Approximately 80% of all aviation accidents occur shortly before, after, or during take off or anding, and are often described as resulting from 'human error'. So how much of this percentage does human error in maintenance contribute and how can it be curbed ?

A Convair 240 takes off from La Aurora International Airport (GUA/MGGT) near Guatemala City, as scheduled. During the initial climb to cruise altitude, the number one engine suffers a failure due to oil exhaustion. The crew is unable to feather the propeller and is forced to attempt an emergency landing in rough terrain. The plane is destroyed in the attempt, killing all 22 passengers and six crews on board. The Government of Guatemala initiates a full investigation. It is found out that the aircraft had undergone maintenance shortly before the flight. In order to perform this maintenance, it was necessary to disconnect a high-pressure oil hose from the engine cylinders. The latter had not been correctly reattached, thus starving the engine of oil.

British Airways Flight 5390 is a regular British Airways flight between Birmingham International Airport in England and Màlaga, Spain. On June 10, 1990 an improperly installed pane of the windscreen faits, blowing the plane's captain halfway out of the aircraft, with his body firmly pressed against the window frame. The flight crew manages to perform an emergency landing in Southampton with no loss of üfe. Accident investigators find out that a replacement windscreen had been installed 27 hours before the flight, and that the procedure had been approved by the Shift Maintenance Manager. However, 84 of the 90 windscreen retention bolts were 0.026 inches (0.66 mm) too small in diameter, while the remaining six were 0.1 inches (2.5 mm) too short. The investigation reveals that the previous windscreen had been fitted with incorrect bolts, which had been replaced on a"like for like" basis by the Shift Maintenance Manager without reference to the maintenance documentation. The air pressure difference between the cabin and the outside during the flight proved to be too much, leading to the failure of the windscreen.

Nigeria Airways Flight 2120 was a McDonnell Douglas DC-8-61 C-GMXQ owned by Canadian airline Nationair and chartered by Nigeria Airways to transport Nigerian pilgrims to and from Mecca. On 11 July 1991 the aircraf catches fire and crashes shortly after takeof from king Abdulaziz International Airport, Jeddah, Saudi Arabia, killing all 261 on board including 14 Canadian aircrew. The cause of the crash is found out to be under-inflated tires, which in turn cause overheated tires to catch fire leading 0o failure of hydraulic systems and eventual in-flight break-up of the aircraft short of making an emergency landing.

The table above is compiled from the PlaneCrashinfo.com accident database and represents 1,843 fatal accidents involving commercial aircraft,world wide,from 1950 through 2006 foe which a specific cause is known. Military, private plane, helicopter and small air taxi accidents are Dot included. After simple addition, it is known that out the 1.843 fatal accidents,only 701 had known specific causes. This gives a 38% efficiency investigation rate for the investigator assigned to investigate the 1,843 accidents. Of the 7O1 accidents of known specific causes, 50 were caused by "Other Human Error" This implies that "Other Human Eror" caused only 7% of all accidents of known specific causes. mindful that "Other Humann Error" includes air traffic controller error ,improper loading of aircraft fuel contamination and improper maintenance procedures, you may want to know, through deductive reasoning that one can safety say fewer than 2% of fatal aviation accidents identified maintenance error as a causual factor. Thus one can arguably conclude that mechanicsare generally very assiduous in their duties?

The Human Factors Interventions Safety Management of Vancouver identifies 7 key elements of error management. They argue that a fair , just and disciplined system facilitates individul reporting. Furthermore, an employee's honest participation in event investigation should not be deemed as an accusatory!and blame session but rather as a good learning experience and prevention mechanism. They request metrics and tracking along with a feedback awareness process which ensure results are communicated to the frontline. A corrective action process and human factors awareness training will also go a long way to assuage accidents ,they postulate.12 factors which could be a productive prevention strategy called "The dirty Dozen'were also considered. They include lack of communication, complacency, lack of knowledge, distraction, lack of teamwork, fatigue,lack of ressources, pressure, lack of aassertiveness,stress, lack of awareness and norms.

The above if properly tackled by management and employees, will greatly reduce the potential of future errors. Nonetheless these human errors notwithstanding, air transport remains the safest means of travel in the world today and is an experience no one should be affraid of.Statistics from the National Transportation and Safety Board (NTSB) of the U.S.A. noted that the death risk was one in 2million comparedto the one in 5,OO0 chances cf dying in a motor vehicle accident. In fact, air travel is even safer than travelling in a train, wherethe odds of dying are one in 400,000 but this will be left an argument for anotherday.