Human Factors Programs Vital To Enhance Safety in Maintenance

NTSB member: 'We have a golden opportunity to take big steps.'
Maintenance mistakes are on the rise, and human factors programs are seen as the antidote to arrest and reverse the grim trend.

Human factors programs are more developed in other regions of the globe, but the Federal Aviation Administration (FAA) is expected soon to require that comparable programs be established in the U.S. aviation industry. Some of the more progressive U.S. carriers with maintenance human factors (HF) programs curtailed or eliminated them outright in the parlous economic circumstances that followed the Sept. 11, 2001, terrorist attacks.

There was virtually unanimous consensus at an Aug. 1 human factors in maintenance workshop that the cost of maintenance mistakes in accidents and incidents is simply unacceptable.

"We need to find a way to mitigate these maintenance mistakes," said John Goglia, a member of the National Transportation Safety Board (NTSB) and the organizing force behind the workshop. "No one comes to work to make a mistake, and most maintenance mistakes are caught before they cause major mayhem," Goglia said. However, the cumulative cost of maintenance error is nothing short of staggering. The death toll in accidents where maintenance error was a contributing or major factor runs to more than 2,000 lives, with insurance losses exceeding $3 billion. A tabulation of maintenance-related accidents acquires a certain brute impact by the sheer number of such accidents, so many of which stemmed from basic mistakes, non-compliance with proven procedures and inadequate oversight.

The trends may be even more sobering. Of the last 14 NTSB investigations of large aircraft accidents, maintenance was a major contributing factor in seven of them.

Despite growing evidence of the challenge to safety, views are mixed among U.S. aviation experts about the utility and cost-effectiveness of investing in HF programs. "We're struggling for economic survival while trying to provide safe transportation for our passengers. In the current environment, human factors in aviation maintenance is not that high a priority," said Ric Anderson of the Air Transport Association (ATA). His organization represents most of the major carriers in the United States.

Allyson Freyre, director of quality assurance at Alaska Airlines [ALK], expressed fervent support for HF, saying the revitalized effort at her carrier is seen as an essential part of its CASS (continuing analysis and safety surveillance) program. The January 2000 crash of Alaska Flight 261 is widely perceived as a maintenance-related tragedy; investigators have focused on improper maintenance of the jackscrew assembly controlling the horizontal stabilizer. In the wake of that accident, and faced with losing FAA approval to conduct and supervise maintenance, Alaska was forced to overhaul its moribund CASS program (see ASW, June 12, 2000 and July 3, 2000). CASS, it should be noted, is the one maintenance oversight program required by the FAA.

Aviation consultant David Marx reminded all concerned of the industry goal to reduce the fatal accident rate 80 percent by 2007. Reducing the maintenance error rate by 80 percent is essential if that goal is to be achieved, Marx cautioned.

The foreign experience
Some overseas experts share doubts expressed by U.S. officials like Anderson about the benefit to safety of HF in maintenance. "The promise of HF has not delivered," declared Nick McDonald, an aerospace psychologist at Trinity College in Dublin, Ireland. "Training for knowledge and awareness can dissipate over time, and training does not change the situation that exists in the first place," McDonald argued.

"I am convinced that many of these problems are deeply embedded in the organization," he said, referring to shortages of trained people, shortages of parts and time pressures. "Errors are system deficiencies, so we have to look at the systems," he said.

McDonald's skepticism, if not outright pessimism, was countered by Robin Wohnsigl, president of Air Canada Technical Services. "The money we've saved in reduced injuries, incidents and accidents has more than paid for our HF program," he said. As of this past June, 38 percent of his people were trained in HF, and 80 percent of those working in engine maintenance. The company is on track to complete HF training for all of its people by the end of 2003. As one example, Wohnsigl said workplace injuries already have dropped by 25 percent.

In the UK, the Civil Aviation Authority (CAA) has mandated that all organizations involved in aircraft maintenance, even down to small shops with as few as two people, will implement HF programs within three years. "It's probably the most popular rule we've issued," said David Hall, a CAA aircraft maintenance standards official.

Hall recounted that the CAA was galvanized into action by three UK accidents in which maintenance was an obvious factor:

Feb. 1995. British Midland B737-400. Oil pressure lost on both engines. Covers had not been replaced from borescope inspection the previous night, resulting in loss of almost all oil from both engines during flight.
Aug. 1993. Excalibur Airways A320. Uncommanded roll in first flight after flap change. Returned to land safely at Gatwick. Lack of adequate briefing on status of spoilers (in maintenance mode) during shift change.
June 1990. British Airways BAC1-11. Captain sucked halfway out of windscreen. Windscreen blew out under effects of cabin pressure; 84 of 90 securing bolts were smaller than the specified diameter.
"Incomplete and inaccurate maintenance data, procedural non-compliance, and poor planning of tasks, equipment and spares featured in all three of these incidents," Hall pointed out.

CAA officials conducted extensive interviews at all levels of maintenance in the British aviation industry. "Managers were saying, 'We need to do this, but my boss will not allocate resources unless you make it a requirement,' " Hall recalled.

"Many CEOs said, 'Your arguments are compelling but it has to be a requirement to ensure a level playing field. Make it a requirement for everyone and we'll do it.' "

The CAA made it so, although the tale is not quite that simple. Aircrew and human factors issues already led the CAA's "Top Ten" safety risk issues. Changes in corporate killing and manslaughter laws provided added impetus. "We used these changes to educate CEOs of their liability in the event of an accident," Hall said.

The CAA published Airworthiness Notice No. 71 in March 2000. This document encouraged those involved in aircraft maintenance to adopt a human factors program known as MEMS (maintenance error management system).

"What we were accomplishing through encouragement was sporadic and patchy," Hall recounted. We had to move to regulatory action, particularly to impact the smaller operations," he said. "We gave the message to industry that this is not a fad and is not going to go away - [so] be a part of it and help us develop practical rules that add value," Hall said.

The UK effort was done in concert with Europe's Joint Aviation Authorities (JAA). The JAA mandate for HF programs in maintenance affect 33 nations. "If the CAA wrote national rules on HF, they would only have been applicable to the UK industry. This way ensured a 'level playing field' across all of Europe," Hall explained. HF standards mandated by the International Civil Aviation Organization (ICAO) also meant that the changes "were inevitable," Hall recounted. The JAA effort was in response to the new ICAO requirements to address human factors in maintenance.

The new European (JAA) HF requirements should be effective as of October. Hall explained the timetable from that point forward:

"European organizations must be in compliance with the requirement to have all their staff trained and competent in applying human factors principles by July 1, 2005. Organizations will have to be in compliance with all the other new HF requirements (error management programs, etc.) by July 1, 2003."

The immediate future
The U.S. is behind.

The NTSB's Goglia said bluntly, "We have an opportunity to take big steps, and we're stupid if we don't take them."

Including HF as one of the essential elements of a CASS program may be one way to expeditiously incorporate it into U.S. practices, Goglia surmised. "There is industry support to do that, and my sense is the FAA will go in that direction," he added. Under section 121.373 of the Federal Aviation Regulations (FARs), every "certificate holder" (which includes airlines and separate repair facilities) is required to have a CASS program. The requirement empowers the FAA administrator to "make any changes in [certificate holders'] programs that are necessary to meet those requirements."

By this provision, Goglia believes the FAA can implement HF programs without having to embark on a lengthy rulemaking process. "The [existing] rule says the FAA will set the parameters of CASS, so human factors can be a parameter," he said.

Mike Spinks, a maintenance technician at US Airways, said the concept "can be sold on the basis of return-on-investment."

"If it were mandated, we'd still have it at US Airways," he added. His carrier was one of those that curtailed its HF program as the industry plummeted into dire economic circumstances after the Sept. 11, 2001, attacks.

Marx said incorporating HF into CASS offers only a partial solution. "We have a culture of non-compliance in aviation maintenance, [because] the voluntary disclosure programs discourage honest reporting."

"You cannot self-disclose in ASAP [aviation safety action program] that you violated a procedure. Even if it's a wrong 1968 procedure, you face penalties and possible loss of your license," he said.

(ASW note: The FAA Office of Aviation Medicine maintains a comprehensive website on human factors in maintenance. See http://HFSKYWAY.faa.gov ) Goglia, e-mail gogliaj@ntsb.gov; Marx, e-mail david@davidmarx.com; Freyre, e-mail Allyson.Freyre@AlaskaAir.com; Hall, e-mail david.hall@srg.caa.co.uk

Is Safety Really the Number 1 Priority?
Observations of David Hall, UK Civil Aviation Authority, Aircraft Maintenance Standards Department:

Most companies will state that safety is their number one priority.
In reality, this is not always demonstrated when there are problems. Production is the first concern.
Organizational processes tend to be weighted in favor of releasing the aircraft or component to service.
Safety is considered as another business risk.
The Trends Are Sobering
Human Factors in Aircraft Maintenance and Inspection:

In the first three years of the 1990s there were 25 accidents involving maintenance concerns. This compares with seven in the first three years of the 1980s.
The increase ... involving maintenance concerns appears to be at least statistically significant. In the last ten years, the annual average has increased by more than 100% while the number of flights has increased by less than 55%.
Traditionally, human factors endeavors have been directed towards flight crew performance ... available literature showed little consideration of the human factors issues which could affect aircraft maintenance personnel.
Aircraft have become more automated and more complex. The current generation of Boeing 747-400s and Airbus A340s has duplicated or triplicated flight management systems. This may have reduced the burden on the flight crew but it has placed a greater demand on aircraft maintenance technicians, many of whom acquired their basic training in mechanical rather than computerized control systems.
In short, complexity acts to shift errors to other people.
Source: UK CAA, Report No. CAP 718, April 2002

'Adopt the Concept'
UK CAA Airworthiness Notice No. 71, March 20, 2000 (extracts)

Introduction. Maintenance errors with serious consequences such as accidents or incidents are routinely investigated ... below these levels are events without operational significance which may rarely be investigated (e.g., the omission of an oil filler cap which, by chance, is noticed and corrected before flight). In order to gain a better understanding of the problems and factors which contribute to errors, it ... is important to examine not just what happened, but why it happened in order to determine the root causes and problems [emphasis in original].

With the issue of this Notice, the CAA is declaring its policy on ... MEMS [maintenance error management system] such that maintenance organizations ... are encouraged to adopt the concept.

Assurances. A MEMS will not be subject to auditing as part of CAA regulatory oversight.

The CAA will not require any organization or individual to make available ... specific reports that are submitted under a MEMS, other than information normally reported ... via the MOR [mandatory occurrence reporting] scheme.

If an organization, in the interests of improving safety, voluntarily elects to share with the CAA the details of a specific occurrence reported under MEMS, the CAA will ... not disclose the name of the person submitting the MEMS report ... nor pass on a MEMS report to a third party unless required to do so by law or unless the person(s) concerned authorizes such disclosure.

Mayhem from Maintenance Mistakes
The toll in aircraft and people from mainteance mistakes has been enormous. Below is a partial listing that focuses on fatal accidents. For the full listing, go to http://www.aviationtoday.com/reports/081202mistakes.htm

The tally: 2,400 killed, 90 injured. Insurance losses of $3 billion at the time in hull and passenger (pax)/third party settlements. Does not include uninsured losses. Insurance losses would be far greater if these events happened today due to significant increases in liability settlements over the years.

May 25, 2002. China Airlines B747-200. Structural failure at top of climb to cruise altitude. Crash into Taiwan Strait. Repair of previous tailstrike used steel doubler, prohibited by structural repair manual. Preliminary findings suggest shortcomings in supplemental structural integrity program (SSIP) to ensure airworthiness of high-time aircraft. Toll: 225 killed.
Aug. 24, 2001. Air Transat A330. Improper engine repair; resulting leak from cracked fuel line caused duel engine flameout at cruise over Atlantic. Glided 135 miles to emergency landing in Azores. No serious injuries.
April 26, 2001. Emery Worldwide Airlines DC-8-71F. Left main landing gear would not extend for landing. Probable cause was failure of maintenance to install the correct hydraulic landing gear extension component and the failure of inspection to comply with post-maintenance test procedures. No injuries.
March 20, 2001. Lufthansa A320. Cross-connected pins reversed the polarity of captain's side stick. Post-maintenance functional checks failed to detect the crossed connection. Aircraft ended up in 21� left bank, almost hitting the ground. Co-pilot switched his side-stick to priority and recovered the aircraft. No injuries.
Jan 21, 2001. Emirates B777. Uncontained engine failure during takeoff caused by loss of one of 26 low-pressure compressor blades. Incident led to shortened inspection intervals, need for more attention to dry lubricant application and blade redesign. No serious injuries.
July 25, 2000. Air France Concorde. During takeoff the front right tire of left landing gear ran over a strip of metal, which had fallen off preceding DC-10, causing tire blowout, loss of two left engines and fire. Spacer improperly installed in left gear of Concorde. Toll: 109 pax and crew, plus 4 killed and 6 injured on ground.
Feb. 16, 2000. Emery Worldwide Airlines DC-8-71F. Crashed attempting to return to Rancho Cordova, Calif. Right elevator control improperly installed. Toll: 3 crew killed.
Jan. 31, 2000. Alaska Airlines MD-83. Crashed in Pacific Ocean near Port Hueneme due to loss of horizontal stabilizer believed to have been aggravated by failure to lubricate jackscrew assembly controlling pitch trim. Toll: all 88 aboard killed.
Oct. 7, 1998. Continental Airlines B727. Catastrophic failure of the 8th stage high-pressure compressor disk from cadmium embrittlement as a result of improper adherence to prescribed procedures. No injuries.
Aug. 7, 1997. Fine Air DC-8-61F. Crashed on takeoff at Miami. Aircraft was improperly loaded, creating aft center of gravity and corresponding incorrect stabilizer trim setting. Pilots unable to counter extreme pitch-up on rotation. Toll: 5 killed.
May 21, 1998. Continental Airlines, DC-10-10. Autopilot malfunction caused the aircraft to begin a sudden uncommanded 2G pull-up, with the control yoke moving rapidly to the left. The cause was a contaminated strain gage, which resulted in excess elevator actuation during recovery by the captain. Toll: 3 crew and 1 pax seriously injured.
Jan 21, 1998. Continental Express ATR-42. Fire in right engine during landing, due to improper overhaul of lugholes in the fuel/oil heat exchanger. No serious injuries.
June 7, 1997. Continental Airlines, B727. Unqualified maintenance employee drove aircraft into the terminal. No injuries.
Sept. 27, 1997. Continental Airlines B737. Separation of aileron bus cable forced the crew to return to the airport shortly after takeoff. Separation was caused by wear in the cable and inadequate inspection of same. No serious injuries.
March 18, 1997. Continental Airlines DC-9-32. Failure of maintenance personnel to perform a proper inspection of the combustion chamber outer case, allowing a detectable crack to grow to a length at which the case ruptured, causing uncontained failure of right engine. No injuries.
Dec. 22, 1996. Airborne Express DC-8-63F. Struck mountainous terrain. Contributing to the accident was the inoperative stick shaker stall warning system. Toll: all 6 on board killed.
Nov. 1996. A320 (operator unknown). Both fan cowl doors detached from No. 1 engine during rotation. Doors likely had been closed but not latched during maintenance. According to UK investigators, "Similar incidents have occurred on at least seven other occasions."
July 17, 1996. TWA Flight 800, B747. Fuel/air explosion due to inadequate maintenance on an aging fleet and noncompliant parts. Toll: all 230 pax and crew killed.
July 6, 1996. Delta Air Lines MD-88. Uncontained engine failure on takeoff due to inadequate parts cleaning, drying, drying, processing and handling. Toll: 2 pax killed, 2 pax seriously injured.
May 11, 1996. ValuJet Airlines DC-9-32. Fire in cargo compartment initiated by actuation of one or more improperly packaged and stowed oxygen generators. Toll: all 110 pax and crew killed.
Aug. 21, 1995. Atlantic Southeast Airlines EMB-120. In-flight fatigue fracture and separation of propeller blade. Toll: 8 pax and 1 crew killed, 10 pax and 2 crew seriously injured.
June 8, 1995. ValuJet Airlines DC-9-32. Maintenance technicians failed to perform a proper inspection of the 7th stage high compression disk, allowing a detectable crack to grow to a length at which it ruptured. Toll: 1 crew seriously injured.
Feb. 1995. British Midland B737-400. Oil pressure lost on both engines. Covers had not been replaced from borescope inspection the previous night, resulting in loss of almost all oil from both engines during flight. Diverted and landed safely. No injuries.
March 1, 1994. Northwest Airlines B747. Narita, lower forward engine cowling ground away as dragged along runway. During maintenance, the No. 1 pylon diagonal brace primary retainer had been removed but not reinstalled. No injuries
Aug. 1993. Excalibur Airways A320. Uncommanded roll in first flight after flap change. Returned to land safely at Gatwick. Lack of adequate briefing on status of spoilers (in maintenance mode) during shift change. Locked spoiler not detected during standard pilot functional checks. No injuries.
Sept. 11, 1991. Continental Express Airlines, EMB-120. Horizontal stabilizer separated from fuselage during flight because maintenance personnel failed to install 47 screw fasteners. Toll: all 14 pax and crew killed.
July 11, 1991. Nation Air DC-8-61. During takeoff, tires and wheels failed on left main undercarriage. Fire developed in main wheel well causing loss of hydraulics and loss of control. Toll: all 261 pax and crew killed.
May 26, 1991. Lauda Air B767. Uncommanded deployment of thrust reverser in climb out from Bangkok. Numerous thrust reverser fault messages in weeks preceding accident flight. According to Thai accident report, the carrier "did not seek assistance from Boeing or Boeing's Vienna-based field service representative. Boeing considers these removals and interchanges as ... ineffective in resolving the cause of the [fault] messages, and not per FIM (fault isolation manual) direction." Accident triggered modifications to thrust reverser. Toll: 223 pax and crew killed.
Aug. 21, 1990. United Airlines B737. Flashlight left by maintenance, sandwiched between cargo floor and landing gear retract/extend linkage, caused crew to make a gear up landing. No injuries.
June 1990. British Airways BAC1-11. Captain sucked halfway out of windscreen. Windscreen blew out under effects of cabin pressure; 84 of 90 securing bolts were smaller than the specified diameter. Toll: 1 serious injury.
July 19, 1989. United Airlines DC-10-10. Catastrophic failure of No. 2 tail mounted engine during cruise. Airplane broke apart and burst into fireball during attempted emergency landing at Sioux City, Iowa, without hydraulic power. Toll: 111 pax and crew killed, 46 pax and crew seriously injured.
Feb. 24, 1989. United Airlines B747. Explosive decompression of cargo door. Toll: 9 pax killed, 2 pax and 3 crew seriously injured.
April 28, 1988. Aloha Airlines B737. Explosive decompression; inadequate inspection/repair of lap joint. Toll: 1 cabin attendant killed, 7 pax and 1 crew seriously injured.
Aug. 12, 1985. Japan Air Lines B-747SR. Improper repair of aft pressure bulkhead led to sudden decompression in flight that damaged hydraulic systems and vertical fin. Aircraft struck Mt. Ogura. Toll: 520 pax and crew killed; 4 surviving pax injured.
May 1983. Eastern Airlines L-1011. Loss of all power from improperly fitted O-ring seals. Aircraft landed on one engine. No injuries.
May 25, 1979. American Airlines, DC-10. Separation of No. 1 engine and pylon assembly on takeoff at Chicago's O'Hare. Toll: all 298 pax and crew plus 2 killed and 2 seriously injured on the ground.
Sources: NTSB, CAA, Airclaims

AIRWORTHINESS NOTICE - B058, EDITION 3 - 15 JANUARY 2002

GUIDELINES FOR THE INTRODUCTION OF HUMAN FACTORS TRAINING REQUIREMENTS INTO THE CANADIAN AVIATION REGULATIONS (CARS)

Purpose

This Airworthiness Notice provides the aviation industry with information regarding the introduction of human factors training requirements into the Canadian Aviation Regulations (CARs). This edition includes clarification on several issues raised by the aviation maintenance community.

GUIDELINES FOR THE INTRODUCTION OF HUMAN FACTORS TRAINING REQUIREMENTS INTO THE CANADIAN AVIATION REGULATIONS

Chris this sounds very promising. I hope that the US (FAA) will follow Canada's lead. Thanks for the update.

I was going through the old sr111 board looking for a particular post and thought this was relevant to this discussion of maintenance and human factors:

One of the great opportunities for maintenance
mistakes and oversights occurs in that brief period of
time between shift changes of maintenance personnel,
cautioned National Transportation Safety Board member John
Goglia. Speaking at a March 11 conference in Miami, Fla.,
Goglia offered a tour de force of cases where improperly
maintained engines, wrongly installed engines and leading
edges, not to mention other maintenance errors, have led
to embarrassments (e.g.engine dangling from a 747),
crashes and deaths. In many cases, the mistakes occurred
when the precise nature of the work remaining to be
done was not passed clearly to the relieving shift.
More broadly, Goglia said the "walls up between
maintenance and management, and between flight crews and
management" impede communications that could reduce errors
and enhance safety. Describing the industry as akin
to a collection of vertical silos, Goglia advised,
"We should be working hard to clean up these
communications issues."