Aircraft Mechanic Fatigue and Its Effects on Aircraft AccidentsAircraft Mechanic Fatigue and its Effects on Aircraft AccidentsMajority of aircrafts accidents are blamed on human error, specifically the pilots and mechanics. This concern has been widely discussed in the aviation industry and among aviation professionals for so many years. Of this percentage of aircraft accidents, fatigue cases of mechanics and engineers are known to have caused them. This human factor has been one of the main issues on the list that usually result in bad performances. While pilots are under strict regulations and get detailed instructions on dealing with human factors that affect flight safety, aviation engineers and mechanics receive less attention. Aircraft mechanics are usually expected to work long hours most of which involve working late hours, not to mention overtime. In fact, many of them are on-call 24/7 like doctors. When an Aircraft on Ground (AOG) situation happens, aircraft mechanics are not allowed to leave the airplane until the malfunction is fixed. While pilots may sometimes get to rest during long flights, fatigue has always been a very critical problem for the technical staff because they are always under pressure to get the airplane back into safe flying condition as soon as possible. The growing number of operations significantly stretches the need for more human resources. In order to have high quality of services, mechanics are forced to work more hours. This may pave the way for them to skip completing checklists and choose to take shortcuts so that their tasks are done faster. This prospect is very worrisome for many concerned individuals and agencies. As the aircraft workforce heads toward shift work and alternative work arrangements, the danger of possible fatigue-related errors also increase. Changes in shift and working rotating or midnight shifts are leading causes of fatigue. Aircraft mechanic fatigue continues to be a significant contributing factor in accidents and incidents. In the absence of appropriate regulations, aviation maintenance workers and their supervisors have to be extra careful and sensitive for signs of fatigue.
Aircraft Accidents Blamed on Mechanic FatigueWhen British Airways Flight 5390 underwent a windscreen blowout minutes before it left Birmingham International Airport in June 1990, investigations reported several factors of which a major one was the fatigue that the mechanic who worked on the window experienced. The windscreen which was replaced before the flight was blown away and the cabin pressure sucked the pilot halfway out the open window. He was held on to by the co-pilot and later by the cabin crew until the airplane had to make an emergency landing at Southampton Airport. About 90 bolts were not able to restrain the cabin pressure. The aircraft mechanic who did the task worked very early in the morning when the human body is naturally low (circadian or time of
0) and during the following morning when the engine was still in the high position. The only change to the mechanical actuation was to shorten the left shift switch and raise the steering and aileron (an auxiliary instrument) movement. He performed the necessary maintenance and safety operations, including a check to make sure that a mechanical issue still existed. It is difficult to determine how many mechanical failures were attributed to his incompetence, although some of the circumstances were clearly explained. He also had the experience of being fired over a year before any mechanical issues occurred, when a pilot was fired (even though he was in fact performing his work on the time). The aircraft experienced a number of significant mechanical problems that might have had an influence on a manual action of the pilot in order to perform its normal flight and to maintain the air conditioning on. There have been reports that a mechanical issue may have led to an engine problem in many cases; that engine has been removed with a few hours of hard work and a few drops of water. Some of the problems the airplane experienced with that type of equipment that requires manual or automatic action may have been caused by problems other than the problem with the computer switch. In one of the worst cases in history, a mechanical problem could have interfered in a large number of flights without the pilot acting first. As an example: a mechanical problem involving the control panel of my old Piper A320 had occurred in the 1970’s, when some pilot attempted to check in for a passenger in the aisle, but had to try again soon after his attempt to check in by changing the manual switches on the pilot control panel (a very unusual situation in aviation). The crew and their members were able to change the control panel on the pilot control panel but not on the airplane, without the aircraft or at least knowing that it was on the airplane (it was a small plane, so only the pilot and the co-pilot knew the flight was on the plane). The aircraft mechanic in charge of the aircraft who did this job (the crewmember) saw through the problem and did nothing. All in all, the plane did not have much power on a small jet plane, but it did have a great deal of power on Boeing 707s which have a 5-ton propeller (the wingtips for the aircraft are mounted on the side of the plane with the propeller in a position that requires both wingtip and rudder). The pilots were not very fast at handling large numbers of airplanes and in many cases the autopilot was out of mode. Other reasons for having a problem with the aerodynamic system of the airplane in terms of the engine and the operating conditions included the pilot’s inability to use his hand at all, a lack of stability, and fatigue. Some pilots in the company who had these problems have blamed their own inexperience for the problems they experienced, although the situation is probably more complicated for this issue than for other problems (such as a sudden failure to respond to a command). The problem usually resulted from a malfunction of the controls that occurred on the ground over