) and return Prevent Hazardous Failures.” Aviation Mechanics Bulletin engines to reverse idle at the published indicated air- Volume 47 (March–April 1999). speed; • If required, use maximum pedal braking; and, FSF Editorial Staff. “Attempted Go-around with Deployed Thrust Reversers Leads to Learjet Accident.” Accident Pre- • As a general rule, do not stop braking until assured vention Volume 56 (January 1999). that the aircraft will stop within the remaining runway length. King, Jack L. “During Adverse Conditions, Decelerating to Stop Demands More from Crew and Aircraft.” Flight Safety The following FSF ALAR Briefing Notes provide informa- Digest Volume 12 (March 1993). tion to supplement this discussion: • 8.3 — Landing Distances; Yager, Thomas J. “The Joint FAA/NASA Aircraft/Ground Vehicle Runway Friction Program.” Flight Safety Digest Vol- • 8.5 — Wet or Contaminated Runways; and, ume 8 (March 1989). • 8.7 — Crosswind Landings.◆ Regulatory Resources References International Civil Aviation Organization (ICAO). Prepara- 1. Flight Safety Foundation. “Killers in Aviation: FSF Task tion of an Operations Manual. Second edition – 1997. Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety U.S. Federal Aviation Administration (FAA). Federal Avia- Digest Volume 17 (November–December 1998) and tion Regulations. 121.97 “Airports: Required data,” 121.117 Volume 18 (January–February 1999): 1–121. The facts “Airports: Required data,” 121.171 “Applicability,” 121.195 presented by the FSF ALAR Task Force were based on “Airplanes: Turbine-engine-powered: Landing limitations: analyses of 287 fatal approach-and-landing accidents Destination airports.” 121.197 “Airplanes: Turbine-engine- (ALAs) that occurred in 1980 through 1996 involving powered: Landing limitations: Alternate airports.” January 1, turbine aircraft weighing more than 12,500 pounds/5,700 2000. kilograms, detailed studies of 76 ALAs and serious inci- FAA. Advisory Circular 91-6A, Water, Slush, and Snow on dents in 1984 through 1997 and audits of about 3,300 the Runway. May 24, 1978. flights. 2. The Flight Safety Foundation Approach-and-landing Joint Aviation Authorities. Joint Aviation Requirements – Accident Reduction (ALAR) Task Force defines causal Operations 1, Commercial Air Transportation (Aeroplanes). factor as “an event or item judged to be directly instru- 1.515 “Landing – Dry Runways,” 1.520 “Landing – Wet and mental in the causal chain of events leading to the ac- contaminated runways.” March 3, 1998. cident [or incident].” Each accident and incident in the U.K. Civil Aviation Authority (CAA). Aeronautical Informa- study sample involved several causal factors. tion Circular (AIC) 11/98, Landing Performance of Large Transport Aeroplanes. January 27, 1998.

Related Reading From FSF Publications U.K. CAA. AIC 61/1999, Risks and Factors Associated with Operations on Runways Affected by Snow, Slush or Wa- FSF Editorial Staff. “Managing Aircraft-tire Wear and Dam- ter. June 3, 1999. age Requires Adherence to Removal Limits.” Aviation Me-

176 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 177 FSF ALAR Briefing Note 8.5 — Wet or Contaminated Runways

The conditions and factors associated with landing on a wet run- surface is covered with water, or equivalent, less than speci- way or a runway contaminated by standing water, snow, slush or fied [for a contaminated runway] or when there is sufficient ice should be assessed carefully before beginning the approach. moisture on the runway surface to cause it to appear reflective, but without significant areas of standing water.”

Statistical Data Contaminated Runway

The Flight Safety Foundation Approach-and-landing Accident JAA says that a runway is contaminated “when more than 25 Reduction (ALAR) Task Force found that wet runways were percent of the runway surface area (whether in isolated areas involved in 11 approach-and-landing accidents and serious or not) within the required length and width being used is incidents involving runway overruns and runway excursions covered by the following: worldwide in 1984 through 1997.1 • “Surface water more than 3.0 mm [millimeters] (0.125 in [inch]) deep, or by slush or loose snow, equivalent to Defining Runway Condition more than 3.0 mm (0.125 in) of water; • “Snow which has been compressed into a solid mass Dry Runway which resists further compression and will hold together

2 or break into lumps if picked up (compacted snow); The European Joint Aviation Authorities (JAA) defines dry or, runway as “one which is neither wet nor contaminated, and includes those paved runways which have been specially • “Ice, including wet ice.” prepared with grooves or porous pavement and maintained to retain ‘effectively dry’ braking action even when moisture The U.S. Federal Aviation Administration3 says that a runway is present.” is considered contaminated “whenever standing water, ice, snow, slush, frost in any form, heavy rubber, or other sub- Damp Runway stances are present.”

JAA says that a runway is considered damp “when the surface Factors and Effects is not dry, but when the moisture on it does not give it a shiny appearance.” Braking Action The presence on the runway of a fluid contaminant (water, slush Wet Runway or loose snow) or a solid contaminant (compacted snow or ice) adversely affects braking performance (stopping force) by: JAA says that a runway is considered wet “when the runway

178 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 • Reducing the friction force between the tires and the friction between the tire and the runway, and in a correspond- runway surface. The reduction of friction force depends ing reduction of friction coefficient. on the following factors: Main wheels and nosewheels can be affected by hydroplan- – Tire-tread condition (wear) and inflation pressure; ing. Thus, hydroplaning affects nosewheel steering, as well as – Type Tire-tread of runway condition surface; (wear) and, and inflation pressure; brakingHydroplaning performance. always occurs to some degree when operating on a fluid-contaminated runway. – Anti-skid Type of runway system surface; performance; and, and, Hydroplaning always occurs to some degree when operating • Creating– Anti-skid a layer system of performance;fluid between and, the tires and the onThe a fluid-contaminateddegree of hydroplaning runway. depends on the following factors: runway, thus reducing the contact area and creating a • Creating a layer of fluid between the tires and the • Absence of runway surface roughness and inadequate risk of hydroplaning (partial or total loss of contact and The degree of hydroplaning depends on the following fac- runway, thus reducing the contact area and creating a drainage (e.g., absence of transverse saw-cut grooves); friction between the tires and the runway surface). tors: risk of hydroplaning (partial or total loss of contact and • Depth and type of contaminant; friction between the tires and the runway surface). • Absence of runway surface roughness and inadequate Fluid contaminants also contribute to stopping force by: •drainage Tire inflation (e.g., pressure;absence of transverse saw-cut grooves); Fluid• contaminantsResisting forward also movement contribute of to the stopping wheels force (i.e., causingby: •• d Groundspeed;epth and type and,of contaminant; displacement drag); and, • Resisting forward movement of the wheels (i.e., causing •• Tire Anti-skid inflation operation pressure; (e.g., locked wheels). • Creatingdisplacement spray drag that); and, strikes the landing gear and airframe (i.e., causing impingement drag). Certification • groundspeed; and, • Creating spray that strikes the landing gear and airframe A minimum hydroplaning speed is defined usually for each regulations require spray to be diverted away from (i.e., causing impingement drag). Certification aircraft• Anti-skid type and operation runway contaminant.(e.g., locked wheels). engine air inlets. regulations require spray to be diverted away from engine air inlets. AHydroplaning minimum hydroplaning may occur at speed touchdown, is defined preventing usually the for wheels each The resulting braking action is the net effect of the above stop- aircraftfrom spinning type and and runway from contaminant.sending the wheel-rotation signal to ping forces (Figure 1 and Figure 2). The resulting braking action is the net effect of the above various aircraft systems. stopping forces (Figure 1 and Figure 2, page 181). Hydroplaning may occur at touchdown, preventing the wheels Hydroplaning (Aquaplaning) fromConducting spinning a and firm from touchdown sending thecan wheel-rotation reduce hydroplaning signal to at varioustouchdown. aircraft systems. Typical Decelerating Forces During Landing Roll ConductingDirectional a Controlfirm touchdown can reduce hydroplaning at touchdown. Autobrake Low Mode On a contaminated runway, directional control should be Directionalmaintained using Control the rudder pedals; do not use the nosewheel- steering tiller until the aircraft has slowed to taxi speed. On a contaminated runway, directional control should be Autobrake Demand maintainedOn a wet runway using the or arudder contaminated pedals; do runway, not use use the ofnosewheel- nosewheel steeringsteering tiller above until taxi the aircraftspeed mayhas slowedcause tothe taxi nosewheels speed. to hydroplane and result in the loss of nosewheel cornering force Stopping Force Stopping Owithn a wet consequent runway or loss a contaminated of directional runway, control. use of nosewheel steering above taxi speed may cause the nosewheels to hydro-

140 120 100 80 60 40 20 planeIf differential and result braking in the loss is necessary,of nosewheel pedal cornering braking force should with be Airspeed (Knots) consequentapplied on lossthe ofrequired directional side control.and should be released on the opposite side to regain directional control. (If braking is not Total Stopping Force Reverse Thrust Ifcompletely differential released braking on is thenecessary, opposite pedal side, braking brake demand should maybe Aerodynamic Drag Braking and Rolling Drag appliedcontinue on to the exceed required the sideanti-skid and shouldregulated be braking;released thus,on the no oppositedifferential side braking to regain may directional be produced.) control. (If braking is not Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force completely released on the opposite side, brake demand may continueLanding to exceed Distances the anti-skid regulated braking; thus, no Figure 1 differential braking may be produced.) Landing distances usually are published in aircraft operating Hydroplaning occurs when the tire cannot squeeze any more manuals (AOMs)/quick reference handbooks (QRHs) for dry Hydroplaning (Aquaplaning) Landing Distances of the fluid-contaminant layer between its tread and lifts off runways and for runway conditions and contaminants such as the runway surface. Ltheanding following: distances usually are published in aircraft operating Hydroplaning occurs when the tire cannot squeeze any more manuals (AOMs)/quick reference handbooks (QRHs) for dry of the fluid-contaminant layer between its tread and lifts off • Wet; Hydroplaning results in a partial or total loss of contact and runways and for runway conditions and contaminants such as the runway surface. • 6.3 millimeters (0.25 inch) of standing water; Hydroplaning results in a partial or total loss of contact and • 12.7 millimeters (0.5 inch) of standing water; friction between the tire and the runway, and in a corresponding MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE • 6.3 millimeters (0.25 inch) of slush; 179 reduction of friction coefficient. • 12.7 millimeters (0.5 inch) of slush; Main wheels and nosewheels can be affected by hydroplaning. • Compacted snow; and, Thus, hydroplaning affects nosewheel steering, as well as braking performance. • Ice.

180 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Effect of Braking Devices on Stopping Energy and Stopping Distance

Maximum Pedal Braking (Typically, 5 Knots per Second)

Autobrake Medium Mode (Typically, 4 Knots per Second)

Autobrake Low Mode (Typically, 3 Knots per Second) 80 No Braking 70

60 Aerodynamic Drag 50

40 Maximum Reverse Thrust 30

20

Braking and Rolling Drag Percent of Total Stopping Energy Stopping Total of Percent 10

0 1,000 2,000 3,000 4,000 Stopping Distance (Meters) On Runway Contaminated with Water

Note: Examples assume that airplane touches down at maximum landing weight and at reference landing speed (VREF) on a runway contaminated with 6.3 millimeters (0.25 inch) of water at sea level and standard pressure and temperature. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 2

theLanding following: distances are published for all runway conditions, and StoppingIn addition, correction Forces factors (expressed in percentages) are assume: published to compensate for the following: • Wet; • An even distribution of the contaminant; Figure• Airport 1 shows elevation: the distribution of the respective stopping • 6.3 millimeters (0.25 inch) of standing water; forces as a function of decreasing airspeed during a typical • Maximum pedal braking, beginning at touchdown; and, – Typically, +5 percent per 1,000 feet; • 12.7 millimeters (0.5 inch) of standing water; landing roll using autobrakes in “LOW” mode (for a low • An operative anti-skid system. deceleration• Wind component: rate) and maximum reverse thrust. • 6.3 millimeters (0.25 inch) of slush; – Typically, +10 percent per five-knot tail wind Landing• 12.7 distances millimeters for automatic (0.5 inch) landingof slush; (autoland) using the Total stopping force is the combined result of: component; and, autobrake system are published for all runway conditions. • Compacted snow; and, • Aerodynamic– Typically, −drag2.5 percent(the term per refers five-knot to drag head on wind the In •addition, Ice. correction factors (expressed in percentages) are airplanecomponent; during and, the roll-out [including impingement published to compensate for the following: drag on a fluid-contaminated runway]); • Thrust reversers: Landing• Airport distances elevation: are published for all runway conditions, and assume: • Reverse– The thrust-reverserthrust; and, effect depends on runway – Typically, +5 percent per 1,000 feet; condition and type of braking. • An even distribution of the contaminant; • Rolling drag. • Wind component: • Maximum pedal braking, beginning at touchdown; and,– Typically, +10 percent per five-knot tail-wind Stopping Forces component; and, Distribution of Stopping Energy on a • An operative anti-skid system. Figure 1 shows the distribution of the respective stopping forces – Typically, −2.5 percent per five-knot head-wind Contaminated Runway as a function of decreasing airspeed during a typical landing Landing distancescomponent; for and,automatic landing (autoland) using the Figureroll using 2 shows autobrakes the contribution in “LOW” modeto the (for total a stoppinglow deceleration energy autobrake• Thrust system reversers: are published for all runway conditions. ofrate) various and maximum braking devicesreverse thrust.as a function of the desired or – The thrust-reverser effect depends on runway achieved landing distance on a runway contaminated with condition and type of braking. water. 180 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 181 • Rolling drag. Figure 2 can be used to determine: Effect of Braking and Runway Condition • For a given braking procedure (pedal braking or an autobrake mode), the resulting landing distance; or, On Landing Distance 4,000 Distribution of Stopping Energy on a • For a desired or required landing distance, the Contaminated Runway necessary braking procedure (pedal braking or an 3,500 autobrake mode). 3,000 Figure 2 shows the contribution to the total stopping energy of 2,500 various braking devices as a function of the desired or achieved Figure 2 shows that on a runway contaminated with standing water (compared to a dry runway): 2,000 landing distance on a runway contaminated with water.

1,500 Manual Landing • The effect of aerodynamic drag increases because of Pedal Braking Figure 2 can be used to determine: 1,000 Autoland impingement drag; Autobrake Medium

Landing Distance (Meters) Distance Landing 500 Autoland • For a given braking procedure (pedal braking or an • The effect of braking and rolling drag (balance of braking Autobrake Low autobrake mode), the resulting landing distance; or, force and displacement drag) decreases; and, 0 Dry Wet Water Water Slush Slush Compacted Ice 6.3 mm 12.7 mm 6.3 mm 12.7 mm Snow • For a desired or required landing distance, the necessary • Thrust-reverser stopping force is independent of runway (0.25 in) (0.5 in) (0.25 in) (0.5 in) braking procedure (pedal braking or an autobrake condition, and its effect is greater when the deceleration Runway Condition mode). rate is lower (i.e., autobrakes with time delay vs. pedal mm = millimeters in = inch braking [see Figure 1]). Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force Figure 2 shows that on a runway contaminated with standing water (compared to a dry runway): Factors Affecting Landing Distance Figure 3 • The effect of aerodynamic drag increases because of Runway Condition and Type of Braking impingement drag; • The effect of braking and rolling drag (balance of Figure 3 shows the effect of runway condition on landing Effect of Thrust Reversers braking force and displacement drag) decreases; and, distance for various runway conditions and for three braking procedures (pedal braking, use of “LOW” autobrake mode and On Landing Distance • Thrust-reverser stopping force is independent of runway use of “MEDIUM” autobrake mode). 0 condition, and its effect is greater when the deceleration

5 rate is lower (i.e., autobrakes with time delay vs. pedal Figure 3 is based on a 1,000-meter (3,281-foot) landing braking [see Figure 1]). distance (typical manual landing on a dry runway with 10 maximum pedal braking and no reverse thrust). 15 Factors Affecting Landing Distance For each runway condition, the landing distances for a manual 20 (Percent) 25 Runway Condition and Type of Braking landing with maximum pedal braking and an automatic landing Manual Landing with autobrakes can be compared. Pedal Braking 30 Autoland Autobrake Medium Figure 3 shows the effect of runway condition on landing Landing Distance Reduction Reduction Distance Landing 35 Autoland Similarly, for a manual landing or an autoland (with Autobrake Low distance for various runway conditions and for three braking autobrakes), the effect of the runway condition can be seen. 40 procedures (pedal braking, use of “LOW” autobrake mode and Dry Wet Water Water Slush Slush Compacted Ice 6.3 mm 12.7 mm 6.3 mm 12.7 mm Snow use of “MEDIUM” autobrake mode). (0.25 in) (0.5 in) (0.25 in) (0.5 in) When autobrakes are used, braking efficiency is a function of Runway Condition the selected autobrake mode and of the anti-skid activation mm = millimeters in = inch Figure 3 is based on a 1,000-meter (3,281-foot) landing dis- point, whichever is achieved first, as shown by Figure 3 and tance (typical manual landing on a dry runway with maximum Source: Flight Safety Foundation Approach-and-landing Accident Figure 4. Reduction (ALAR) Task Force pedal braking and no reverse thrust).

On a runway contaminated with standing water or slush, the Figure 4 For each runway condition, the landing distances for a manual landing distances with a “MEDIUM” or a “LOW” autobrake landing with maximum pedal braking and an automatic landing mode are similar because the deceleration rate is affected with autobrakes can be compared. primarily by aerodynamic drag, rolling drag and reverse thrust, Total stopping force is the combined result of: When autobrakes are used, the thrust reverser effect (i.e., and because the selected autobrake deceleration rate (e.g., Similarly, for a manual landing or an autoland (with auto- “MEDIUM” mode) cannot be achieved. contribution• Aerodynamic to landing-distance drag (the term reduction) refers is to a functiondrag on of:the brakes), the effect of the runway condition can be seen. airplane during the roll-out [including impingement • The selected deceleration rate and the time delay on Thrust Reversers drag on a fluid-contaminated runway]); autobrake activation, as applicable; and, When autobrakes are used, braking efficiency is a function of the selected autobrake mode and of the anti-skid activation Figure 4 shows the effect of reverse thrust with both thrust • •Reverse Runway thrust; condition and, (contribution of contaminant to the reversers operative. deceleration rate). point, whichever is achieved first, as shown by Figure 3 and

182 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 181 Figure 4. • Approach on glide path and at the target final approach speed; On a runway contaminated with standing water or slush, the landing distances with a “MEDIUM” or a “LOW” autobrake • Aim for the touchdown zone; mode are similar because the deceleration rate is affected pri- • Conduct a firm touchdown; marily by aerodynamic drag, rolling drag and reverse thrust, and because the selected autobrake deceleration rate (e.g., • Use maximum reverse thrust as soon as possible after “MEDIUM” mode) cannot be achieved. touchdown (because thrust reverser efficiency is higher at high airspeed); Thrust Reversers • Confirm the extension of ground spoilers/speed Figure 4 shows the effect of reverse thrust with both thrust brakes; reversers operative. • do not delay lowering the nosewheel onto the runway. This increases weight-on-wheels and activates aircraft When autobrakes are used, the thrust reverser effect (i.e., con- systems associated with the nose-landing-gear squat tribution to landing-distance reduction) is a function of: switches; • The selected deceleration rate and the time delay on • Monitor the autobrakes (on a contaminated runway, the autobrake activation, as applicable; and, selected deceleration rate may not be achieved); • Runway condition (contribution of contaminant to the • As required or when taking over from autobrakes, apply deceleration rate). the pedal brakes normally with a steady pressure; On a dry runway or on a wet runway, the effect of the thrust • For directional control, use rudder pedals (and differential reversers on landing distance depends on the selected autobrake braking, as required); do not use the nosewheel-steering mode and on the associated time delay (e.g., “MEDIUM” tiller; mode without time delay vs. “LOW” mode with time delay), as shown by Figure 1 and Figure 4. • If differential braking is necessary, apply braking on the required side and release the braking on the opposite side; and, Operational Guidelines • After reaching taxi speed, use nosewheel steering with When the destination-airport runways are wet or contaminated, care. the crew should: • Consider diverting to an airport with better runway Summary conditions or a lower crosswind component when actual conditions significantly differ from forecast conditions Conditions associated with landing on a wet runway or a run- or when a system malfunction occurs; way contaminated by standing water, snow, slush or ice require a thorough review before beginning the approach. • Anticipate asymmetric effects at landing that would prevent efficient braking or directional control (e.g., The presence on the runway of water, snow, slush or ice ad- crosswind); versely affects the aircraft’s braking performance by: • Avoid landing on a contaminated runway without anti- • Reducing the friction force between the tires and the skid or with only one thrust reverser operational; runway surface; and, • For inoperative items affecting braking or lift-dumping • Creating a layer of fluid between the tires and the capability, refer to the applicable: runway, which reduces the contact area and leads to a risk of hydroplaning. – AOM/QRH for in-flight malfunctions; or, Directional control should be maintained on a contaminated – Minimum equipment list (MEL) or dispatch deviation runway by using the rudder pedals and differential braking, guide (DDG) for known dispatch conditions; as required; nosewheel steering should not be used at speeds • Select autobrake mode per SOPs (some AOMs/QRHs higher than taxi speed because the nosewheels can hydro- recommend not using autobrakes if the contaminant is plane. not evenly distributed);

182 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 The following FSF ALAR Briefing Notes provide information Stop Demands More from Crew and Aircraft.” Flight Safety to supplement this discussion: Digest Volume 12 (March 1993). • 7.1 — Stabilized Approach; Yager, Thomas J. “The Joint FAA/NASA Aircraft/Ground Ve- • 8.3 — Landing Distances; hicle Runway Friction Program.” Flight Safety Digest Volume 8 (March 1989). • 8.4 — Braking Devices; and, • 8.7 — Crosswind Landings.◆ FSF. “Adapting To Winter Operations.” Accident Prevention Volume 46 (February 1989).

References Regulatory Resources 1. Flight Safety Foundation. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-landing and International Civil Aviation Organization. Preparation of an Controlled-flight-into-terrain Accidents.”Flight Safety Digest Operations Manual. Second edition – 1997. Volume 17 (November–December 1998) and Volume 18 (January–February 1999): 1–121. The facts presented by U.S. Federal Aviation Administration (FAA). Federal Avia- the FSF ALAR Task Force were based on analyses of 287 tion Regulations. 121.97 “Airports: Required data,” 121.117 fatal approach-and-landing accidents (ALAs) that occurred “Airports: Required data,” 121.171 “Applicability,” 121.195 in 1980 through 1996 involving turbine aircraft weighing “Airplanes: Turbine-engine-powered: Landing limitations: more than 12,500 pounds/5,700 kilograms, detailed studies Destination airports.” 121.197 “Airplanes: Turbine-engine- of 76 ALAs and serious incidents in 1984 through 1997 and powered: Landing limitations: Alternate airports.” January audits of about 3,300 flights. 1, 2000.

2. Joint Aviation Authorities. Joint Aviation Requirements FAA. Advisory Circular 91-6A, Water, Slush, and Snow on the — Operations. 1.480 “Terminology.” Runway. May 24, 1978.

3. U.S. Federal Aviation Administration. Flight Services, Joint Aviation Authorities. Joint Aviation Requirements – 7110.10N. Appendix A “Pilot/Controller Glossary.” Operations 1. Commercial Air Transport (Aeroplanes). 1.515 “Landing – Dry Runways,” 1.520 “Landing – Wet and con- taminated runways.” March 3, 1998.

Related Reading From FSF Publications U.K. Civil Aviation Authority (CAA). Aeronautical Informa- tion Circular (AIC) 11/98, Landing Performance of Large Flight Safety Foundation (FSF) Editorial Staff. “Business Jet Transport Aeroplanes. January 27, 1998. Overruns Wet Runway After Landing Past Touchdown Zone.” Accident Prevention Volume 56 (December 1999). U.K. CAA. AIC 61/1999, Risks and Factors Associated with Operations on Runways Affected by Snow, Slush or Water. King, Jack L. “During Adverse Conditions, Decelerating to June 3, 1999.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 183 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

184 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FSF ALAR Briefing Note 8.6 — Wind Information

Wind information is available to the flight crew from two Data averaged over the past two-minute period provide the au- primary sources: tomatic terminal information service (ATIS) or tower-reported “average wind.” • Air traffic control (ATC); and, • Aircraft systems. The average wind is available to the controller on a display terminal. (Some control towers, however, have instantaneous indications of wind direction and wind velocity.) Statistical Data A wind profile of data collected over the past 10-minute period The Flight Safety Foundation Approach-and-landing Acci- shows the maximum (peak) wind value recorded during this dent Reduction (ALAR) Task Force found that adverse wind period; this value is reported as the gust. conditions (i.e., strong crosswinds, tail winds or wind shear) were involved in about 33 percent of 76 approach-and-landing ICAO recommends that gusts be reported if the 10-minute accidents and serious incidents worldwide in 1984 through peak value exceeds the two-minute average wind by 10 knots 1 1997. or more.2 Nevertheless, gust values lower than 10 knots often are provided by AWSs. Reporting Standards Figure 1 shows a 10-minute wind profile with: Recommendations for measuring and reporting wind informa- • A two-minute average wind of 15 knots; and, tion have been developed by the International Civil Aviation Organization (ICAO). • A gust of 10 knots (i.e., a 25-knot peak wind velocity) during the 10-minute period. They have been implemented by ICAO member states’ national weather services (NWSs) and local airport weather services This wind condition would be shown in an aviation routine (AWSs). weather report (METAR) as “XXX15G25KT,” where XXX is the wind direction, referenced to true north. ATIS and tower- reported winds are referenced to magnetic north. Average Wind and Gust If the peak wind value is observed during the past two-minute Wind direction and wind velocity are sampled every second period, the gust becomes part of the average wind (Figure by wind sensors that may be distant from the runway touch- 2). down zone. Such a wind condition would be shown as:

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 185 Wind Profile Resulting in ATC/ATIS Wind Profile Resulting in METAR Report of 15-Knot Wind Velocity Report of 15-Knot Wind Velocity And Gusts to 25 Knots And Gusts to 23 Knots Gust Gust 25 25

20 20

15 15

10 10 Wind (Knots) Wind (Knots) Wind (Knots) Wind (Knots) 5 5

0 0 012345678910 01 23 45678910 Minutes Minutes ATC = Air traffic control METAR = Aviation routine weather report ATIS = Automatic terminal information service Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force Figure 3 Figure 1 TheMaximum two-minute Demonstrated average wind and Crosswindthe 10-minute peak gust are used by ATC for: Wind Profile Resulting in ATC/ATIS The• maximumATIS broadcasts; demonstrated and, crosswind published in the approved airplane flight manual (AFM), aircraft operating Report of 20-Knot Wind Velocity approved airplane flight manual (AFM), aircraft operating manual• Wind (AOM) information and/or quick on ground,reference tower, handbook approach (QRH) and is With Gusts to 25 Knots the maximuminformation crosswind frequencies. component that was encountered and Gust documented during certification flight tests or subsequent tests 25 Gusts METARsby the manufacturer. include a 10-minute average-wind velocity and the 10-minute peak gust (Figure 3). 20 The wind value is recorded during a time period bracketing the touchdown (typically from 100 feet above airport elevation 15 Maximumto when the airplane Demonstrated reaches taxi speed). Crosswind 10 10 TheFor some maximum aircraft demonstrated models, if a significant crosswind gust publishedis recorded induring the Wind (Knots) Wind (Knots) approvedthis period, airplane a demonstrated flight manualgust value (AFM), also isaircraft published. operating 5 manual (AOM) and/or quick reference handbook (QRH) is The maximum demonstrated crosswind; 0 the maximum crosswind component that was encountered and 01 23 456 78 910 documented• Is not anduring operating certification limitation flight (unless tests otherwise or subsequent stated); tests Minutes by the manufacturer. • Is not necessarily the maximum aircraft crosswind ATC = Air traffic control The windcapability; value is and,recorded during a time period bracketing the ATIS = Automatic terminal information service touchdown• Generally (typically applies from to a100 steady feet abovewind. airport elevation to Source: Flight Safety Foundation Approach-and-landing Accident when the airplane reaches taxi speed). Reduction (ALAR) Task Force ForMaximum some aircraft Computed models, if Crosswinda significant gust is recorded Figure 2 during this period, a demonstrated gust value may also be The maximum computed crosswind reflects the design published. • “XXX20G25KT”; or, capability of the aircraft in terms of: The two-minute average wind and the 10-minute peak gust The• maximum Rudder authority; demonstrated crosswind; are• used “XXX20KT” by ATC for: (if the five-knot gust is not included). • Is Roll-control not an operating authority; limitationand, (unless otherwise Average-wind• ATIS broadcasts; values and and, gust values displayed to a controller stated); are updated every minute. • Wheel-cornering capability. • Wind information on ground, tower, approach and • Is not necessarily the maximum aircraft crosswind information frequencies. Crosswindcapability; Capability and, METARs include a 10-minute average-wind velocity and the Crosswind capability is affected adversely by the following 10-minute peak gust (Figure 3). factors: 186 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 186 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 • Runway condition (e.g., contaminated by standing water, Depending on the equipment, different time delays for snow, slush or ice); “smoothing” (i.e., averaging) the wind value are applied, as discussed below. •• Systems generally malfunctions applies to a (e.g.,steady rudder wind. jam); or, – The direction of the wind arrow is referenced to • Minimum equipment list (MEL)/dispatch deviation guide The windmagnetic information north on andthe NDindicates is updated the wind typically direction; 10 times Maximum(DDG) conditions Computed (e.g., inoperativeCrosswind nosewheel steering). per second.– The length of the wind arrow may be fixed (velocity information is displayed separately), or the length WindThe maximum Information computed crosswindon Navigation reflects the Display design capabil- IRS Wind ity of the aircraft in terms of: of the wind arrow may be varied to indicate the wind velocity (depending on aircraft models and The• windRudder information authority; on the navigation display (ND) consists IRS windstandards); is assessed and, geometrically using the triangle of true of two elements (Figure 4): airspeed (TAS), groundspeed and wind vectors. • Roll-control authority; and, – The wind arrow is the primary visual wind reference • A wind arrow: The TAS duringvector and the groundspeed final approach vector (togetherare defined, with in terms the • Wheel-cornering capability. – The direction of the wind arrow is referenced to of velocitygroundspeed and direction, display); as follows: and, Crosswindmagnetic Capability north and indicates the wind direction; • TAS digital vector: wind information showing wind direction – The length of the wind arrow may be fixed (velocity (typically referenced to true north) and wind velocity: Crosswind capability is affected adversely by the following – Velocity: TAS from the air data computer (ADC); and, information is displayed separately), or the length of the – digital wind information is used primarily to compare factors: – Direction: magnetic heading from the IRS; and, wind arrow may be varied to indicate the wind velocity the current wind to the predicted wind, as provided • Runway(depending condition on aircraft (e.g., contaminated models and standards); by standing and, water, • Groundspeedon the computerized vector: flight plan. –snow, The slush wind orarrow ice); is the primary visual wind reference – Velocity: groundspeed from the IRS; and, • Systemsduring malfunctions the final approach(e.g., rudder (together jam); or, with the Depending on aircraft models and standards, the wind informa- groundspeed display); and, tion may– Direction:be computed magnetic either bytrack the from inertial the referenceIRS. system • Minimum equipment list (MEL)/dispatch deviation (IRS) or by the flight management system (FMS). • Digitalguide (DDG wind) conditionsinformation (e.g., showing inoperative wind nosewheeldirection The IRS wind is computed and is transmitted typically 10 times (typicallysteering). referenced to true north) and wind velocity: perDepending second to on the the electronic equipment, flight different instrument time system delays (EFIS) for – Digital wind information is used primarily to compare for“smoothing” display on (i.e., the ND.averaging) the wind value are applied, as Wind Informationthe current wind onto the Navigation predicted wind, Display as provided discussed below. on the computerized flight plan. The IRS wind display provides, for practical purposes, near- The wind information on the navigation display (ND) consists real-timeThe wind windinformation information. on the ND is updated typically 10 times Dependingof two elements on aircraft(Figure 4):models and standards, the wind per second. information• A wind may arrow: be computed either by the inertial reference FMS Wind system (IRS) or by the flight management system (FMS). IRS Wind FMS wind is computed similarly to IRS wind, but FMS wind isIRS averaged wind is over assessed a 30-second geometrically period. using the triangle of true Lower-left Corner of Navigation Display airspeed (TAS), groundspeed and wind vectors. Shows Winds From 212 Degrees FMS wind is more accurate than IRS wind because distance- The TAS vector and groundspeed vector are defined, in terms At 20 Knots measuring equipment (DME) position or global positioning systemof velocity (GPS) and position,direction, when as follows: available, are included in the computation.• TAS vector: GS 180° CDN 482 17 18 FMS wind– Velocity: is less accurate TAS from (i.e., the delayed) air data under computer the following (ADC); TAS 19 50 NM 16 20 conditions:and, 468 15 21 14 22 • Shifting– direction: wind; magnetic heading from the IRS; and, AMB • Sideslip; groundspeed or, vector: • Climbing or descending turn. 80 – Velocity: groundspeed from the IRS; and, FMS wind– d irection:cannot be magnetic considered track instantaneous from the IRS. wind, but the CDN FMS wind shows: 40 The IRS wind is computed and is transmitted typically 10 times per• second More tocurrent the electronic wind information flight instrument than the ATISsystem or (EFIS)tower for displayaverage on wind;the ND and,. 212/20 • The wind conditions prevailing on the aircraft flight path The IRS wind display provides, for practical purposes, near- (aft of the aircraft). real-time wind information. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force Summary Figure 4 METAR wind is a 10-minute average wind.

FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 187

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 187 FMS Wind References

FMS wind is computed similarly to IRS wind, but FMS wind 1. Flight Safety Foundation. “Killers in Aviation: FSF Task is averaged over a 30-second period. Force Presents Facts About Approach-and-landing and Controlled-flight-into-terrain Accidents.” Flight Safety FMS wind is more accurate than IRS wind because distance- Digest Volume 17 (November–December 1998) and measuring equipment (DME) position or global positioning Volume 18 (January–February 1999): 1–121. The facts system (GPS) position, when available, are included in the presented by the FSF ALAR Task Force were based on computation. analyses of 287 fatal approach-and-landing accidents (ALAs) that occurred in 1980 through 1996 involving FMS wind is less accurate (i.e., delayed) under the following turbine aircraft weighing more than 12,500 pounds/5,700 conditions: kilograms, detailed studies of 76 ALAs and serious • Shifting wind; incidents in 1984 through 1997 and audits of about 3,300 flights. • Sideslip; or, 2. International Civil Aviation Organization (ICAO). • Climbing or descending turn. International Standards and Recommended Practices, Annex 3 to the Convention of International Civil Aviation, FMS wind cannot be considered instantaneous wind, but the Meteorological Service for International Air Navigation. FMS wind shows: Chapter 4, “Meteorological Observations and Reports.” • More current wind information than the ATIS or tower Thirteenth edition – July 1998. average wind; and, • The wind conditions prevailing on the aircraft flight path Related Reading From FSF Publications (aft of the aircraft). Flight Safety Foundation (FSF) Editorial Staff. “Crew Fails to Compute Crosswind Component, Boeing 757 Nosewheel Summary Collapses on Landing.” Accident Prevention Volume 57 (March METAR wind is a 10-minute average wind. 2000). ATIS wind or tower average wind is a two-minute average FSF Editorial Staff. “Unaware of Strong Crosswind, Fokker wind. Crew Loses Control of Aircraft on Landing.” Accident Preven- tion Volume 56 (November 1999). ATIS gust or tower gust is the wind peak value during the past 10-minute period. FSF Editorial Staff. “MD-88 Strikes Approach Light Struc- ture in Nonfatal Accident.” Accident Prevention Volume 54 The ATIS broadcast is updated only if the wind direction chang- (December 1997). es by more than 30 degrees or if the wind velocity changes by more than five knots over a five-minute time period. FSF Editorial Staff. “Flight Crew of DC-10 Encounters Mi- croburst During Unstabilized Approach, Ending in Runway If an instantaneous wind reading is desired and is requested from Accident.” Accident Prevention Volume 53 (August 1996). ATC, the phraseology “instant wind” or “wind check” should be used in the request. (ATC may provide instant-wind information without request under shifting/gusting wind conditions.) Regulatory Resources IRS wind is near-real-time wind. International Civil Aviation Organization. International Stan- dards and Recommended Practices, Annex 11 to the Conven- FMS wind is a 30-second-average wind. tion of International Civil Aviation, Air Traffic Services. Air Maximum demonstrated crosswind generally applies to a Traffic Control Service, Flight Information Service, Alerting steady wind and is not a limitation (unless otherwise stated). Service. Twelfth edition – July 1998, incorporating Amend- ments 1–39. The most appropriate source of wind information should be selected for the flight phase. World Meteorological Organization. Guide to Meteorologi- cal Instruments and Methods of Observation. Sixth edition The following FSF ALAR Briefing Notes provide information – 1996. to supplement this discussion: • 8.5 — Wet or Contaminated Runways; and, • 8.7 — Crosswind Landings.◆

188 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 189 FSF ALAR Briefing Note 8.7 — Crosswind Landings

Operations in crosswind conditions require adherence to ap- • Reported runway friction coefficient (if available); or, plicable limitations or recommended maximum crosswinds and • Equivalent runway condition (if braking action and recommended operational and handling techniques, particu- runway friction coefficient are not reported). larly when operating on wet runways or runways contaminated by standing water, snow, slush or ice. Equivalent runway condition, as defined by the notes in Table 1, is used only for the determination of the maximum recom- Statistical Data mended crosswind.

The Flight Safety Foundation Approach-and-landing Acci- Table 1 cannot be used for the computation of takeoff perfor- dent Reduction (ALAR) Task Force found that adverse wind mance or landing performance, because it does not account for conditions (i.e., strong crosswinds, tail winds or wind shear) the effects of displacement drag (i.e., drag created as the tires were involved in about 33 percent of 76 approach-and-landing make a path through slush) and impingement drag (i.e., drag accidents and serious incidents worldwide in 1984 through caused by water or slush sprayed by tires onto the aircraft). 1997.1 Recommended maximum crosswinds for contaminated run- The task force also found that adverse wind conditions and ways usually are based on computations rather than flight tests, wet runways were involved in the majority of the runway but the calculated values are adjusted in a conservative manner excursions that comprised 8 percent of the accidents and seri- based on operational experience. ous incidents. The recommended maximum crosswind should be reduced for Runway Condition and Maximum Recom- a landing with one engine inoperative or with one thrust re- mended Crosswind verser inoperative (as required by the aircraft operating manual [AOM] and/or quick reference handbook [QRH]). The maximum demonstrated crosswind and maximum com- Some companies also reduce the recommended maximum puted crosswind are applicable only on a runway that is dry, crosswind when the first officer is the pilot flying (PF) during damp or wet. line training and initial line operation. On a runway contaminated with standing water, slush, snow AOMs/QRHs prescribe a maximum crosswind for conducting or ice, a recommended maximum crosswind (Table 1) usually an autoland operation. is defined as a function of: • Reported braking action (if available); The pilot-in-command should request assignment of a more favorable runway if the prevailing runway conditions and

190 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Table 1 Factors Included in Typical Recommended Maximum Crosswind

Reported Braking Reported Runway Equivalent Recommended Action (Index) Friction Coefficient Runway Condition Maximum Crosswind Good (5) 0.40 and above (See Note 1) 35 knots Good / Medium (4) 0.36 to 0.39 (See Note 1) 30 knots Medium (3) 0.30 to 0.35 (See Notes 2 and 3) 25 knots Medium / Poor (2) 0.26 to 0.29 (See Note 3) 20 knots Poor (1) 0.25 and below (See Notes 3 and 4) 15 knots Unreliable (9) Unreliable (See Notes 4 and 5) 5 knots

Note 1: Dry, damp or wet runway (less than three millimeters [0.1 inch] of water) without risk of hydroplaning. Note 2: Runway covered with dry snow. Note 3: Runway covered with slush. Note 4: Runway covered with standing water, with risk of hydroplaning, or with slush. Note 5: Runway with high risk of hydroplaning.

Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Approachcrosswind are Techniquesunfavorable for a safe landing. Flare• Align Techniques the aircraft with the runway centerline, while preventing drift, by applying into-wind aileron and Figure 1 (page 191) shows that, depending on the When oppositeapproaching rudder; the flare point with wings level and with Approach Techniques recommendations published in the AOM/QRH, a final a crab• Maintain angle, as the required crab angle for for drift drift correction, correction untilone theof threemain approach in crosswind conditions may be conducted: techniques can be used: Figure 1 shows that, depending on the recommendations landing gear touch down; or, published• With in wings the AlevelOM/QR (i.e.,H applying, a final a driftapproach correction in crosswind to track • PerformAlign the a aircraftpartial withdecrab, the usingrunway the centerline, cross-controls while conditionsthe runway may be centerline); conducted: this type of approach usually is techniquepreventing to drift, track bythe applyingrunway centerline. into-wind aileron and referred to as a crabbed approach; or, opposite rudder; • With wings level (i.e., applying a drift correction to track Some AOMs and autopilot control requirements for autoland • Withthe runway a steady centerline); sideslip (i.e.,this type with of the approach fuselage usually aligned is • Maintain the crab angle for drift correction until the recommend beginning the alignment phase well before the flare withreferred the runwayto as a crabbed centerline, approac using h;a combination or, of into- main landing gear touch down; or, wind aileron and opposite rudder [cross-controls] to point (typically between 200 feet and 150 feet), which results • correctWith a thesteady drift). sideslip (i.e., with the fuselage aligned in a• steady-sideslipPerform a partial approach decrab, down using to the theflare. cross-controls with the runway centerline, using a combination of technique to track the runway centerline. The followinginto-wind factors aileron should and opposite be considered rudder [cross-controls]when deciding betweento correct a wings-level the drift). approach and a steady-sideslip LandingSome AOMs Limitations and autopilot control requirements for autoland approach: recommend beginning the alignment phase well before the flare The following factors should be considered when deciding Knowledgepoint (typically of between flight dynamics200 feet and can 150 providefeet), which increased results between• Aircraft a wings-level geometry approach(pitch-attitude and limitsa steady-sideslip and bank-angle ap- understandingin a steady-sideslip of the approach various crosswinddown to the techniques. flare. proach:limits, for preventing tail strike, engine contact or wing- tip contact); Landing Capabilities • Aircraft geometry (pitch-attitude limits and bank-angle Landing Limitations • Aileronlimits, for (roll) preventing and rudder a tail(yaw) strike, authority; engine and, contact or Figure 2 (page 192) and Figure 3 (page 193) show the • Thewing-tip magnitude contact); of the crosswind component. limitationsKnowledge involved of flight in dynamicscrosswind can landings provide (for increased a given steadyunder- • Aileron (roll) and rudder (yaw) authority; and, crosswindstanding of component): the various crosswind techniques. The recommended maximum crosswind and the recommended crosswind• The magnitudelanding technique of the crosswind depend on component. the aircraft type and • Bank angle at a given crab angle or crab angle at a given Landing Capabilities model; limitations and recommendations usually are published bank angle: inThe the recommended AOM/QRH. maximum crosswind and the recommended – The graphs show the bank-angle/crab-angle crosswind landing technique depend on the aircraft type and Figure 2 and Figure 3 show the limitations involved in cross- relationship required to correct drift and to track model; limitations and recommendations usually are published wind landings (for a given steady crosswind component): the runway centerline at the target final approach Flarein the A TechniquesOM/QRH. • Bankspeed. angle at a given crab angle or crab angle at a given bank angle: When approaching the flare point with wings level and with a Positive crab angles result from normal drift crab angle, as required for drift correction, one of three correction and sideslip conditions (i.e., with the techniques can be used: aircraft pointing into the wind).

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 191 190 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Crabbed Approach and Sideslip Approach

Crosswind Crosswind Component Component

Crabbed Sideslip Approach Approach

Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 1

– NegativeThe graphs crab angles show are the shown bank-angle/crab-angle but would require an – ThisNegative limitation crab angles results are from shown the butaircraft’s would maximumrequire an excessiverelationship sideslip required rudder to input,correct resulting drift and in toa more-track capabilityexcessive sideslip to maintain rudder input, a steady resulting sideslip in a undermore- than-desiredthe runway centerlinebank angle; at the target final approach crosswindthan-desired conditions. bank angle; speed. • Aircraft geometry limits: • Aircraft geometry limits: Positive crab angles result from normal drift correction Figure 2 and Figure 3 assume that the approach is stabilized – Limits result from the maximum pitch attitude/bank and that– the limits flare result is conducted from the at maximum a normal pitchheight attitude/bank and rate. angleand sideslip that can conditions be achieved (i.e., without with the striking aircraft the pointing runway angle that can be achieved without striking the runway into the wind). with the tail or with the engine pod (for underwing- with the tail or with the engine pod (for underwing- The data in these figures may not apply to all aircraft types mounted engines), the flaps or the wing tip; and, and models, but all aircraft are subject to the basic laws of • Aileron/rudder authority: flight dynamics that the data reflect.

192 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 191 Crab Angle/Bank Angle Requirements in 10-knot Crosswind

16 Pitch Attitude/Bank Angle Limit

14 Aileron/Rudder Limit

12 0-degree Bank Angle

10 2-degree Bank Angle

8 4-degree Bank Angle 6-degree Bank Angle 6 B 8-degree Bank Angle 4 10-degree Bank Angle 2 12-degree Bank Angle 0 A −2

Crab Angle (Degrees) −4

−6

−8

−10

−12

−14 115 120 130 140 150 160 Target Final Approach speed Indicated Airspeed (Knots) Examples: A sideslip landing (zero crab angle) requires about a three-degree bank angle at touchdown (point A). A wings-level landing (no decrab) requires a crab angle between four degrees and five degrees at touchdown (point B). Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 2

Figure 2mounted shows engines), that with the a flaps 10-knot or the steady wing tip; crosswind and, safetyfive degrees margins of relativebank angle to geometry restores significantlimits or to safetyaileron/rudder margins component:• Aileron/rudder authority: authorityrelative to limits. geometry limits and aileron/rudder authority limits while eliminating the risk of landing-gear damage (i.e., moving • Achieving a steady-sideslip landing (zero crab angle) – This limitation results from the aircraft’s maximum Figurefrom point 3 shows A to pointthat with C). a 30-knot steady crosswind com- requirescapability only a tothree-degree maintain into-winda steady bank sideslip angle under(point ponent: A oncrosswind the graph); conditions. or, On• aircraftAchieving models a steady-sidesliplimited by their landing geometry, (zero increasing crab angle) the • Achieving a wings-level landing (no decrab) requires final approachrequires speednearly (e.g.,a nine-degree by applying into-wind a wind correctionbank angle, to Figure 2 and Figure 3 assume that the approach is stabilized only a four-degree to five-degree crab angle at the finalplacing approach the aircraft speed, evencloser under to its full geometry crosswind) limits would and and that the flare is conducted at a normal height and rate. touchdown (point B). increaseaileron/rudder the safety margin authority with limits respect (point to this A limitationon the graph); (i.e., movingor, from point A to point D). TheA sideslip data in landing these figures can be conductedmay not apply while to retainingall aircraft significant types and models,safety margins but all relativeaircraft toare geometry subject tolimits the basicor to aileron/rudderlaws of flight Operational• Achieving Recommendations a wings-level landing and (no Handling decrab) would dynamicsauthority limits.that the data reflect. Techniquesresult in a 13-degree crab angle at touchdown, potentially resulting in landing gear damage (point B). Figure 32 shows shows that that with with a 30-knot a 10-knot steady steady crosswind crosswind component: com- Figure 2 and Figure 3 show that: With a 30-knot crosswind component, adopting a combination ponent:• Achieving a steady-sideslip landing (zero crab • With a relatively light crosswind (typically up to a 15- of sideslip and crab angle with five degrees of crab angle and angle) requires nearly a nine-degree into-wind bank knot to 20-knot crosswind component), a safe crosswind • Achieving a steady-sideslip landing (zero crab angle) five degrees of bank angle restores significant safety margins angle, placing the aircraft closer to its geometry landing can be conducted with either: requires only a three-degree into-wind bank angle (point relative to geometry limits and aileron/rudder authority limits limits and aileron/rudder authority limits (point A A on the graph); or, while eliminating– A steady the sideslip risk of (no landing-gear crab); or, damage (i.e., moving on the graph); or, from point A to point C). • Achieving a wings-level landing (no decrab) requires – Wings level, with no decrab prior to touchdown; • Achieving a wings-level landing (no decrab) would only a four-degree to five-degree crab angle at touchdown and, result(point in B). a 13-degree crab angle at touchdown, potentially On aircraft models limited by their geometry, increasing the resulting in landing gear damage (point B). final• Withapproach a strong speed crosswind (e.g., by (typicallyapplying aabove wind acorrection 15-knot toto A sideslip landing can be conducted while retaining significant the final20-knot approach crosswind speed, component), even under a safefull crosswindcrosswind) landing would With a 30-knot crosswind component, adopting a combination requires a crabbed approach and a partial decrab prior of sideslip and crab angle with five degrees of crab angle and to touchdown.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 193 192 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Crab Angle/Bank Angle Requirements in 30-knot Crosswind

16 Pitch Attitude/Bank Angle Limit

14 Aileron/Rudder Limit B 12 0-degree Bank Angle

10 2-degree Bank Angle 8 4-degree Bank Angle

6 6-degree Bank Angle C 4 8-degree Bank Angle

2 10-degree Bank Angle 0 A D 12-degree Bank Angle −2

Crab Angle (Degrees) −4

−6

−8

−10

−12

−14 115 120 130 140 150 160 Target Final Approach Speed Indicated Airspeed (Knots) Examples: A sideslip landing (zero crab angle) requires about a nine-degree bank angle at touchdown (point A). A wings-level landing (no decrab) requires about a 13-degree crab angle at touchdown (point B). Point C represents a touchdown using a combination of sideslip and crab angle (about five degrees of bank angle and about five degrees of crab angle). Point D represents a steady-sideslip

landing conducted about four knots above VREF. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 3

Forincrease most transport the safety category margin airplanes,with respect touching to this downlimitation with (i.e.,a The• choice Wheel ofrotation, handling unless technique hydroplaning should be isbased experienced. on the pre- five-degreemoving from crab point angle A (withto point an Dassociated). five-degree bank vailingWheel crosswind rotation component is the trigger and for:on the following factors: angle) is a typical technique in strong crosswinds. • Wind gusts; Operational Recommendations and Handling Tech- – Automatic-ground-spoiler extension (as applicable); Theniques choice of handling technique should be based on the • –Runway Autobrake length; system operation; and, prevailing crosswind component and on the following factors: • Runway surface condition; Figure 2 and Figure 3 show that: – Anti-skid system operation. • Wind gusts; • Type of aircraft; and, • With a relatively light crosswind (typically up to a 15- To minimize the risk of hydroplaning and to ensure rotation • Runway length; knot to 20-knot crosswind component), a safe crosswind of the• wheels,Pilot experience a firm touchdown in type. should be made when landing • Runwaylanding surface can be condition;conducted with either: on a contaminated runway. • Type– Aof steady aircraft; sideslip and, (no crab); or, Touchdown• Buildup of friction — Friction forces begins Forces between the tires and the runway surface because of the combined effect of: • Pilot– Wingsexperience level, in withtype. no decrab prior to touchdown; Upon touchdown following a crabbed approach down to flare and, – Wheel-braking forces; and, with a partial decrab during flare, the flight deck should be on Touchdown• With a strong — Friction crosswind Forces (typically above a 15-knot to the upwind– Tire-cornering side of the runway forces (Figurecenterline 4, topage ensure 194). that the main 20-knot crosswind component), a safe crosswind landing landing gear is close to the runway centerline. Upon touchdownrequires a following crabbed approach a crabbed and approach a partial down decrab to priorflare to Wheel-braking forces and tire-cornering forces are based on with a partialtouchdown. decrab during flare, the flight deck should be on tireAfter conditions the main and landing runway gear conditions, touches down, and also the aircrafton each is other influ- the upwind side of the runway centerline to ensure that the —enced the higher by the the laws braking of ground force, dynamics. the lower the cornering force, mainFor landingmost transport gear is closecategory to the airplanes, runway centerline.touching down with a as shown by Figure 5 (page 194). five-degree crab angle (with an associated five-degree bank The following are among the events that occur upon touch- Afterangle) the is main a typical landing technique gear touchesin strong down, crosswinds. the aircraft is Transientdown: effects, such as distortion of tire tread (caused by a influenced by the laws of ground dynamics. yawing movement of the wheel) or the activation of the • Wheel rotation, unless hydroplaning is experienced. anti-skid system, affect the tire-cornering forces and wheel- The following are among the events that occur upon braking forces (in both magnitude and direction), and therefore touchdown: affect the overall balance of friction forces. 194 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009

FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 193 ToWhen minimize touching the down risk of with hydroplaning some crab andangle to onensure a contaminated rotation of Tire-cornering and Wheel-braking Forces therunway, wheels, the aaircraft firm touchdown tends to continue should betraveling made whenwith landinga crab onangle a contaminated along the runway runway. centerline. • Buildup of friction forces begins between the tires and Aircraft Motion Effectthe of runway Wind surface on the because Fuselage of the combined and effect of: Control– Wheel-braking Surfaces forces; and,

Crosswind As the– aircraftTire-cornering touches forcesdown, (Figurethe side 4). force created by the Component crosswind striking the fuselage and control surfaces tends to make Wheel-braking forces and tire-cornering forces are based on Tire-cornering the aircraft skid sideways off the centerline (Figure 6, page 195). Force tire conditions and runway conditions, and also on each other — the higher the braking force, the lower the cornering force, asThrust shown byReverser Figure 5. Effect

Wheel-braking TransientWhen selecting effects, reverse such thrustas distortion with some of crabtire treadangle, (caused the reverse by Force athrust yawing results movement in two force of the components wheel) or (Figurethe activation 6): of the anti skid system, affect the tire-cornering forces and wheel- •‑ A stopping force aligned with the aircraft’s direction of brakingtravel forces (runway (in both centerline); magnitude andand, direction), and therefore affect the overall balance of friction forces. Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force • A side force, perpendicular to the runway centerline, Thus, whichthe ideal further balance increases of forces the shown aircraft’s in Figuretendency 3 is to main skid- Figure 4 tained sideways.rarely during the initial landing roll. The thrust-reverser effect decreases with decreasing airspeed. Effect of Touchdown on Alignment Interaction of Tire-cornering and Rudder authority also decreases with decreasing airspeed and Wheel-braking Forces Whenis reduced touching further down by airflow with some disturbances crab angle created on a dryby the runway, thrust thereversers. aircraft Reduced tends to realignrudder itselfauthority with canthe directioncause directional- of travel 100 Anti-skid downcontrol the problems. runway. Activation 90

80 When touching down with some crab angle on a contaminated Effect of Braking 70 runway, the aircraft tends to continue traveling with a crab angle along the runway centerline. 60 In a strong crosswind, cross-control usually is maintained after

50 touchdown to prevent the into-wind wing from lifting and to Braking Force Cornering Force 40 Effectcounteract of the Wind weather-vane on the effect Fuselage (i.e., the aircraft’s and Con tendency- Force (Percent) Force trolto turn Surfaces into the wind). (Some flight crew training manuals say 30 that the pilot should continue to “fly the aircraft” during the 20 Aslanding the aircraftroll.) touches down, the side force created by the 10 crosswind striking the fuselage and control surfaces tends to 0 makeHowever, the aircraftinto-wind skid aileron sideways decreases off the the centerline lift on the (Figure into-wind 6). 0 5 10 15 20 25 30 35 40 45 50 Free-rolling Wheel wing, thus resulting in an increased load on the into-wind Slip Ratio (Percent) landing gear.

Source: Flight Safety Foundation Approach-and-landing Accident Thrust Reverser Effect Reduction (ALAR) Task Force Because braking force increases as higher loads are applied Whenon the selecting wheels andreverse tires, thrust the withbraking some force crab angle,increases the reverseon the Figure 5 thrustinto-wind results landing in two gear, force creating components an additional (Figure tendency 6): to turn into the wind (Figure 7, page 195). • A stopping force aligned with the aircraft’s direction of Wheel rotation is the trigger for: Thus, the ideal balance of forces shown in Figure 3 is When travelrunway (runway contamination centerline); is not and, evenly distributed, the anti- maintained– Automatic-ground-spoiler/speed-brakes rarely during the initial landing roll. extension skid• systemA side mayforce, release perpendicular only the to brakesthe runway on one centerline, side. which (as applicable); further increases the aircraft’s tendency to skid sideways. Effect– Autobrakeof Touchdown system operation; on Alignment and, Maintaining Directional Control The thrust-reverser effect decreases with decreasing air- – Anti-skid system operation. speed. When touching down with some crab angle on a dry runway, The higher the wheel-braking force, the lower the tire- the aircraft tends to realign itself with the direction of travel cornering force. Therefore, if the aircraft tends to skid down the runway. sideways, releasing the brakes (i.e., by taking over from the MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 195 194 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 Recovery From a Skid Caused by Crosswind and Reverse Thrust Side Forces Crosswind ComponentCrosswind Component

Touchdown Aircraft Skidding Touchdown Aircraft Skidding Reverse Cancelled Reverse Thrust with Partial Sideways Because of Reverse Cancelled Reverse Thrust with Partial Sideways Because of and Brakes Released, and Pedal Decrab Body Side Force and Brakes Released, and Pedal Decrab Body Side Force Directional Control Braking and Reverse Thrust Directional Control Braking and Reverse Thrust Regained Reapplied Side Force Regained Reapplied Side Force Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force Source: Flight Safety Foundation Approach-and-landing Accident Reduction (ALAR) Task Force

Figure 6

autobrakes) will increase the tire-cornering force and help autobrakes)Rudder authority will alsoincrease decreases the tire-cornering with decreasing force airspeed and help and maintain directional control. Effect of Uneven Braking Forces maintainis reduced directional further by airflowcontrol. disturbances created by the thrust Effect of Uneven Braking Forces reversers. Reduced rudder authority can cause directional- On Main Landing Gear Selecting reverse idle thrust will cancel the side-force component Selectingcontrol problems. reverse idle thrust will cancel the side-force component caused by the reverse thrust, will increase rudder authority and will further assist in returning to the runway centerline. Effect of Braking After the runway centerline and directional control have been regained:In a strong crosswind, cross-control usually is maintained after touchdown to prevent the into-wind wing from lifting and to • Pedal braking can be applied (autobrakes were Crosswind counteract• Pedal the braking weather-vane can effect be applied (i.e., the (autobrakes aircraft’s tendency were ComponentCrosswind previously disarmed) in a symmetrical or asymmetrical Component to turnpreviously into the wind). disarmed) (Some in flight a symmetrical crew training or asymmetrical manuals say manner, as required; and, that themanner, pilot should as required; continue and, to “fly the aircraft” during the landing• Reverse roll.) thrust can be reselected.

FactorsHowever, into-wind Involved aileron in Crosswinddecreases the lift Incidents on the into-wind wing,and Accidentsthus resulting in an increased load on the into-wind andlanding Accidents gear. The following factors often are involved in crosswind-landing Becauseincidents brakingand accidents: force increases as higher loads are applied incidentson the wheels and accidents: and tires, the braking force increases on the • Reluctance to recognize changes in landing data over into-wind• Reluctance landing gear,to recognize creating changesan additional in landing tendency data to overturn Source: Flight Safety Foundation Approach-and-landing Accident Source: Flight Safety Foundation Approach-and-landing Accident time (e.g., wind shift, wind velocity/gust increase); Reduction (ALAR) Task Force into thetime wind (e.g., (Figure wind 7). shift, wind velocity/gust increase); Reduction (ALAR) Task Force • Failure to seek additional evidence to confirm initial When runway contamination is not evenly distributed, the anti- Figure 7 information and initial options (i.e., reluctance to change Figure 7 skid system may release only the brakes on one side. plans); releasingSummary the brakes (i.e., by taking over from the autobrakes) • Reluctance to divert to an airport with more favorable Summary • Reluctance to divert to an airport with more favorable will increase the tire-cornering force and help maintain direc- Maintainingwind conditions; Directional Control To increase safety during a crosswind landing, flight crews wind conditions; tionalTo increase control. safety during a crosswind landing, flight crews should: • Insufficient time to observe, evaluate and control aircraft should: The• higher Insufficient the wheel-braking time to observe, force, evaluate the lowerand control the tire-cor aircraft- attitude and flight path in a highly dynamic situation; Selecting• Understand reverse idle allthrust applicable will cancel the operating side-force factors,compo- neringattitude force. Therefore, and flight ifpath the aircraftin a highly tends dynamic to skid sideways,situation; • Understand all applicable operating factors, and/or, nent causedrecommended by the reverse maximum thrust, values will increase and limitations; rudder authority • Pitch effect on aircraft with underwing-mounted engines • Use flying techniques and skills designed for crosswind caused by the power changes required in gusty conditions. landings; 196 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 195 FLIGHT SAFETY FOUNDATION • FLIGHT SAFETY DIGEST • AUGUST–NOVEMBER 2000 195 and will further assist in returning to the runway centerline. service (ATIS) broadcasts and tower messages (e.g., wind shift, wind velocity/gust increase); and, After the runway centerline and directional control have been regained: • Understand small-scale local effects associated with strong winds: • Pedal braking can be applied (autobrakes were previously disarmed) in a symmetrical or asymmetrical manner, as – Updrafts and downdrafts; and, required; and, – Vortices created by buildings, trees or terrain. • Reverse thrust can be reselected. The following FSF ALAR Briefing Notes provide information Factors Involved in Crosswind Incidents to supplement this discussion: and Accidents • 8.1 — Runway Excursions and Runway Overruns; The following factors often are involved in crosswind-landing • 8.2 — The Final Approach Speed; incidents and accidents: • 8.3 — Landing Distances; • Reluctance to recognize changes in landing data over • 8.4 — Braking Devices; time (e.g., wind shift, wind velocity/gust increase); • 8.5 — Wet or Contaminated Runways; and, • Failure to seek additional evidence to confirm initial information and initial options (i.e., reluctance to change • 8.6 — Wind Information.◆ plans); • Reluctance to divert to an airport with more favorable Reference wind conditions; 1. Flight Safety Foundation. “Killers in Aviation: FSF Task • Insufficient time to observe, evaluate and control aircraft Force Presents Facts About Approach-and-landing and attitude and flight path in a highly dynamic situation; and/or, Controlled-flight-into-terrain Accidents.”Flight Safety Digest Volume 17 (November–December 1998) and Volume 18 • Pitch effect on aircraft with underwing-mounted (January–February 1999): 1–121. The facts presented by engines caused by the power changes required in gusty the FSF ALAR Task Force were based on analyses of 287 conditions. fatal approach-and-landing accidents (ALAs) that occurred in 1980 through 1996 involving turbine aircraft weighing Summary more than 12,500 pounds/5,700 kilograms, detailed studies of 76 ALAs and serious incidents in 1984 through 1997 and To increase safety during a crosswind landing, flight crews audits of about 3,300 flights. should: • Understand all applicable operating factors, recommended Related Reading From FSF Publications maximum values and limitations; Flight Safety Foundation (FSF) Editorial Staff. “Crew Fails • Use flying techniques and skills designed for crosswind to Compute Crosswind Component, Boeing 757 Nosewheel landings; Collapses on Landing.” Accident Prevention Volume 57 (March 2000). – A wings-level touchdown (i.e., without any decrab) usually is safer than a steady-sideslip touchdown with FSF Editorial Staff. “Unaware of Strong Crosswind, Fokker an excessive bank angle; Crew Loses Control of Aircraft on Landing.” Accident Preven- tion Volume 56 (November 1999). • Request assignment of a more favorable runway if the prevailing runway conditions and crosswind are unfavorable for a safe landing; Regulatory Resources

• Adjust the autopilot-disconnect altitude for prevailing International Civil Aviation Organization. Preparation of an conditions to provide time to establish manual control Operations Manual. Second edition – 1997. and trimming of the aircraft before the align/decrab and flare; Joint Aviation Authorities. Joint Aviation Requirements – Op- erations 1, Commercial Air Transportation (Aeroplanes). 1.1045 • detect changes in automatic terminal information “Operations Manual – structure and contents.” March 1, 1998.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 197 Notice The Flight Safety Foundation (FSF) Ap- • Glass flight deck (i.e., an electronic flight This information is not intended to supersede proach-and-landing Accident Reduction instrument system with a primary flight operators’ or manufacturers’ policies, prac- (ALAR) Task Force has produced this briefing display and a navigation display); tices or requirements, and is not intended to note to help prevent ALAs, including those • Integrated autopilot, flight director and supersede government regulations. involving controlled flight into terrain. The autothrottle systems; briefing note is based on the task force’s da- • Flight management system; ta-driven conclusions and recommendations, Copyright © 2000 Flight Safety Foundation as well as data from the U.S. Commercial • Automatic ground spoilers; Suite 300, 601 Madison Street Aviation Safety Team (CAST) Joint Safety • Autobrakes; Alexandria, VA 22314 U.S. Analysis Team (JSAT) and the European Telephone +1 (703) 739-6700 Joint Aviation Authorities Safety Strategy • Thrust reversers; Fax: +1 (703) 739-6708 Initiative (JSSI). • Manufacturers’/operators’ standard oper- www.flightsafety.org ating procedures; and, The briefing note has been prepared primar- In the interest of aviation safety, this publication may • Two-person flight crew. ily for operators and pilots of turbine-powered be reproduced, in whole or in part, in all media, but may not be offered for sale or used commercially airplanes with underwing-mounted engines This briefing note is one of 34 briefing notes without the express written permission of Flight (but can be adapted for fuselage-mounted that comprise a fundamental part of the FSF Safety Foundation’s director of publications. All uses turbine engines, turboprop-powered aircraft ALAR Tool Kit, which includes a variety of must credit Flight Safety Foundation. and piston-powered aircraft) and with the other safety products that have been devel- following: oped to help prevent ALAs.

198 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Reducing the Risk of Runway Excursions

FSF Runway Safety Initiative Briefing Note Pilot Braking Action Reports

Pilot braking action reports that are based on reliable assess- Braking Action Advisories ment procedures and that use the proper terminology are potentially valuable supplements to other runway condition When braking action is less than good or weather conditions are information. The limitations of pilot braking action reports conducive to deteriorating or rapidly changing braking action, should be understood. air traffic control (ATC) should advise pilots that braking ac- tion advisories are in effect. This means that reports on braking action are expected from the pilots of landing aircraft. Statistical Data During the time that braking action advisories are in effect, The Flight Safety Foundation Runway Safety Initiative (RSI) Task ATC will issue the latest braking action reports for the runway Force found that overruns were involved in 50 percent of the runway 1 2 in use to each arriving and departing aircraft. The report issued excursion accidents that occurred in 1995 through March 2008. should include the type of aircraft that made the report and the time the observation was made. Both of these items are very Braking Action Braking deceleration is normal for When stopping an aircraft, the pilot expects a deceleration level GOOD the wheel braking effort applied. that is proportional to the amount of wheel braking applied and Directional control is normal. to runway surface friction. When the actual deceleration is less than expected, braking action is degraded. The degree to which Braking deceleration is noticeably reduced for the wheel braking deceleration by the wheel brakes is degraded is indicated by MEDIUM the use of the terms “good,” “medium” and “poor.” The term effort applied. Directional control may be slightly reduced. “nil” is used in the United States for braking action that is less than poor (Table 1). Braking deceleration is significantly reduced for the wheel braking effort Braking action is directly affected by friction between the tire POOR applied. Directional control may be and the runway/taxiway surface. The available tire-to-surface significantly reduced. friction is not only affected by the surface macro-/micro-texture but also by contaminants such as standing water, snow, slush Braking deceleration is minimal to nonexistent for the wheel braking and ice. In addition, the level of longitudinal braking force is NIL inversely affected by the level of lateral force acting on the effort applied. Directional control may be uncertain. tires, sometimes referred to as “cornering force.” Cornering forces are caused by pilot input, such as in nosewheel steering, or by crosswinds acting on the aircraft. Table 1

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 1 Braking deceleration is normal for the wheel GOOD braking effort applied. Directional control is normal. Braking deceleration is noticeably reduced for the MEDIUM wheel braking effort applied. Directional control may be slightly reduced. Braking deceleration is significantly reduced for important to assess the validity of the report. anti-skid limit because the resultant braking forces are more the wheel braking effort POOR than enough to stop the aircraft. In fact, most pilots of large applied. Directional controltransport aircraft have never reached maximum manual braking Pilot Braking Action Assessment on dry runways. It would be a very uncomfortable experience may be significantly due to the very high deceleration rates. When the pilot appliesreduced. wheel brakes, the wheels begin to slow down relative to theBraking velocity of thedeceleration aircraft. Wheel speed is is The pilot’s perception of increasing deceleration with applica- expressed as a “slip ratio.” A slip ratio of zero percent means tion of pedal brakes is the key to pilot braking action reports, that the wheel is rollingminimal freely, and to a slip nonexistent ratio of 100 percent for even when thrust reverse also is being used. meansNIL that the wheelsthe are lockedwheel and notbraking rotating at all;effort values between these extremes indicate the extent to which the wheels applied. Directional controlFor example, when thrust reverse is selected after landing, the are skidding (Figure 1). pilot feels a certain level of deceleration. As wheel brakes are may be uncertain. applied, an increase in deceleration should be felt if the surface As the slip ratio increases, braking force increases — to a point. friction can support it. Figure 1 shows that there is an optimum slip ratio for maximum Table 1 braking force. The effect of reduced surface friction is to lower Autobrakes are designed to generate a specified level of decel- the possible braking force for a given slip ratio. eration. If thrust reverse alone meets the required deceleration for the autobrake setting used, the system will not apply any Anti-skid braking systems are designed to maintain the opti- wheel brake pressure. The pilot may not know this has oc- curred. Consequently, in this case, pilot braking action cannot be assessed until autobrakes are overridden. By overriding the autobrakes with application of pedal braking, the pilot can assess braking action because he or she directly controls the wheel slip up to the anti-skid limit.

This is not to imply that autobrakes should not be used. On the contrary, autobrakes should be used in accordance with the manufacturer’s recommendations. An advantage of using autobrakes is that the system will promptly apply wheel brakes after touchdown, thus avoiding pilot-induced delays.

Pilots can assess braking action by noting whether the decelera- tion force felt is increasing with increasing brake pedal force (Figure 2). The point at which the deceleration force remains constant with increasing brake pedal force is the anti-skid limit. If this occurs when only light pedal pressure is applied, braking action is poor. If this occurs with moderate brake pedal pressure, braking action is medium. If the anti-skid limit is reached with heavy braking, braking action is good.

It is important to understand that for proper operation of anti- skid braking systems, a steady increase in brake pedal force is mum slip ratio regardless of the surface conditions. The opti- needed. The pilot’s goal in assessing braking action is to note mum slip ratio can be thought of as the anti-skid limit. The pilot at what brake pedal force the airplane’s deceleration ceases has control of the level of wheel slip through the application to increase. However, the pilot should continue to increase of pedal braking as long as the anti-skid limit is not reached. the brake pedal pressure to maximum if necessary to ensure Once the anti-skid limit is reached, pressing the brake pedals that the airplane remains at the anti-skid limit, providing the any harder will not increase the wheel braking force because optimum wheel slip ratio. the runway friction capability has been reached.

Consider an aircraft with anti-skid only, no thrust reverse or Benefits of Pilot Braking Action Reports autobrakes. As the wheel brakes are applied upon landing, the pilot begins to feel the deceleration of the aircraft. The Although pilot braking action reports are subjective, they deceleration builds as brake pedal pressure increases. On a do provide valuable information about rapidly deteriorating dry runway, it is unlikely that the pilot will ever reach the runway surface conditions.

2 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Reliable Braking Action Reports

A reliable braking action report is one that is submitted by the pilot of an airplane with landing performance capabilities similar to those of other airplanes being operated.

Consider the following aircraft characteristics when assessing the reliability of a braking action report: • Type of power plant (turboprop or turbojet); • Weight class (super, heavy, large, small); • Main landing gear configuration (twin, dual twin- tandem, etc.); and, • Thrust reverse configuration (turboprop, tail- mounted or wing-mounted turbine engines).

When the reporting airplane does not have similar charac- teristics to the airplane being operated, the pilot will have to decide the extent to which the report should be considered in the decision-making process. Such reports should not be sum- marily disregarded, especially if the report is conservative. In addition, some aircraft manufacturers provide advisory landing distance performance information as a function of pilot Making a Pilot Braking Action Report braking action reports. They do this by choosing a conserva- tive aircraft braking coefficient for the braking action terms When braking action advisories are in effect, the pilot might of good, medium and poor. The appropriate value of aircraft be asked to provide a braking action report to ATC. The report braking coefficient is used in the manufacturer’s advisory should include the following: landing distance calculations. • The appropriate braking action term (i.e., good, medium, poor or nil); Limitations of Pilot Braking Action Reports • The portion of the runway for which the braking Because the pilot is basing a braking action assessment on the action report applies; amount of deceleration that he perceives, it may be challenging • The type of aircraft; and, to discern the true “braking action” because it may be masked • Where the runway was exited. by the use of reverse thrust and any displacement/impingement drag from loose surface contamination. When relaying a pilot braking action report, ATC should The technique to get around this limitation is to note whether include the time since the report was made. For example: deceleration increases with the application of manual wheel “Braking action reported 10 minutes ago as medium by a braking. An increase in deceleration above that from thrust Boeing 737 that exited at Taxiway A7.” The time of the last reverse may be felt, the magnitude of which will depend on braking action report is very important; if it is not provided, the runway surface conditions. the pilot should ask for it.

If no increase in deceleration is felt with the application of The report also should include braking action that varies along manual wheel braking, the pilot should continue using thrust the runway. For example, “First half of landing roll medium, reverse, all the way to a stop if necessary. last half poor.” However, the use of terms such as “good to medium” and “medium to poor” apply to intermediate levels Variability in pilot braking action reports can occur for rea- of braking action, not to braking action that varies along the sons other than pilot subjectivity. The portion of the runway runway length. used by the landing airplane, as well as the type of airplane, may cause differences between what is reported and what is Additionally, when providing a braking action report for taxi- experienced by the pilot. ways or ramps, include the surface for which the report applies.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 3 For example, “Runway good, turn-off Taxiway A6 poor.” good, ATC advisories should state that braking action advi- sories are in effect. This alerts pilots that pilot braking action The U.S. National Transportation Safety Board recommends reports are expected. that if mixed braking action reports are received, such as me- dium to poor, the most conservative term should be used to The pilot should report the braking action experienced, the type increase landing safety margins. of aircraft and the exit taxiway whenever possible.

ATC should report to arriving and departing aircraft the latest NIL Braking Action braking action report, including the type of aircraft and where that aircraft exited the runway. The term nil is not currently part of International Civil Aviation Organization (ICAO) braking action terminology; however Although pilot braking action reports are subjective assess- it is used in the United States, where it would indicate to the ments of runway conditions, they provide valuable informa- airport authorities that runway treatment is required before tion to supplement other runway condition information. Pilots further aircraft operations are allowed on that runway. are encouraged to use the descriptions of the braking action terms in Table 1 to provide standardized and reliable braking Historically, there has been some hesitation by pilots to report action reports. nil runway conditions. Perhaps this is due in part to the realiza- tion that reporting nil runway conditions will close the runway It is important that pilots not base their runway surface assess- to subsequent aircraft. ment solely on pilot braking action reports. Pilots must consider all available information such as contaminant type and depth, Because of this, it may be helpful to pilots to have specific Mu values, pilot braking action reports, snow-related notices target criteria for determining when runway conditions are to airmen (SNOWTAMs), aviation routine weather reports likely to be nil. A nil report should be made when any of the (METARS) and personal observations. following conditions are encountered during a maximum-effort landing on a contaminated runway (following an on-speed and The FSF RSI Briefing Note Runway Condition Reporting on-path crossing of the threshold): provides information to supplement this discussion.◆ • As brake pedal pressure is applied, the pilot per- ceives little or no increase in deceleration; References • Stowing the thrust reversers produces a sensation of acceleration despite having wheel brakes applied; 1. The Flight Safety Foundation Runway Safety Initiative (RSI) Task Force analyzed 548 runway-excursion acci- • Actual landing distance exceeds the distance calcu- dents that occurred in 1995 through March 2008 involving lated for poor braking action or for runway condi- civil airplanes weighing more than 12,500 pounds/5,700 tions equivalent to poor braking action, for those kilograms. operators that have operational landing distances as a function of runway condition; or, 2. The FSF RSI Task Force defines arunway excursion ac- cident as “a mishap characterized by an aircraft departing • Discontinuing the use of reverse thrust was required the usable surface of a runway during takeoff or landing.” to restore directional control when the crosswind The task force said, “An excursion can occur either by was within limits for the reported runway condi- overrunning the end of the runway or by veering off its tions. side. A runway excursion during takeoff assumes that the aircraft started its takeoff roll on the runway surface If any of these results are experienced on at least some part of and later departed that surface with its wheels still on the the runway, there has been a significant loss of friction and a ground. Runway excursions during landing are generally report of nil is justified. If a nil report is not made, the following predicated on an aircraft having initially touched down crew will not consider it a favor if they go off the end of the on the runway surface, followed by a departure from that runway on which the previous aircraft only just got stopped. surface with its wheels still on the ground. Events where aircraft depart the runway while airborne are not consid- ered runway excursions.” Summary

Whenever braking action is less than good or runway surface conditions are conducive to braking action that is less than

4 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Related Reading From FSF Publications Johnsen, Oddvard. “Improving Braking Action Reports — Us- ing performance data from landing aircraft would eliminate Mook, Reinhard. “Treacherous Thawing —Slush may induce current inaccuracies.” AeroSafety World Volume 2 (August poor/nil aircraft braking action, contrary to runway friction 2007): 36-40. readings.” AeroSafety World Volume 3 (October 2008): 14- 19. Rosenkrans, Wayne. “Knowing the Distance — The FAA plans to require commercial and fractional turbojet flight crews to Lacagnina, Mark. “Missed Assessment — Tired pilots neglect- confirm landing distance capability on arrival in specific situ- ed to perform a required review before landing.” AeroSafety ations.” AeroSafety World Volume 2 (February 2007): 22-25. World Volume 3 (October 2008): 20-24.

Werfelman, Linda. “Safety on the Straight and Narrow — Regulatory Resources Aviation safety experts aim for the Runway Safety Initiative to provide the tools to help prevent runway incursions.” Ae- International Civil Aviation Organization. International Stan- roSafety World Volume 3 (August 2008): 12-17. dards and Recommended Practices, Annex 14 to the Conven- tion on International Civil Aviation: Aerodromes. Lacagnina, Mark. “Overrun at Midway — The crew applied reverse thrust too late.” AeroSafety World Volume 3 (February U.S. Federal Aviation Administration (FAA). Aeronautical In- 2008): 28-33. formation Manual. Paragraph 4-3-8, “Braking Action Reports and Advisories.” Paragraph 4-3-9, “Runway Friction Reports Werfelman, Linda. “Blindsided — The pilots of an Airbus and Advisories.” A340 did not anticipate the ‘severe deterioration’ of weather as they approached the runway threshold at Toronto.” AeroSafety FAA. Advisory Circular 91-79, Runway Overrun Protection. World Volume 3 (February 2008): 40-45. FAA Safety Alert for Operators 06012, Landing Performance Mook, Reinhard. “Insidious Ice — Basic physics makes slip- Assessments at Time of Arrival (Turbojets). Aug. 31, 2006. pery-runway issues crystal clear.” AeroSafety World Volume 2 (October 2007): 24-28.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 5 Reducing the Risk of Runway Excursions

FSF Runway Safety Initiative Briefing Note Runway Condition Reporting

Flight dispatchers and flight crewmembers should obtain ac- of ice,” “5 mm of slush,” “compact snow,” “10 mm of dry curate and timely information on runway conditions. Runway snow” and “standing water.” These surface condition reports conditions are not static, they change with time as surface provide an indication of braking action, but they can also be temperature changes and precipitation accumulates. misleading if all the appropriate information is not known. For example, very cold, compact snow on the runway may have Measuring and reporting runway condition is the airport’s relatively good friction characteristics, but with a change of responsibility; however, understanding the information and a few degrees in temperature, causing the snow to change to its possible problems is the operator’s responsibility. slush, and/or additional precipitation in the form of wet snow, runway friction will deteriorate. Dispatchers and flight crewmembers can make good decisions only by understanding the basis for and limitations of the When evaluating surface condition reports, it is important to information that has been reported to them. know how much additional contamination has occurred since the report was issued. For example, a report might say that there is a trace of residual snow on a runway that had just been Statistical Data cleaned. However, snow may continue to fall, and the report quickly becomes out of date. With a snowfall rate between The Flight Safety Foundation Runway Safety Initiative (RSI) 20 and 40 mm (0.7 and 1.6 in) per hour, braking action can Task Force found that runways contaminated by standing deteriorate from good to poor within 15 minutes. water, snow, slush or ice were involved in approximately 80 percent of the runway excursion accidents1 that occurred in 1995 through March 2008.2 Pilot Reports of Braking Action

Pilot braking action reports can be affected by the reporting Runway Condition Reporting crew’s experience and the equipment they are operating. The terminology recommended by the International Civil Runway condition typically is provided in pilot reports of Aviation Organization (ICAO) is “good,” “good to medium,” braking action, physical descriptions of runway conditions “medium,” “medium to poor” and “poor.” The terminology and/or friction measurements. recommended by the U.S. Federal Aviation Administration (FAA) is “good,” “fair,” “poor” and “nil.” The following table Physical Description of Runway Condition provides a conservative correlation of reported braking action with runway states. The airport provides a physical description of runway surface condition using terms such as “wet,” “flooded,” “patches

6 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 Friction measurements are taken at specific times, and runway GOOD Wet condition may change between reports. More precipitation may MEDIUM Compact Snow fall, the temperature may change, or other traffic may cause changes in the runway condition. These changes may increase POOR Ice or decrease runway friction.

Pilot braking action reports generally are the most recent Manufacturers currently do not supply performance informa- information available and therefore provide information tion based on friction measurements due to concerns about about changing runway conditions. However, pilot the accuracy of relating the measured friction to an airplane’s reports are subjective. The pilot of a small airplane may performance capability. perceive different braking conditions than the pilot of a large airplane. The braking action assessment also can be influenced by the airplane’s weight, approach speed, amount How Reports Are Disseminated of wheel braking applied and the location on the runway where the highest amount of wheel braking is used. Runway condition reports may be included in routine notices to airmen (NOTAMs), snow-related NOTAMs (SNOWTAMs), aviation routine weather reports (METARs), automatic termi- Friction Measurement nal information system (ATIS) broadcasts or via ATC com- munication with the flight crew. For a short flight, the flight Runway friction is reported numerically (e.g., 30 or 0.30). crew may have NOTAMs and/or SNOWTAMs available prior The reports are derived from measurements by a variety of to departure that will enable them to perform a preliminary vehicles and by different methods. For example, some vehicles evaluation of the airplane’s capability based on conditions have decelerometers that measure the deceleration of the test reasonably expected at the time of arrival. The flight crew must vehicle during a maximum-effort stop. This deceleration is recognize that conditions may change during the flight and that then converted to a friction reading. updated reports will be required as they near the airport. Another method is to use a device, typically towed, that con- tinuously measures the force on a braked wheel. Friction is then Best Practices calculated from the forces on this wheel. Typically, these friction measurements are reported for each third of the runway. During the preliminary evaluation, the flight crew should con- sider whether it is probable or possible that the conditions will Runway friction reports are objective and predictive. However, change by the time of arrival and whether the conditions will the different methods used to measure friction can provide change for the better or worse. A second evaluation should be different results. performed to help with operational decisions such as: • How long can a hold be maintained until a diversion Measurements by either the same vehicle/device — or the same decision must be made? type of vehicle/device — can vary between runs. Especially on “soft” surfaces (e.g., loose snow, slush, standing water), the • Should extra fuel be loaded in order to hold while the vehicles/devices modify the surface over which they are run runway is being improved? due to their contact with the deformable contaminate. The FAA • Are there any minimum equipment list (MEL) items states that ground friction vehicle reports are not considered that would affect the airplane’s performance? reliable when the depth of the contaminant exceeds: • Should landing weight (and therefore takeoff weight) • 1 mm of water; be restricted to ensure the airplane’s performance • 3 mm of slush or wet snow; or, capability? • 2.5 cm (1 in) of dry snow. • Should the flight be delayed? • Should an alternate airport be specified that has a higher ICAO provides a similar warning. likelihood of adequate runway conditions? A decelerometer should not be used in loose snow or slush, • What is the possibility that the expected wind condi- as it can provide misleading friction values. Other friction tions will exceed the recommended crosswind for the measuring devices also can give misleading friction values runway conditions? under certain combinations of contaminants and air/pavement temperature. On a long flight, the flight crew should perform another evalu-

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 7 ation two to four hours before arrival. If it is determined that experience in the area. the conditions likely will change for the worse, the evaluation should include the following considerations: Company Prevention Strategies • How long can a hold be maintained until a diversion decision must be made? To help flight crews cope with contaminated runways, the • Are there any MEL items that would affect the air- airline or aircraft operator should provide the following: plane’s performance? • Winter operation/slippery runway standard operating • What is the possibility that the expected wind condi- procedures (SOPs); tions will exceed the recommended crosswind for the • Interpretation of the manufacturer’s data; runway conditions? • Analysis of specific runway conditions; As the flight nears the airport, the flight crew should perform • No-fault diversion policy; and, a landing distance assessment based on the data provided by the airline. This assessment should take into account: • Training programs that include winter-operations ele- ments such as evaluation of runway condition informa- • Known and anticipated conditions at the airport; tion. • Runway condition; • Pilot braking action reports; Summary

• Weather conditions; Flight crews need timely, accurate information on runway • Runway to be used; conditions so that they can make informed decisions about the suitability of the runway for landing. • Runway length and slope (if available); • Planned landing configuration and approach speed; There are three primary methods of reporting runway condi- tions: • Planned use of autobrakes or manual braking; • Runway descriptions, which are the responsibility of • Thrust reverser status; the airport; • Expected speed at the threshold (per manufacturer’s • Friction measurements, which also are the responsibil- recommendation) and the possibility of hydroplan- ity of the airport; and, ing; • Pilot braking action reports transmitted from flight • Expected visibility of runway markings; and, crews to ATC and then to other pilots. • Runway lighting configuration. Runway descriptions and friction measurements are made at As part of the landing distance assessment, the flight crew specific times and may not reflect changing conditions. should develop a strategy that results in a land/no-land decision if additional information is received late in the approach. Pilot braking action reports reflect the changing conditions at an airport; however, these reports are subjective.

Human Factors In changing conditions, flight crews should determine ahead of time the worst runway condition they will accept, so that they The flight crew’s training and experience will directly affect can make an informed decision if runway condition informa- how they evaluate the information they receive on runway tion becomes available very late in the flight. conditions. Flight crews who fly in specific areas — such as Alaska, northern Europe or Russia — may have more confi- Flight crews should not ignore parts of a condition report and dence in and place more importance on specific information rely on a single runway condition description; the most precise based on local knowledge. is not necessarily the most accurate.

During international operations, the flight crew may have The FSF RSI Briefing Note Pilot Braking Action Reports less confidence in runway-condition information because the provides information to supplement this discussion.◆ terminology, measuring equipment and methods of reporting vary. In addition, the flight crew may have limited training or

8 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 References did not anticipate the ‘severe deterioration’ of weather as they approached the runway threshold at Toronto.” AeroSafety World 1. The Flight Safety Foundation Runway Safety Initiative Volume 3 (February 2008): 40-45. (RSI) Task Force analyzed 548 runway-excursion acci- dents that occurred in 1995 through March 2008 involving Mook, Reinhard. “Insidious Ice — Basic physics makes slip- civil airplanes weighing more than 12,500 pounds/5,700 pery-runway issues crystal clear.” AeroSafety World Volume 2 kilograms. (October 2007): 24-28. 2. The FSF RSI Task Force defines a runway excursion ac- Johnsen, Oddvard. “Improving Braking Action Reports — Us- cident as “a mishap characterized by an aircraft departing ing performance data from landing aircraft would eliminate the usable surface of a runway during takeoff or land- current inaccuracies.” AeroSafety World Volume 2 (August ing.” The task force said, “An excursion can occur either 2007): 36-40. by overrunning the end of the runway or by veering off its side. A runway excursion during takeoff assumes that Rosenkrans, Wayne. “Knowing the Distance — The FAA plans the aircraft started its takeoff roll on the runway surface to require commercial and fractional turbojet flight crews to and later departed that surface with its wheels still on the confirm landing distance capability on arrival in specific situ- ground. Runway excursions during landing are generally ations.” AeroSafety World Volume 2 (February 2007): 22-25. predicated on an aircraft having initially touched down on the runway surface, followed by a departure from that surface with its wheels still on the ground. Events where Regulatory Resources aircraft depart the runway while airborne are not considered runway excursions.” International Civil Aviation Organization (ICAO). International Standards and Recommended Practices, Annex 14 to the Con- vention on International Civil Aviation: Aerodromes. Related Reading From FSF Publications ICAO. International Standards and Recommended Practices, Mook, Reinhard. “Treacherous Thawing — Slush may induce Annex 15 to the Convention on International Civil Aviation: poor/nil aircraft braking action, contrary to runway friction Aeronautical Information Services. readings.” AeroSafety World Volume 3 (October 2008): 14- 19. ICAO. Doc 9137, Airport Services Manual. Part 2, Pavement Surface Conditions. Lacagnina, Mark. “Missed Assessment — Tired pilots neglected to perform a required review before landing.” AeroSafety World U.S. Federal Aviation Administration (FAA). Advisory Circular Volume 3 (October 2008): 20-24. (AC) 150-5200.30C, Airport Winter Safety and Operations. Werfelman, Linda. “Blindsided — The pilots of an Airbus A340 FAA. AC 91-79, Runway Overrun Prevention.

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 9 APPENDIX III

Report of the Runway Safety Initiative

Report on the Design and Analysis of a Runway Excursion Database (click to open pdf document) APPENDIX IV

Report of the Runway Safety Initiative

Selected Flight Safety Foundation Publications Reducing the Risk of Runway Excursions

Selected Flight Safety Foundation Publications

(Available from the Publications section of the FSF web site flightsafety.org.)

Lacagnina, Mark. “Too Long at the Wheel — Fatigue factors in a runway excursion.” AeroSafety World Volume 4 (March 2009): 28-31.

Burin, James M. “Steady State — Accident categories in 2008 were mostly familiar, including the unwelcome return of the no-flaps takeoff.”AeroSafety World Volume 4 (February 2009): 18-23.

Rosenkrans, Wayne. “Moment of Truth — Rigid adherence to procedures for takeoff weight, center of gravity and stabilizer trim setting reduces the likelihood of uncommanded or delayed rotation.” AeroSafety World Volume 4 (February 2009): 44- 47.

Dean, Alan; Pruchnicki, Shawn. “Deadly Omissions — Human memory fails in predictable patterns that can be avoided by paying close attention to SOPs when distractions occur.” AeroSafety World Volume 3 (December 2008): 10-16.

Mook, Reinhard. “Treacherous Thawing —Slush may induce poor/nil aircraft braking action, contrary to runway friction readings.” AeroSafety World Volume 3 (October 2008): 14-19.

Lacagnina, Mark. “Missed Assessment — Tired pilots neglected to perform a required review before landing.” AeroSafety World Volume 3 (October 2008): 20-24.

Lacagnina, Mark. “Snowed — The runway was in and out of sight, but the crew pressed ahead.” AeroSafety World Volume 3 (September 2008): 22-27.

Werfelman, Linda. “Calculating Errors — Mistakes in determining takeoff parameters are frequent, a French study says, and methods of detecting them are not always effective.” AeroSafety World Volume 3 (September 2008): 28-32.

Werfelman, Linda. “Safety on the Straight and Narrow — Aviation safety experts aim for the Runway Safety Initiative to pro- vide the tools to help prevent runway excursions.” AeroSafety World Volume 3 (August 2008): 12-17.

Lacagnina, Mark. “Margin for Error — Enhancing overrun survivability with runway end safety areas.” AeroSafety World

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 1 Volume 3 (August 2008): 22-26.

Lacagnina, Mark. “Bad Call — A relayed company message distracted the crew during an autoland approach.” AeroSafety World Volume 3 (July 2008): 12-17.

Lacagnina, Mark. “Overrun at Midway — The crew applied reverse thrust too late.” AeroSafety World Volume 3 (February 2008): 28-33.

Werfelman, Linda. “Blindsided — The pilots of an Airbus A340 did not anticipate the ‘severe deterioration’ of weather as they approached the runway threshold at Toronto.” AeroSafety World Volume 3 (February 2008): 40-45.

Lacagnina, Mark. “High, Hot and Fixated — Despite several warnings, the Garuda 737 pilot stayed focused on landing.” Ae- roSafety World Volume 3 (January 2008): 42-46.

Carbaugh, David. “Good for Business — Conclusion of a series focusing on the development and safety benefits of preci- sion-like approaches, a project of the FSF International Advisory Committee.” AeroSafety World Volume 2 (December 2007): 11-15.

Johnsen, Oddvard. “Go or No-Go? — A tire burst, and a decision had to be made quickly.” AeroSafety World Volume 2 (De- cember 2007): 28-29.

Baron, Robert. “Cockpit Discipline — Violating the ‘sterile cockpit’ rule and ignoring other standard operating procedures can lead to tragedy.” AeroSafety World Volume 2 (December 2007): 47-48.

Bateman, Don; McKinney, Dick. “Dive-and-Drive Dangers — Third in a series focusing on the development and safety benefits of precision-like approaches, a project of the FSF InternationalAdvisory Committee.” AeroSafety World Volume 2 (November 2007): 13-17.

Lacagnina, Mark. “Mistaken Identity — The CRJ crew lined up for takeoff on the wrong runway.” AeroSafety World Volume 2 (November 2007): 38-43.

Rosenkrans, Wayne. “ADS-B On Board — UPS Airlines takes aim at runway incursions and unstabilized approaches.” Aero- Safety World Volume 2 (November 2007): 44-47.

Tarnowski, Etienne. “From Nonprecision to Precision-Like Approaches — Second in a series focusing on the development and safety benefits of precision-like approaches, a project of the FSF InternationalAdvisory Committee.” AeroSafety World Volume 2 (October 2007): 12-21.

Mook, Reinhard. “Insidious Ice — Basic physics makes slippery-runway issues crystal clear.” AeroSafety World Volume 2 (October 2007): 24-28.

Douglass, John W. “Technology Can Reduce Runway Mishaps — ADS-B moving map displays will cut through bad vis- ibility and provide pilots not only with their position on the airport grounds, but also with information about all other ground traffic and the positions of other aircraft flying near the runways.”AeroSafety World Volume 2 (October 2007): 36-37.

FSF International Advisory Committee. “Pursuing Precision — Introduction to a series focusing on the development and safety benefits of precision-like approaches.”AeroSafety World Volume 2 (September 2007): 20-21.

Johnsen, Oddvard. “Improving Braking Action Reports — Using performance data from landing aircraft would eliminate cur- rent inaccuracies.” AeroSafety World Volume 2 (August 2007): 36-40.

Chiles, Patrick. “Planning the Departure — Takeoff performance myths and methods.” AeroSafety World Volume 2 (July

2 RUNWAY SAFETY INITIATIVE • Flight Safety Foundation • MAY 2009 2007): 26-32.

Rosenkrans, Wayne. “Real-Time Defenses — Wind shear avoidance can reach the next level if airlines and ATC update their procedures to match current detection capabilities.” AeroSafety World Volume 2 (May 2007): 34-38.

Lacagnina, Mark. “Streaking Into Vegas — Failure of a business jet’s lift-dump system was the last ingredient in a spoiled landing.” AeroSafety World Volume 2 (April 2007): 38-41.

Donoghue, J.A. “Incursions, Excursions & Confusions.” AeroSafety World Volume 2 (March 2007): 5.

Lacagnina, Mark. “Off-Balance Overrun — Nose-heavy Challenger would not rotate for takeoff.” AeroSafety World Volume 3 (March 2007): 30-36.

Fahlgren, Gunnar. “Tail Wind Traps — Birds never land downwind. Should we?” AeroSafety World Volume 2 (March 2007): 46-47.

Rosenkrans, Wayne. “Knowing the Distance — The FAA plans to require commercial and fractional turbojet flight crews to confirm landing distance capability on arrival in specific situations.”AeroSafety World Volume 2 (February 2007): 22-25.

Agur, Peter V. Jr. “Discipline as Antidote — The importance of procedures and the adherence to procedures cannot be over- stated.” AeroSafety World Volume 2 (February 2007): 35-38.

Berman, Benjamin A.; Dismukes, R. Key. “Pressing the Approach — A NASA study of 19 recent accidents yields a new per- spective on pilot error.” AviationSafety World Volume 1 (December 2006): 28-33.

Rosenkrans, Wayne. “Break, Distort or Yield — Updated approach lighting system standards address risks during the 100-millisecond impact of an airplane.” AviationSafety World (December 2006): 36-39.

Rash, Clarence E. “Flying Blind — When an aircraft is engulfed in blowing dirt or snow, the onset of IMC usually is instan- taneous.” AviationSafety World Volume 1 (December 2006): 44-46.

Werfelman, Linda. “Fatal Calculation — Failure of the flight crew to detect a computer programming error led to inadequate takeoff performance by their 747.” AviationSafety World Volume 1 (October 2006): 18-24.

Rosenkrans, Wayne. “Rethinking Overrun Protection — Midway International Airport’s December 2005 accident makes air- port operators reconsider installing the latest engineered materials arresting system.” AviationSafety World Volume 1 (August 2006): 13-19.

Rosenkrans, Wayne. “Making ALAR Pervasive — Five years of workshops have propelled the FSF Approach and Landing Accident Reduction Tool Kit into many corners of the world. That’s not enough.” AviationSafety World Volume 1 (July 2006): 26-39.

Flight Safety Foundation Approach-and-Landing Accident Reduction (ALAR) Task Force. “Killers in Aviation: FSF Task Force Presents Facts About Approach-and-Landing and Controlled-Flight-Into-Terrain Accidents.” Flight Safety Digest Vol- ume 17 (November–December 1998) and Volume 18 (January–February 1999): 1-121.◆

MAY 2009 • Flight Safety Foundation • RUNWAY SAFETY INITIATIVE 3 APPENDIX V

Report of the Runway Safety Initiative

Additional Resources (click to open pdf documents) Runway Excursions, Part 1: A worldwide review of commercial jet aircraft runway excursions Australian Transport Safety Bureau

Takeoff Safety Training Aid U.S. Federal Aviation Administration

Stabilized Approaches: Good Practice Guide Direction Générale de l’Aviation Civile, France

Unstabilized Approaches Direction Générale de l’Aviation Civile, France Runway Overrun Prevention U.S. Federal Aviation Administration APPENDIX VI

Report of the Runway Safety Initiative

Runway Safety Initiative Participating Organizations Air Traffic Control The Netherlands (LVNL) Air Line Pilots Association, International Airbus Airports Council International (ACI) Asociación Latinoamericana de Transporte Aéreo (ALTA) Association of Asia Pacific Airlines (AAPA) Association of European Airlines (AEA) Civil Air Navigation Services Organisation (CANSO) Direction Générale de l’Aviation Civile (DGAC), France Embraer Eurocontrol European Aviation Safety Agency (EASA) European Regions Airline Association (ERA) Flight Safety Foundation (FSF) Honeywell International Air Transport Association (IATA) International Federation of Air Line Pilots’ Associations (IFALPA) International Federation of Air Traffic Controllers’ Associations (IFATCA) National Aerospace Laboratory–The Netherlands (NLR) The Boeing Co. U.S. Federal Aviation Administration (FAA) U.S. National Transportation Safety Board (NTSB) ◆