Aerosafety World December 2006
AviationSafety w o r l d
pressing the approach A new perspective on pilot error Break, Distort or Yield Frangible airport lighting blast-free fuel tanks Tank inerting a decade after TWA 800 leaders log Rosenker, Coyne
ANTONOV BLACKLIST A QUESTION OF CONTINUED AIRWORTHINESS
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Left unchecked, it could threaten the openness William R. Voss and innovation upon which our industry’s safety President and CEO record is built. Flight Safety Foundation www.flightsafety.org | AviationSafetyWorld | December 2006 | AviationSafetyWorld
contents December2006 Vol 1 Issue 6 N N
N features N N 13 FlightTech | Blast-Free Fuel Tanks?
N 18 CoverStory | Antonov Blacklist
13 24 InSight | Filling the Envelope
28 HumanFactors | Pressing the Approach
34 AuditReview | Auditing Human Management
36 GroundSafety | Break, Distort or Yield
44 FlightOps | Flying Blind 18 47 ThreatAnalysis | Change of Plan departments
1 President’sMessage | Your Voice
5 EditorialPage | Instilling Culture
6 FoundationFocus | Laura Taber Barbour Award
7 SafetyCalendar | Industry Events 36 8 InBrief | Safety News
| flight safety foundation | AviationSafetyWorld | December 2006 47 contents 40 44 AviationSafetyWORLD William R. Voss, publisher, 11 LeadersLog | Mark V. Rosenker FSF president and CEO [email protected], ext. 108 27 FoundationFocus | Membership Update J.A. Donoghue, editor-in-chief, FSF director of publications [email protected], ext. 116 40 LeadersLog | James K. Coyne Mark Lacagnina, senior editor [email protected], ext. 114 50 DataLink | Close Calls Wayne Rosenkrans, senior editor [email protected], ext. 115 Linda Werfelman, senior editor 53 InfoScan | Mind in Flight [email protected], ext. 122 Rick Darby, associate editor 57 OnRecord | Recent Accidents and Incidents [email protected], ext. 113 Karen K. Ehrlich, web and print production coordinator [email protected], ext. 117 Ann L. Mullikin, production designer [email protected], ext. 120 Susan D. Reed, production specialist [email protected], ext. 123 Patricia Setze, librarian [email protected], ext. 103
Editorial Advisory Board About the Cover David North, EAB chairman, consultant The Antonov list of questionable aircraft includes a number of An-12s. William R. Voss, president and CEO © Steve Lake Flight Safety Foundation J.A. Donoghue, EAB executive secretary We Encourage Reprints (For permissions, go to
www.flightsafety.org | AviationSafetyWorld | December 2006 | Serving Aviation Safety Interests for More Than 50 Years Officers and Staff Chairman, light Safety Foundation is an international membership organization dedicated to Board of Governors Amb. Edward W. the continuous improvement of aviation safety. Nonprofit and independent, the Stimpson President and CEO William R. Voss FFoundation was launched officially in 1947 in response to the aviation industry’s need Executive Vice President Robert H. Vandel for a neutral clearinghouse to disseminate objective safety information, and for a credible General Counsel and knowledgeable body that would identify threats to safety, analyze the problems and and Secretary Kenneth P. Quinn, Esq. Treasurer David J. Barger recommend practical solutions to them. Since its beginning, the Foundation has acted in the public interest to produce positive influence on aviation safety. Today, the Foundation Administrative provides leadership to more than 1,000 member organizations in 143 countries. Manager, Support Services Linda Crowley Horger Financial MemberGuide Chief Financial Officer Penny Young Flight Safety Foundation Staff Accountant Maya Barbee 601 Madison Street, Suite 300, Alexandria, VA, 22314-1756 USA tel: +1 703.739.6700 fax: +1 703.739.6708 Membership www.flightsafety.org Director, Membership and Development Ann Hill Membership Manager David Chu Membership Services Coordinator Namratha Apparao
Communications Director of Communications Emily McGee
Technical Director of Technical Programs James M. Burin Technical Programs Specialist Millicent Wheeler Managing Director of Air Member enrollment ext. 105 Transport Safety Services Louis A. Sorrentino III Ann Hill, director, membership and development [email protected] Technical Specialist/ Safety Auditor Robert Feeler Seminar registration ext. 101 Namratha Apparao, membership services coordinator [email protected] Manager, Data Systems and Analysis Robert Dodd, Ph.D. Seminar/Aviation Safety World sponsorships ext. 105 Manager of Ann Hill, director, membership and development [email protected] Aviation Safety Audits Darol V. Holsman Exhibitor opportunities ext. 105 Ann Hill, director, membership and development [email protected] Past President Stuart Matthews Aviation Safety World orders ext. 102 Founder Jerome Lederer David Chu, membership manager [email protected] 1902–2004 Technical product orders ext. 101 Namratha Apparao, membership services coordinator [email protected] Library services/seminar proceedings ext. 103 Patricia Setze, librarian [email protected] Web Site ext. 117 Karen Ehrlich, web and print production coordinator [email protected]
| SINCE 1947 flight safety foundation | AviationSafetyWorld | DECEMBER 2006 Editorialpage INSTILLING Culture
are must be taken in viewing safety Arslanian relates his experience in- others. If we don’t protect them from in the developing world not to vestigating the Dec. 25, 2003, crash of a this sort of competition, [cheating] may assign blame too quickly, nor to Boeing 727 attempting to take off from become contagious, imitated just to gain assume that the lapses in adher- Cotonou, Benin, that killed 141 people. the same efficiency. Cence to proven safety procedures are the A group based in the United Arab Emir- “We must develop the [safety] culture. result of a pervasive disregard. This is ates bought the aircraft out of the U.S. They have the training, they have money, the judgment of Paul-Louis Arslanian, desert that January. It was used by the what they need is culture, developing the director of France’s Bureau d’Enquêtes owner under the guise of three different team concept at the level of the workers et d’Analyses (BEA), the nation’s accident operators that year, registered successively and the level of the rulers. In Benin, investigation agency. in Afghanistan, Swaziland and Guinea. we did not meet bandits in positions of “There are two worlds of safety,” he The operations manual, approved by authority. They just are isolated from says. One world is “the classic Western Guinean aviation authorities months after normal world activities and it is not their world, pushing safety toward its pres- operations began, lacked, the BEA ac- fault, it is our fault.” ent achievement, developing a culture cident report says, “a chapter on loading There remains, Arslanian says, a need of safety.” The other is developing na- and balancing the aircraft.” to punish the “bandits, but when we iden- tions, where problems arise mostly when The 727 was heavily loaded with a cen- tify a failure we should do it the same way people from outside aviation come into ter of gravity far forward of limits when a as in our safety culture — no blame, just the industry believing it to be just another takeoff was attempted on a hot day. The air- correct the problem.” business. plane had just left the ground at the end of “In the developing world, you find the runway when its landing gear hit a small excellent people with the proper culture, concrete building that housed navigation highly competent, some more competent aids. The airplane veered left, crashed on a than we have in [developed] countries beach and slid into the ocean. because they have so many challenges “The whole [Benin] government was to overcome,” Arslanian says. “But these totally concerned; none were saying, people usually are at the level of action, ‘Well, this is just another accident.’ They not at the level of decision.” were aware that aviation is a must for Those people coming from out- their country, not only for the economic side aviation “are mercenaries, coming stimulation it brings, but also for opening with just one logic — to make money. their door to the world,” Arslanian says. This logic is colliding with our safety When “mercenaries” cut corners, “the logic.” cheaters can take business away from www.flightsafety.org | AviationSafetyWorld | December 2006 | FoundationFocus
The Laura Taber Barbour Award 1956-2006
Sixty-one years ago — April 14, 1945 It was 7 mi off course. The airplane was • A significant individual or group — a Douglas DC-3 with 17 passengers destroyed by the impact and a subse- effort contributing to improving and three crewmembers was en route quent fire, and all its occupants were aviation safety, with emphasis on from Pittsburgh to Birmingham, Ala- killed. original contributions. bama, U.S. The captain of Pennsylvania- The terrible event probably didn’t • A significant individual Central Airlines Flight 142 had checked attract much attention, except among or group effort performed several sources to learn the weather at grieving relatives, in a nation that had above and beyond normal Morgantown, West Virginia, a scheduled been fighting a world war for more responsibilities. Sstop where minimums were a 1,000-ft than three years. But it resulted in the The award has been presented every ceiling and 1 mi visibility and instru- creation of an award, presented by year since 1956. The recipients in re- ment approaches were not authorized. Flight Safety Foundation at its annual cent years are Capt. Robert L. Sumwalt The captain and first officer discussed International Air Safety Seminar, recog- (2003), Kay Yong, Ph.D. (2004) and the weather. The captain reported that nizing individual or group effort that Capt. Ralph S. Johnson (2005). The he would “take a look” in the Morgan- helps avoid aviation tragedies. award for 2006 went to Don Bateman town vicinity and decide whether to The Laura Taber Barbour Award for his many outstanding contribu- land or proceed to the next scheduled was established in 1956 by Clifford tions to aviation safety, particularly his destination. E. Barbour and his son in memory of leadership in developing the ground- The pilots encountered a continual- Laura Taber Barbour, killed in the proximity warning system, which has ly lowering ceiling and flew the airplane controlled-flight-into-terrain accident been instrumental in reducing CFIT through the irregular cloud base. At at Morgantown. The recipient is se- accidents such as that which took the 1658 local time, the airplane crashed lected by independent aviation profes- life of Mrs. Barbour. near the top of a ridge at about 2,100 ft. sionals on the basis of these criteria: — Rick Darby
FSFSeminars Exhibit and Sponsorship Opportunities Available Staying Safe in Times of Change March 12–14, 2007 Flight Safety Foundation and European Regions Airline Association 19th annual European Aviation Safety Seminar EASS Grand Hotel Krasnapolsky, Amsterdam, Netherlands Safety — The Foundation for Excellence May 8–10, 2007 Flight Safety Foundation and National Business Aviation Association 52nd annual Corporate Aviation Safety Seminar CASS
Hilton Tucson El Conquistador Golf & Tennis Resort, Tucson, Arizona, USA © 2006 Getty Images Inc. Inc., Dreamstime
| flight safety foundation | AviationSafetyWorld | December 2006 ➤ safetycalendar
Jan. 21–25 ➤ Transportation Research March 12–14 ➤ 19th annual European April 24–26 ➤ 9th Annual Canadian Airport Board 86th Annual Meeting. Washington. Aviation Safety Seminar (EASS): “Staying Management Conference. Airports Council
www.flightsafety.org | AviationSafetyWorld | December 2006 | inBrief Safety News Australia Plans Multi-Crew Licensing
multi-crew pilot license for pilots The new license is intended trained specifically to be first of- to address research findings that Aficers in air transport operations failures in teamwork are a primary is being planned by the Civil Aviation contributor to aviation accidents, Safety Authority (CASA) of Australia, in part because traditional training iStockphoto© Copyright which is now developing regulations for methods emphasize individual skills the new category license. and independence, CASA said. “People training for the multi-crew CASA said that the new license will focus on large-aircraft flying regulations are intended to “keep skills, crew resource management, and Australia at the forefront of inter- threat and error management throughout national changes in air safety, in their year-long training,” CASA said. They line with the latest standards issued will be required to complete 240 hours of by the International Civil Aviation training, including up to 70 flight hours. Organization.”
NTSB Cautions Pilots About Severe Weather Canada Considers Changes in Emergency Response Plans he U.S. National Transportation “Severe-weather avoidance is the Safety Board (NTSB), citing several responsibility of the pilots,” NTSB ertified Canadian airports would Taccidents in which severe weather Chairman Mark V. Rosenker said. “We be required to comply with “clear was either a cause or a contributing fac- … feel that it is imperative to reiter- Cand consistent” criteria in develop- tor, is urging pilots to “actively maintain ate the seriousness of this task during ing and evaluating emergency response awareness of severe weather” during flight.” plans if regulatory amendments pro- flight. NTSB said that its accident inves- posed by Transport Canada are adopted. The accidents cited by NTSB tigations found that pilots of the acci- “Travelers expect to feel safe involved aircraft being flown under dent aircraft “were either not advised when they use Canadian airports,” instrument flight rules (IFR), with pilots about areas of severe weather ahead said Lawrence Cannon, minister of in contact with air traffic control (ATC). or were given incomplete informa- transport, infrastructure and com- Although ATC is primarily responsible tion.” The pilots did not use alterna- munities. “These amendments will for keeping IFR aircraft separated, tive sources of information — such as ensure that our airports have the nec- controllers also provide pilots with weather alerts broadcast by ATC and essary tools to successfully respond to weather advisories and, at an individual various on-board weather-avoidance an emergency situation.” pilot’s request, suggested headings to technologies — that probably would The proposed amendments would avoid precipitation — but only when a have prevented the accidents, NTSB require a more structured method of controller’s workload permits. said. handling emergency planning and AeroTech Research (USA) evaluation of the emergency plans, Transport Canada said. Emergency plans would be required for various scenarios. The plans would describe how each type of emergency would be handled and would identify airport and community organizations that could provide as- sistance during an emergency. The proposals were published Oct. 7, 2006. After a 30-day response period and subsequent review of the responses by Transport Canada, final regulations will be published.
| flight safety foundation | AviationSafetyWorld | December 2006 inBrief
Better SOPs Sought for EMS Flights Anxiety Suspected in Pilot Incapacitation tandard operating procedures and The board recommended that crew coordination should receive the Swedish Civil Aviation Authority Boeing 767-300ER pilot who Sgreater emphasis in emergency “act to ensure that operators who fly had been taking an antidepres- medical services (EMS) helicopter to places which are not established A sant to treat anxiety and stress operations, the Swedish Accident takeoff and landing grounds possess, may have suffered “an anxiety reac- Investigation Board says. and follow, operational procedures for tion” during a passenger The board’s recommendation fol- such flights similar to those used for flight from Auckland, New Zea- lows its investigation of a Sept. 18, 2004, [instrument flight rules] flights” and land, to Melbourne, Australia, the accident in which a Sikorsky S-76C that it “act to ensure that operators fly- Australian Transport Safety Bureau struck the water during an overwater ing under VFR, with two pilots or with (ATSB) said in its final report on the nighttime visual flight rules (VFR) [a medical crewmember] develop and incident. approach to a landing site on a small, follow some form of crew cooperation The report said that during relatively undeveloped island. The final for VFR flight corresponding to that in cruise, the pilot complained first of report on the accident said that the use for IFR flights.” increasing fatigue, and later of nau- pilots “underestimated the difficulty” The board also recommended that sea, headache and neck pain. A cabin of the landing and that the accident the authority “seek internationally to crewmember administered oxygen, occurred because of “a lack of adequate ensure that requirements for the use and the captain was relieved of duty; routines and procedures for the activity of [flight data recorders] and [cockpit the first officer flew the airplane in question, and existing procedures voice recorders] are introduced for this to its destination. After landing, were not followed completely.” category of helicopter operations.” the captain was taken to a hospital, where medical tests were inconclu- sive but ruled out any heart-related problem. The captain had a “history of stress-related difficulties over several years” and had been treated with stress management and a type of
© Copyright Getty© Copyright Images antidepressant medication known as a selective serotonin reuptake inhibitor (SSRI). He also had been treated for high blood pressure, or hypertension. “It is possible that the incapacita- tion of the [captain] was related to an anxiety reaction precipitated by a combination of factors, including low Cold-Weather Reminder blood pressure due to hypertension medication, fatigue and a head cold,” he U.K. Civil Aviation Authority (CAA) has issued a reminder to all operators the report said. about two problems accompanying winter flight operations: contaminated Unlike many other civil aviation Trunways and airframe icing. authorities, the Civil Aviation Safety The Flight Operations Division Communication from the Safety Regulation Authority (CASA) of Australia issues Group says that operators should avoid using snow- and ice-contaminated runways medical certification to some pilots whenever possible and that flight crews should use the most current information in who take SSRIs. their performance calculations. CASA’s policy complies with In addition, flight crews should be reminded that using electronic flight bag recommendations of the Aerospace products in performance calculations on a contaminated runway “often produces Medical Association. A 2005 review optimum flap-setting performance where the computer uses the available runway concluded that the policy was “ap- length to accelerate the airplane to a higher speed in order to improve the climb propriate and that there were no performance. This is unlikely to be appropriate in such conditions where a shorter safety concerns relating to the prac- ground roll would be preferred.” tice,” the ATSB report said.
www.flightsafety.org | AviationSafetyWorld | December 2006 | inBrief
ATSB Urges More Guidance for ATC FAA Issues AD on Airbus Crew Seats he Australian Transport Safety Before the incident, the control- Bureau (ATSB) has recommended ler had told the pilot of the Cessna ne year after the French Direc- Tthat Airservices Australia review to “make an orbit and then continue tion Générale de l’Aviation guidance material and training for downwind” for separation from other OCivile issued an airworthiness airport air traffic controllers to ensure aircraft, but the Cessna pilot did not directive (AD) to require inspections that they provide pilots with all relevant complete a full orbit and then turned of flight crew seats in some Airbus traffic information. onto base while the 717 was on airplanes, the U.S. Federal Aviation The recommendation was issued final. The Cessna pilot had not read Administration (FAA) has taken as a result of an ATSB investigation of back his instructions to continue on similar action. an April 30, 2005, incident at Hobart downwind, and the controller had not Both ADs require inspections Airport in Tasmania in which separa- requested a readback; published docu- to determine if a specific actuator tion between a converging Cessna 152 ments did not require a readback, the is installed at the pilots’ seats and and a Boeing 717-200 was as little as incident report said. performance of applicable corrective 400 m (1,312 ft) horizontally and 300 In addition, the report said, actions. ft vertically. Pilots of each aircraft took “The controller did not provide the FAA said that the AD was required action to avoid the other. pilot of the C-152 or the B-717 with because of a report of “heavy wear traffic information or a number in at the driving gear of the rotor-shaft the landing sequence, as required by end of the electrical driven motor on published documents. This led to a certain actuators of the pilot’s and reduction in the situational aware- copilot’s seats.” Implementation of the ness of the pilots of both aircraft and AD is intended to prevent uncom- excluded them from participating manded movement of the seats during effectively in the separation process.” takeoff or landing; this movement After the incident, Airservices could interfere with airplane opera- Australia said that it was “addressing tions and result in temporary loss of the issue of obtaining readbacks” and control, FAA said. had begun a standardization program The AD applies to some models to emphasize use of correct phraseol- of the A318, A319, A320, A321, A330
© Copyright iStockphoto© Copyright ogy and readback. and A340.
In Other News … © Copyright Embraer he Italian Air Safety Board has introduced a voluntary, confidential Taviation safety reporting system intended to help prevent accidents. … Embraer and CAE have agreed to establish a global joint venture to provide pilot and ground crew training for operators of Phenom 100 Very Light Jets and Phenom 300 Light Jets; training programs will begin in 2008 in Dallas and expand to sites in the eastern United States and Western Europe. … Sherry Carbary has been named president of Alteon Training; she formerly was vice president of strategic management for Boeing Commercial Airplanes.
Compiled and edited by Linda Werfelman.
10 | flight safety foundation | AviationSafetyWorld | December 2006 LeadersLOG
Margins of Safety BY MARK V. ROSENKER
n the snowy evening of Dec. 8, 2005, When the crew input “WET-POOR,” the OPC Southwest Airlines Flight 1248, a Boeing calculated a 30-ft (9-m) stopping margin. 737-7H4, ran off the end of Runway The assumption that engine thrust revers- 31C upon landing at Chicago’s Midway ers would be deployed on touchdown is consis- OAirport. The airplane struck two cars on a city tent with Southwest Airlines’ Flight Operations street, killing a child. Manual, which states While the flight was en route from Balti- that, when landing more, the flight crew obtained updated weather under less than good information and runway braking action reports braking conditions, from air traffic control. Based on this informa- the thrust reversers tion, the crew planned for fair braking action on are to be used as soon Runway 31C. About 30 minutes before the ac- as possible during the cident, airport ground personnel had performed landing roll and are a runway friction measurement, which indicated to be applied with the that the runway friction was “good.” brakes. However, the The flight crew used an on-board laptop flight data recorder performance computer (OPC) provided in the revealed that about cockpit of Southwest Airlines’ airplanes to calcu- 18 seconds passed late expected landing performance. Flight crews from the time the air- enter flight specific data into the OPC, including plane touched down the expected landing runway, wind speed and to the time the thrust direction, airplane gross weight at touchdown reversers were de- and the reported runway braking action. The ployed; at that point, 737-700 OPC is programmed to assume that only about 1,000 ft the engine thrust reversers will be deployed on (305 m) of usable touchdown and to calculate the stopping margin runway remained. (the amount of runway remaining after the During post-accident airplane comes to a stop). interviews, the The flight crew entered weather data into captain stated that the OPC and input “WET-FAIR” as the runway he attempted to immediately deploy the thrust Mark V. Rosenker is braking condition. The OPC calculated that the reversers but was unable to do so. According to chairman of the U.S. airplane would be able to stop on Runway 31C the first officer, at some point during the roll- National Transportation Safety Board. with about 560 ft (171 m) of runway remaining. out, he noticed that the thrust reversers were www.flightsafety.org | AviationSafetyWorld | December 2006 | 11 LeadersLog
not deployed, and he then deployed them. The reverse thrust credit in landing performance late deployment of the thrust reversers almost calculations. completely negated the stopping-distance ben- The NTSB staff was informed that FAA efit that had been expected from their use. agreed with the intent of the recommendation, The U.S. Federal Aviation Administration and intended to develop a new requirement that (FAA) does not allow the use of the reverse would yield an even greater safety benefit than a thrust credit when determining dispatch landing blanket prohibition against taking credit for re- distances. The stopping benefit from thrust re- verse thrust. Subsequently, on June 7, 2006, FAA verser use typically has provided a built-in safety published “Announcement of Policy for Landing margin to offset other variables. However, FAA Performance Assessments After Departure for allows the reverse thrust credit to be used in cal- All Turbojet Operators.” This announcement culating en route operational landing distances stated that FAA considered a 15 percent margin for some transport-category airplanes, such as between the expected actual airplane landing the accident airplane, a 737-700. Accordingly, distance and the landing distance available at the when using the reverse thrust credit for con- time of arrival as the minimum acceptable safety taminated runways, the required runway length margin for normal operations. As a result, FAA for 737-700 model airplanes is about 1,000 ft was planning to issue Operations Specification/ less than the required runway length without the Management Specification (OpSpec/MSpec) The late deployment reverse thrust credit. The OPCs of Southwest C082 implementing this requirement by Oct. 1, Airlines’ 737‑300 and ‑500 model airplanes do 2006. of the thrust not use the reverse thrust credit; therefore, these While the proposed FAA action was not airplanes have a greater landing safety margin. precisely what NTSB had recommended, it reversers almost In this accident, when the thrust reversers were would have provided the additional safety mar- not (or could not be) used in a timely manner, gin that NTSB was seeking; it went beyond the completely negated the airplane could not be stopped on the run- NTSB recommendation by including all turbojet way because of the absence of this extra safety operators, not just carriers operating under the stopping- margin. Federal Aviation Regulations Part 121, Domestic, If the reverse thrust credit had not been Flag and Supplemental Operations. However, on distance benefit that factored into the stopping distance calculations Aug. 31, FAA abandoned this plan and instead made by the OPC, it would have indicated that published a “Safety Alert for Operators (SAFO),” had been expected a safe landing on Runway 31C was not pos- in which FAA announced that it would begin sible under a braking condition of either fair or a rulemaking process to require the practices from their use. poor. The U.S. National Transportation Safety described in the policy statement. In the mean- Board (NTSB) is concerned that the landing time, FAA recommended that operators volun- distance safety margin is significantly reduced tarily comply with the policy statement. on a contaminated runway when the reverse NTSB’s concern is that rulemaking can take thrust credit is allowed in landing stopping years and that the next snow and ice season is distance calculations. As a result, a single event, upon us (in the Northern Hemisphere). Some the delayed deployment of the thrust reversers, major airlines have indicated that they will can lead to an unsafe condition, as it did in this comply with C082, but without a requirement, accident. NTSB believes that the safety margin it could be years before all passengers have the must be restored to those airplanes for which additional safety margin that NTSB believes is the reverse thrust credit is currently allowed in required for landing on short, contaminated run- landing performance calculations. ways. NTSB urges FAA to follow its first course On Jan. 27, 2006, NTSB issued an urgent of action and hopes that, in the interim, all op- recommendation, A-06-16, to FAA to im- erators will comply with the SAFO. Let’s not see a mediately prohibit airlines from using the repeat of the Chicago Midway tragedy. ●
12 | flight safety foundation | AviationSafetyWorld | December 2006 FLIGHTtech
O O Illustrations: Susan D. Reed (FSF) Illustrations: Susan D. CC O O
N N Br N Br N Fl Fl
C Fl Fl C Fl
Fl The FAA has a plan that it says will reduce the risk of aircraft fuel tank explosions. Critics aren’t so sure.
BY LINDA WERFELMAN Blast-Free Fuel Tanks ore than 10 years after a Trans World Others, including the U.S. National Transpor- Airlines (TWA) Boeing 747 crashed tation Safety Board (NTSB), say that the rule into the Atlantic Ocean following — which would apply only to center wing fuel takeoff from New York’s Kennedy tanks and only to passenger airplanes — would MInternational Airport — an accident blamed on not go far enough. 1 ? an explosion in the center wing fuel tank — the The proposed rule would require more than U.S. Federal Aviation Administration (FAA) is 3,200 existing passenger jets, as well as some reviewing comments on a proposed rule that new jets, to have “acceptable levels of flammabil- FAA officials say would substantially reduce the ity exposure in tanks most prone to explosion or risk of similar accidents. require the installation of an ignition-mitigation However, some critics, including major means in an affected fuel tank.”2 airplane manufacturers and a number of FAA says that the best method of meet- airlines, call the proposed rule unnecessary. ing the requirement is fuel tank inerting — a
www.flightsafety.org | AviationSafetyWorld | DECEMBER 2006 | 13 FLIGHTtech
Fuel-Inerting System The proposed rule “should greatly reduce the chances of a catastrophic fuel Bleed Air Duct tank explosion,” FAA said in its notice of Heat exchanger cools air to proposed rulemaking. 180 degrees F (82 degrees C) Line from existing bleed air duct supplies In the past, fuel tank hot pressurized air explosions have been a “constant threat,” FAA said, citing data that High/low ow ori ces show that, from 1960 regulate nitrogen ow through November 2005, there were 17 Filter captures accidents in which air- dust/oil planes were destroyed contaminants Oxygen enriched air removed from the Nitrogen enriched air by fuel tank explosions, ASM and dumped exits ASM and is including the TWA overboard plumbed to fuel tank accident that prompted the proposal (see “Re- lated Accidents,” page 16). Without remedial measures, nine similar accidents involving
Air inlet provides Pressurized air ASM separates transport category air- cooling ow to enters air separation most oxygen planes would be likely heat exchanger module (ASM) from incoming air in the next 50 years,
Source: U.S. Federal Aviation Administration Illustration adaptation: Susan D. Reed (FSF) FAA said. “We believe at least Figure 1 eight of these explo- sions are preventable if process in which an inert gas such as nitrogen we adopt a comprehensive safety regime to reduce is introduced into a fuel tank to replace oxygen both the incidence of ignition and the likelihood of (Figure 1). The process is effective because, un- an explosion following ignition,” FAA said. Of the like oxygen, which accelerates fire, inert gases eight, four could be prevented through implemen- are fire suppressants. tation of the proposed rule, FAA said. “Fuel tank inerting, originally thought to Four others could be prevented through O be prohibitively expensive, can now be accom- the implementation of Special Federal Aviation C O plished in a reasonably cost-effective fashion Regulation (SFAR) 88, which was adopted in O C O and protect the public from future calamities, 2001 to minimize ignition sources — an action which, we have concluded, are otherwise virtu- that resulted in the identification of more than ally certain to occur,” the proposed rule says. 200 potential sources. FAA estimates the cost of retrofitting exist- “While the work accomplished by the ing airplanes at US$313 million — or about industry to comply with SFAR 88 has certainly $140,000 to $225,000 per plane. The total cost improved safety, the FAA believes that the added for the U.S. fleet probably will total $808 million safety net of reducing the flammability of the over 49 years, FAA said. tank is also necessary,” FAA said.
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NTSB Chairman Mark V. Rosenker agreed In 2005, an inerting system developed by N N but said that progress toward adopting new safe- Boeing was certified and is now the subject of an guards is slow and the proposed rule does not do “in-service evaluation” involving two 737s and enough to reduce fuel tank flammability risks. two 747s. The Boeing system — designed to be N “Ten years after the TWA accident, fuel installed on new and retrofitted 737s and 747s tank inerting systems are not in place on our as early as 2007, and on other Boeing airplanes airliners, and flammability exposure is largely by 2008 — diverts engine bleed air into an air unchanged,” Rosenker said. “And proposed separation module that separates the nitrogen rule changes do not include the majority of and pipes the nitrogen into the center wing fuel fuel tanks, which are in the wings of transport tanks. The new composite 787 has been de- airplanes, nor this country’s large fleet of cargo signed with inerting systems for all fuel tanks. aircraft.” In comments on the proposed rule, Boeing Elimination of flammable fuel/air vapors in suggested revisions to exempt from the retrofit- all the fuel tanks of transport category aircraft ting requirement older airplanes estimated to be — an item recommended by NTSB in its final within five years of retirement, questioned FAA’s report on the TWA accident — has been on contention that cargo airplanes should not be the board’s list of “most-wanted transportation subject to the rule, and challenged FAA’s projec- safety improvements” since 2002. tion that a fuel tank explosion might occur once in every 60 million flight hours. A more realistic Military Beginnings projection would be once every 100 million The inerting process has been used for decades flight hours, Boeing said. in military aircraft. Inerting systems first were used during World War II to reduce the risk Workplace Hazards of fuel tank explosions during combat. Ini- Airbus also challenged FAA’s projection, saying Inerting systems tially, engine exhaust was used to produce the that the proposal was developed using faulty first were used inert gas; the use of nitrogen is a more recent data that overstated not only the risk of a fuel development. tank explosion but also the benefits of the pro- during World War II The inerting systems used by the military posed safety improvements. have long been considered too heavy, too “Specifically ... the number of future ac- to reduce the risk of complex and too expensive to function well in cidents to passenger airplanes that might be commercial airplanes. In addition, the military prevented in the next 50 years by enacting fuel tank explosions systems were designed to be used for relatively this proposal is not four, as the FAA estimates, during combat. short periods — not for the lengthy flying days but 0.67 accidents,” Airbus said in comments that are typical for many passenger jets. submitted in response to the proposed rule. FAA researchers — working with their coun- “FAA estimates that some 546 statistical fatali- terparts at Boeing — spent years developing a ties would be avoided by enactment of these more practical system for commercial airliners, proposals. Our comments estimate that 31 and in 2002, six years after the TWA accident, statistical fatalities would be avoided in the they tested a prototype, on-board inerting next 50 years.” system that relies on engine bleed air, weighs far Airbus also noted that its aircraft were less than the systems used by the military and is not involved in the accidents cited by FAA less complex and less expensive. The research- in proposing the rule, and said that because ers determined that, if a properly sized inerting there are “significant differences” between system were operated during flight, the fuel fuel tank designs on its airplanes and those of tank would remain inert after landing and there other manufacturers, “each fuel tank should be would be no need for ground operation of the assessed on an individual basis.” Airbus said inerting system. that a primary difference between its fuel tank www.flightsafety.org | AviationSafetyWorld | DECEMBER 2006 | 15 FLIGHTtech
design and that of the 747 is that, on the 747, Other airplane manufacturers also ques- environmental control system packs are located tioned the FAA’s proposal to require action by “directly beneath the [center wing tank] without manufacturers other than Boeing. any evident means of limiting heat transfer”; on “FAA notes that none of the previous tank Airbus aircraft, one of two ventilation devices is explosions have occurred on Airbus aircraft but used to spread heat over a larger area, thereby then claims the historical data [imply] that tank causing lower peak temperatures and fewer igni- explosions on Airbus types should have oc- tion source scenarios. The proposed rule will curred by now,” BAE Systems Regional Aircraft not affect the new A380, which was designed said. “The only possible basis for this claim without a center wing fuel tank. would be if Airbus fuel tanks, fuel system com- In addition, Airbus projected that the pro- ponents and adjacent equipment installations posed changes would create “widespread work- (e.g., air conditioning packs) were very similar place asphyxiation hazards” that would result in to their Boeing counterparts. They are not.” between 1.4 and 4.7 workplace fatalities every Embraer agreed, saying in its response to the year. “Workplace hazards could actually result in proposed rule, “In general ... the flammability statistical fatalities that exceed those that would concern should be limited to tank designs that be avoided by enactment of this proposal,” have shown an unacceptable service history. The Airbus said. cost associated with applying these standards to Airbus said that, in the decade since the conventional wing tanks is not justified by the TWA crash, the aviation industry had worked negligible benefits that will occur.” with regulatory authorities to adopt other Several regional airline associations — the rules changes that “significantly reduced Air Transport Association of America (ATA), the risk of further heated center wing tank the Association of European Airlines (AEA) and explosions.” the Association of Asia Pacific Airlines (AAPA)
Related Accidents
ince the 1996 Trans World Airlines crash, • Substantial structural damage was report- two other accidents involving airplane fuel ed to the area surrounding the left wing Stank explosions have been reported: fuel tank of a Transmile Airlines 727-200 • A Thai Airways Boeing 737-400 was on May 4, 2006, when the tank exploded destroyed March 3, 2001, when the cen- while ground personnel in Bangalore, ter wing fuel tank exploded while the India, were preparing to tow the airplane airplane was at the terminal in Bangkok, after maintenance to repair a fuel leak. No Thailand, being prepared for a domestic one was injured in the explosion, which passenger flight. One flight attendant remains under investigation. The blast oc- was killed, and six other people received curred while the airplane’s auxiliary power serious injuries. NTSB said that the final unit was operating; the tow crew felt “a report on the accident, issued in April jolt” and observed that a circuit breaker 2005 by the Accident Investigation for the left wing fuel-tank boost pump 2 Committee of Thailand, said that the had tripped. most likely source of the ignition energy Notes was “an explosion originating at the 1. U.S. National Transportation Safety Board (NTSB). center wing tank pump as a result of Accident report DCA01RA024. March 3, 2001. running the pump in the presence of 2. NTSB. Accident report DCA06RA040. May 4, 1 metal shavings and a fuel/air mixture”; 2006. and, — LW
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— said in their responses that the actions 100 aviation accidents worldwide and victims’ Br described in the proposed rule could not be families, asked FAA to approved the proposed justified, largely because of steps already taken rule as soon as possible. Fl by the industry to address safety issues. “The public has waited too long for the safest C “Existing and planned ignition-prevention fuel tanks on aircraft to prevent the possibility Fl Fl improvements will reduce the risk of a catastrophic of explosions, such as TWA [Flight] 800,” the Br fuel tank explosion for airplanes that are affected organization said. Fl by the [proposed rule] to less than one occurrence The Air Line Pilots Association, Interna- C in 1 billion flight-hours, which is the FAA’s goal,” tional (ALPA) said that it supports the intent Fl ATA said. “In other words, [ignition-prevention of the proposal but takes “strong exception Fl improvements] alone can reduce the risk of cata- to the exclusion of airplanes used in all-cargo strophic fuel tank explosion to the point that it is operations.” ALPA said that excluding all-cargo unlikely one will occur during the operational life operations from the requirement is a “totally of any given airplane type.” unacceptable approach to aviation safety.” AEA, which questioned FAA’s data on the costs and benefits that would follow adoption of Safety Modifications the rule, added that fuel tank explosions “are not Despite NTSB’s criticism of some aspects of the a major cause of aviation accidents (statistically, proposed rule, Rosenker said that other steps the percentage of both accidents and fatalities taken by FAA as a result of the TWA crash re- due to fuel tank explosions is approximately 1.2 sulted in significant safety improvements. percent over the last 20 years.)” “Fleet-wide inspections and analytical AEA said that, in addition, European cost reviews of fuel tank design have resulted in estimates are “significantly higher” than FAA’s, significant measures that have the potential with “the investment required to achieve the to reduce the likelihood of an ignition event safety benefit promised by this proposal … 23 inside a tank,” he said, “and … fuel pumps, times higher than the value of the benefit.” fuel-quantity indicating systems, in-tank AAPA said that it opposes the mandatory wiring, co-routed wiring and operational retrofitting of airplanes with inerting systems, procedures have been modified to make fuel but if FAA decides to “unilaterally mandate the systems safer.” retrofit of in-service aircraft, it should con- The period for receiving public comments sider removing the requirement to complete 50 on the proposed rule ended in May 2006; final percent of the fleet within four years, as this will action from FAA is expected late in 2007. ● impose a tremendous burden on our members to realign their heavy maintenance schedules to Notes meet the deadline.” 1. U.S. National Transportation Safety Board (NTSB). AAPA said that FAA also should recognize Aircraft Accident Report: In-Flight Breakup Over “the disparity of the efforts undertaken by the the Atlantic Ocean, Trans World Airlines Flight 800, respective manufacturers” by allowing them Boeing 747-131, N93119, Near East Moriches, New more time to develop flammability-reduction York, July 17, 1996. systems that meet the requirements of the pro- 2. U.S. Department of Transportation (DOT), Federal posed rule. Aviation Administration. “Reduction of Fuel Tank Flammability in Transport Category Airplanes; ‘Waited Too Long’ Proposed Rule.” Federal Register, Nov. 23, 2005. Comments on the proposed rule from airplane Support for the proposal has come from groups manufacturers, airlines, regulatory and investigative representing airline passengers and pilots. authorities, and others can be viewed at
Avi a tionS a fety World World | |
D ecember 2006 ecember 2 - coverStory
Eight An-24s are on Antonov’s list of aircraft whose airworthiness cannot be confirmed. Introduced in 1959, the twin-turboprop aircraft are registered, the aircraft models, serial to carry cargo or as many as 10 passengers. The carried more numbers, registration numbers, dates of manu- SAA said that Kazakhstan’s Civil Aviation Com- than one-third of facture, airworthiness expiration dates, and mittee did not comply with ICAO requirements the passengers operators (see appendix, page 22). when it established overhaul periods allow- transported in the The list includes 362 An‑2s operated domes- ing extension of the service lives of the An‑2s Soviet Union for tically by 35 airlines in Kazakhstan. The An‑2 registered in the country without Antonov’s several decades. The is a 5,500-kg (12,125-lb) biplane powered by a participation. aircraft reportedly has 746-kW (1,000-hp), nine-cylinder radial engine. Also on the list are the following aircraft, a design service life Originally designed for aerial application, the which are not considered airworthy because of 30,000 hours. aircraft first flew in 1947 and later was modified they apparently had not been returned to www.flightsafety.org | AviationSafetyWorld | December 2006 | 19 Coverstory
Antonov for overhauls that were required before of aircraft, 18, on its registry, followed by the they reached established service-life limits: Democratic Republic of the Congo, with eight; Congo and Sudan, with seven each; Angola, Si- • Twenty-seven An‑12s, a four-engine tur- erra Leone, Surinam and Togo, with five each; boprop freighter with a maximum takeoff Kenya, with four; Venezuela, with three; Iran, © Michael Fabry/Jetphotos.net weight of 61,000 kg (134,481 lb), which with two; and Cambodia, Nicaragua, South also can carry 14 passengers; Africa and Uganda, with one each. • Twenty-three An‑28s, a 5,700-kg (12,500- The airworthiness-expiration dates range lb) general-purpose twin-turboprop; from October 1991, for two An‑28s in Sudan, to June 2006, for an An‑12 in Congo. • Ten An‑26s, a 24,000-kg (52,910-lb) pressurized short-haul twin-turboprop Communications Breakdown that can carry freight or as many as 40 ICAO said that there was a breakdown in passengers; communications between Antonov and the After overrunning Ukraine SAA, and the states of registry of the the runway at • Eight An‑24s, a 21,000-kg (46,297-lb) aircraft. “There is an international standard N’Djamena, Chad, in predecessor of the An‑26; that requires the state of registry and the state October 2004, this • Three An‑32s, a development of the An‑26 of manufacture or design to communicate An-12 reportedly was for operation at high density altitudes; regularly,” Lamy said. returned to service ICAO Annex 8, Airworthiness of Aircraft, following repair of the • One An‑8, a military transport that pre- requires, for example, that states of design notify landing gear. ceded the An‑12; the states of registry of any information essential to the continuing airworthiness of the aircraft. • One An‑72, a 33,000-kg (72,752-kg) The states of registry, typically through their twin-turbofan, short-takeoff-and-landing CAAs, are responsible for ensuring that every Kazakhstan’s transport that replaced the An‑26; and, extension of aircraft on their registers is maintained in an airworthy condition. States of registry also are An-2 service life • One An‑74, a development of the An‑72 responsible for establishing the channels for without Antonov’s for operation in arctic regions. participation landed communication between their CAAs and the 362 of the workhorse In addition to the 362 An‑2s, Kazakhstan’s aircraft operators in their countries, and the biplanes on the registry includes one of the An‑24s on the states of design. blacklist. list. Moldova has the second largest number ICAO believes that in some cases, the calls for action on unairworthy aircraft that were issued by the Ukraine SAA in 2004 and 2005 either did not reach the responsible parties or were ignored. Publication of the list was an ef- fort to resolve both problems. “Making this information public was very important because, of all the people who should have received the information, there were quite a few who did not receive it because of a break- down in communications,” Lamy said. “In a mi- nority of cases — but we still have to take them into account — people may have chosen to look the other way. The ICAO policy on transparency and the sharing information is not to allow this © Steve Lake kind of behavior. By making the information
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© Steve Lake
public, we want to make sure that there is no compliance with airworthiness directives and Antonov built more possibility of looking the other way.” any special conditions established for continuing than 1,000 An-12 Annex 8 says, “Any failure to maintain an airworthiness. ● freighters for a variety aircraft in an airworthy condition as defined by of military and civil the appropriate airworthiness requirements shall Notes applications from render the aircraft ineligible for operation until 1959 through 1973. 1. Among the actions taken by the International the aircraft is restored in an airworthy condi- The blacklist includes Civil Aviation Organization (ICAO) in response to tion.” Accordingly, ICAO expects the aircraft on recommendations made during the conference was 27 of the aircraft.. the list to be grounded by their states of registry the establishment of the Flight Safety Information or by other states in which they are operated Exchange (FSIX) Web site,
Appendix Aircraft Considered Unairworthy by the Antonov Aviation Scientific/Technical Complex
Antonov Aircraft Registration Date of Airworthiness State of Registry Model Serial Number Number Manufacture Expiration Date Operator Angola An-12 4342209 D2-MBH 29/07/1964 29/01/1998 unknown Angola An-12 3402007 D2-MBE 1964 1999 unknown Angola An-12 5343405 D2-MAZ 30/09/1965 20/01/1997 unknown Angola An-12 2340608 D2-MBD 1962 1997 Service not extended unknown to civil aviation. Angola An-12 7345210 D2-FRI 1967 1997 Service not extended unknown to civil aviation. Cambodia An-24B 99902009 XU-335 30/06/1969 01/07/2005 Imtrec Aviation Airlines Democratic Republic of An-28 1AI006-03 9XR-KI 17/04/1989 17/04/1993 unknown the Congo Democratic Republic of An-28 1AI005-09 9Q-GZN 30/07/1988 30/07/1992 Blue Airlines the Congo Democratic Republic of An-28 1AI006-01 9Q-GZL 13/04/1989 13/04/1993 Blue Airlines the Congo Democratic Republic of An-28 1AI008-05 9XR-KV 10/07/1990 10/07/1994 Blue Airlines the Congo Democratic Republic of An-28 1AI008-09 9Q-CSP 16/08/1990 16/08/1997 Malu Aviation Airlines the Congo Democratic Republic of An-28 1AI008-21 EX-018 29/09/1990 29/09/1994 unknown the Congo Democratic Republic of An-28 1AI005-10 9Q-GZM 28/07/1988 28/07/1992 Blue Airlines the Congo Democratic Republic of An-32 22-10 9Q-CMD 31/01/1990 31/07/2002 unknown the Congo Iran An-26B 140-01 EP-SAK 04/02/1985 05/12/2006 Saffat Aviation Services Airlines Iran An-26B 140-02 EP-SAJ 13/02/1985 23/07/2004 Saffat Aviation Services Airlines Kenya An-28 1AI006-11 9XR-IM 12/06/1989 12/06/1993 unknown Kenya An-28 1AI007-06 9XR-SR 14/12/1989 14/06/2003 unknown Kenya An-28 1AI004-15 9XR-KG 28/02/1988 28/02/2006 SPD Savran P.V. Kenya An-28 1AI0010-02 ER-AKA 25/09/1991 25/09/1995 Valan Airlines, Moldova Nicaragua An-32 30-07 YN-CGA 31/03/1992 31/12/2003 Aerocharter Airlines Republic of Kazakhstan* An-2 Republic of Kazakhstan An-24 10-04 UN-47736 23/12/1966 21/11/2005 ACA Airlines Republic of Moldova An-12 9346909 ER-AXY 1969 31/05/2001 unknown Republic of Moldova An-12 2340605 ER-ADT 1962 01/01/1992 unknown Republic of Moldova An-12 9346502 ER-AXD 1969 1999 unknown Republic of Moldova An-12 2340403 ER-ADD 1962 29/12/1999 unknown Republic of Moldova An-12 00347407 ER-AXG 15/08/1970 2000 Tiramavia S.R.L. Airlines Republic of Moldova An-24 27307605 ER-47698 25/02/1972 06/12/2001 Air Moldova Airlines Republic of Moldova An-24 108-10B ER-AFB 23/12/1978 20/04/2004 Aerocom Airlines Republic of Moldova An-24 37308801 ER-AZN 24/071973 24/01/2006 Pecotox Airlines Republic of Moldova An-24 17306907 ER-AWD 04/1971 01/2003 Aerocom Airlines Republic of Moldova An-24 87304102 ER-46417 02/1968 06/2001 Air Moldova Airlines Republic of Moldova An-24 97305109 ER-46599 04/1969 02/2001 Air Moldova Airlines Republic of Moldova An-26 126-03 ER-AFU 15/01/1983 20/12/2001 Aerocom Airlines Republic of Moldova An-26 117-05 ER-AFE 08/12/1981 08/12/2001 Aerocom Airlines Republic of Moldova An-26 90-05 ER-AZT 28/12/1979 17/09/2004 Aerocom Airlines Republic of Moldova An-26 22-06 ER-AZE 30/05/1974 30/06/1994 Aerocom Airlines Continued on next page
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Appendix Aircraft Considered Unairworthy by the Antonov Aviation Scientific/Technical Complex
Antonov Aircraft Registration Date of Airworthiness State of Registry Model Serial Number Number Manufacture Expiration Date Operator Republic of Moldova An-26 108-07 ER-26046 27/02/1981 27/02/2001 Air Moldova Airlines Republic of Moldova An-72 365.720.94889 ER-AEJ 23/01/1992 23/01/2003 unknown Republic of Moldova An-74 365.470.95898 ER-AEN 31/03/1992 21/03/2001 Renan, Kishinev Republic of South Africa An-26 42-06 9U-BNO 28/07/1976 27/07/2004 Inter Sky Airline, Swaziland Republic of the Congo An-12 347003 3C-AAL 25/02/1970 25/05/2005 Trans Air Congo Republic of the Congo An-12 4341705 UN-11002 29/12/1963 15/03/2001 Trans Air Congo Republic of the Congo An-12 8345504 TN-AHD 31/03/1968 30/06/2004 Natalco Congo Republic of the Congo An-12 401912 3X-GDM 14/07/1964 06/07/2005 Aero-Service Republic of the Congo An-12 5343108 4L-12008 31/05/1965 18/02/2006 Aero Freight Partner Republic of the Congo An-12 402006 TN-AGK 29/11/1963 28/06/2006 Trans Air Congo Republic of the Congo An-26 86-02 9Q-CVR 31/08/1979 31/01/2004 Aviatrade Congo Republic of Togo An-12 2340606 S9DAF 30/08/1962 06/06/2001 unknown Republic of Togo An-12 1340206 TN-AHA 31/12/1961 Service not extended unknown according to civil aviation documentation. Republic of Togo An-12 901306 TN-AGY 05/1960 Service not extended unknown according to civil aviation documentation. Republic of Togo An-12 7345403 TN-AGZ 23/11/1967 09/1995 unknown Republic of Togo An-12 8345805 UN-11376 01/07/1968 Service not extended unknown according to civil aviation documentation. Sierra Leone An-8 OG 3410 9L-LEO 23/06/1960 23/06/1995 unknown Sierra Leone An-12 5343408 9L-LEA 30/09/1965 22/12/1996 unknown Sierra Leone An-12 4341803 9L-LEA 02/1964 02/1999 unknown Sierra Leone An-12 2340805 9L-LDW 30/11/1962 29/08/2003 unknown Sierra Leone An-32 22-06 9L-LDO 22/12/1989 22/06/2003 unknown Sudan An-12 7345310 ST-ARV 25/12/1967 30/03/2006 Azza Transport Sudan An-12 9346504 ST-AQQ 30/06/1969 30/12/2003 Sudanese State Sudan An-26 102-05 ST-ARO 30/09/1980 30/09/2004 Ababeel Sudan An-28 1AJ004-06 ER-AIP 26/07/1988 26/07/1992 AU/AMIS Sudan An-28 1AJ004-07 ER-AJH 28/10/1987 28/10/1991 AU/AMIS Sudan An-28 1AJ004-08 ST-GWA 27/10/1987 27/10/1991 G. Wings, Poland Sudan An-28 1AJ0010-19 EK-28019 25/03/1992 25/03/1996 Badr Airlines Surinam An-28 1AI007-21 PZ-TSA 22/11/1990 22/11/1994 Blue Wing Airlines Surinam An-28 1AI007-10 PZ-TSV 18/01/1990 18/01/1994 Blue Wing Airlines Surinam An-28 1AI007-20 PZ-TSN 22/11/1990 22/11/1994 Blue Wing Airlines Surinam An-28 1AI008-04 PZ-TST 10/07/1990 10/07/1994 Blue Wing Airlines Surinam An-28 1AI007-17 PZ-TSO 02/04/1990 02/04/1994 Blue Wing Airlines Uganda An-12 7344801 3C-AAG 28/02/1967 28/03/2003 unknown Venezuela An-28 1AI009-11 28945 02/01/1991 02/01/1995 Angar 74 Venezuela An-28 1AI007-15 28730 06/02/1990 06/02/1994 Angar 74 Venezuela An-28 1AI007-12 28727 25/01/1990 25/01/1994 Angar 74
* Antonov said that 362 An-2 aircraft are being operated by 35 airlines in the Republic of Kazakhstan. In accordance with Decree No. 272, dated 30 November 2005, issued by the chairman of the Civil Aviation Committee of the Republic of Kazakhstan, rules for the extension of the service life of An‑2 civil aviation aircraft in the Republic of Kazakhstan have been established with respect to overhaul periods. These rules provide for procedures for extension without the participation of the aircraft designer, which runs contrary to ICAO regulatory documents.
Source: International Civil Aviation Organization
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Filling the Envelope How Risky Are Average Weights?
BY PATRICK CHILES he inaugural issue of Aviation Safety which typically includes a graphic depiction World carried an InSight column titled of the loading envelope and specific loading “One Size Fits All? The Danger of Aver- instructions. age Weights” (July 2006, page 55). The Tauthor made a good case for requiring actual Certified vs. Operational weights and seating control, but that solution It is important to recognize the fundamental would be impractical for many operators. difference between the manufacturer’s certi- While average weights may not reflect all pas- fied limits and the airline’s operating limits. senger types, the risks of deviation were not The certified envelope provided in the aircraft considered in the proper context. There are flight manual (AFM) represents the approved methods by which we account for these vari- safe limits for the airplane. However, it is not ables, and they are described in the advisory intended for use in actual load planning. The circular cited by the author.1 manufacturer’s certified envelope by itself Potential errors in weight distribution will not protect against center of gravity (CG) are recognized and allowed for in a properly changes from inevitable loading variations. engineered loading envelope. It is not absolutely An operating envelope must be developed to necessary to determine exact seating locations. account for this. Even when that’s done, we can never be certain Probable deviations are accounted for by that people or their carry-ons will stay where we creating curtailments, or reductions, that are want them. Factors such as in-flight movement, applied to the certified limits. Simply stated, this fuel usage and landing gear retraction also have restricts the planned CG range, which protects effects that must be accounted for. A practical against exceeding the certified limits (Figure 1, method of compensating for distribution errors, page 25). and preventing them from creating an unsafe For an approved weight-and-balance pro- condition, should already exist in the gram, the airline must account for the distri- airline’s loading schedule, bution of passengers and allow for reasonable
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seating assumptions. One way of dealing with Sample Certified vs. Operational Envelope this is the “window-aisle-remaining” method. 680 It assumes that window seats will be filled first, Structural Limits 660 Certi ed Limits followed by aisle seats and middle seats, with Operational Limits 640 worst-case moment changes calculated from 620 the front and back. The potential variation 600 from the cabin’s centroid becomes the envelope 580 curtailment and is subtracted from the certified 560 forward and aft limits.2 This protects against 540 differences between planned and actual cabin 520 centroids. Cabins frequently are subdivided 500 480 into separate loading zones to further reduce 460 potential error and to minimize reductions of 440 the certified limits. 420 Curtailment for the in-flight movement of 400 Gross Weight (thousands of pounds) Weight Gross passengers and crewmembers depends on the 380 same seating assumptions. The predicted mag- 360 nitude of this movement places another limit on 340 the loading envelope. 320 300 280 Cargo Loading Variation 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 The author’s statement that “there are too many Center of Gravity (% mean aerodynamic chord) variables in how the baggage is loaded to allow The horizontal lines at 430,000 to 440,000 lb gross weight are the zero fuel weight limits. for any reasonable predictions of probability” Source: Patrick Chiles is inconsistent with common practice. Load- ing schedules account for the fact that baggage Figure 1 and cargo may not be distributed evenly. As with the cabin, cargo compartments can be The Envelope, Please subdivided into multiple zones with probable Probable CG variations are determined by the variations to each zone centroid applied to the airline’s weight engineer and applied to the new envelope. manufacturer’s certified envelope. The resulting Some curtailments are more complicated operational envelope will appear on the aircraft- than others, and it is true that cargo variations specific weight-and-balance form, or loadsheet. are difficult to predict if the individual balance Loading schedules are commonly created by arms of each item are considered. The calcula- the manufacturers, airline engineering depart- tions must consider compartment design and ments, or third-party vendors and completion other factors, such as whether the cargo is centers. Pilots, dispatchers and load planners bulk-loaded or “containerized.” For example, must be diligent to use a properly calculated Boeing’s single-aisle 737 and 757 are designed loading schedule and operating envelope, and for simplified bulk-loading, requiring not confuse them with the manufacturer’s certi- only that the bags are evenly fied envelope. distributed around the This does not relieve the operator of the compartment centroid. responsibility to use the most realistic average Wide-body aircraft have weights available. For instance, while a 30-lb more complex consider- (14-kg) baggage allowance is “legal,” an operator ations for containerized load- can use a higher weight allowance if it is believed ing and lateral imbalance. to be more realistic. Likewise, the operator may www.flightsafety.org | AviationSafetyWorld | December 2006 | 25 insight
account for a higher ratio of male to female intuitive notion that a particular error is less passengers and use the appropriate higher aver- likely to occur as its severity increases. While age weight. Operators should conduct their own it is possible that the worst-case distribution passenger and baggage surveys if they believe the could happen, the given probability was 1 in standard average weights are not appropriate. 7.7x10160. Those are astronomically high odds, With smaller aircraft, there are more op- much higher than the recently reported 1 in portunities for adverse effects from nonstandard 5.3x107 probability of being involved in an weights. One solution is to use segmented weights airline accident.3 as provided for in the advisory circular. This in- For passenger carriers, mandating the use of volves adding back part of the standard deviation actual weights and distribution probably is not to the average weight to improve the likelihood necessary or even practical. It also would reduce that actual weights won’t exceed the new average. the magnitude of the envelope curtailments Finally, average weights cannot be used when commonly used as a safety margin. If certified operating sports or military charters. Some type envelopes were used in daily operations, with of actual-weight program must be used. no accounting for probable errors, weight and distribution errors would be much more danger- In Practice ous. But in current use, envelope curtailments The author’s hypothetical airplane is similar to mitigate the risks well enough to operate safely. If Of greater concern a 737-700 — 132 passengers, 200 bags, 118,000 the loading schedule is properly constructed and lb (53,525 kg) zero fuel weight. Beginning with adhered to, it then becomes a matter of training are smaller operators a fairly nose-heavy CG of 15 percent mean aero- our personnel and being vigilant for extreme
that do not have dynamic chord (MAC), the given worst-case loading conditions. Mandating an actual-weight/ forward passenger distribution would move the distribution program won’t change that. ●
engineering CG to 9.6 percent MAC. This is still within the Patrick Chiles is the technical operations manager for airplane’s certified limits. the NetJets Large Aircraft (BBJ) program and has been departments and Of greater concern are smaller operators a member of the Flight Safety Foundation Corporate that do not have engineering departments and Advisory Committee since 2000. mistakenly use the mistakenly use the manufacturers’ certified en- Notes manufacturers’ velopes for load planning. For example, consider a large airplane like a BBJ that has been loaded 1. U.S. Federal Aviation Administration. Advisory certified envelopes to within a few percent of the forward limit and Circular 120‑27E, Aircraft Weight and Balance has additional water tanks in the aft compart- Control. June 10, 2005. for load planning. ment that have not been filled or have faulty 2. The centroid is the center of gravity of an aircraft gauges. With 800–900 lb (363–408 kg) “missing” section, such as the cabin, when passengers and/or from the back end, the CG creeps forward. The baggage are distributed evenly in the section. airplane still is able to take off because AFM 3. U.S. National Transportation Safety Board. Press re- performance assumes the most forward limit. lease SB-06-14, “NTSB Reports Increase in Aviation Soon, however, the CG will be pushed further Accidents in 2005.” March 2006. forward when the landing gear and flaps are retracted. What happens then? That’s precisely why we have curtailments. InSight is a forum for expressing personal opinions about issues Use of a good loading schedule helps prevent any of importance to aviation safety and for stimulating constructive of those variables from causing the airplane to discussion, pro and con, about the expressed opinions. Send your exceed its envelope and become uncontrollable. comments about the author’s call for computing aircraft CG based on the actual weights and distributions of passengers and baggage to Magnitude of risk depends on the likeli- J.A. Donoghue, director of publications, Flight Safety Foundation, 601 hood of a given event actually occurring. Madison St., Suite 300, Alexandria VA 22314-1756 USA. The author’s probability model illustrates the
26 | flight safety foundation | AviationSafetyWorld | December 2006 FoundationFocus
MembershipUPDATE
ave you ever watched 873 During the IASS, Flight Safety people emerge from an air- Foundation and International Fed- plane in 78 seconds? eration of Airworthiness presented No, we didn’t think so … awards to outstanding individuals and Hunless you were in Hamburg, Germany, companies who have made the aviation Flight Safety Foundation–Airbus last March or at the 59th annual Inter- industry safer. They were: Human Factors in Aviation Safety Award national Air Safety Seminar in Paris, FSF President’s Citation October 23–26. Attendees saw a video of R. Curtis Graeber, Ph.D., Boeing Commercial Airplanes the Airbus A380 evacuation trial — one Hans Almér, Saab Aircraft AB (retired) of many interesting presentations. Admiral Luis de Florez By all accounts, the seminar was a Susan Coughlin, Flight Safety Award Member, Board of Governors, huge success. More than 450 delegates Flight Safety Foundation J. Kenneth Higgins, Boeing Commercial Airplanes from 53 countries attended. Flight Capt. Alex de Silva, Safety Foundation and its co-presenters, Singapore Airlines FSF Cecil A. Brownlow International Federation of Airworthi- Dmitry Kiva, General Designer, Publication Award ness and International Air Transport Antonov Design Bureau Larry Pynn, Association, would like to particularly Vladimir Kofman, Flight Safety Vancouver Sun thank this year’s host committee for Foundation International making the seminar possible: Anatoly Kolisnyk, Chairman, The Laura Taber Barbour SAA of Ukraine Air Safety Award Aer Lingus Air France Capt. Dan Maurino, International Don Bateman, Civil Aviation Organization Honeywell Airbus ATR Valery Shelkovnikov, Flight Safety Foundation International IFA Whittle Award Aviation Safety Alliance James Terpstra, Stuart Matthews, CFM Jeppesen (retired) Flight Safety Foundation Dassault Aviation Edward R. Williams, DGAC Grande Médaille d’Or de l’Aéro-Club The Metropolitan Aviation Group de France EADS Eurocontrol Richard Teller Crane Founder’s Award Stuart Matthews, Flight Safety Foundation Eurocopter Embraer GIFAS Hamilton Sundstrand Flight Safety Foundation–Boeing If you would like more information Aviation Safety Lifetime KLM Royal Dutch Airlines Achievement Award on the Flight Safety Foundation award Rockwell Collins program, please visit our Internet site: Minister Yang Yuanyuan, Safran General Administration of
une 1, 1999 — American far beneath the airplane as the captain ly completed U.S. National Aeronautics Airlines Flight 1420 was seconds nosed Southwest Airlines Flight 1455 and Space Administration (NASA) study from landing at Little Rock, Arkan- down at a steep angle to try to land near of these and 17 other recent accidents sas, U.S., when the captain’s view of the beginning of the 6,032-ft (1,840- gives a different perspective on pilot error, Jthe runway was obscured by heavy rain m) strip. Air traffic control (ATC) had and this perspective holds keys to making lashing the windshield. “I can’t see it,” he brought the Boeing 737-300 in high flights safer in the future.3 said, but the runway quickly reappeared. and fast, and there was a shearing tail- Our analysis suggests that almost From 200 ft to the ground, he struggled wind aloft. As the captain looked at the all experienced pilots operating in the against the thunderstorm’s crosswinds situation on final approach, he thought same environment in which the accident to align the McDonnell Douglas MD-82 he could make it; in quick succession, crews were operating, and knowing only with the centerline, and the ground- he called for gear and flaps to try to what the accident crews knew at each proximity warning system (GPWS) slow the 737. The first officer could moment of the flight, would be vulner- produced two warnings of excessive see that the airplane was exceeding the able to making similar decisions and sink rate. The first officer thought about limits for a stabilized approach. How- errors. Our study draws upon growing telling the captain to go around, but if he ever, he said nothing because he could scientific understanding of how the spoke, his voice was too soft to be heard. see that the captain was doing all he skilled performance of experts, such as Saturated with high workload during the could to correct it. The jet landed near airline pilots, is driven by the interaction last stages of the approach, the crew had the normal touchdown point — but of moment-to-moment task demands, forgotten to arm the jet’s ground spoilers at 182 kt, the airspeed was more than the availability of information and the pressingBY BENJAMIN A. BERMAN and R. KEY DISMUKES, Ph.D. approach
for automatic deployment and had not 40 kt faster than the computed target social/organizational factors with the completed the last steps of the landing speed. The pilots were unable to stop inherent characteristics and limitations checklist, which included verification the airplane, and it crashed through of human cognitive processes. Whether of the spoilers; consequently, braking a blast fence at the end of the runway, a particular crew in a given situation performance was greatly degraded. crossed a street and came to a stop near makes errors depends as much, or more, During the landing rollout, the airplane a service station. Two passengers were on this somewhat random interaction veered left and right by as much as 16 seriously injured, and the airplane was of factors as it does on the individual degrees before departing the left side substantially damaged.2 characteristics of the pilots. of the runway at high speed. The crash Flights 1420 and 1455 came to grief, into the approach light stanchions at the in part, because of two of the most far end of Runway 04R destroyed the Why did these experienced common themes in the 19 accidents airplane and killed 11 people, including professional pilots make these errors? studied: plan continuation bias — a the captain.1 The U.S. National Transportation Safety deep-rooted tendency of individuals to Board (NTSB) concluded that the crews continue their original plan of action caused both accidents. It’s true that the even when changing circumstances arch 5, 2000 — pilots’ actions and errors led to the ac- require a new plan — and snowball- Runway 08 at Burbank, cidents — and that in the final moments ing workload — workload that builds California, U.S., would have they were in a position to prevent the on itself and increases at an accelerat- Mappeared very short and very crashes but did not. However, our recent- ing rate. Although other factors not 28 | flight safety foundation | AviationSafetyWorld | December 2006 humanfactors
© Scroggins Aviation/Jetphotos.net
A NASA study of 19 recent accidents yields a new pressing the approach perspective on pilot error. © Joe Pries–ATR Team/Airliners.net © Joe Pries–ATR
www.flightsafety.org | AviationSafetyWorld | December 2006 | 29 humanfactors
discussed here played roles in these on-board weather radar to identify a ibility. In hindsight, assembling all the accidents, the problems encountered thunderstorm cell northwest of the field. cues that were available to the crew, one by the crews seem to have centered on At that point, the crew had no way of can readily infer that the thunderstorm these two themes. knowing whether they could land before had arrived at the airport. Yet the crew the thunderstorm arrived. of Flight 1420 persevered, accepting a Plan Continuation Bias Later, as Flight 1420 continued its change of runways to better accommo- The pilots of Flight 1420 were aware from approach, the pilots received a series date the winds, attempting a close-in vi- the outset that thunderstorms could affect of ATC radio transmissions suggesting sual approach to expedite their arrival, their approach to Little Rock. Before be- that the thunderstorm was beginning and then, as conditions continued to ginning the approach, they saw lightning to affect the airport: reports of shifting deteriorate, changing to an instrument and rain near the airport, and they used winds, gusts, heavy rain and low vis- landing system (ILS) approach and
Radar Data and Partial Air Traffic Communication Southwest Airlines Flight 1455, March 5, 2000, Burbank, California, U.S.
9,000
18:03:33 SOCAL: SW 1455, turn left heading 190, vector to final, descend and maintain 6,000. 8,000
18:04:05 SOCAL: SW 1455, maintain 230 or greater until advised.
7,000
6,000 18:05:10 SOCAL: SW 1455, turn left heading 160. 18:05:56 SOCAL: SW 1455, descend and maintain 5,000. If you’d like the visual, you will be following company. Right now they’re your 1 o’clock and 12 miles, turning onto the final out of 4,600.
18:07:45 SOCAL: SW 1455, descend and maintain 3,000. Company’s over Van Nuys now at 3,000. 5,000
18:08:21 SOCAL: SW 1455, cross Van Nuys at or above 3,000. Cleared visual approach Runway 8.
Altitude (ft)Altitude 4,000
3,000 18:09:53 Tower: SW 1455, wind 210 at 6, Runway 8, cleared to land.
2,000
1,000 BUDDE OM & Van Nuys VOR/DME VINEE MM
0 10 8 6 4 2 0 2 Distance From Runway Threshold (nm)
MM = Middle marker OM = Outer marker SOCAL = Southern California Approach Control
Source: U.S. National Transportation Safety Board
Figure 1
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pressing that approach to a landing instead of ingly similar to Flights 1420 and 1455.5,6,7 executing a missed approach. Our study suggests that, when standard op- Similarly, the pilots of Flight 1455 tried to cope erating procedures are phrased not as require- in a situation in which their airplane was obviously ments but as strong suggestions that may appear high and fast, and they continued their approach to tacitly approve of bending the rules, pilots despite numerous cues that landing safely would may — perhaps without realizing it — place too be challenging (Figure 1). For example, 1,000 ft much importance on schedule and cost when above touchdown elevation, where company op- making safety/schedule/cost tradeoffs. Also, erating procedures specified that flights should be pilots may not fully understand why guidance stabilized, this flight was unstabilized, far above the should be conservative; that is, they may not glide path, more than 50 kt too fast and descend- recognize that the cognitive demands of recov- ing at more than three times the desired rate; flaps ering an airplane from an unstabilized approach were at the approach setting because of excessive severely impair their ability to assess whether airspeed, and idle thrust was set. Below 1,000 ft, the approach will work out. For all these rea- the GPWS repeatedly annunciated “SINK RATE” sons, many pilots, not just the few who have and “PULL UP,” and the approach remained highly accidents, may deviate from procedures that unstabilized through touchdown. the industry has set up to build extra safety into Too often, pressing an approach in these cir- flight operations. Most of the time, the result of cumstances is attributed to complacency or an these deviations is a successful landing, which intentional deviation from standards, but these further reinforces deviant norms. terms are labels, not explanations. To under- Our study suggests that as pilots amass expe- stand why experienced pilots sometimes con- rience in successfully deviating from procedures, Many pilots, not tinue ill-advised approaches, we must examine they unconsciously recalibrate their assessment the insidious nature of plan continuation bias. of risk toward taking greater chances. This just the few who Plan continuation bias appears to underlie recalibration is abetted by a general tendency of have accidents, what pilots call “press-on-itis,” which a Flight individuals to risk a severe negative outcome of Safety Foundation task force found to be in- very low probability — such as the very small risk may deviate from volved in 42 percent of accidents and incidents of an accident — to avoid the certainty of a much they reviewed.4 Similarly, this bias was apparent less serious negative outcome — such as the procedures that in at least nine of the 19 accidents in our study. inconvenience and the loss of time and expense the industry has set Our analysis suggests that this bias results from associated with a go-around. the interaction of three major components: Another inherent and powerful human cog- up to build extra social/organizational influences, the inherent nitive bias in judgment and decision making is characteristics and limitations of human cogni- expectation bias — when someone expects one safety into flight tion, and incomplete or ambiguous information. situation, he or she is less likely to notice cues Safety is the highest priority in commer- indicating that the situation is not quite what it operations. cial flight operations, but there is an inevitable seems. Having developed expectations that the trade-off between safety and the competing goals thunderstorm had not yet reached the airport of schedule reliability and cost effectiveness. To (Flight 1420) and that the descent and approach ensure conservative margins of safety, airlines profile was manageable (Flight 1455), the crews establish written guidelines and standard proce- in these accidents may have become less sensi- dures for most aspects of operations, including tive to cues that reality was deviating from their specifications for minimum clearance from thun- mental models of the situation. derstorms and criteria for stabilized approaches. Expectation bias is worsened when crews are Yet considerable evidence exists that the norms required to integrate new information that ar- for actual flight operations often deviate consid- rives piecemeal over time in incomplete, some- erably from these ideals, in ways that are strik- times ambiguous, fragments. Human working www.flightsafety.org | AviationSafetyWorld | December 2006 | 31 humanfactors
memory has extremely limited capacity Snowballing Workload crew’s attention contributed to their to hold individual chunks of informa- Errors that are inconsequential in forgetting to arm the spoilers and to tion, and each piece of information themselves have a way of increasing complete the landing checklist. Also, decays rapidly from working memory. crews’ vulnerability to further errors the pilots had been awake more than Further, the cognitive effort required to and combining with happenstance 16 hours at the time of this approach, interpret and integrate these fragments events — with fatal results. By con- and they were flying at a time of day can reach the limits of human capacity tinuing the unstabilized approach, the when they were accustomed to sleep- to process information under the com- captain of Flight 1455 increased the ing. Among the effects of fatigue are peting workload of flying an approach. crew’s workload substantially. Getting slowing of information processing and The crew of Flight 1420 had to the aircraft configured and down to the narrowing of attention. The combina- make inferences about the position glideslope made strong demands on the tion of fatigue, the stress of a chal- of the thunderstorm and the threat pilots’ attention — a very limited cogni- lenging approach and heavy workload it presented by using information tive resource. The high speed of the can severely undermine cognitive obtained from their view through the aircraft (197 kt), with a 2,624 foot-per- performance. windshield, cockpit radar, automatic minute descent rate, increased the rate A particularly insidious manifesta- terminal information service (ATIS) of events and reduced the time available tion of snowballing workload is that information and a series of wind for responding. This situation would it pushes crews into a reactive, rather reports from ATC spread over time. produce stress, and acute stress narrows than proactive, stance. Overloaded The information available from these the field of attention (“tunneling”) and crews often abandon efforts to think sources was incomplete and ambigu- reduces working memory capacity. ahead of the situation strategically, ous; for example, the weather radar was An airplane that landed ahead instead simply responding to events as pointed away from the thunderstorm of Flight 1455 was slow clearing the they occur and failing to ask, “Is this for several minutes while the flight was runway — another development that going to work out?” being vectored, and in any case, this placed demands on the crew’s attention. radar does not delineate the wind field These factors combined to impair the Implications and Countermeasures extending from a thunderstorm. crew’s ability to monitor all relevant Simply labeling crew errors as “failure The situation facing the crew of flight parameters and to determine to follow procedures” misses the es- Flight 1455 may seem to have been whether they could land the airplane sence of the problem. All experts, no obvious from several miles before safely. In post-accident interviews, the matter how conscientious and skilled, touchdown, as the 737 joined the final captain said that he had no idea the air- are vulnerable to inadvertent errors. approach course above the glideslope speed was so fast. Also, the snowballing To develop measures to reduce this at a very fast airspeed. But although the workload made it less likely that the pi- vulnerability, we first must understand excess energy — in the form of altitude lots would remember that the assigned its basis in the interaction of task and speed — was apparent, it was not runway was considerably shorter than demands, limited availability of infor- at all clear that the approach could not the runways they were accustomed to mation, sometimes conflicting organi- be stabilized in time for a safe landing. and recognize the implications. zational goals and random events with No display in any airline cockpit directly Similarly, the decision of the the inherent characteristics and limita- indicates or projects the energy status of crew of Flight 1420 to continue the tions of human cognitive processes. the aircraft all the way to the stopping approach in the face of challenging Even actions that are not inadvertent, point on the runway; thus, the pilots had weather substantially increased their such as continuing an unstabilized to continuously observe cues about the workload. After the accident, the first approach, must be understood in this gradient path to the runway, airspeed, officer told investigators, “I remem- context. pitch attitude, altitude and thrust, and ber that around the time of making Almost all airline accidents are integrate them with other factors that the base-to-final turn, how fast and system accidents. Human reliability in were not displayed — lift, drag and compressed everything seemed to hap- the system can be improved — if pilots, braking performance — to update their pen.” Undoubtedly, this time compres- instructors, check pilots, managers and understanding of the situation. sion and the high demands on the the designers of aircraft equipment
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and procedures understand the nature and checklists for design features that Notes of vulnerability to error. For example, invite errors. Examples of correctable 1. U.S. National Transportation Safety Board monitoring and checklists are essential design flaws are checklists conducted (NTSB). Runway Overrun During Landing, defenses, but in snowballing-workload during periods of high interruptions, American Airlines Flight 1420, McDonnell situations, when these defenses are critical items that are permitted to Douglas MD-82, N214AA, Little Rock, most needed, they are most likely to “float” in time (e.g., setting takeoff flaps Arkansas, June 1, 1999. NTSB report no. AAR-01-02. be shed in favor of flying the airplane, at an unspecified time during taxi) and managing systems and communicating. actions that require the monitoring 2. NTSB. Southwest Airlines Flight 1455, Monitoring can be made more reli- pilot to go “head-down” during critical Boeing 737-300, N668SW, Burbank, able, though, by designing procedures periods, such as when a taxiing airplane California, March 5, 2000. NTSB report no. AAB-02-04. that accommodate the workload and nears a runway intersection. by training and checking monitoring Operators should carefully exam- 3. Dismukes, R.K.; Berman, B.A.; as an essential task, rather than as a ine whether they are unintentionally Loukopoulos, L.D. (in press). The Limits of Expertise: Rethinking Pilot Error and secondary task.8 Checklist use can be giving pilots mixed messages about the Causes of Airline Accidents. Aldershot, improved by explaining the cognitive competing goals such as stabilized U.K.: Ashgate. reasons that effectiveness declines with approaches versus on-time perfor- 4. Flight Safety Foundation (FSF). “Killers extensive repetition and showing how mance and fuel costs. For example, if a in Aviation: FSF Task Force Presents this can be countered by slowing the company is serious about compliance Facts About Approach-and-Landing pace of execution to be more deliberate, with stabilized approach criteria, it and Controlled-Flight-Into-Terrain and by pointing to or touching items should publish, train and check those Accidents.” Flight Safety Digest Volume 17 being checked. criteria as hard-and-fast rules rather (November–December 1998) and Volume We also must accept that some vari- than as guidelines. Further, it is crucial 18 (January–February 1999). ability in skilled human performance is to collect data about deviations from 5. Rhoda, D.A.; Pawlak, M.L. An Assessment inevitable and put aside the myth that those criteria — using flight opera- of Thunderstorm Penetrations and because skilled pilots normally perform tional quality assurance (FOQA) and Deviations by Commercial Aircraft in the Terminal Area. Massachusetts Institute of a task without difficulty, they should be line operations safety audits (LOSA) Technology, Lincoln Laboratory, Project able to perform that task without error — and to look for organizational fac- Report NASA/A-2. (1999). 100 percent of the time. tors that tolerate or even encourage Although plan continuation bias is those deviations. 6. NTSB. Flight Into Terrain During Missed Approach, USAir Flight 1016, DC-9-31, powerful, it can be countered once ac- These are some of the ways to N954VJ, Charlotte/Douglas International knowledged. One countermeasure is to increase the reliability of human Airport, Charlotte, North Carolina, July 2, analyze situations more explicitly than performance on the flight deck, mak- 1994. NTSB report no. AAR-95-03. is common among crews. This would ing errors less likely and helping the 7. Chidester, T.R. “Progress on Advanced include explicitly stating the nature of system recover from the errors that Tools for Flight Data Analysis: Strategy for the threat, the observable indications of inevitably occur. This is hard work, but National FOQA Data Aggregation.” Paper the threat and the initial plan for deal- it is the way to prevent accidents. In presented at Shared Vision of Flight Safety ing with the threat. Crews then should comparison, blaming flight crews for Conference. San Diego, California, U.S. explicitly ask, “What if our assumptions making errors is easy, but ultimately 2004. are wrong? How will we know? Will we ineffective. ● 8. Sumwalt, R.L. III; Thomas, R.J.; know in time?” These questions are the Benjamin A. Berman is a senior research as- Dismukes, R.K. “Enhancing Flight- basis for forming realistic backup plans sociate at the U.S. National Aeronautics and Crew Monitoring Skills Can Increase Flight Safety.” In Keeping Safety a and implementing them in time, but Space Administration (NASA) Ames Research Worldwide Priority: Proceedings of the they must be asked before snowballing Center/San Jose State University and a pilot for a major U.S. air carrier. R. Key Dismukes, 55th International Air Safety Seminar. workload limits the pilots’ ability to Ph.D., is chief scientist for aerospace hu- Alexandria, Virginia, U.S.: Flight Safety think ahead. man factors in the Human Factors Research Foundation, 2002. Airlines should periodically review and Technology Division at the NASA Ames normal and non-normal procedures Research Center. www.flightsafety.org | AviationSafetyWorld | December 2006 | 33 auditreview Auditing Human Management By Darol Holsman
ooking at how aviation departments should be available and compiled at one managed their operational personnel, designated location such as the scheduling of- the Flight Safety Foundation (FSF) Audit fice. Staff at that location would track all crew team found that 14 of the 20 departments duty or rest deviations caused by corporate Laudited — 70 percent — had no administrative requirements. tracking of crew duty or rest deviations from The department should review deviation flight operations manual (FOM) standards. reports quarterly to verify that nonstandard The team recommended that the depart- operations are not becoming the norm in opera- ments develop a deviation tracking form to tions planning, and, if the deviations become record all FOM exceptions and require its excessive, evaluate the FOM standards for pos- use by all staff and line personnel. The forms sible revision.
© Chris Sorensen Photography
34 | flight safety foundation | AviationSafetyWorld | December 2006 auditreview Auditing Human Management
Operators in seven of the audits develop management reports and to enhancement program that all opera- — 35 percent — did not have any days alert the scheduling office when pilots tors should adopt. The SOPs should off or vacations scheduled in advance, do not meet recent flight experience define each critical step and pilot action a situation that adversely affects the requirements, are due for a check ride during the operation of an aircraft, staff’s quality of life. and when scheduling conflicts exist. from preflight to postflight. The FSF Audit Team recommended Training programs for department The Audit Team recommended that the departments analyze their pilot personnel should be coordinated by that departments contact other op- requirements for the flight operation the scheduling office to maximize the erators of the type of aircraft in their and determine if existing manpower use of the computer-based scheduling company’s fleet to determine if they meets the scheduling requirements. If program. have developed SOPs that can be used not, sufficient pilots should be hired to In 40 percent of the audits — eight to guide the development of in-house meet those requirements. departments — the team found that the SOPs. Some OEM pilot handbooks can In conducting this analysis, con- operator had not developed a consistent serve as valuable resources for SOPs, sideration should be given to training, pattern of pilot line checks or standard- the audit team believes. vacation, days off and illness for all ization checks. Specific aircraft-type SOPs should personnel. Vacation plans should be The only effective means for an be published as a separate appendix in submitted six to 12 months in ad- operator to verify the implementa- the FOM. vance. On the other hand, the depart- tion of standard operating procedures Pilots should be trained on SOPs ment should provide advance notice (SOPs) is through the use of a third during their initial training in an of scheduled days off to enhance pilot observing the cockpit activities. aircraft and closely monitored for their the quality of life for crewmembers. The industry best practice is to conduct adherence to the standards during pilot Finally, at the end of the year, manage- annual pilot line or standardization check rides. ● ment should assess the staff’s opinion checks. of the effectiveness of the scheduling Line or standardization checks process. should be recorded on an appropriate This article extends the discussion of the Operators did not make full use of form, with both the examiner and the aviation department problems most frequently the capability of their computer-based evaluated pilot signing the form. The found by the FSF Audit Team, based on the final scheduling program in seven of the 20 form should be filed in the pilot’s train- reports submitted to clients that contracted for audits. ing record. The FSF Audit Team also operational safety audits during 2004, detailing Departments should evaluate the suggested that departments consider the observations, findings and recommendations identified during the review (Aviation Safety full capability of the computer-based conducting line or standardization World, Sept. 2006, page 46). Observations are scheduling program, the team recom- checks while observing pilots in a documented policies, procedures and practices mended, and analyze the specific needs simulator. that exceed the industry best practices; findings of the flight operations to determine if In seven departments — 35 percent identify areas in which the team advises the the existing scheduling program can be of the total — the team found either a client to adopt better policies, procedures or used to meet requirements. lack of aircraft type-specific SOPs or practices to parallel industry best practices; and recommendations describe actions that could be Once a good program is found in SOPs that were not fully developed. taken by the client to meet industry best prac- place or is obtained, the department The development and imple- tices. The recommendations cited in this story should use the scheduling program to mentation of SOPs is a proven safety are the opinions of the FSF Audit Team.
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f an airplane strikes an approach or weak structural members and/or during an instrument landing system lighting system (ALS), the severity of connections, and proven break-away or (ILS) approach in poor weather at Salt aircraft damage and likelihood of oc- failure mechanisms such as disintegra- Lake City International Airport. No cupant injuries primarily depend on tion during impact. injuries occurred; the left main wheel Ithe ALS design. With this in mind, a 25- Design engineers in several coun- splash guard was damaged, the no. 2 year-old ALS safety initiative this year tries began cooperating in the 1970s on tire was cut, a 1-inch square (6.5 sq produced its final product: Frangibility, reducing the hazards of aircraft–ALS cm) piece of metal was lodged in the Part 6 of the International Civil Aviation collisions. Part 6 of the ICAO manual left engine noise-suppression mate- Organization (ICAO) Aerodrome Design reflects their extensive full-scale dy- rial, and the left engine fan section Manual. The new part covers not only namic testing of ALS designs in the was damaged. FAA’s incident report ALS but many other visual and nonvisu- early 1990s and a series of dynamic said, “Upon reaching the gate, the al navigation aids installed by necessity tests and computer simulations from captain notified the control tower that within airport operational areas. 1998 through 2004. he had ‘possibly touched down short ICAO defines a frangible object as A frangible ALS can reduce of the runway.’ … Subsequent inspec- having “low mass designed to break, outcome severity in scenarios such tion revealed debris on Runway 34R. distort or yield so as to present the as the December 2000 incident in The airplane [had] struck the ap- minimum hazard to aircraft.” A fran- which a Delta Air Lines McDon- proach lights 400 ft [122 m] short of gible ALS design can involve light- nell Douglas–Boeing MD-90 landed the runway. Two threshold lights and
Thorn Airfield Lighting weight materials, intentionally brittle short of the threshold of Runway 34R one light each from the 100-ft [30-m] Break, Distort or Yield Updated approach lighting system standards address risks during the 100-millisecond impact of an airplane.
By Wayne Rosenkrans © Antti Salo/Airliners.net Groundsafety
Exel Oyj and 200-ft [61-m] approach light bars Africa, continued through the ap- frangible systems have already been were found knocked off.” proach lights for about 150 m (492 placed. Elsewhere, you may find impro- Global accident and incident records ft) — during which three tires burst vised, locally constructed systems.” show that aircraft–ALS collisions have and the flaps were jammed in the A European company that tracks directly and indirectly caused fatali- takeoff position — and completed airport compliance with frangible ALS ties. For example, after the June 1999 the takeoff; they jettisoned fuel, standards also sees room for improve- American Airlines Flight 1420 overrun and four more tires failed during ment in some regions. “Part 6 require- accident involving an MD-82, the U.S. landing at the departure airport. ments differ quite a lot from the [ICAO] National Transportation Safety Board 1991 Interim Guidance on Frangibility, (NTSB) said, “The FAA determined that • In June 2004, the aircraft received [and] some installations which con- the Runway 22L [ALS] at Little Rock minor damage when an A300 B4- formed to interim guidance may not [Arkansas], which is located in a flood 200 operated by EgyptAir overran comply with Part 6 [— such as in] new plain area of the Arkansas River, could Runway 18 at Khartoum (Sudan) limitations [on] frangible behavior of not be retrofitted to a frangible design Airport and traveled through the a mast,” said Jaakko Martikainen, sales because of the possibility that moving ALS onto rough ground. manager, airport products, for Exel Oyj, a water, ice and floating debris would manufacturer of ALS poles and lattice- • In January 2005, a Boeing 747- affect the structural integrity of the type masts based in Finland. Specifically, 200F operated by Atlas Air over- system. … The airplane’s collision with earlier designs with relatively long dis- ran Runway 23L at Düsseldorf the nonfrangible lighting system was tances between frangible points in their (Germany) International Airport the direct cause of the fatal blunt-force- break-away or failure mechanisms may and struck the ALS and the trauma injuries sustained by the captain not comply, he said. “We have estimated instrument landing system (ILS) and the passengers in seats 3 and 8A and that some 85 to 90 percent of European before coming to a stop. [damage; see related article on page 28] and North American airports have been on the left side of the fuselage.” upgraded,” Martikainen said. “Outside of Break, Distort or Yield ALS Installations Vary One example of loss of control these [regions], the overall percentage is following an aircraft–ALS collision oc- Dr. Ir. Jaap Wiggenraad, a research far below 50 percent, with some positive curred in May 2002, when six crew- engineer who has specialized in ALS exceptions. We are talking about quite members, 67 passengers and 30 people frangibility research and business large numbers that require replacement.” on the ground were killed; one passen- manager of the Aerospace Vehicles Divi- Early frangible ALS designs can be ger, one crewmember and 24 people on sion of National Aerospace Laboratory traced to FAA research during the 1970s. the ground were seriously injured; and (NLR)–Netherlands, considers the most “These structures consisted of hollow the aircraft and more than 25 buildings relevant advance of 2006 to be increased poles made of aluminum or glass/epoxy, were destroyed by impact and post- awareness of the need for frangible ALS aluminum truss structures and an alu- impact fire after a British Aerospace installations. “Awareness also applies to minum tripod structure of an originally BAC One-Eleven Series 500 operated other structures at airports such as ILS Swedish design,” one report said. “Initial by EAS Airlines struck approach lights towers — the key is lightweight design, engineering analysis suggested that during takeoff from Kano Airport, whereas the tendency was to build the important parameters required to Nigeria, according to Ascend. The fol- robust structures to withstand weather, define frangibility were the peak force lowing occurrences, which involved no vandalism, abuse, etc.,” Wiggenraad said. occurring during the impact, the energy injuries to aircraft occupants, also were NLR has observed significant varia- absorbed during the contact period and reported by Ascend: tion among frangible ALS designs that the duration of the impact.”1 comply with current standards and ICAO’s Frangible Aids Study Group • In April 2004, the flight crew of among those that do not. “I think a few — formed in 1981 with members an Airbus A340-310 operated by providers exist in Canada, Finland, the from Airports Council International, Emirates overran Runway 21R on United States, Germany and Norway, Canada, The Netherlands, the United takeoff at Jan Smuts International each with a different concept,” Wiggen- Kingdom and the United States who Airport, Johannesburg, South raad said. “In many Western countries, last met in 1998 and 2003 — was
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Exel Oyj disbanded upon completion of Part 6, objects, only that part of the computer simulation. “The objective … according to Sue-Ann Rapattoni, an structure that extends above the was to simulate the transient dynamic ICAO spokeswoman, although related surrounding objects should be impact,” said the report. “There was standards were implemented on earlier frangible.” good correlation between deformation dates as specified in Annex 14, Volume mode, location and timing of failure, • “The location of break-away or 1, Aerodromes. States were expected to impact force and energy absorption failure mechanisms should be comply with a protection date of Jan. curves obtained from full-scale test re- such that disintegration results 1, 2005, for their existing elevated ap- sults and simulation. Evaluation of the in components of predictable proach lights. “The new [design] guid- model showed that it was computation- mass and size, which, in case of ance took effect in June 2006,” she said. ally stable, reliable and repeatable.”2 secondary impact, do not present Closely associated with several David Zimcik, Ph.D., one of the a greater hazard [to the aircraft] ICAO annexes, Part 6 has been writ- NRCC researchers, in April 2006 noted than they present as part of the ten to reduce the risk of an accident that computer simulation reduces costs. undamaged structure.” primarily by making the ALS “frangible “Dynamic testing is expensive and dan- and mounted as low as possible to as- • “The design materials selected gerous; it’s also difficult because there sure that impact will not result in loss should preclude any tendency for are so many parameters to investigate,” of control of the aircraft.” ICAO’s goal is the components, including the Zimcik said. “The analytic tools we’re to help states implement Part 6 speci- electrical conductors, etc., to ‘wrap developing allow us to become proac- fications so that guidance on design is around’ the colliding aircraft or tive — to design in [frangibility] as op- applied uniformly, Rapattoni said. The any part of it. … After a collision, posed to [designing] after-the-fact, so following excerpts summarize the key the structure should not become that fewer tests are required. Airplanes concepts of a frangible ALS: entangled with the aircraft in do hit towers. We wanted to understand a manner that will prevent the the phenomena so we could design a • “A frangible structure should … aircraft from maneuvering safely safer tower. That was the driver.” As a break, distort or yield readily either in flight or on the ground. result of such studies, Part 6 allows vali- when subjected to the sudden col- … In the case of towers that may dated computer simulation of aircraft– lision forces of a 3,000-kg [6,614- be impacted by airborne aircraft, ALS collisions to prove frangibility. lb] aircraft airborne and traveling it is desirable to not only mini- at 140 km/h (75 kt) or moving on mize the amount of damage to the Advisory Circular Update the ground at 50 km/h (27 kt). aircraft but also to not significantly A few months after Part 6 was pub- … To allow the aircraft to pass, impede the flight trajectory.” lished, FAA issued an advisory circular the failure mode of the structure (AC) embodying the current state of should be one of the following: • “It is recommended that [electri- U.S. and ICAO research and experi- fracture; windowing [opening a cal] conductors be designed such ence in the agency’s ALS Improvement space]; or bending.” that they do not rupture but break at predetermined points within Program (ALSIP), which began in 1978. • “Elevated approach lights and the limits for frangibility of the The Airport Engineering Division their supporting structures should structure. … In addition, the con- issued AC 150/5345-45B, Low-Impact be frangible except that, in that nectors should be protected by a Resistant (LIR) Structures, on Sept. 5, portion of the approach light- break-away boot … to contain any 2006. “The most significant advance ing system beyond 300 m [984 possible arcing at disconnection.” is the work being done toward the ap- ft] from the threshold, where the proval of the use of frangible bolts for height of a supporting struc- Among influences on Part 6 was a study anchoring devices,” said Paul Takemoto, ture exceeds 12 m [39 ft], the published in 2004 by National Research an FAA spokesman. “FAA intends to frangibility requirement should Council Canada (NRCC), compar- use the force and energy standards apply to the top 12 m only; and ing full-scale dynamic impact testing in Part 6 in establishing performance where a supporting structure of airport approach lighting towers standards for the approval of frangible is surrounded by nonfrangible using truck-mounted impactors with bolts, called ‘fuse bolts’ in Part 6.”
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FAA’s current standard equipment requirements based on local site [under ALSIP]. An additional nine for Category III approaches is a dual- conditions,” Takemoto said. “A typical MALSR and 11 ALSF-2 projects were mode high-intensity approach lighting low-impact-resistant structure fiber- completed [to establish new service].” system with sequenced flashing lights glass pole with base plate mounting One clue to other near-term U.S. model 2 (ALSF-2)/simplified short on break-away anchor bolts and light research is a $300,000 grant by the approach lighting system with runway- crossbar costs approximately $2,000 Airport Cooperative Research Program alignment indicator lights (SSALR), for the hardware. That would [total] of the Transportation Research Board which enables air traffic controllers to $22,000 if all the MALSR support of the National Academies. The an- operate the system in the energy-saving structures beyond 600 ft [183 m] nouncement said, “The [fiscal year 2007 SSALR mode during Category I or II from threshold were a nominal 20 ft ALS] research will explore and identify conditions. Today’s ALSIP projects [6 m] tall. If the terrain drops off, the nonmetallic, all-composite construction involve either total ALS replacement or hardware for [each of] the 40-ft [12 m] with sufficient durability [for] sustain- a new installation, although a few sal- fiberglass poles can cost $4,500.” ability, yet optimize frangibility through vaged components may be refurbished Ongoing research also addresses engineered fragmentation to specific as spare parts for older ALS equip- what NTSB has classified as FAA’s “open energy forces; identify design options ment still in service. “The cost for the acceptable response” to a safety recom- and possible solutions of an in-pavement complete replacement of a 2,400-ft long mendation left from the Little Rock in- automated de-energizing sensor/trigger [732-m] medium-intensity approach vestigation: that frangible ALS designs be to immediately cut all electrical power lighting system with runway-alignment developed as soon as technology allows downstream when traversed by aircraft indicator lights (MALSR) starts at for sites with exceptionally difficult design within the runway safety area; and equip US$750,000 with the more complicated challenges, such as flood plains. “FAA [ALS] with [an] indicator pilot light for ALSF-2 starting at $1.5 million,” Take- design engineers consider the installation emergency responders to rapidly assess moto said. of fiberglass pole LIR structures in flood the power status of the system.” FAA sometimes has attributed plains wherever practical,” Takemoto Also on the horizon are concepts for variation in ALSIP project completion said. “Several years ago, the ALSF-2 in installing next-generation ALS flush with to funding limitations and the nature Chattanooga, Tennessee, survived [except the ground. “The implementation of of expenditures in the field. “The bulk for some ground-level electronic equip- in-pavement ALS has great potential to of the costs involves construction to ment] when many of the fiberglass pole improve runway safety,” Takemoto said. replace unreliable underground power approach light supports were subjected “Future studies include the technical cables and control lines, new foun- to significant flooding. In the last two evaluation of light-emitting diodes for dations, [engine-powered] back-up years, the FAA completed … 24 MALSR use on above-ground and inside-semi- generators and other infrastructure and eight ALSF-2 improvement projects flush approach lighting fixtures. Semi- flush approach lighting fixtures are very useful as airports extend their runways Tidewater and move thresholds/runway ends closer ● compounds the to the perimeter of their property.” challenges of Notes designing a stable approach lighting 1. Wiggenraad, Jaap F.M.; Zimcik, David G. “Frangibility of Approach Lighting system at coastal Structures at Airports.” National Aerospace sites such as Laboratory (NLR)–Netherlands. NLR-TP- Lanzarote Airport, 2001-064, Feb. 13, 2001. Arrecife, Spain. 2. Zimcik, D.G.; Ensan, M. Nejad; Jenq, S.T.; Chao, M.C. “Finite Element Analysis Simulation of Airport Approach Lighting © Tony Marlow/Airliners.net Tony © Towers.” Journal of Structural Engineering, May 2004.
www.flightsafety.org | AviationSafetyWorld | december 2006 | 39 LeadersLog Saving an Airport
BY JAMES K. COYNE With Safety © Copyright Nick Onkow
eterboro Airport (TEB), the primary New not-in-my-backyard opposition that so many Jersey-based general aviation airport serv- urban airports face. Last year, the casus belli ing the New York metropolitan area, has — the issue at the heart of the conflict — was James K. Coyne, long been a case study in confrontational aviation safety. president of Taviation dynamics. Local politicians, media and A heavily loaded Bombardier Challenger the National Air citizens groups watch every new development failed to climb after takeoff from Runway 06, Transportation at the airport like a hawk, and when something crossed a busy highway, struck several cars and Association, goes wrong, they’re ready to attack. careened into a nearby warehouse. Network presented the safety From day to day, the issue might be aircraft television cameras were there in minutes; program to the press noise, nighttime operations, pollution, traf- within hours, local politicians were demanding and community fic congestion, terrorism risks, the threat of that the airport be closed or, at a minimum, representatives. unwanted commercial service or just the general that the number of flights and operations be limited. Their message was simple: If there are © Copyright David Almy fewer flights at Teterboro, there will be fewer accidents — and no flights would be even better! The airport’s safety record over the past decade or so is, in fact, quite good. The Port Au- thority of New York and New Jersey, the airport operator, spares no expense in keeping facilities up to date, and since most users of Teterboro are corporate and commercial operators whose aircraft are professionally flown, the equip- ment and crews are typically first-rate. Still, the airport’s opponents had a point: The status quo wasn’t good enough. By late 2005, the Teterboro Airport Industry Working Group was formed with the help of the Port Authority and several national aviation as- sociations to seek a community-wide solution to the challenges the airport faced. The goal, sim- ply put, was that Teterboro should be the safest general aviation airport in the nation — a tough
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goal for any airport, let alone one as complex as Having said that, the content of the promise Teterboro. needed to be settled. In October 2006, airport and Port Author- The participants concluded that the essen- ity officials, local politicians and representatives tial element required to improve safety was the of the four major general aviation associations creation of safety management systems (SMS) joined aircraft operators to present formal that all operators, including the airport itself, pledges to improve operations and enhance would implement. The airline community has safety. No general aviation airport in the United long relied on such systems, and today, virtu- States has ever taken such a step; time will tell if ally all airlines consider them essential. But the such a collaborative safety program is a model question remained whether the hundreds of A successful airport- for other airports. There’s no doubt, however, aviation businesses that want access to Teterboro that a successful airport-based safety program is could make the same kind of commitment. For based safety program an essential part of Teterboro’s future. big operators, like NetJets, this might not be is an essential part of From this point on, it was declared, manag- difficult; but would smaller operators have the ing safety shall be a fundamental business goal resources to support such a change? Anything Teterboro’s future. for every business operator at Teterboro. Like less, it was decided, would have little effect. The any management goal, success will only come if group decided that a Teterboro-wide SMS was there is commitment. Thus, the new Teterboro the solution. Safety Initiative began with the most basic dem- “Raising the bar on safety” is not simple, onstration of commitment that the participants nor is it easy. Convincing the Teterboro-based can make: A promise. operators and other major users to “make the
© Copyright David Almy
www.flightsafety.org | AviationSafetyWorld | December 2006 | 41 LeadersLog
pledge” was pretty straightforward: private and commercial operators man- risk of operational errors and provide They’re easy to contact, understand age safety be achieved without federal meaningful mitigation of traditional the importance of the mission, and regulations forcing their hand? Would airport hazards. generally have both the resources to independent aviation businesses volun- Adverse operational outcomes can support the program and an incen- tarily make costly investments in safety occur in any area of activity subject tive to do so. But if improvements in in a real-world marketplace where to human error, on the ground or in safety truly are to be achieved, then competitors are less willing to meet the air. Reducing the risk of human hundreds of other transient and occa- higher standards? Can a public airport error primarily depends on training, sional users of the airport will have to insist on superior safety procedures technological support, oversight, pro- make the same kind of commitment. and still meet the “equal access” provi- grammed redundancies and systemic To reach them, a broader strategy was sions of federal grant assurances? Most management of human factors. The needed. fundamentally, can one airport, with its Teterboro Safety Initiative seeks to The solution was to get the working unique political and operational issues, promote procedures, within company- group’s major members to contact more craft its own program within its com- based SMSs, that address each of these than 95 percent of Teterboro opera- munity of users to improve safety and areas. Fixed base operators, charter tors and persuade them to voluntarily ensure its survival? operators and flight departments implement an SMS that would reduce The Teterboro Safety Initiative as- based at Teterboro have enrolled in the risk of operational errors on flights sumed that the answer to these ques- SMS programs developed by the Na- to or from Teterboro. Operators who tions is “yes” and developed a very tional Air Transportation Association are unwilling to make this kind of com- different framework for aviation safety (NATA) and others that recommend mitment will be most helpful if they advancement at a public airport, an specific operational improvements in just stay away. airport that faces organized opposition each of these areas. Airport officials But steps such as these inevita- to its very existence. Now, the challenge are committed to similar reforms bly raise new questions: Can such a is to produce specific safety recommen- of their own safety management transformation in the way numerous dations that significantly reduce the programs.
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Employee training is perhaps the system (EMAS) that soon will be in- cornerstone of effective SMS implemen- stalled at the end of Runway 06. tation, with one significant difference Finally, the Working Group empha- from more typical training regimes: sized that improved navigational and everyone gets trained — from veteran surveillance technologies, along with CEO to the entry-level apprentice — and advanced flight management systems, the training never stops. Training at the can enhance safety at Teterboro by en- airport itself is one thing, but training abling more-stabilized approaches and thousands of pilots at companies around eliminating circle-to-land procedures the country who might fly to Teterboro necessitated by long-standing air traffic only occasionally is a much tougher management practice in the New York challenge. With the support and guid- region. Many Teterboro users already ance of the U.S. Federal Aviation Ad- have the onboard equipment necessary ministration (FAA), NATA is developing to support advanced required naviga- an online training program to bring tion performance (RNP) approaches, Teterboro-specific operational issues to and the Port Authority and others have the attention of pilots thousands of miles pledged to promote timely implementa- away. Many charter and fractional jet tion of the new procedures. operators already consider such repeti- The group’s broadest priority, tive training programs the best way to however, is to accept responsibility for a © Copyright David Almy address a fundamental human factors progressive safety agenda and not wait challenge: complacency. for regulators or others to direct how The Challenger’s Physical improvements in the air- or when the users can do better. That failed takeoff last port environment are another element means establishing a permanent safety year was caused by of the Teterboro Safety Initiative. The improvement program at Teterboro a center of gravity Working Group has identified more that brings the most experienced users far forward of than a dozen important safety projects of the airport together on a regular limits, the National for the Port Authority and FAA to con- basis to plan and promote new solu- Transportation Safety sider, ranging from better ramp lighting tions to age-old problems of aviation Board said. to an engineered material arresting safety. Today it may be EMAS or online training programs, tomorrow it could be human-computer cross-challenging interactive checklists or refuse-to-crash navigational systems, but only with a consistently managed and dynamic airport-based SMS can ambitious safety U.S. National Transporation Safety Board Safety Transporation National U.S. goals like those at Teterboro become a reality. In the final analysis, safety is as important to airports as it is to pilots and passengers. Only by constantly improving safety can an airport like Teterboro, where good enough is never good enough, fulfill the expectations of political leaders and promise the public that it will be there when it’s needed, today and for years to come. ● www.flightsafety.org | AviationSafetyWorld | December 2006 | 43 FlightOPS
he sudden loss of visual cues dur- ing periods of blowing dust and dirt, or blowing snow, typically re-
sults in an instantaneous and com- Staff Sgt. Jason by Serrit photo Force U.S.Air Tplete onset of instrument meteorological conditions (IMC), which can result in pilot disorientation and loss of control.1 Coming at the end of an approach in When an aircraft is engulfed in blowing dirt or otherwise unthreatening conditions, the snow, the onset of IMC usually is instantaneous. startling onset of total IMC can exacer- bate pilot disorientation. BY CLARENCE E. RASH Pilots who understand the phe- nomena of brownout and whiteout and know how to operate their aircraft to avoid — or, if that fails, to fly their air- craft out of — such adverse conditions are best equipped to avoid the severe consequences. Brownout occurs in the presence developed, causing the pilot to lose all driven into the air by propeller or rotor of dust, fine dirt or sand. The smaller visual cues. The helicopter touched wash. Approaches and landings on the particulate matter, the denser the downFlying hard, first on the right skid and snow-covered ground are particularly BLIND cloud that develops when these particles then on the left. No one was injured, but likely to create blowing-snow white- are agitated by an aircraft’s spinning the helicopter was substantially dam- outs. Whiteout also may be encoun- propeller or rotor blades. IMC typically aged. The U.S. National Transportation tered some distance from shore during develops 10 to 20 ft (3 to 6 m) above Safety Board (NTSB) cited as a probable flight over large frozen bodies of water. ground level (AGL), and visual referenc- cause the pilot’s “failure to maintain a For example, in February 1995, a es to the ground are instantly obscured. proper descent rate during the land- Beechcraft A100 King Air was nearing In the best circumstances, pilots shift ing approach and misjudged landing the end of a regularly scheduled flight immediately to instrument flight and fly flare, which resulted in a hard landing”; from Sioux Lookout, Ontario, Canada, the aircraft out of the cloud; in the worst, a contributing factor was “brownout to Big Trout Lake, with nine passengers loss of control leads to a crash.2 Often, conditions created by the dust cloud that and a crew of two. The captain briefed the result is a hard landing. interfered with the pilot’s perception of an instrument approach with a circling For example, in June 2004, a Eu- proximity to the ground.” procedure to the landing runway. Dur- rocopter AS 350B3 on an emergency The sudden loss of external visual ing the approach, the crew could see the medical services (EMS) flight landed references also occurs during white- ground; visibility was estimated at 1.0 hard in Cibecue, Arizona, U.S., where a out. There are two uses of the term mi (1.6 km). To ensure safe separation patient was to be picked up for transport whiteout: atmospheric whiteout — also from another aircraft, the crew flew the to a hospital in Scottsdale.3 The pilot referred to as flat-light conditions airplane away from the airport under was familiar with the landing zone, a — and the more common blowing- visual flight rules; during this maneuver, baseball field, and in a previous land- snow whiteout. Atmospheric whiteout as they flew the airplane over the frozen ing and takeoff at this same location, he is encountered during flight and occurs surface of a lake, they encountered had encountered blowing dirt. On this when snow-covered ground cannot be whiteout conditions. The airplane struck approach, the pilot briefed the medical distinguished from a white, overcast the ice. Both pilots and seven passengers aircrew about the possibility of a dust sky. As a result, the horizon is virtually received serious injuries, and the air- cloud and selected a nearby grassy area indistinguishable. In blowing-snow plane was destroyed. The Transportation for touchdown. About 3 ft (1 m) AGL whiteout, visibility is restricted drasti- Safety Board of Canada (TSB) said that and at a speed of 10 kt, a dust cloud cally by ground snow that has been the cause of the accident was that “while
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1978 through Oct. 20, 2006, found one accident/incident report involv- ing brownout — the 2004 Eurocopter accident in Arizona — and 79 reports involving whiteout (Figure 1, page 46).8 Of the 79 whiteout accidents/incidents, 57 (72 percent) involved airplanes, and 22 (28 percent) involved helicopters. Atmospheric whiteout was cited as a causal factor in 52 accidents/incidents (66 percent); of these, 43 involved airplanes and nine involved helicopters. The remaining 27 accidents/incidents (34 percent) involved blowing-snow © Oliver Baumberger/Jetphotos.net © Oliver whiteout; of these, 14 involved airplanes, and 13 involved helicopters. Prevention Is the Best Solution the crew were maneuvering the aircraft propellers of fixed-wing aircraft also Pilot awareness of the potential for to land and attempting to maintain can induce whiteout. brownout and whiteout is the first step Flying BLINDvisual flying conditions in reduced vis- In military operations, because of in preventing these accidents. Experi- ibility, their workload was such that they frequent operations in hostile environ- ence and confidence in handling these missed, or unknowingly discounted, ments, brownout and whiteout are phenomena can be achieved through critical information provided by the more frequent than in civil aviation. training, which should teach pilots to altimeters and vertical speed indicators.” Two 1998 U.S. Army studies of spatial conduct a risk assessment before all Contributing factors were “the whiteout disorientation in helicopter operations landings. The pilot should determine the conditions and the crew’s decision to fly found that the sudden loss of visual potential for brownout or whiteout, be a visual approach at low altitude over cues, as associated with brownout and aware of nearby obstacles in case visual an area where visual cues were minimal whiteout, accounted for 25 percent and cues are lost and have a go-around plan and visibility was reduced.”4 13 percent, respectively, of all spatial before committing to the approach. disorientation accidents.5 A 2004 report When anticipating the occurrence Civil vs. Military said that brownout has been the most of brownout or whiteout, available In civil aviation, brownout occurs frequent cause of aviation accidents crewmembers should inform the pilot infrequently. As in the EMS accident during the war in Iraq,6 and the U.S. of any developing clouds of dirt or scenario, it is most likely in rural military has identified brownout and snow. Landing speed should be just fast regions or where undeveloped landing whiteout as critical flight safety issues. enough to minimize the cloud’s effects zones are encountered. Helicopters are A review of the aviation accident da- and the terminating hover should be more likely than fixed-wing aircraft to tabase maintained by TSB for the period eliminated or minimized. The pilot encounter brownout. 1990–2005 found 22 accidents in which should be ready for an immediate tran- Whiteout is much more frequent in whiteout was cited as a major or contrib- sition to instrument flight. civil aviation because snow is common uting factor. These were evenly divided in many locales and can be prevalent between atmospheric and blowing-snow Technological Remedies even in the most built-up environ- whiteout scenarios, and evenly divided Military services have been pursuing an ments. While helicopters — because of between helicopters and airplanes.7 aggressive program of prevention and their many operations in remote, un- A similar review of the Aviation mitigation of whiteout and brownout conventional locales — are susceptible Accident and Incident Data System accidents and incidents. They have to whiteout caused by rotor wash, the maintained by NTSB for the period increased training, using enhanced
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Whiteout-Related simulations of degrad- way into civil aviation. In the immediate future, U.S. Civil Aircraft Events* ed visual environments however, pilots in civil aviation will have to rely in which these events on their knowledge, training and experience. occur. They also have They must understand the causes and effects of investigated the use of brownout and whiteout, and maintain sufficient Rotary-wing advanced technologies, instrument skills to avoid disorientation when (blowing-snow whiteout) both as immediate and the resulting inadvertent IMC occurs. ● 13 long-term solutions. Clarence E. Rash is a research physicist at the U.S. Rotary-wing For example, the Fixed-wing (atmospheric Army Aeromedical Research Laboratory in Fort whiteout) U.S. Navy is evaluat- (atmospheric 9 Rucker, Alabama, U.S. He has more than 25 years whiteout) ing a device called the 43 of experience in Army aviation research and de- Fixed-wing tactile situation aware- (blowing-snow velopment and is the editor of “Helmet-Mounted whiteout) ness system (TSAS), Display: Design Issues for Rotary Wing Aircraft,” 14 which consists of a SPIE Press, 2000. vest with small, pneu- matically or electro- Notes magnetically driven stimulators called 1. A similar phenomenon sometimes affects helicopters *Accidents and incidents from 1978–Oct. 20, 2006 hovering over water. This occurs when water droplets tactors. The tactors Source: U.S. National Transportation Safety Board that have been blown upward then move downward provide a touch input and are seen in sunlight or moonlight; when this Figure 1 to the pilot’s body or occurs, ground references are obscured. In reacting to legs to signal that the aircraft is drifting or re- this illusion, the pilot may initiate a descent that could quires a correction. The use of TSAS is intended result in unexpected ground contact at rates sufficient to reduce the pilot’s overall workload, allowing to damage the aircraft and produce injuries. other tasks that demand visual attention to be 2. Brock, J. Fatal Illusions. Aviation Medical Society of performed more effectively.9 Australia and New Zealand. 1998. Advanced sensing technologies — such as 3. U.S. National Transportation Safety Board (NTSB). ultra-wideband radar and thermal and laser sen- Aviation Accident and Incident Data System (AIDS). sors — also have been studied to evaluate their Accident report no. LAX04LA285. June 26, 2004. ability to allow pilots to “see through” obscuring 4. Transportation Safety Board of Canada (TSB). clouds. Accident investigation report no. A95C0026. 1995. Another technique being studied for combat- 5. Braithwaite, M.G.; Durnford, S.J.; Crowley J.S.; ing brownout involves the use of chemical ground Rosado, N.R.; Albano, J.P. “Spatial Disorientation in treatments to reduce the propensity of sand, dust U.S. Army Rotary-Wing Operations.” Aviation Space and fine dirt to form obscuring clouds. For these and Environmental Medicine Volume 69 (1998): treatments to be successful, they must be durable 1031–1037. and resistant to weather exposure. 6. Hasenauer, H. “Cutting Down Casualties.” Soldier’s The most ambitious approach to prevent- Magazine Volume 29 (2004) No. 4, 8–15. ing brownout and whiteout is a change in rotor 7. TSB. Query of accident investigation reports. blade/propeller design. This has been proposed October 2006. for the US101, a U.S. variant of the Agusta 8. NTSB. Query of AIDS. September 2006. Westland’s EH-101 helicopter.10 In contrast 9. McGrath, B.; Gierber, G.; Rupert, A. “Can We to standard designs, which push dust toward Prevent SD? The Tactile-Situation-Awareness the fuselage and create brownout, the US101’s System.” Approach May–June 2004.
blades push dust away from the fuselage. 10. Kennedy, H. “Whose Chopper Has the Right Stuff Eventually, after testing by the military, for the Air Force?” National Defense News August some of these techniques are likely to find their 2006.
46 | flight safety foundation | AviationSafetyWorld | December 2006 threatanalysis L 22.5
24.3 10 NM
054° 553
859 1400 2600 L06 DME R22 1400 RADAR 19.6 1500 1306
CATEGORY 1400 CATEGORY A B CATEGORY 272/241400 C 200 (200½) 700/24 D CATEGORY 628 (700-½) 272/40 700-1 Learning700 From Experience200 (200½) 620(700-1) 628 (700-1¼)/60 Incident No. 6 700-1½ 700-1¾ 628(700-1½) Aviation/Airliners.net © Eric Dunetz–NYC 620 (700-1¾) 700-2 Change of Plan 620(700-2)
Sixth in a series focusing on approach and landing incidents that might have resulted in controlled flight into terrain but for timely warnings by TAWS.
BY DAN GURNEY
late change to a different instrument omnidirectional radio)/DME approach, a approach procedure, a hurried approach “straight-in” nonprecision approach procedure briefing and difficulty in deciphering a to the same runway. cluttered chart might have been involved The aircraft was 6 nm (11 km) from the Ain a premature descent that took a commercial runway threshold and descending through 500 aircraft about 1,500 ft below the proper altitude ft above ground level (AGL) when the terrain in instrument meteorological conditions. awareness and warning system (TAWS) generat- The flight crew had been cleared for — and ed a “TERRAIN, PULL UP” warning. The crew likely planned and briefed for — the ILS/DME responded immediately and initiated a climb to (instrument landing system/distance measuring a safe altitude. equipment) approach to the airport. However, The aircraft’s flight path before the TAWS just before the aircraft reached the initial ap- warning was equivalent to a final descent begun proach fix, the tower controller told the crew about 4 nm (7 km) before reaching the appro- that the ILS ground equipment had failed and priate descent point, an error that might have re-cleared the crew to conduct the VOR (VHF resulted from mental workload imposed by the
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complex approach chart that the crew is believed supporting information for the three proce- to have used. dures. Although this decreases clarity, the chart content is typical of many charts that depict Mixed Procedures amalgamated procedures. Civil aviation authorities (CAAs) are respon- The chart identifies a common descent point sible for designing and approving instrument at the final approach fix (FAF) for all three ap- approach procedures for airports in their proach procedures by its distances from two DME countries. They publish master copies that all ground stations: “D6.8 YY,” or 6.8 nm from the chart providers must follow, but not necessarily DME ground station for the ILS/DME approach, using the same formatting and symbology. In and “D2.9 AAA,” or 2.9 nm from the DME ground this incident, the CAA had published separate station for the VOR/DME approach (Figure 1). master copies of the ILS/DME approach and Next to each distance figure is a callout to a note the VOR/DME approach. Each chart clearly identifying its respective approach procedure. The identifies the associated descent point and notes indicate that “D6.8 YY” should be used to provides an altitude/range table specific to the identify the descent point while conducting the approach. The altitude/range table on the CAA’s ILS/DME approach and that “D2.9 AAA” should VOR/DME approach chart has ranges from the be used to identify the FAF during the VOR/DME DME ground station and also from the runway approach. The callouts are included in the chart’s threshold to enable flight management system plan view and profile view; the notes, however, are vertical navigation monitoring. included only in the plan view. The chart that the incident flight crew is The plan view depicts the approximate loca- believed to have used, however, depicts an tions of the DME ground stations. YY, which is amalgamation of the ILS/DME and VOR/DME colocated with the glideslope transmitter, is 0.1 procedures, and includes details for a localizer nm beyond the runway threshold. AAA is about procedure. The chart contains extensive 0.2 nm beyond the VOR, which is 4 nm from the runway threshold. Approach Profile View and Aircraft Flight Path However, the positions of the ground stations D1.0 YY are not depicted on the GS 310' (300') VOR profile view. 2,000' The altitude/ range table also is an D6.8 YY D2.9 AAA * amalgamation of data VOR from the CAA’s mas- LOC ter copies. Its format ILS provides the oppor- 0 4.0 tunity for misreading the data and is a po- LOC YY DME 2.0 3.0 4.0 5.0 6.0 (GS out) ALTITUDE (HAT) 600' (590') 890' (880') 1,180 (1,170') 1,470' (1,460') 1,760' (1,750') tential threat to safety. AAA DME 2.0 1.0 0.0 1.0 2.0 2.9 VOR After AAA After AAA Before AAA Before AAA Before AAA The table is divided DME ALTITUDE (HAT) 560' (550') 850' (840') 1,140' (1,130') 1,430 (1,420') 1,720' (1,710') 2,000' (1,900') horizontally into “LOC,” or localizer,
* Callouts ➊ and ➋ refer to notes on approach plan view indicating that D6.8YY is used for the ILS/DME approach and D29.AAA and “VOR/DME” sec- is used for the VOR/DME approach. tions, and the altitude Source: Dan Gurney and range data are shown together — in Figure 1 much smaller type
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VOR/DME approach; as previously discussed, the descent should have been initiated 2.9 nm from the station. This could have resulted from the crew following information reviewed during their first briefing, for the ILS approach, in which descent is begun 6.8 nm from the DME associated with that approach. This lapse might have been compounded by the use of the LOC altitude/range data, rather The approach than the VOR/DME altitude/range data, to monitor the flight path. The approach likely likely appeared safe appeared safe and correct to the crew — until and correct to the TAWS sounded the alarm. Among lessons to be learned from this inci- crew — until TAWS dent are the following: sounded the alarm. • Late changes of plan and hurried briefings expose flight crews to seemingly innocu- ous threats and opportunities for errors. A rule of thumb to remember is: “Retuning frequencies always requires retuning the © Chris Sorensen Photography mental map.”
than appears in Figure 1. For each range figure, • Latent threats can originate from well- an altitude and a height above touchdown intentioned alterations of the chart for- (HAT) are provided. This adds visual clutter mat to simplify procedures or improve that could slow data acquisition and increase efficiency. mental workload. Similarly, the “After AAA” and “Before AAA” notations for the VOR/DME • Monitoring is only effective if the correct ranges also add complexity. data are being used. Crews should take Moreover, the table shows the range values extra precautions when using amalgam- above the altitudes. As noted in the discussion of ated charts. ● incident no. 2 in the August 2006 Aviation Safety [This series, which began in the July issue ofAviation World, it is essential to check altitude before range Safety World, is adapted from the author’s presenta- when monitoring the flight path. Thus, the table tion, “Celebrating TAWS Saves, But Lessons Still to Be format, which is commonly used by chart pro- Learned,” at the 2006 European Aviation Safety Seminar, viders, could bias the crew to check range before the 2006 Corporate Aviation Safety Seminar and the altitude, a procedure that could result in being at a 2006 International Air Safety Seminar.] dangerously low altitude at longer ranges. Dan Gurney served in the British Royal Air Force as a fighter pilot, instructor and experimental test pilot. He Lessons to Be Learned is a co-author of several research papers on all-weather Based on the author’s analysis, which was re- landings. Gurney joined BAE Systems in 1980 and was viewed by a select group of aviation safety profes- involved in the development and production of the HS125 sionals, the most likely scenario for this incident and BAe 146, and was the project test pilot for the Avro RJ. In 1998, he was appointed head of flight safety for BAE is that the flight crew retuned their navigation re- Systems. Gurney is a member of the FSF CFIT/ALAR ceivers to the radio frequency for the VOR/DME Action Group, the FSF European Advisory Committee and approach but began the descent when the aircraft the FSF steering team developing the “Operators Guide to was 6.8 nm from the DME ground station for the Human Factors in Aviation.”
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Close Calls Similar call signs were the most frequent contributing factor in reported air-ground communication incidents in European airspace.
BY RICK DARBY
onfusion caused by similar call signs was from Oct. 25, 2004, to March 31, 2005, “simi- the most frequently reported contribut- lar call sign” was a contributing factor in 33 ing factor in air-ground voice commu- percent. The next most frequent contributing nication incidents in European airspace, factor, “frequency change,” was found in 12 Caccording to a study of data from a survey of percent.2 airlines and air navigation service providers.1 The study, undertaken by National Aero- In 535 reported incidents during communica- space Laboratory (NLR)–Netherlands for tion between pilots and air traffic controllers Eurocontrol, analyzed incidents classified as loss of communication; readback/hearback error; communication equipment problem; European Air-Ground Voice Communication Incidents no pilot readback; or hearback error. Another Oct. 25, 2004, through March 31, 2005 category — the largest — included incidents
Category No. of Incidents Percentage that did not fit into any of those and were clas- Loss of communication 137 26 sified as “other communication problem.” In some incidents, the type of problem was not re- Readback/hearback error 52 10 ported. The number of incidents and percent- Communication equipment problem 44 8 ages by category are shown in Table 1. In every Hearback error 6 1 category, “similar call sign” was at the top of No pilot readback 5 1 the list of contributing factors. Other communication problem 194 36 Numerous other factors contributed to the Type of communication problem not reported 97 18 535 incidents, but most played a role in less than Total 535 100 5 percent of incidents (Figure 1). Incidents were reported by 12 airlines and 10 air navigation service providers in European The study found that 36 percent of all countries. incidents had no safety consequence (Fig- Source: Eurocontrol ure 2, page 52). About one-fourth involved Table 1 a “prolonged loss of communication.” Other
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consequences included Contributing Factors “altitude deviation,” “loss of separation” and “wrong air- Similar call sign 33.0% craft accepted clearance.” Frequency change 12.0% The term “loss of com- Radio equipment malfunction — air 8.0% munication” refers to situa- Radio interference 8.0% tions in which the flight crew Content of message inaccurate/incomplete 5.0% has no radio contact with Radio equipment malfunction — ground 4.0% air traffic control (ATC) for Frequency congestion 4.0% “some time for some reason,” Sleeping VHF receiver* 4.0% the report says. Most of these Pilot distraction 4.0% incidents (73 percent) oc- Pilot expectation 3.0% curred in the cruise phase of Controller workload 3.0% flight; 9 percent and 4 percent Controller distraction 3.0% occurred during the approach Garbled message 1.0% phase and landing phase, Pilot workload 1.0% respectively. Blocked transmission 1.0% In “loss of communica- Language problems 1.0% tion” incidents, the three most Untimely transmission 1.0% common contributing factors Controller nonstandard phraseology 1.0% were “frequency change” Ambiguous phraseology 1.0% (35 percent), “sleeping VHF Partial readback 1.0% 3 receivers” (15 percent) and Issue of a string of instructions to di erent aircraft 1.0% “radio equipment malfunction Controller accent/non-native speaker 1.0% — air” (12 percent). Stuck microphone 0.4% The most frequent conse- Pilot fatigue 0.4% quence, found in 81 percent of Long message 0.4% the “loss of communication” Pilot nonstandard phraseology 0.2% incidents, was “prolonged loss Controller high speech rate 0.2% of communication.” Controller fatigue 0.2% The report says, “An Pilot high speech rate 0.0% incorrect readback was Pilot accent/non-native speaker 0.0% reported in 15 of the 52 ‘readback/hearback error’ Contributing factors are based on analysis of 535 air-ground voice communication incidents in a study of European occurrences, while in 11 of airspace, Oct. 25, 2004, through March 31, 2005. More than one contributing factor could be assigned to a single incident. * Sleeping VHF receiver is defined as a loss of communication type in which the VHF frequency becomes silent for a those 15 cases, the incorrect time. readback was not detected by Source: Eurocontrol the controller.”4 Contribut- ing factors in the category Figure 1 included “similar call sign” (37 percent), “pilot expectation” (17 percent) Communication equipment problems were and “frequency change” (15 percent). Conse- involved in 44 of the 535 incidents. The most quences of a readback/hearback error included frequent problems in this category were “radio “altitude deviation” (in 37 percent), “wrong equipment malfunction — air” (52 percent), aircraft accepted clearance” (31 percent) and “radio equipment malfunction — ground” (36 “heading/track deviation” (8 percent). There percent) and “radio interference” (11 percent). were no safety consequences in 13 percent. In 34 percent of the incidents there were no www.flightsafety.org | AviationSafetyWorld | December 2006 | 51 DataLink
Consequences call sign” (64 percent). Of the consequences with safety implications, most frequent were “loss of None 36% separation,” found in 12 percent, “instruction is-
Prolonged loss of communication 23% sued to wrong aircraft” in 10 percent and “wrong aircraft accepted clearance” in 8 percent. Other 16% The report also includes results of a Altitude deviation 7% survey of pilots and controllers about the Loss of separation 7% findings, discussion of causal factors and safety Wrong aircraft accepted clearance 6% recommendations. ●
Instruction issued to wrong aircraft 4% Notes Unknown 2% 1. The study, Air-Ground Communication Safety Heading/track deviation 2% Study: Causes and Recommendations, by Rombout Runway transgression 1% Wever, Gerard van Es and Marcel Verbeek, is available via the Internet at
safety consequences; “prolonged loss of com- 2. “Frequency change” included such events as the munication” occurred in 27 percent; “other” in receiver tuned incorrectly, air traffic control (ATC) neglecting to hand off the flight to the next control- 23 percent; “altitude deviation” in 7 percent; ler, the flight crew missing a call from ATC and and “loss of communication” and “wrong air- radio equipment malfunction. craft accepted clearance,” each in 2 percent. The study found “no pilot readback” and 3. A “sleeping VHF receiver” problem was defined as a “loss of communication type in which the “hearback error” in five and six incidents, VHF frequency becomes silent for a period of respectively, and researchers considered the time.” It was a problem with the VHF receivers on samples too small for meaningful findings. the aircraft, not always recognized as such by the “Other communication problem” repre- pilots and controllers.
sented the largest single category, with 194 4. In a “readback/hearback error,” a pilot reads 5 incidents representing 36 percent of the total. back the clearance incorrectly, and the controller The most frequent contributing factors were fails to correct the error, or a pilot of the wrong “similar call sign” (46 percent), “radio inter- aircraft reads back the instruction. Four of the 15 ference” (13 percent) and “content of message “incorrect readbacks” were reported as “readback/ hearback errors” and therefore classified as such, inaccurate/incomplete” (9 percent). although it was not specifically stated that the con- There were no safety consequences in 49 troller did not detect the incorrect readback. percent of the incidents in this category and “other” consequences in 29 percent. The most In a “hearback error,” a pilot reads back the clearance correctly, and the controller fails to notice his or frequently identified safety consequences her own error or fails to correct critical erroneous included “loss of separation” (8 percent), “al- information in a pilot’s statement of intent. titude deviation” (4 percent) and “instruction 5. “Other communication problem” was a miscel- issued to wrong aircraft” (4 percent). laneous category for reported incidents that fit Among incidents categorized as “type of com- no other. Reported examples included, “Three munication problem not reported,” the contrib- aircraft with similar call signs are confusing ATC” uting factor most often identified was “similar and “there was some noise on frequency.”
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Mind in Flight The nature of aviation creates its own psychological challenges that call for specialized monitoring and help.
BOOKS other professionals who may not be personally known to the individual. When operating as Aviation Mental Health: Psychological part of a crew, a pilot’s actions are constantly Implications for Air Transportation monitored by other crewmembers, a situation Bor, Robert; Hubbard, Todd (editors). Aldershot, England, and that the editors describe as feeling like an end- Burlington, Vermont, U.S.: Ashgate, 2006. 375 pp. Figures, tables, less driving test. Being repeatedly away from references, index. home for days at a time, possibly in a foreign viation professionals tend to distrust psy- environment, creates further pressures. chological evaluation and mental health The editors hope their book will make the Atherapy. Those processes involve subjectiv- case that aviation mental health practitioners are ity and ambiguity, which are not valued in the there to help with the issues that flight intro- realm of aviation, where clarity and precision duces, not to find fault. are standard procedure. It also appears to many “This book seeks to present a modern, who work in aviation that mental health issues informed, balanced and useful application of arise only as a sign of something wrong, which mental health issues in aviation and to challenge can endanger a career. outdated and negative impressions held by some Nevertheless, the human organism was not about what mental health insights can offer to designed by evolution to fly — to be in a to- aviation,” the editors say. “It is about the mental tally artificial environment disconnected from health of the millions of professionals worldwide the earth for hours, sometimes in abnormal responsible for flight. It is not, however, a book spatial attitudes, experiencing daytime and a about aviation human factors.” demand for alertness when body and mind Aviation mental health is concerned with insist it’s night and time to sleep — and some six main tasks, the editors say: identifying those psychological difficulties are to be expected as who are psychologically unfit for the work; a result. monitoring the psychological health of those in No matter how well trained and expe- training and employment in the aviation indus- rienced crewmembers are, they cannot be try; assessing and treating those who develop completely immune to stressors that aviation psychological problems at work; determining presents. Some, like jet lag, are mainly physio- whether and for how long an individual is unfit logical. Others are psychological or emotional: for aviation duty; emotionally supporting those the need to make decisions with potentially considered unfit for duty, whether temporar- catastrophic consequences if they are wrong, ily or long term; and preventing mental health the requirement for concentration and per- problems through intervention, health promo- ception, and having to depend on and trust tion and research. www.flightsafety.org | AviationSafetyWorld | December 2006 | 53 InfoScan
The papers comprising the book are or- models. Following a section about production, ganized under three headings: “Psychological including materials, the book examines the sys- Issues of Flight and Cabin Crew”; “Psychologi- tems that enable the airplane to do its job. Varia- cal Processes Among Passengers and Crew”; tions in systems among versions of the airplane and “Related Themes in Aviation.” Among the and upgrades to systems are discussed. topics of papers are psychiatric disorders and Numerous photographs, all black-and-white syndromes among pilots; psychiatric evaluation except the front and back covers, illustrate the of crewmembers; psychological factors in flight points covered by the text. Descriptions, while crew selection; and psychological problems technical, sometimes have a personal touch: among cabin crew. The several chapters about “On a couple of occasions, I have seen three reds psychological problems of passengers in connec- and three greens [gear position indicator lights] tion with flight might at first seem off-topic, but after the gear has been selected ‘DOWN.’ This fear of flying and on-board psychiatric emergen- was because the telescopic gear handle had not cies affect cabin crewmembers. fully compressed back toward the panel. If this “The field of aviation mental health should happens to you, give it a tap back in and the red not be seen to be limited to the diagnosis and lights should extinguish.” treatment of psychopathology and psychiatric A section titled “Pilots’ Notes” gives back- problems,” the editors say. “A book of this scope ground information on topics such as Boeing’s is also concerned with the prevention of psycho- new “Normal” checklists, crosswind takeoff logical problems, especially among crew.” They and landing guidelines, landing techniques, acknowledge that some important groups are procedures for loss of thrust from both engines, left out of the discussion, particularly air traffic and sample type rating examination questions. controllers and maintenance technicians. The The notes are to aid understanding and do not reason, they say, is a lack of scientifically sound supersede company operational policies. published literature on those populations. Every 737 hull-loss accident is described, and many descriptions include the investigative The Boeing 737 Technical Guide authority’s determination of causal factors. Brady, Chris. United Kingdom: Tech Pilot Services, 2006. Version 15. 366 pp. Figures, diagrams, photographs, index. REPORTS n old engineering joke says, “When all else fails, read the manual.” This guide is Assessing Institutional Resilience: Adesigned for Boeing 737 pilots who have A Useful Guide for Airline Safety Managers? read the flight operations manual and want to Wood, Margot; Dannatt, Robert; Marshall, Verena. Australian Transport know more. The author, easyJet’s maintenance Safety Bureau (ATSB). B2004/0240. Final report. June 2006. 63 pp. test pilot, started and maintains The Boeing 737 References, appendix. Available via the Internet at
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human error, has developed a checklist for assess- still a long way to go. 1–5 — The organization is ing institutional resilience, including a version very vulnerable. 0 — Jurassic Park.” for the airline industry. This report presents the New Refractive Surgery Procedures and findings of a qualitative study investigating fac- Their Implications for Aviation Safety tors perceived to facilitate institutional resilience in airlines, obtained through interview questions Nakagawara, Van B.; Wood, Kathryn J.; Montgomery, Ron W. U.S. Federal Aviation Administration (FAA) Office of Aerospace Medicine. DOT/ adapted from Reason’s checklist. Senior managers FAA/AM-06/9. Final report. April 2006. 45 pp. Figures, tables, references, at 12 airlines operating in the Asian and Pacific appendixes. Available via the Internet at
aviation’s frontline personnel, including pilots, controllers, mechanics, flight attendants and dis- patchers.” Currently, more than 130,000 incident records compiled from more than 700,000 sub- mitted reports are in the database. The online database contains incident records from 1988 to the present and is updated monthly. The purpose of the program is “to lessen the likelihood of aviation accidents.” Data are used by government, industry and academia to identify and remedy deficiencies and discrepancies in the aviation system; formulate policy and plan- ning; and support human factors safety research. are given drop-down selection lists with recog- Depending on an individual researcher’s needs nized aviation terms. Narratives of individual and creativity, any number of uses are possible records usually contain FAA terms and abbrevia- — education and training aids, examples of spe- tions and ASRS codes unique to this database, so cific event types, identification of risks associated ASRS provides encoding and decoding lists on with certain actions, and information to support line. Researchers can print all information as it a personal opinion or observation, to name a few. appears on the viewing screen or reformat search Confidential incident reports of occurrences results for customized reports. in the most recent month are submitted to ASRS, This database is complex. Users will ben- where they are analyzed by a professional staff of efit from reviewing background and support- former air traffic controllers and pilots. Identifying ing information in advance of searching. For information is removed to protect confidential- optimum results, they should read descriptions ity, and safety hazards are identified and flagged. of database content and structure and ASRS’s The U.S. Federal Aviation Administration (FAA) recommendations for creating queries, formu- or the U.S. National Transportation Safety Board lating search strategies, manipulating data and (NTSB) determines whether to corroborate re- displaying reports. ported events and address remedies. The reporting Until now, access to this type of information system is non-punitive, and the FAA cannot use has been limited. Researchers had to contact these reports for enforcement action. There are ASRS directly, or access brief reports of similar two exceptions – accident reports are forwarded to data at the FAA’s National Aviation Safety Data NTSB and reports involving criminal offenses are Analysis Center (NASDAC) web site, using a forwarded to the U.S. Department of Justice. search form with limited options and a search Reports of events appearing in the database engine with limited capability. (NASDAC was are “soft” data, meaning that the data should be recently renamed Aviation Safety Information reviewed with care. Submissions are selectively Analysis and Sharing [ASIAS].) ● corroborated, reporter biases and perceptions Sources may exist, and multiple reports of the same * Australian Transport Safety Bureau incident may be combined into a single record. P.O. Box 967, Civic Square Individual database records can contain more ACT 2608 Australia than 40 categories of information, plus the Internet:
56 | flight safety foundation | AviationSafetyWorld | December 2006 OnRecord Wake Turbulence Triggers Control Loss Challenger pilot could not correct an uncommanded roll during landing.
BY MARK LACAGNINA
The following information provides an aware- spar was bent and buckled,” said the report by ness of problems in the hope that they can be the U.S. National Transportation Safety Board avoided in the future. The information is based (NTSB). The pilot, copilot and passenger were on final reports on aircraft accidents and inci- not injured. dents by official investigative authorities. NTSB said that the probable cause of the ac- cident was “the flight’s encounter with wake tur- JETS bulence from the departing airplane, resulting in the pilot’s inability to control the airplane.” Another Jet Departed in Opposite Direction Canadair CL-600. Substantial damage. No injuries. Brake Failure Leads to Ground Accident he airplane was inbound to land on Runway Boeing 737-8AS. Minor damage. No injuries. 15 at Aspen–Pitkin (Colorado, U.S.) County he aircraft was landed and taxied to a stand TAirport in daytime visual meteorological at Glasgow–Prestwick (Scotland) Airport on conditions (VMC) on Feb. 9, 2006. While clear- TNov. 26, 2005. Approaching the parked air- ing the flight crew to land, the tower controller craft, the driver of a baggage belt-loading vehicle said that the winds were calm. applied the wheel brakes, but the brake pedal The pilot told investigators that the airplane went to the floor without slowing the vehicle. was 50 ft above ground level (AGL) when it The driver tried unsuccessfully to engage the encountered wake vortices from a British Aero- parking brake. The vehicle struck the aircraft, space BAe 146 that had departed from Runway denting the lower fuselage aft of the front cargo 33. The Challenger rolled into a steep left bank, hold and breaking a radar antenna. and the stall-warning horn sounded. The pilot The U.K. Air Accidents Investigation Branch increased power. The airplane then rolled (AAIB) report said that the hydraulic brake pipe steeply right and pitched nose-down. The pilot had fractured, causing a loss of fluid and pres- said that he was unable to stop the roll, and the sure for the brake cylinder, and a hand-brake right main landing gear struck the runway. cable had seized, rendering the hand brake “The right main landing gear strut penetrat- inoperative. “The impending brake pipe failure ed the right wing, the leading edge of the right and the defective parking brake might have been wing was crushed aft, and the right aft wing detected had a daily check, or quarterly service, www.flightsafety.org | AviationSafetyWorld | December 2006 | 57 OnRecord
together with an effective defect-reporting sys- applied full power and retracted the flaps to the tem been used,” the report said. takeoff position, but the airplane did not accel- AAIB recommended that the U.K. Civil erate to flying speed. It overran the runway and Aviation Authority “remind airport operators struck several objects before coming to a stop that their safety management systems should 400 ft (122 m) beyond the departure end. ensure that safe standards of maintenance and NTSB said that the probable causes of the use are applied to all vehicles and mobile ground accident were “the pilot’s improper preflight equipment used in the proximity of aircraft.” planning, his failure to consult performance data and his failure to obtain the proper touch- Wet-Runway Overrun down point.” Cessna 525 CJ1. Substantial damage. One minor injury, two uninjured. Blocked Grease Fitting Causes Nosewheel Jam he pilot conducted a go-around after losing BAE Systems Avro RJ85. Substantial damage. No injuries. sight of the runway during a visual ap- oon after takeoff from the Gothenborg/ Tproach to Old Bridge (New Jersey, U.S.) Landvetter (Sweden) airport in nighttime Airport on July 17, 2005. Clouds associated with SVMC on March 10, 2006, the flight crew a nearby thunderstorm had moved into the area, observed an indication that the nose landing said the NTSB report. The pilot requested and gear had not retracted. The crew made several received clearance to conduct a global position- unsuccessful attempts to resolve the problem ing system (GPS) approach to Runway 24. and then requested and received clearance to An airport 14 nm (26 km) from Old Bridge return to the departure airport, said the report was reporting surface winds from 160 degrees at by the Swedish Accident Investigation Board 11 kt, gusting to 14 kt, 10 mi (16 km) visibility (SHK). and a broken ceiling at 1,500 ft. Air traffic control (ATC) approved the crew’s Performance data in the aircraft flight request to conduct the instrument landing sys- manual (AFM) indicated that at the airplane’s tem (ILS) approach to Runway 03 and conduct a landing weight of 9,500 lb (4,309 kg), landing low pass near the control tower. After being told distance on a dry runway, with no wind, was that ground personnel believed that the landing 2,770 ft (845 m). However, the report said that gear was extended, the crew landed the aircraft the runway was wet, increasing the no-wind on Runway 03. The report said that the aircraft landing distance to 3,550 ft (1,083 m). Runway touched down smoothly on the main landing 24, the only runway at the airport, has a 400-ft gear at about 100 kt; however, the nose landing (122-m) displaced threshold and an available gear collapsed soon after it was lowered onto the landing length of 3,194 ft (974 m). runway. “The nose of the aircraft hit the runway Landing reference speed, VREF, was calculat- and the aircraft slid further, supported by its Clouds associated ed as 107 kt. The airplane was about 0.1 nm (0.2 nose and the main landing gear for about 300 m km) from the runway threshold when its terrain [984 ft] before it stopped,” the report said. There with a nearby awareness and warning system (TAWS) gener- was no fire. The four crewmembers and 28 pas- ated a “SINK RATE” warning. Data obtained sengers were not injured. thunderstorm had from the TAWS indicated that the airplane’s The report said that the technical investiga-
moved into the area. groundspeed was 133 kt and its descent rate was tion showed that the accident was caused by 1,522 fpm. “seizure of the nosewheel-locking mechanism TAWS data also indicated that the airplane as a result of a blocked grease nipple, which touched down about 815 ft (249 m) beyond prevented correct lubrication.” the displaced threshold. The pilot attempted The report noted that the evacuation of to reject the landing when he realized that the passengers through the left rear door had been airplane could not be stopped on the runway. He difficult because a cabin crewmember had been
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unable to lock the door in its full-open position. the van and came to a stop against it. By then, the “Certification requirements for emergency evac- copilot had moved back into his seat; he closed uation from an inclined aircraft do not contain a the right thrust lever and shut down the engine. requirement for the door to be capable of being secured in the open position,” the report said. As TURBOPROPS a result of this finding, SHK recommended that Crew Had ‘No Viable Landing Option’ the European Aviation Safety Agency (EASA) Beech King Air A100. Substantial damage. No injuries. “ensure that physical strength is not a decisive factor for opening and locking emergency exits he aircraft was on a scheduled flight from on aircraft … even in the case of abnormal tilt- Purvirnituq, Quebec, Canada, to Kuujjuaq, ing angles.” Tin northern Quebec, the evening of Dec. 24, 2004. The report by the Transportation Safety Learjet Hits Van After Engine Start Board of Canada (TSB) said that weather condi- Learjet 45. Substantial damage. One serious injury. tions at the destination were worse than had he aircraft was at a stand at London Gatwick been forecast. Airport and was being prepared for a flight The King Air was 97 nm (180 km) from the Tto Paris the evening of March 17, 2006. The airport when a Kuujjuaq Flight Service Station copilot set the parking brake and started the (FSS) specialist told the flight crew that the right engine to provide electrical power and air- winds were from 310 degrees at 28 kt, gusting to conditioning for the cabin. The aircraft was not 38 kt; visibility was 1/8 mi (200 m); vertical vis- equipped with an auxiliary power unit. While ibility was 200 ft; and Runway 07 RVR (runway moving out of his seat, the copilot inadvertently visual range) was 2,600 ft (800 m) with moder- moved the right thrust lever nearly to the detent ate snow, heavy blowing snow and drifting snow. for maximum cruise power, said the AAIB The specialist also said that Runway 07 was report. covered with frost and compacted snow, and The report said that the copilot had not that there were 6-in (15-cm) snowdrifts cover- activated the auxiliary hydraulic pump before ing almost half of Runway 31. setting the parking brake, and there might not The crew requested and received informa- have been sufficient pressure in the accumulator tion from the FSS specialist on weather condi- to apply the wheel brakes. If there was sufficient tions at three alternate airports. The crew then pressure, the wheel brakes likely were overcome advised the company’s dispatch office that they by the thrust being produced by the engine. The would attempt one approach at Kuujjuaq and, if nosewheel had been chocked with relatively unable to land, proceed to an alternate airport. lightweight chocks carried aboard the aircraft, The captain, who had 5,500 flight hours, but the chocks were pushed aside when the including 1,500 flight hours in type, was the aircraft began to move forward while accelerat- pilot flying. He told the first officer that they ing rapidly. would conduct the ILS approach to Runway 07 The captain, who was stowing his baggage in and land on that runway or on Runway 31 if the the rear of the cabin, observed that the aircraft winds were still strong. was moving and called to the copilot, who did However, the report said that the crew had not hear him. While moving forward through no viable landing option at Kuujjuaq. During the cabin, the captain fell out of the aircraft the approach, the pilots were told three times through the open door and was seriously in- that the winds were from 320 degrees at 30 kt, jured. A ramp-handling agent was knocked to gusting to 45 kt. The reported ceiling was below the ground by the aircraft. the minimum descent altitude for a circling ap- The left wing struck a parked service van. proach to Runway 31. “Regardless, the surface of The aircraft pivoted almost 180 degrees around Runway 31 was 40 percent covered with www.flightsafety.org | AviationSafetyWorld | December 2006 | 59 OnRecord
six-inch snow drifts,” the report said. Landing that the high-speed pinion bearings in the gear- on Runway 07, the aircraft had a crosswind box had failed after a fatigue-induced failure of component of 28 kt to 44 kt and a tailwind com- an oil-supply tube. ponent between 10 kt and 15 kt. The pilot had purchased the aircraft about a A crosswind and runway-friction-index month before the accident occurred. “The pilot The aircraft had a reference chart in the Canadian Aeronautical had stated to personnel at the place where he Information Publication indicates that, with the purchased the aircraft that he had not received, crosswind component wind conditions that existed at Kuujjuaq, a landing nor did he need, recurrent training in this aircraft of 28 kt to 44 kt and a should be attempted only on a dry runway. “Use of as he had several thousand hours in the aircraft,” the crosswind chart in preparation for landing on the report said. “Flight logs … indicated that the tailwind component Runway 07 at Kuujjuaq would have clearly shown pilot had accumulated about [2,170 flight hours, that a landing [on the contaminated runway] including] 551 hours in a Mitsubishi; however, between 10 kt and would have little chance of success,” the report said. the last time that the pilot had flown this make 15 kt. The crew said that the drift angle required and model was 14 years prior to the [purchase of to maintain the localizer was not excessive, and the aircraft]. Logbook entries indicated that only they obtained visual contact with the runway a few hours of flight time had been accumulated environment after crossing the final approach in all aircraft during the approximately two years fix. The captain decided to land on Runway 07. prior to the accident.” The pilot had flown the “Immediately after landing, the aircraft started MU-2 about 11 hours after purchasing it. skidding to the right and departed the landing NTSB said that the probable cause of surface, coming to rest 1,600 ft [488 m] from the accident was “the pilot’s failure to obtain the threshold and 40 ft [12 m] to the right of the minimum controllable airspeed during the runway,” the report said. “The captain advised takeoff climb, which resulted in a loss of aircraft the FSS of the runway excursion, and help was control when the left engine lost partial power.” sent to assist the four passengers and crew.” The board said that the pilot’s failure to follow procedures, his lack of recent experience and Engine Loses Power During Steep Takeoff recurrent training, and the oil-tube failure were Mitsubishi MU-2B-25. Destroyed. Four fatalities. contributing factors. ilots who witnessed the accident said that after the aircraft lifted off the runway at No Explanation for Control Loss PPortland–Hillsboro (Oregon, U.S.) Air- Reims Cessna F406 Caravan II. Destroyed. One fatality. port on May 24, 2005, it entered a nose-high he AAIB said that because of extreme frag- pitch attitude of about 40 degrees, climbed to mentation of the wreckage and the absence about 1,000 ft AGL, rolled into a steep left bank, Tof recorded flight and voice data, no conclu- pitched nose-down and spun to the ground. The sions could be made on what might have caused pilot and three passengers were killed. the twin-turboprop aircraft to depart from con- The NTSB report said that the AFM indicated trolled flight soon after the pilot began a descent that the takeoff climb performance described by in instrument meteorological conditions (IMC) the witnesses could have been achieved only by to land at Inverness, Scotland, the morning of maintaining airspeed below 100 kt — the mini- Oct. 22, 2004. The aircraft was in a steep spiral mum control speed with the critical engine inop- dive when it struck the ground at about 350 kt.
erative, VMC — and near 86 kt, the power-off stall The trip had begun at Inverness about five speed with flaps extended 5 degrees. Normal climb hours earlier, and the pilot, who had 2,735 speed under the existing conditions was 125 kt. flight hours, including 510 flight hours in type, Investigators determined that a partial loss had completed four flight segments transport- of power from the left engine had occurred. A ing newspapers and magazines to Scotland’s teardown examination of the engine indicated northern and western islands. There was no
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cargo aboard the aircraft for the fifth segment, a Soon after takeoff, the aircraft encountered positioning flight to Inverness from Stornoway. icing conditions at 4,000 ft. The pilot observed The last radio transmission received from the that the wing deice boots were shedding the pilot was his acknowledgement of clearance to ice, and he requested and received clearance to descend from cruise altitude, Flight Level 95 climb to 6,000 ft. The pilot later told investiga- (about 9,500 ft), to FL 75. He did not respond to tors, “After attempting to climb several times, I subsequent calls from ATC. realized the aircraft could not climb and [had] A mountain rescue team found the wreckage started to buffet, and the speed was beginning the next day on a 2,500-ft ridge 30 nm (56 km) to decrease.” He requested a descent to 3,000 northwest of Inverness. “The severity of the im- ft and was cleared to descend to 3,200 ft, the pact had scattered the aircraft over a wide area minimum en route altitude. The pilot said that and into many pieces,” the report said. while descending, “I realized that I could not The elevator trim actuators were found to hold altitude. I was unable to level; the airplane be near their full nose-down positions, which continued to descend and buffet.” might have been caused by a fault in the electric The air traffic controller, who had lost radar trim system or in the autopilot, the report said. contact with the airplane, asked the pilot if he The trim position also might have been set could conduct a landing at Emporia (Kansas) involuntarily by the pilot, who was 6 ft 4 in tall, Airport, which was nearby. The pilot replied, if he had become incapacitated after striking his “No, sir. I’m going down.” The airplane struck head on the ceiling of the cockpit during an en- a tree and came to rest, upright, in a field 4 nm counter with a vertical gust. “A severe encounter (7 km) from the airport. NTSB said that the could have rendered him unconscious, and if he probable causes of the accident were “the pilot’s started to regain consciousness, any involuntary attempted flight into adverse weather conditions arm and leg movements might have been suf- and improper in-flight planning, which resulted ficient to ‘upset’ the aircraft,” the report said. in loss of control.” However, there was “insufficient evidence from which to draw a firm conclusion [about] Neither Pilot Looked for ‘Three Green’ the cause or causal factors for [the] rapid devia- Piper PA-31 Navajo. Substantial damage. No injuries. tion from controlled flight,” the report said. he pilot, who was receiving instruction for Noting that the installation of flight data record- a class endorsement in the aircraft, said that ers in aircraft like the F406 is “impractical and The moved the landing gear selector to the economically unacceptable,” AAIB recommend- “DOWN” position late on the downwind leg to ed that EASA “develop standards for appropri- land at Birdsville (Queensland, Australia) Airport ate recording equipment that can be practically on Nov. 12, 2005. “Both pilots reported that they implemented on small aircraft.” usually checked for landing-gear-down indica- tions but could not recall whether the three green PISTON AIRPLANES ‘Down-Locked’ lights or the red ‘Not-Locked’ light were illuminated,” said the report by the Aztec Crippled by Ice Australian Transport Safety Bureau (ATSB). Piper PA-23-250. Substantial damage. One serious injury. The instructor said that the approach and ark nighttime IMC prevailed for the landing were normal until the propellers struck unscheduled cargo flight from Kansas the runway. Neither pilot recalled hearing the DCity, Missouri, U.S., to Wichita, Kansas, on gear-unsafe warning horn, which sounds when March 20, 2006. During his preflight weather a throttle is reduced below 12 in manifold pres- briefing, the pilot was told that he could expect sure with the landing gear retracted. icing conditions and that the freezing level was The landing gear selector was found in the at 1,500 ft AGL. “DOWN” position after the aircraft landed www.flightsafety.org | AviationSafetyWorld | December 2006 | 61 OnRecord
gear-up on the runway. “The pilot’s operat- no sign of a preimpact mechanical malfunction ing handbook explained that the gear selector or failure. moved from the ‘DOWN’ to a neutral posi- NTSB said that the probable causes of the tion when the landing gear extension cycle was accident were “the pilot’s failure to maintain complete,” the report said. “It stated that the gear the published minimum descent altitude and lights were the primary means of confirming not adhering to the published missed approach the landing gear status.” The report noted that in procedures.” most aircraft with retractable landing gear, the selector remains in the “DOWN” position after HELICOPTERS the gear are extended. Post-accident tests conducted by a mainte- Engines Fail to Respond on Approach to Glacier nance engineer indicated that the landing gear Bell 212HP. Substantial damage. No injuries. system operated normally. ATSB said that the he pilot was conducting heli-skiing op- investigation did not determine why the landing erations in the Blue River area of British gear did not extend during the landing at Birds- TColumbia, Canada, on Feb. 24, 2005. He ville. “It was possible that the pilot flying did not departed, alone, from the top of a glacier at fully engage the landing gear selector and used 8,000 ft and conducted a downwind approach to the position of the gear selector as an indica- a pick-up area at the bottom of another glacier tion of landing gear extension,” the report said. at about 6,100 ft. The helicopter was 150 ft “More importantly, it appeared that neither pilot above the ground, and airspeed was about 30 kt, confirmed that the landing gear was down and when the pilot increased collective pitch to slow locked by checking that the three green ‘Down- the rate of descent. The engines did not respond, Locked’ lights were illuminated.” however, and rotor speed decreased. “The pilot flew the helicopter toward a Descent Below Minimums snow-covered, frozen lake,” said the TSB report. Piper PA-34-200T Seneca. Destroyed. One fatality. “The sink rate could not be arrested as the rotor he automated weather observation at Skagit rpm [revolutions per minute] had not recovered, Regional Airport in Burlington, Wash- and the helicopter landed hard, yawed right Tington, U.S., the evening of Jan. 6, 2006, about 90 degrees and remained upright. … After included 5 mi (8 km) visibility, a broken ceiling the landing, the rotor rpm appeared to start ac- at 100 ft AGL and an overcast at 800 ft AGL. celerating, and the pilot shut the engines down The pilot, who was inbound on an unscheduled immediately.” cargo flight from Seattle, requested and was Investigators found that the power-turbine cleared to conduct the NDB (nondirectional governors were not rigged correctly; their beacon) approach. The published minimum control arms were statically positioned at about descent altitude is 1,240 ft, or 1,096 ft above the 74 degrees, rather than the standard 85 degrees runway touchdown zone elevation. or 90 degrees. When the control arms were The airport also had two GPS approaches, positioned to 90 degrees, the engines operated but the airplane’s GPS receiver was certified only normally. for visual flight rules navigation. Radio and radar contact were lost soon after Pilot Loses Control in Low Visibility the pilot, who had 4,685 flight hours, includ- Robinson R44 Raven. Destroyed. Two fatalities, one serious injury. ing 220 flight hours in type, reported that the n the morning of July 9, 2005, the pilot airplane was inbound on the procedure turn. telephoned the Waterford (Ireland) The wreckage was found the next morning in a OAirport control tower to request per- heavily wooded area 2,090 ft (637 m) from the mission to fly from New Ross to an area over runway threshold. The report said that there was the ocean south of Waterford, so that he and
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his passengers could view the beginning of a AAIU said that the probable cause of the ac- yacht race. The controller rejected the request cident was “the pilot’s loss of spatial orientation because of low visibility and clouds in the Wa- resulting from inadequate visual reference with terford ATC zone, said the report by the Irish the ground due to limited visibility.” Air Accident Investigation Unit (AAIU). The pilot told the controller that he would fly west Crosswind Thwarts Vertical Takeoff and would not enter the ATC zone. Bell 206-L1. Substantial damage. One fatality, three serious injuries. The pilot, who had 123 flight hours, includ- he pilot landed the emergency medical ing 58 flight hours in type, then filed a visual services helicopter on the front lawn of a flight rules flight plan to the helicopter’s home Tresidence in Gentry, Arkansas, U.S., on Feb. base, a heliport near Galway Airport, which is 21, 2005, to pick up a patient who had been on the west coast of Ireland, about 170 km (92 severely injured in a motor vehicle accident. nm) northwest of New Ross. The pilot estimated “The 3,438-hour commercial pilot was 50 minutes en route at 2,000 ft. unable to determine wind direction; however, About 40 minutes after takeoff, the pilot he knew the wind was forecast to be out of the attempted to establish radio contact with the north between 330 and 030 degrees between Galway Airport control tower but received 10–15 knots,” the NTSB report said. Another no response. “The duty controller had left the pilot said that winds at the accident site were tower for a brief break,” the report said. Another from 030 to 050 degrees at 10 kt or less. helicopter pilot heard the accident pilot’s radio The helicopter was on a 360-degree heading transmissions, told him that the tower was when the pilot conducted a vertical ascent to “off-air at the moment” and relayed the local avoid striking the residence and 60-ft power- altimeter setting. lines that crossed over the property. The report “Radar tracking indicates that the heli- noted that when a helicopter is maneuvered in a copter slowed down and then made a sharp high-power, low-airspeed environment, a cross- turn before disappearing off the screen,” the wind or tailwind can cause a loss of tail rotor report said. The wreckage was found in dense effectiveness and an uninitiated turn. forest on a mountain slope near Derrybrien. The helicopter was just below the level of One passenger had been killed, and the pilot the powerlines when it began an uncommand- died that evening in a hospital. The surviving ed right turn. “The pilot had full left torque passenger told investigators that the flight had pedal applied at the time, and he attempted to been uneventful before the helicopter suddenly gain forward airspeed; [he] also used the cyclic The helicopter was entered cloud. “We seemed to hit something, to follow the nose of the aircraft in an attempt and I saw [the pilot] struggling with the to fly out of the turn,” the report said “The pilot just below the level controls,” he said. “I remember that we went was unable to gain airspeed, and the helicopter of the powerlines chopping through trees before coming to an began to spin to the right and descend. The abrupt halt.” pilot initiated an autorotation by lowering the when it began an Investigators determined that the pilot collective and placing the throttle in the idle likely lost control of the helicopter, which was position.” uncommanded in a steep descent with a high nose-down pitch The helicopter landed hard in an adjacent attitude when it struck the trees. The engine field. The patient was killed; the pilot, flight right turn. was producing power and the rotor blades were nurse and paramedic were seriously injured. turning on impact. “The reports of various wit- NTSB said that the probable causes of the ac- nesses indicated that the cloud was sitting on the cident were “the pilot’s improper decision to high ground in the Derrybrien area at the time maneuver in an environment conducive to a of the accident and that visibility was poor,” the loss of tail rotor effectiveness and his failure to report said. properly execute an autorotation.” ● www.flightsafety.org | AviationSafetyWorld | December 2006 | 63 OnRecord
Preliminary Reports
Date Location Aircraft Type Aircraft Damage Injuries Oct. 2, 2006 Decatur, Illinois, U.S. Learjet C-21 destroyed 2 none Winds were from 220 degrees at 17 kt, gusting to 20 kt, when the flight crew was cleared to conduct an “option approach” to Runway 24 during a U.S. Air Force training flight. The airplane, a military version of the Learjet 35, crashed on a taxiway and burned. Oct. 3, 2006 Tirana, Albania Boeing 737-400 none 113 none Soon after takeoff from Tirana for a scheduled flight to Istanbul, Turkey, the airplane was hijacked by an unarmed man who threatened to blow himself up if the flight was not diverted to Italy. The airplane was landed in Brindisi. Oct. 3, 2006 Tarakan, Indonesia Boeing 737-200 substantial 110 NA Visibility at the Tarakan–Juwata Airport was about 400 m (1/4 mi) in smoke from nearby forest fires when the airplane overran the 1,845-m (6,053-ft) runway on landing and came to a stop in a swamp. There were no fatalities. Oct. 5, 2006 Colville Lake, Northwest Territories, Canada Bell 206L substantial 1 minor, 3 none The pilot conducted an autorotative landing after a loss of engine power occurred during an approach to a remote landing site. One passenger received minor injuries. Oct. 5, 2006 Villamblard, France Agusta-Bell AB206A destroyed 3 serious The helicopter was in cruise flight in visual meteorological conditions (VMC) when it struck powerlines and terrain. Oct. 10, 2006 Stord, Norway British Aerospace BAe 146 destroyed 4 fatal, 9 minor, 3 none The airplane caught fire after running off the end of the 1,200-m (3,937-ft) runway while landing in VMC at the Stord–Sorstokken Airport. Oct. 11, 2006 Sosua, Dominican Republic Robinson R44 destroyed 4 fatal The helicopter was en route from the Playa Grande golf resort to Puerto Plata International Airport when a loss of control occurred while it was being maneuvered in unknown weather conditions. The two pilots and two passengers were killed. Oct. 11, 2006 Denver, Colorado, U.S. McDonnell Douglas MD-90 substantial 145 none The flight crew heard an unusual noise and observed a nose landing gear “UNSAFE” indication when they extended the landing gear on approach. After attempting unsuccessfully to resolve the problem, the crew landed the airplane on Runway 16R with the nose gear retracted. Oct. 15, 2006 Antlers, Oklahoma, U.S. Aero Commander 690A destroyed 4 fatal The airplane broke up in instrument meteorological conditions during a flight from Oklahoma City to Orlando, Florida. Recorded air traffic control radar data indicate that the airplane was cruising at 23,000 ft when it began a 180-degree left turn and a 13,500-fpm descent. Radar contact was lost at 15,100 ft. Oct. 18, 2006 Besancon, France Beech King Air 90 destroyed 4 fatal The airplane crashed during takeoff in nighttime VMC from La Veze Airport. Oct. 18, 2006 Perkinsville, Arizona, U.S. Piper Cheyenne III destroyed 5 fatal The tail section separated from the Cheyenne while it was being maneuvered below a MiG 21. Both airplanes had departed from Prescott for an aerial photography flight. The MiG pilot had a problem retracting the landing gear, and the Cheyenne pilot was visually checking the jet’s gear when radio contact between the pilots was lost. The Cheyenne crashed in desert terrain. The MiG was landed uneventfully, and no sign of contact with the Cheyenne was found. Oct. 25, 2006 Tulear, Madagascar Cessna 425 Conquest destroyed 6 fatal The airplane struck terrain and burned soon after takeoff in nighttime VMC. Oct. 26, 2006 Falsterbokanalen, Sweden CASA 212-200 destroyed 4 fatal All four crewmembers were killed when the airplane crashed in a canal and sank in 6 m (20 ft) of water during a research flight conducted by the Swedish Coast Guard. Oct. 29, 2006 Abuja, Nigeria Boeing 737-200 destroyed 104 fatal The airplane crashed and burned in a corn field soon after takeoff from Abuja International Airport.
NA = not available This information, gathered from various government and media sources, is subject to change as the investigations of the accidents and incidents are completed.
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for more than 50 years Wright Flyer photo/source: U.S. National Aeronautics and Space Administration
If your organization is interested in joining Flight Safety Foundation, we will be pleased to send you a free membership kit.
Send your request to: Flight Safety Foundation 601 Madison Street, Suite 300, Alexandria, VA 22314 USA Telephone: +1 703.739.6700; Fax: +1 703.739.6708 E-mail: [email protected] Visit our Internet site at www.flightsafety.org Flight Safety Foundation
19th annual European Aviation Safety Seminar EASS Staying Safe in Times of Change
March 12–14, 2007 Amsterdam, Netherlands
To receive agenda and registration information, contact Namratha Apparao, tel: +1 703.739.6700, ext. 101; e-mail: [email protected]. To sponsor an event, or to exhibit at the seminar, contact Ann Hill, ext. 105; e-mail: [email protected]. © Copyright 2006 Getty© Copyright Images Inc.