Human Factors Programs Vital To Enhance Safety in Maintenance

Air Safety Week, August 12, 2002

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.