error. “A maintenance activity that may have caused an incident could have taken place days, weeks or even months before the incident occurred,” he explains. Without a comprehensive log of the technician’s duty schedule and amount of rest, there is no way of clearly judging fatigue’s role.
Everglades,” says Dr. Mark Rosekind, one of the NTSB’s five board members. He references the infamous Flight 592, in which mishandled, hazardous materials in a DC-9’s cargo hold caused a fire and crash that took 109 lives in May 1996. In fact, across all means of transportation, the NTSB has made more than 200 recommendations regarding fatigue, according to Rosekind. Incidents in addition to the ValuJet crash add fuel to the argument that aircraft-engineer fatigue can cause maintenance errors. Dale Forton, president of the Professional Aviation Maintenance Association (PAMA) offers as another prime example British Airways Flight 5390, in which the aircraft’s captain was nearly blown out of an improperly installed windscreen panel in June 1990. An employee responsible for the windscreen’s installation “was off work for a couple of weeks, then went on the night shift,” says Forton, adding, “the work was done while [the employee] was apparently fatigued.” A research and analysis report (AR-2008- 055) by the Australian Transport Safety Bureau reveals still more examples of aircraft accidents pointing to maintenance error brought by fatigue. These include: • The Japan Airlines Boeing 707-100 that, in August 1985, crashed into a mountain after a failure of the rear pressure bulkhead allowed air to escape and damage flight- control components. • The Eastern Airlines Lockheed L-1011
Beyond the Incidents Rosekind notes that 70 to 80 percent of all accidents are “because of human error.” He adds, that “all humans need sleep” and that in assessing human error, “we’ve grossly underestimated the fatigue factor.” Anecdotal evidence from accident investigations doesn’t give the full scope and makeup of the fatigue issue, however. A more complete perspective derives from in-depth studies, such as ones by Dr. Terry von Thaden, president of Illumia Corp., a consulting and research firm, and by Marco Giovannoli, field service representative with Airbus. Giovannoli submitted his study early this year for his Masters degree in aircraft maintenance management at City University London. Thaden, who also is a professor at the University of Illinois, conducted her survey last summer. (Of note, the University of Illinois decided in 2011 to close its 50-year-old aviation program, where she formerly taught.) There are as many contributing factors to maintenance-personnel fatigue as there are symptoms. Long working hours is an obvious factor. Thaden discovered that more than half (56 percent) of the nearly 2,500 aircraft- maintenance professionals who responded to her survey work 40 to 80 hours a week, and 12 percent said they hold second jobs. Giovannoli found that 11 percent in his survey spend extra time in academic pursuits.
Logging 12- to 16-hour shifts is common
Dr. Mark Rosekind, National Transportation Safety Board Member
that, in 1983, had to land on one engine because magnetic chip detectors were installed without O-rings, causing oil leaks; and • The Aloha Airlines Boeing 737 that had cabin skin pealed away; maintenance personnel failed to detect significant disbanding and fatigue damage. “[Maintenance-personnel] fatigue could have played a much greater role in incidents than we know of,” says Rosekind. He defines the main challenge NTSB investigators face when trying to determine what role technician fatigue might play in maintenance
20 Aviation Maintenance |
avm-mag.com | June / July 2012
in aircraft maintenance. Giovannoli’s research found that 27 percent of aircraft maintenance professionals he surveyed reported six to 12 extra hours of weekly overtime and seven percent put in 13 to 18 extra hours.
When Thaden asked if survey respondents
felt tired while working the week previous to their interviews, 17 percent said they were fatigued all seven days and only 10 percent said they felt no fatigue. Who requests’ overtime? Giovannoli found that “33 percent said it is a manager’s request.” But technicians are often more than willing to put in more hours for extra income. (AM asked Transport Workers Union of America [TWU] its view of fatigue and crew duty time but received no reply.) “Both management and labor have the best intentions, but workers want
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