Abstract-The technology used in aviation has changed markedly over the past 50 years, particularly in terms of its reliability. Researches has shown that the internal reliability of humans has not improved noticeably over the same period. Thus engines, airframes and aircraft systems have contributed progressively less to the accident rate, the proportion of accidents attributable to human error has necessarily increased [1]. According to International Ergonomics Association [2] "Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance". "The overall goal of Aviation Maintenance human factors research is to identify and optimize the factors that affect human performance in maintenance and inspection" [3]. Human factors affect the quality of the jobs performed by the aircraft maintenance technicians, pilots and flight engineers.The aircraft maintenance technician is the center part of the aircraft maintenance system. It is very important to understand how human body and mental process function and how performance limitations can influence a technician"s effectiveness at work [4].Several factors can affect a maintenance technician"s performance. A person"s vision, hearing, information processing, attention and perception, memory, judgement and decision making are among the physical and mental human performance characteristics which are likely to affect the quality of his work.Stress, time pressure, workload, fatigue, distraction, overconfidence, lack of communication and awareness etc. may affect a technician"s performance. In this study, the impacts of stress on the quality of the work performed by an aircraft maintenance technician are investigated. Some aviation accidents, for which this factor is causal or contributory, is studied along with the desired requirements in aviation legislation. Thus, it has been tried to emphasize the importance of human factors in aircraft maintenance. It is expected that these studies on human factors and accidents will induce more research work on aviation safety.