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QTR_01 15 A QUARTERLY PUBLICATION BROUGHT TO YOU BY THE BOEING EDGE

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Building Better Communication

Advanced Ultrasonic Inspection

Preventing Loss of Control in Flight

Commercial Operations on Runways with Arresting Systems Cover photo: 737-800 Vertical Fin Assembly AERO Contents

03 Building Better Communication: Readership Survey You have an opportunity to provide input that will help shape future issues of AERO.

05 AERO Advanced Ultrasonic Readership Survey Inspection Boeing has introduced advanced Share your opinions, ultrasonic inspection techniques that insights, and ideas at provide operators with significant www.boeing.com/aerosurvey. cost improvements over traditional 05 ultrasonic testing technologies.

09 Preventing Loss of Control in Flight A multiyear industry analysis of loss-of control–in-flight events generated feasible solutions in areas of training, operations, and airplane design.

17 Commercial Operations on Runways with Arresting Systems Airports with joint commercial and military operations are often equipped with runway arresting systems for tactical military air 09 craft. Airlines working closely with airports can take steps to ensure safe commercial operations in these situations.

01 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Issue 57 _Quarter 01 | 2015 AERO

Publisher Design Cover photography Editorial Board Chris Villiers Methodologie Jeff Corwin Don Andersen, Gary Bartz, Richard Breuhaus, David Carbaugh, Laura Chiarenza, Justin Hale, Darrell Hokuf, Al John, Doug Lane, Jill Langer, Duke McMillin, Editorial director Writer Printer Keith Otsuka, David Presuhn, Wade Price, Jerome Schmelzer, Corky Townsend Jill Langer Jeff Fraga ColorGraphics Technical Review Committee Editor-in-chief Distribution manager Web site design Gary Bartz, Richard Breuhaus, David Carbaugh, Laura Chiarenza, Justin Hale, Jim Lombardo Nanci Moultrie Methodologie Darrell Hokuf, Al John, David Landstrom, Doug Lane, Jill Langer, Duke McMillin, David Presuhn, Wade Price, Jerome Schmelzer, Corky Townsend, William Tsai

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AERO is published quarterly by Boeing Commercial Airplanes and is distributed at Information published in AERO is intended to be accurate and authoritative. However, no no cost to operators of Boeing commercial airplanes. AERO provides operators with material should be considered regulatory-approved unless specifically stated. Airline supplemental technical information to promote continuous safety and efficiency in personnel are advised that their company’s policy may differ from or conflict with their daily fleet operations. information in this publication. Customer airlines may republish articles from AERO without permission if for distribution only within their own organizations. They thereby The Boeing Edge supports operators during the life of each Boeing commercial assume responsibility for the current accuracy of the republished material. All others airplane. Support includes stationing Field Service representatives in more than must obtain written permission from Boeing before reprinting any AERO article. 60 countries, furnishing spare parts and engineering support, training flight crews and maintenance personnel, and providing operations and maintenance publications. Print copies of AERO are not available by subscription, but the publication may be viewed on the Web at www.boeing.com/boeingedge/aeromagazine. Boeing continually communicates with operators through such vehicles as technical meetings, service letters, and service bulletins. This assists operators in addressing Please send address changes to [email protected]. Please send all other regulatory requirements and Air Transport Association specifications. communications to AERO Magazine, Boeing Commercial Airplanes, P.O. Box 3707, MC 21-72, Seattle, Washington, 98124‑2207, USA. Copyright © 2015 The Boeing Company E-mail: [email protected]

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02 AERO QUARTERLY QTR_01 | 15 Building Better Communication: Readership Survey

At Boeing, we are always looking for ways how we are doing by sharing your to better serve our customers. That opinions, insights, and ideas in the 2015 includes regularly evaluating how AERO Survey. The survey, which is we provide the information that you need conducted by an independent research to operate your Boeing fleets safely and firm, should take fewer than 15 minutes to efficiently. We want to know how we can complete. Your survey responses will be better serve you — you have an kept strictly confidential, and the findings opportunity to provide input that will help will be reported in aggregate only. shape future issues of AERO. You may complete this survey by As a matter of daily business, we visiting www.boeing.com/aerosurvey. continually communicate through such Thank you in advance for taking the vehicles as multi-operator messages, time to help us serve you better and for service letters and bulletins, and the operating Boeing airplanes. Boeing Fleet Team Xchange on the MyBoeingFleet.com Web portal. LYNNE THOMPSON HOPPER The goal of AERO is to provide you Vice President, Customer Support with supplemental technical information Boeing Commercial Aviation Services that increases your awareness of Boeing products and services. Please let us know

03 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE New advanced ultrasonic inspection techniques available to operators reduce inspection time by a factor of five or more. Advanced Ultrasonic Inspection

Boeing has introduced advanced ultrasonic inspection techniques that provide operators with significant cost improvements over traditional ultrasonic testing technologies.

By John Linn, Technical Fellow, Service Engineering, and Jeff Kollgaard, Technical Fellow, Nondestructive Test

All in-service airplanes are subject to element probe and is widely used in the tions. In one example, this technology fatigue, environmental, and accidental aviation industry. Two new advanced eliminated the need to remove paint from damage. Detecting damage may require ultrasonic techniques, which are funda large areas of an airplane, reducing down nondestructive testing (NDT), such as mentally similar in concept to pulse echo, time by about as much as two days, as ultrasonic inspection. Portable advanced use multiple sensors in a probe to detect required by the pulse echo technique ultrasonic inspection technologies have damage. The use of multiple sensing used previously. improved significantly during the last elements increases scan coverage and The advantages of multiple-element few years. Two new advanced portable detection capability while providing a sensor (in comparison to single-element ultrasonic technologies that are now display that is more like an x-ray view and sensor) include: available are the Ultrasonic Testing Phased far more informative than the traditional ■■ A reduction of labor by 400 percent Array (UTPA) and the Synthetic Aperture oscilloscope trace. The result is improved for composite part inspections. Focusing Technique (SAFT). decision making by those evaluating the ■■ Enhanced display information. This article explains these technologies ultrasonic signals. ■■ Reduced inspection time. and their importance to operators. The new technologies, UTPA and SAFT, ■■ High-sensitivity inspection of a wide area. The traditional inspection technology, can dramatically reduce airplane downtime called pulse echo technique, uses a single and the labor time associated with inspec

05 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 1: UTPA instrumentation A UTPA instrument gives enhanced display capabilities to the operator.

The UTPA technology probes (see fig. 1) 40 to 75 degrees. All 16 elements listen of a traditional 0.25-inch (0.64-centimeter) have been developed in cooperation with for the return echoes after they are pulsed. diameter transducer but with more control Olympus NDT and GE Inspection Technol Software configures the return echo signals of the ultrasonic behavior and response. ogies; the SAFT technology probes have based on the timed pulses and the time of All five elements, defined as an aperture, been developed in cooperation with the received echoes. The range of angles listen for the return echoes. The aperture Toshiba. UTPA shear-wave sector mode is is displayed in an image of the structure is incremented down an array of up to currently used for scribe-line inspections called a sector scan image (see fig. 2). 128 elements to sweep across a scan area. and chemical mill edge inspections. The advantages of UTPA shear-wave The linear array probe can be used with The UTPA shear-wave probe is com inspection are its capability to: an X-Y scanner to produce an image of the posed of 16 multiple small rectangular structure (see fig. 3). ■■ Sweep a range of angles. sensors called elements. Each element The advantages of the linear array scan ■■ Display the image in real time through is electronically pulsed one at a time in a are the capability to inspect a wide area a range of swept angles. timed sequence to produce constructive with high sensitivity and display the image ■■ Focus the ultrasound signals. interference at a specific angle and a in real time. ■■ Eliminate the need to remove paint prior specific depth in the airplane part. These Currently SAFT is used for composite to inspection. time delays can be incremented over a laminate inspection. range of angles to sweep the beam over UTPA linear-wave mode is currently The SAFT electronically pulses one to the desired range. used for composite inspections. five elements while up to 32 other elements For example, a 40- to 75-degree The UTPA linear array probe uses five listen for the return echo. Although similar beam sweep would be accomplished by small rectangular elements that are pulsed to UTPA, the SAFT method employs time- calculating the time delays to produce simultaneously to produce a singular wave correction of the received signals, rather constructive interference at each point from front, traveling in the material like the pulse than pulse timing of the outgoing signals,

06 AERO QUARTERLY QTR_01 | 15 Figure 2: UTPA shear-wave sector scan Figure 3: UTPA linear array scan UTPA shear-wave sector scans can be used to inspect for scribe lines UTPA linear array can be used to inspect composites for damage and and doubler edge cracks. bonded repairs for processing defects. This scan shows impact damage to a stiffener.

to produce sharp ultrasonic images and bonded composite repairs. Both options Boeing will continue to evaluate and three-dimensional reconstructions of the offer wide field imagery, increased inspec integrate new nondestructive technologies data. SAFT can focus at multiple depths tion speed, measurement tools, and easier as they become available to offer operators simultaneously, providing a precise volu interpretation of complex signals resulting and maintenance, repair, and overhaul metric data set that can be sliced in various in significant return-on-investment advan facilities a choice of inspection methods and ways for data analysis. tages to maintenance organizations. These to enable them to implement the methods UTPA and SAFT procedures are specified in that work best for their specific needs. service bulletins, structural repair manuals, UTPA AND SAFT IN USE and NDT manuals. SUMMARY Advanced ultrasonic techniques offer The UTPA method is offered as an option to significant advantages over traditional pulse traditional single-element inspection proce New advanced ultrasonic inspection tech echo, such as: dures for scribe-line inspections and to niques offer a number of advantages over detect cracks in chemically milled fuselage ■■ Detection of cracks at varying angles traditional testing approaches, including skins. Because paint is not required to be and orientations. reducing inspection time by a factor of five removed prior to UTPA scribe-line inspec ■■ Compensation for attenuative effects or more. Boeing is making these technol tions, it has been shown that the return on of coatings. ogies available to operators.A investment is the elimination of one repeat ■■ Imagery of the structure and suspect inspection cycle on one airplane. damage that assist interpretation of Both UTPA and SAFT are offered as complex signals. inspection options to the traditional inspec ■■ Measurement tools that speed and tion technology for damage detection of improve decision making. composite materials and for inspection of

07 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Proposed loss-of-control– in-flight interventions cover a broad spectrum of potential solutions, including flight simulator training.

08 AERO QUARTERLY QTR_01 | 15 Preventing Loss of Control in Flight

Boeing, as part of the Commercial Aviation Safety Team, recently completed a multiyear effort to analyze loss-of-control–in-flight events and generate feasible solutions in areas of training, operations, and airplane design. These safety enhancements have now been adopted by the Commercial Aviation Safety Team for implementation in the United States and are being advocated for worldwide adoption.

By Michael Snow, Ph.D., Associate Technical Fellow, Human Performance, Aviation Safety, and Randall J. Mumaw, Ph.D., Associate Technical Fellow, Human Factors, Flight Deck Design Center, Flight Crew Operations Integration

In the last decade, loss of control– in-flight reduce the risk of future airplane state previous work done by a LOC-I Joint Safety (LOC-I) has become the leading cause of awareness events approximately 70 percent Analysis Team in 2000. The primary fatalities in commercial aviation worldwide. by 2018 and 80 percent by 2025. purpose of the Airplane State Awareness A subcategory, flight crew loss of airplane Joint Safety Analysis Team was to analyze a state awareness, has risen as a causal representative set of LOC-I accidents and A LARGE, COMPLEX PROBLEM factor in these accidents. incidents in which the flight crew lost aware This article explains safety enhance ness of the airplane’s state, defined as: Accident rates and fatalities in commercial ments that were recently adopted by the aviation are at historic lows in recent years, ■■ Attitude (pitch or bank angle) or Commercial Aviation Safety Team (see even as air traffic has climbed. However, ■■ Energy (the combination of airspeed, “What is the Commercial Aviation Safety Boeing continues to work with industry and altitude, vertical speed, thrust, and Team?” on page 13) and the process that government partners to improve safety for configuration control surfaces). drove the development of the enhance the traveling public. In August 2010, the ments. Implementation of the resulting A review of worldwide transport airplane Commercial Aviation Safety Team chartered training, operations, and airplane design accidents during the period from 2003 to the Airplane State Awareness Joint Safety safety enhancements is estimated to 2012 revealed that more than half of all Analysis Team as a follow-on activity to

09 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 1: Worldwide jet transport fatal accidents, 2003–2012 The loss of airplane state awareness has been a major factor in worldwide jet transport fatal accidents during the last 10 years.

50 ■ Total Onboard Fatalities 1,648 ■ External (On Ground) Fatalities ■ Fatalities within the Attitude Awareness Dataset ■ Fatalities within the Energy State Awareness 674 Dataset

1 971 28 765 596

0 38 12 2 202 1 1 154 153 154 6 0 121 96 1 4 Loss of Controlled Runway Unknown Runway System Midair Other Windshear or Ground Fire — Control– Flight Into Excursion — Excursion — Component Collision Thunderstorm Handling Non-impact In-flight Terrain Landing Takeoff Failure — Powerplant 18 17 16 3 5 2 2 2 1 7 2 NUMBER OF FATAL EVENTS

LOC-I accidents and resulting fatalities STUDYING LOSS OF CONTROL– airplane state awareness dataset, which involved flight crew loss of airplane state IN-FLIGHT may be representative of common issues awareness (see fig. 1). present in similar events (see fig. 3). Note The Airplane State Awareness Joint Nine of the events analyzed involved loss that no single factor causes an accident Safety Analysis Team was co-chaired by of attitude awareness and nine involved or incident. In these events, it took a Boeing and the U.S. Federal Aviation loss of energy awareness (see fig. 2). The combination of at least six themes to result Administration and staffed with subject objective of the analysis was to identify in a hazardous situation. The Airplane State matter experts from major airplane manu underlying problems that contributed to the Awareness Joint Safety Analysis Team did facturers and suppliers, pilot unions, airlines, accidents and incidents analyzed. In the not assign a ranking to these themes and research organizations, data mining organi course of this analysis, the teams identified notes that higher frequency of occurrence zations, and government aviation safety 161 distinct problems, of which 117 were (i.e., appearance in more events) should departments and agencies. Two analysis common with those identified by previous not necessarily imply greater importance. teams studied 18 events, identified problems Joint Safety Analysis Teams and 44 were ■■ Lack of external visual references. In 17 and major themes, and developed interven newly developed by the Airplane State of the 18 events, the event airplane was tion strategies. A data team complemented Awareness Joint Safety Analysis Team. flying at night, in instrument meteoro the work of the analysis teams by assessing The analysis teams then identified a total logical conditions, or in a combination the presence, frequency, and characteris of 274 intervention strategies to address of night and instrument meteorological tics of airplane state awareness precursors these problems, of which 181 had been conditions, sometimes at high altitude (conditions commonly leading to these documented previously and 93 were newly or over dark land or water. As a result, events, such as stall warnings or extreme developed. the crew had to rely on instrumentation bank angles) in U.S. Part 121 operations, to establish and maintain orientation. based on information available in the COMMON THEMES AMONG LOSS OF ■■ Aviation Safety Information Analysis and CONTROL–IN-FLIGHT Flight crew impairment. In seven of the Sharing database. 18 events, at least one member of the flight crew was affected by fatigue, The Airplane State Awareness Joint Safety illness, or alcohol consumption, and in Analysis Team discovered 12 major themes some cases by a combination of factors. that appeared across the events in the

10 AERO QUARTERLY QTR_01 | 15 Figure 2: Airplane State Awareness Joint Safety Analysis Team event dataset Of the 18 events studied by the Airplane State Awareness Joint Safety Analysis Team, nine involved loss of attitude awareness and nine involved loss of energy awareness.

UNITED STATES Baltimore, MD Union Star, MO Lubbock, TX Buffalo, NY 757-200 717 ATR-42 DHC-8

98 99 00 01 02 03 04 05 06 07 08 09 10

London Newfoundland Amsterdam 747-200F DHC-8 737-800

Hsinchu Oslo, Norway Sochi France Saab 340 757-200 A320 A320

Venezuela Sulawesi Perm, Russia MD-82 737-400 737-500

Bahrain Sharm el-Sheikh Bournemouth, UK A320 737-300 737-300

Douala, Cameroon 737-800 WORLDWIDE

Attitude Accident Attitude Incident Energy State Accident Energy State Incident

■■ Training. In nine of the 18 events, flight ■■ Safety culture. Safety culture played attack vanes or sensors, or other signals crew training played a role. In some a role in 12 of the 18 events. In some were used as input to primary flight cases, the crew had not received train cases, the operator had a poor safety displays, the autoflight system, or the ing that is generally considered industry record, extending back for months or navigation systems with little or no indi standard and is widely available. In other years. Many of the flights operated with cation the data were invalid. cases, the training had taken place but compromised safety, such as with less ■■ Distraction. Distraction played a role in was not recalled properly or did not than fully functioning systems or with all 18 events and manifested itself in two address the scenario encountered. a poorly defined flight plan. In several ways. First, a flight crew would make a In some instances, the Joint Safety events, the coordination and interaction decision based on faulty information or Analysis Team considered the training with the air traffic management, both in incorrect reasoning (sometimes when that the crew had received counter flight planning and during the flight, was task-saturated) and would be distracted productive or negative. poor. Schedule pressure was prevalent, by pursuit of actions or thought pro resulting in crews pressing on with ■■ Airplane maintenance. Airplane main cesses associated with that decision, flights or other activities despite warning tenance was an issue in six of the a phenomenon known as confirmation signals that the situation was deteri 18 events. In some cases, maintenance bias. Second, the flight crew would orating. Crew pairing — particularly the was not performed in a timely manner, become focused on one instrument pairing of pilots with low time in type — allowing problems to persist until they or one response to the exclusion of all was also an issue (see the section on became factors in the accident chain. other relevant inputs, comments, or crew resource management). In other cases, maintenance was per alerts and would essentially block out formed, but it did not directly address ■■ Invalid source data. In five of the any information that may have led the actual problem or was performed 18 events, invalid source data from them to fully understand the problem on the wrong system. the air data system sensors or probes, they faced, a phenomenon known inertial or rate gyro systems, angle-of- as channelized attention.

11 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 3: Summary of significant themes across all events

Lack ofVisual External References Flight ImpairmentCrew Training AirplaneMaintenance Safety Culture InvalidSource Data Distraction SystemsKnowledge Crew ResourceManagement AutomationConfusion Awareness / IneffectiveAlerting InappropriateControl Actions Total Formosa Airlines Saab 340 x x x x x x x 7 Korean Air 747-200F x x x x x x 6 Flash Airlines 737-300 x x x x x x x x 8 Adam Air 737-400 x x x x x x x x x 9 Kenya Airways 737-800 x x x x x x x 7 Aeroflot-Nord 737-500 x x x x x x x x x x x 11 Gulf Air A320 x x x x x x 6 Icelandair 757-200 (Oslo) x x x x x x 6 Armavia A320 x x x x x x x x 8 Icelandair 757-200 (Baltimore) x x x x x x x x x 9 Midwest Express 717 x x x x x x x 7 Colgan Air DHC-8-Q400 x x x x x x x x x x 10 Provincial Airlines DHC-8 x x x x x x 6 Thomsonfly 737-800 x x x x x x x 7 West Caribbean MD-82 x x x x x x x x x 9 XL Airways A320 x x x x x x x x x x 10 Turkish Airlines 737-800 x x x x x x x x 8 Empire Air ATR-42 x x x x x x x 7 Overall 17 7 9 6 12 5 18 7 16 14 18 12

■■ Systems knowledge. In seven of the ■■ Automation confusion/awareness. In ■■ Inappropriate control inputs. In 12 of the 18 events, the flight crew lacked 14 of the 18 events, the flight crew was 18 events, the flight crew responded to understanding of how major airplane either confused about the state (i.e., hazardous airplane states and conditions subsystems — such as autoflight, air data on/off) or mode of the autoflight system with control inputs that were opposite measurement, navigation, and inertial or else was unaware of trim or control to what was necessary to recover the systems — interact and how information inputs made by the autoflight system. airplane. The term “inappropriate” is from one system influences another. intended to convey only that the control ■■ Ineffective alerting. In all 18 events, inputs were not correct for the purpose ■■ Crew resource management. In 16 of alerting was an issue. The intended of recovering the airplane and should the 18 events, crew resource manage function of a flight deck alert is not not be construed to automatically imply ment was not practiced effectively. simply to go off: rather, it is to raise flight pilot error. Specifically, flight crews failed to crew awareness to a potential hazard, communicate effectively or work assist the crew in understanding the together to understand and resolve hazard, and (where possible) provide PREVENTING LOSS OF CONTROL– problems or confusion. In a number of guidance to avoid or recover from the IN-FLIGHT events, the pilot monitoring failed to hazard. The term “ineffective” in this properly perform the monitoring func context is meant to convey only that Hundreds of intervention strategies were tion. Crews also failed in some instances the alert, if present, failed to impact flight identified by the Airplane State Awareness to manage their workload properly. In crew awareness, understanding, and Joint Safety Analysis Team to mitigate the a few events, an authority gradient behavior in the manner intended. It is problems observed in the 18 Airplane State between the captain and first officer important to note that alerting effec Awareness Joint Safety Analysis Team likely played a role in preventing the first tiveness is not solely the result of events, and they were grouped into cate officer from taking control of the airplane airplane design: it is also significantly gories, based on how, and by whom, they from the captain, even when the captain affected by flight crew training, would be implemented. These categories was clearly failing to correct a hazardous communication, attention, and other include airplane design, flight crew training, airplane state. factors in the flight deck environment. maintenance, and safety data and research.

12 AERO QUARTERLY QTR_01 | 15

The Commercial Aviation Safety Team is a voluntary collaboration between U.S. government and industry that was founded in 1998. Its goal is to reduce fatality risk 50 percent in airline operations by 2025. It operates by consensus, deciding as a group which problems represent the greatest threats to aviation safety, chartering teams (e.g., Joint Safety Analysis Teams) to analyze those problems and underlying issues, determining feasibility of potential solutions (via Joint Safety Implementation Teams), and then tracking the implementation and effectiveness of adopted solutions (i.e., safety enhancements).

Airplane design. These interventions called ■■ Expanded upset prevention and Safety data. These interventions called for for action on the part of airplane manufac recovery training. expanded data mining and sharing programs turers or suppliers related to the design of Scenario-based situations. and safety management principles. The current and future airplanes. The highest- Stall recognition and recovery. interventions related to safety data fell into rated interventions related to airplane Spatial disorientation recognition these general areas: design fell into these general areas: and recovery. ■■ Sharing of safety-related data (e.g., the ■■ Reemphasized/expanded crew resource ■■ Flight envelope protection. Aviation Safety Information Analysis and management. ■■ Improved alerting. Sharing Program). ■■ Flight crew proficiency. ■■ Flight path/control guidance on displays. ■■ Operator safety management systems. ■■ Flight simulator fidelity. ■■ Source data integrity. ■■ Sharing of service difficulty reports. ■■ “Day-visual meteorological conditions” Airline operations and maintenance. These Research. Research interventions based display systems. interventions called for action on the part on the Joint Safety Analysis Team process ■■ Automation design. of operators or air traffic management to do not receive an overall effectiveness ■■ Energy management display/prediction improve and expand operating policies or score. Ranking of research interventions systems. procedures. The interventions related to for priority was based on which research airline operations, including air traffic control Flight crew training. These interventions interventions addressed the highest issues and airplane maintenance, fell into called for updates to current flight crew number of high-scoring problems. The these general areas: training curricula, standards, additional top research interventions, based on this training, and improvements to flight simu ■■ Maintenance procedures. methodology, fell into these general areas: lator fidelity. The highest-rated interventions ■■ Flight crew qualifications. ■■ Spatial disorientation. related to flight crew training fell into these ■■ Nonstandard flight operations. Displays to prevent spatial general areas: ■■ Reemphasis and rationale for standard disorientation. operating procedures. ■■ Revised approach-to-stall training. Alerting of spatial disorientation ■■ Flight crew impairment. conditions. ■■ Safety culture.

13 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 4: Bank angle alerting with recovery guidance Boeing is implementing auditory and visual bank angle alerting with recovery guidance in the 737 MAX and the Next-Generation 737.

“Roll Right!”

■■ Maintaining flight crew awareness in operations safety enhancements focus that the Commercial Aviation Safety high-workload environments. primarily on: Team has adopted and that Boeing and ■■ Automatic systems for error detection, other Commercial Aviation Safety Team– ■■ Revisions and improvements to existing prevention, and recovery. represented airplane manufacturers have flight crew training in upset prevention ■■ Human performance benefits of post- committed to implementing on their next and recovery, including revised stall recovery training using advanced all-new type designs: approach-to-stall training. flight simulator aerodynamic models. ■■ Revisions to go-around training. ■■ Flight envelope protection. This ■■ Policies and training for prioritizing safety enhancement has already been DEVELOPING SAFETY ENHANCEMENTS controlled flight in non-normal situations. implemented by Boeing on its latest ■■ Training verification and validation. fly‑by-wire commercial airplanes, the After the Airplane State Awareness Joint ■■ Enhancement of crew resource man 777 and the 787. Safety Awareness Team identified inter agement training to further define and ■■ Bank angle alerting with recovery vention strategies, the Commercial Aviation practice the duties of the pilot monitoring. guidance. Boeing is now working to Safety Team chartered the Airplane State ■■ Monitoring and understanding of implement this safety enhancement in Awareness Joint Safety Implementation habitual noncompliance to standard the 737 MAX and the Next-Generation Team to review them; assess them for operating procedures and improvements 737 (see fig. 4). technical, financial, operational, schedule, to standard operating procedures. regulatory, and social feasibility; and develop ■■ Policies for conducting nonstandard, ■■ Virtual day-visual meteorological new safety enhancements. The team then nonrevenue flights. conditions displays. Boeing's com developed detailed implemen tation plans mitment is contingent on successful In addition to training and operations based on the approved safety enhance completion of relevant research and safety enhancements, the team generated ment concepts. The proposed training and development and supporting industry three airplane design safety enhancements

14 AERO QUARTERLY QTR_01 | 15 The airplane state awareness safety enhancements are integrated into a coordinated safety plan. The goal is to balance short-term tactical mitigations, provided by operational and training programs, with longer term, more strategic solutions resulting from improved design.

standards. Boeing recently demon approach to addressing the issue of flight with the International Civil Aviation Organiza strated these displays, also referred to crew loss of airplane state awareness. Like tion and the international safety community as synthetic vision systems, in the 787 the underlying problem being solved, the to increase adoption worldwide. The plan EcoDemonstrator. Because these solution set is complex and addresses can be found at http://www.skybrary.aero/ displays are effective at supporting multiple issues. The analysis estimates that index.php/Portal:CAST_SE_Plan. flight crew attitude awareness, Boeing implementation of the training, operations, continues to engage with government and airplane design safety enhancements SUMMARY and industry partners in research and would reduce the risk of future airplane development to bring these systems to state awareness events approximately Loss of airplane state awareness plays a application readiness. 70 percent by 2018 and 80 percent by 2025. significant role in at least half of allLOC -I The Airplane State Awareness Joint The airplane state awareness safety category events. Safety Implementation Team recommended enhancements are integrated into a An industry analysis of a representative adoption by all U.S. Commercial Aviation coordinated safety plan with a goal of set of events identified specific problems Safety Team members of the training, oper balancing short-term tactical mitigations and major themes and resulted in proposed ations, and design safety enhancements, provided by operational and training interventions that cover a broad spectrum and it recommends these enhancements programs with longer term, more strategic of potential solutions in the areas of airplane be communicated to international aviation solutions resulting from improved design. design, flight crew training, airline operations safety communities for their review and The airplane state awareness safety and maintenance, and safety data. implementation where applicable. The enhancement portfolio was constructed by The Commercial Aviation Safety Team Commercial Aviation Safety Team and its the Airplane State Awareness Joint Safety has now officially adopted the resulting members have now officially adopted and Implementation Team to provide both near- safety enhancements and is working to published these safety enhancements as and far-term solutions that reinforce each implement them in the United States part of the Commercial Aviation Safety Team other and provide a balanced, redundant and worldwide.A Safety Enhancement Plan and are working

15 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Commercial airplanes can safely use runways with arresting systems designed for military use.

16 AERO QUARTERLY QTR_01 | 15 Commercial Operations on Runways with Arresting Systems

A number of airports throughout the world have joint commercial-military operations. Runways at these airports often are equipped with arresting gear systems (such as cables or barriers/nets) for tactical military aircraft to use. These systems pose a potential damage and safety hazard to commercial airplanes that use the same runways. Airports and airlines can take steps to help ensure safe commercial operations under such circumstances, including writing airport procedures specifically for commercial airplane operations, modifying existing arresting systems, reducing declared landing and takeoff distances, and increasing inspections of airplanes with nosegear spray deflectors.

By Brad Bachtel, Manager, Airport Compatibility Engineering

Of the nearly 36,000 airports around the This article is intended to help minimize tactical aircraft, such as fighter and attack world that are classified as civil, military, the commercial operational impact at jets, but they are also found on joint-use or joint-use, approximately 3,800 are used airports with runway arresting systems by runways. The third system is used at for scheduled commercial operations. describing the types of systems, operational commercial airports that do not have Worldwide, approximately 2,500 aircraft concerns for airlines, and measures to help sufficient safety areas at the end of the arresting systems are installed on runways ensure safe commercial operations. runway. (See “U.S. and International Aircraft in 74 countries. Approximately 400 airports Arresting Systems” on page 23.) with arresting gear cable have reported TYPES OF AIRCRAFT ARRESTING Aircraft arresting barriers. These devices, commercial airplane traffic. If the nosegear SYSTEMS which do not depend on arresting hooks spray deflectors used on some legacy on aircraft, stop an aircraft by absorbing its commercial airplanes come in contact with The three basic systems used to arrest forward momentum in a landing or aborted the arresting systems, there is a possibility aircraft are aircraft arresting barriers, aircraft takeoff overrun. These systems are most that the deflectors could shatter, creating arresting cables, and engineered materials commonly net devices (see fig. 1), but they foreign object debris (FOD). In extreme arresting systems. The first two systems also include older devices that catch the cases, the FOD could damage a critical are primarily military systems used for main gear struts. The barriers typically are airplane system.

17 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 1: Barrier net Arresting barriers, such as this net system, stop an aircraft by absorbing its forward momentum in a landing or aborted takeoff overrun.

■1 Auxiliary Energy Absorber 6 ■2 Stanchion ■3 Anchor Strap Aircraft Travel ■4 Net Webbing ■5 Runway Overrun Area ■6 Main Energy Absorber 4

2 3

Figure 2: Arresting cables Arresting cables are engaged by an arresting gear hook on the landing aircraft.

18 AERO QUARTERLY QTR_01 | 15 Figure 3: Typical arresting gear cable installation locations At this airport, an aircraft operating on runway 10R would use the cable at the far end for both landing and aborted takeoff unless the aircraft had an emergency, at which point the arresting gear nearest the approach end of the runway would be used.

When most operations are conducted under instrument meteorological conditions

2,200–2,500 ft (671–762 m) 10R Arresting Gear Cables 28L

1,500–1,800 ft (457– 549 m)

When most operations are conducted under visual meteorological conditions

located in the overrun of the runway, are The engagement direction is the Engineered materials arresting systems unidirectional, and can have collocated or anticipated direction from which an aircraft (EMAS). EMAS, which are constructed of interconnected arresting cables as part of will engage the cable. The system runout is high-energy-absorbing materials of specific their configuration. the distance from the original cable location strengths, are located in the safety area, or to the location at which the aircraft stops, overrun, of the runway. They are designed Aircraft arresting cables. Arresting cables which is typically 950 to 1,200 feet (290 to to crush under the weight of commercial span the width of the runway surface and 360 meters). The meteorological condition airplanes as they exert deceleration forces are engaged by the aircraft arresting gear is whether the system is used under visual on the landing gear. Since EMAS are located hook (see fig. 2). Cables are typically 1 to meteorological conditions or instrument in the overrun area of the runway, the EMAS 1.25 inches (2.5 to 3.2 centimeters) in meteorological conditions (see fig. 3). do not affect the normal landing and takeoff diameter and suspended 1.5 to 3 inches The installation criteria for cable systems of airplanes. More information concerning (3.8 to 7.6 centimeters) above the pave on commercial runways are identified in the EMAS is in FAA AC 150/5220-22B, Engi ment surface by rubber donuts 6 inches U.S. Federal Aviation Administration (FAA) neered Materials Arresting Systems (EMAS) (15.2 centimeters) in diameter. Used primarily Advisory Circular (AC) 150/5220-9A, Aircraft for Aircraft Overruns. by military aircraft built in the United States Arresting Systems for Joint Civil/Military Air and Europe, arresting cables have been ports. The location of the cable is marked used by the military since the late 1920s on OPERATIONAL CONCERNS FOR on the runway by a series of reflective aircraft carriers and land-based runways. AIRLINES discs 10 feet (3 meters) in diameter painted While commercial airplanes have become “identification yellow.” These discs are laid engaged or tangled in arresting cables, Airlines may have concerns about operating out with 30 feet (9.1 meters) between these occurrences are rare. commercial airplanes on runways with centers and extend the full width of the Three main factors determine where aircraft arresting systems. These concerns runway (see fig. 2). (See the definition of cables are located on runways: include airplane nosegear interference, location identification in “Common terms” trampling of the arresting cable, adjustments 1. Engagement direction. on page 20.) to declared distances, dealing with arresting 2. System runout. barriers, runway availability, airplane main 3. Meteorological condition. tenance, and unintentional engagement of an arresting system.

19 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 4: Nosegear device An MD-80 type is equipped with a combination nosegear spray–FOD deflector for normal operations. The ground clearance of this deflector is 0.75 to 1.5 inches (1.9 to 3.8 centimeters).

Common terms

Arresting Gear Cable Status: ■■ Rigged and up — Also referred to as Location identification — A description the gear being “in battery.” This means identifying the location of arresting systems ■■ Derigged — The cable is removed the cable is under tension across the by the approach or departure end, runway from the runway surface and is not an runway and elevated off the surface by designation, and position in hundreds of operational concern. use of rubber donuts (BAK-9/-12/-13) feet from the threshold. For example, the ■■ Out of battery (slack cable) — The or rubber elevation arms (BAK-14 or location identification “extended runout cable is extended across the runway Type H modification). BAK-12 at +1,500 on approach runway but is not under tension. 36” indicates a 1,200-foot (366-meter) BAK — U.S. designation for a barrier runout BAK-12 arresting system located ■■ Rigged and down — The cable is arresting system. Non-U.S. arresting 1,500 feet (457 meters) beyond the under tension across the runway but systems carry other designations. (See threshold of runway 36. not elevated off the surface by use of “U.S. and International Aircraft Arresting rubber donuts (BAK-9/-12) or rubber Systems” on page 23.) Reset time — The time required to ready elevation arms (BAK-14 or Type H the arresting system for another engage Cycle time — A measure of time modification). ment after aircraft release. (This does not between engagement of an aircraft and include time to disengage the aircraft the point when the arresting system is from the arresting system but does certified fully operational and ready for include the time required to inspect and another engagement. certify that the system is fully operational.

20 AERO QUARTERLY QTR_01 | 15 Figure 5: Adjusting declared distances In this example of adjustments to declared distances, an 8,000-foot (2,438-meter) runway could be reduced to 5,000 feet (1,524 meters) of usable runway length for each of the following declared distances: takeoff distance available, takeoff runway available, accelerate stop distance available, and landing distance available.

1,500 ft 5,000 ft 1,500 ft (457 m) (1,524 m) (457 m) 10R Arresting Gear Cables 28L

Figure 6: Examples of reduced Airfield Length Takeoff Weight Weight Loss runway lengths on weight Airplane ft (m) lb (kg) lb (kg) If the distance between the threshold and the cable is not used, the remaining runway can 8,000 (2,438) 378,000 (171,458) 767-300ERF substantially reduce the available payload on 5,000 (1,254) 308,000 (139,707) 70,000 (31,752) 767‑300ERF and 737-800 operations.

8,000 (2,438) 174,000 (78,926) 737-800 5,000 (1,254) 140,300 (63,640) 33,700 (15,286)

Nosegear interference. Some Boeing early slow-taxi over the cable, avoiding the donuts It is important to note that the cable model commercial airplanes have unique (if the cable is raised). If the nosegear spray must be kept under tension, whether lying nosegear devices to deflect either spray or deflector is damaged and removed, in on the pavement or elevated by the donuts. FOD. DC-9s, MD-80s, MD-90s, and 717s accordance with the FAA-approved airplane Otherwise, the cable could be lifted by are equipped with nosegear spray-FOD flight manual’s configuration deviation list, the airplane landing gear and contact the deflectors (i.e., DC-9s having chine tires or the airplane is limited to operating on dry bottom of the fuselage or antennae located the 717 that can have the outboard deflector runways until the deflector is replaced. on the lower fuselage. (See definitions of and support missing).The ground clearance out of battery, rigged and down, and rigged Trampling of the arresting cable. The 737 of this deflector is 0.75 to 1.5 inches (1.9 to and up in “Common terms” on page 20.) (excluding those with gravel deflectors), 747, 3.8 centimeters) (see fig. 4). Because 757, 767, 777, and 787 families can land and Adjustments to declared distances. Some most arresting cables are 1 to 1.25 inches taxi over the arresting cable/donuts at any airlines that operate on runways with (2.5 to 3.2 centimeters) in diameter and speed without exceeding design limit loads arresting cables have reduced the available suspended in the center of rubber donuts of the main and nose landing gears. How runway length by the distance from the that are 6 inches (15.2 centimeters) in ever, because the nosegear load increases approach end of the runway, or threshold, diameter, nosegear deflectors are at risk substantially when taxiing above 25 knots, to the cable (see fig. 5). of being damaged if a donut is struck. it is recommended to taxi below 25 knots If the distance between the threshold Typical installation is for the rubber donuts and initiate takeoff roll once past the cable if and the cable is not used, however, the to be approximately 6 feet (1.8 meters) apart, raised. Hard braking should be avoided while remaining runway available for use substan starting 3 feet (0.91 meters) from the runway traversing the cable during taxi. If an operator tially reduces the allowable payload on a centerline on runways 200 feet (61 meters) considers the trampling, or rolling over, of a 767-300ERF and 737-800 operation, based or less in width. For runways wider than cable to be too rough on the airplane, the on the conditions of a standard day, optimal 200 feet (61 meters) or that have the donuts that elevate the arresting cable above flap setting, zero wind, no obstacles, and additional system to raise/lower the cable, the runway surface can be moved to the zero slope (see fig. 6). This method of the donuts are placed 8 feet (2.4 meters) sides of the runway during commercial reducing available runway may be usable apart, starting 4 feet (1.22 meters) from the operations. This allows the cable to rest for a short-haul flight, but it is not a runway centerline. To minimize potential directly on the pavement surface, minimizing preferred long-term solution. damage to the nosegear deflectors, air the bump effect on the airplane. planes with such attachments should 21 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 7: Retractable cable A BAK-14 modification enables air traffic control personnel to remotely raise (left) and lower (right) an arresting cable.

Dealing with arresting barriers. Nets are Airplane maintenance. If the flight crew the arresting system. Educating the various located in the overrun area near the runway believes the airplane nosegear deflector parties on the operational needs of com threshold. If the net is in the raised position has contacted one of the hard rubber mercial airplanes can alleviate many at the lift-off end, it should be treated as an donuts supporting an arresting gear cable, limitations. Six ways to minimize the impact obstruction that has to be cleared by 35 feet a visual inspection of the nosegear spray of arresting systems located on runways (11 meters) in accordance with typical regu deflector should be conducted to verify used by commercial airplanes are: lations, and an adjustment should be made whether it has been damaged. A similar ■■ If the airport has parallel runways, nor to the takeoff runway available. There are visual inspection would apply if the flight mally only one of the two runways has rare situations in which a net has been crew thought that the cable had made the arresting system installed. Consider located across the actual runway. If a net contact with the belly of the airplane. For limiting commercial operations to the is lying on top of the runway, the airplane airlines that routinely operate on runways runway without the arresting system. should not cross it. with arresting-gear cables, additional visual ■■ Coordinate the permanent removal inspections may be conducted depending Runway availability. A commercial airplane of the arresting system. The military on the type of arresting systems installed following a military aircraft in to land could aircraft using the runways may no longer and to what extent the airplane interacts experience a delay in landing if the military need the arresting cable, which could with the system. aircraft engages the arresting gear. The flight be removed. crew of the commercial airplane should ■■ Install a system to lower the arresting expect to execute a missed approach while MEASURES TO HELP ENSURE SAFE cable flush into a track on the runway the military aircraft is removed and the COMMERCIAL OPERATIONS (see fig. 7). This modification, referred arresting gear is reset. Typical cycle times to as BAK-14 or Type H, allows the air for arresting gear can vary from 3 to The key to dealing with the presence of traffic control tower to remotely raise the 10 minutes depending on the type of arresting cables on runways is coordination arresting cable for military operations system. (See definitions of cycle time and among the airline operator, the airport and lower it into a track flush-mounted reset time in “Common terms” on page 20.) authority, and the agency having control of on the runway for commercial operations.

22 AERO QUARTERLY QTR_01 | 15 U.S. and International Aircraft Arresting Systems

TAIL HOOK SYSTEMS 1300 Rotary hydraulic (water brake) BEFAB 12:3* N/A

2800 Rotary hydraulic (water brake) BEFAB 21:2 N/A Bidirectional AAE-64 Rotary hydraulic (water BEFAB 24:4** N/A BAK-6 Water squeezer brake) RAF MK-6 N/A BAK-9 Rotary friction brake BEFAB 8:3, Pneumatic disc brake 20:4, 56:2 RAF MK-12A All nylon net BAK-12 Rotary friction brake There are three types of DUALBAK-12 Rotary friction RAF TYPE A N/A installation for the BAK-12 E5-1, E5-2, Chain RAF TYPE B N/A (net only; may be system: E5-3 attached to energy absorber Standard BAK-12 — 950-ft from any arresting gear) E6 runout, 1-in cable, and Chain SAFE-BAR 40,000-lb weight setting. N/A (engage with closed E15, E27 Rotary friction (Safe-land canopy) Extended BAK-12 — 1,200-ft barrier) 1 E28 Rotary hydraulic (water brake) runout, 1 ⁄4-in cable, and 61QSII Barricade net system 50,000-lb weight setting. M21 Rotary hydraulic (water Dual BAK-12 — Two energy brake) mobile 62NI Net barrier with hook cable absorbers on each side of the interconnect MAG I thru Rotary hydraulic (mobile runway connected to a single MAG X arresting gear) 63PI Dual-cable interconnect for cable; runout varies. hook engagement PAAG Portable aircraft arresting MAAS/ Essentially a BAK-12 system gear (British) A30 Aerazur 30-element net (F30) Portarrest mobilized on a specially devel oped trailer. Basic system UNKAGEAR Unknown type of energy A40 Aerazur 40-element net (F40) has 990-ft runout and is absorber equivalent to standard BAK- HOOK CABLE Unspecified type of tail hook 12. MAAS may be modified to MAIN STRUT OR WING engagement accommodate different ENGAGEMENT SYSTEMS HP-NET Zodiac high-performance net configurations equivalent to various BAK-12 systems. Unidirectional J-BAR Generic barrier (non-hook cable) engagement BAK-13 Rotary hydraulic MA-LA Web barrier between stanchions attached to a MA-1 Net barrier main gear cable E28 Rotary hydraulic (water brake) chain energy absorber. engagement M21/M-31 Rotary hydraulic (water Designed primarily for main NET Unspecified type of net brake) mobile strut engagement, but tests reveal successful hook engagement backup capability. Unidirectional UNK Unknown E5/E5-1/E5-3 Chain type. Rated by chain MA-LA Web barrier between DEVICES USED WITH SOME AIRCRAFT weight and length. The rating modified or adjustable stanchions MA-1A/E-5 ARRESTING SYSTEMS is used to determine the combined with a hook pickup maximum aircraft engaging cable and chain energy BAK-11 Pop-up engaging device speed. A dry rating applies to absorber. with a mechanical energy a stabilized surface (dry or MA-1A/BAK-9 Web barrier between absorber (BAK-9, BAK-12) wet), while a wet rating takes or MA-1A/ adjustable stanchions com- to engage main struts into account the amount (if BAK-12 bined with a hook pickup any) of wet overrun that is not BAK-14/Type H A device that raises a hook cable and a mechanical capable of withstanding the cable out of a slot in the energy absorber (bidirectional aircraft weight. runway surface and is on request). remotely positioned for Foreign cable BAK-15 Web barrier between engagement by the tower stanchions attached to an on request 34B-1A, 1B, 1C Rotary hydraulic (water energy absorber (water brake) squeezer, rotary friction, 44B-2E, 2F, 2H, Rotary hydraulic (water chain). Designed for wing 2I, 2L, 3A, 3H, brake) engagement. 3L, 4C, 4E, 4H BAK-15 (NI) Web barrier between * May alternatively be fitted with a cable 500S, 500S-4, Rotary friction stanchions interconnected 500S-6 with a hook pickup cable and ** Cable attached energy absorber. System is 500S-8 (TAG) Rotary friction (trans-arresting Source: U.S. Department of Defense (DOD) called BAK-15 with Net gear) en route supplement, a DOD Flight Information Interconnect (NI). Publication (FLIP) produced and distributed by 500S-8 Rotary friction the National Imagery and Mapping Agency BEFAB 6:3* Description not available (N/A) (NIMA).

23 WWW.BOEING.COM/BOEINGEDGE/AEROMAGAZINE Figure 8: Disconnecting an arresting cable In some situations, an arresting cable can simply be disconnected and laid on the side of the runway during periods of commercial operations.

At the majority of joint-use airports in the runway so that the cable lies flat on SUMMARY United States, this modification has been the pavement but is still under tension. made to the standard BAK-9/-12/-13 The airplane then can roll over the top Commercial airplanes can safely use systems that previously were supported of the cable. runways with aircraft arresting systems. by rubber donuts. Worldwide, there are ■■ Although not considered an optimal Approximately 400 airports with arresting approximately 500 BAK-14 and 25 Type solution, the runway length can be gear systems have reported commercial H systems installed. Roughly 95 percent reduced. This is feasible if the runway is airplane traffic. Safe operation requires of joint-use runways have BAK-14 or of sufficient length that the mission of the coordination among airline operators, Type H modifications installed. (See the airplane can be achieved on the usable airport authorities, and the agencies that definition ofBAK in “Common terms” on runway distance between arresting gears control the arresting systems. page 20.) installed at each end of the runway. For more information, e-mail ■■ Disconnect the cable and lay it on the At a minimum, operators may consider [email protected] side of the runway during periods of reducing only the distance from the commercial operations (see fig. 8). approach end of the runway to the gear. Temporarily disconnecting the cable ■■ Operators may want to increase the is a workable solution provided the frequency of maintenance inspection scheduled commercial operations do of the nosegear and lower fuselage not interfere with the flight schedule of areas for airplanes that routinely operate military aircraft. Alternatively, the rubber over arresting-gear cables. donuts could be slid to the edge of the

24 AERO QUARTERLY QTR_01 | 15 Share your opinions, insights, and ideas in the 2015 AERO Survey at www.boeing.com/aerosurvey. www.boeing.com/boeingedge/aeromagazine