Flight safety is mostly dependent on repair and maintenance issues which if it is not done correctly, it will lead to accidents at different scales. In comparison, among multiple threats in the aviation industry, tracing a technician’s faults in the repair and maintenance could be extremely difficult. Although most of the times, these errors remain unseen, uncorrected, and hidden and therefore have negative impacts on helicopter safety. Thus, analyses of these various factors which influence human performance help people to work in close collaboration with each other more effectively. In this study, we indented to identify human factors influencing repair and maintenance aviation industry and then evaluate the importance and impact degree of affecting factors on each other and helicopter accidents. In order to identify the human factors, some documents such as handbooks, standards, organizational procedures, and relevant literature in this area have been used. Given that the identified factors are not independent of each other and there is a casual relationship between them, a combined method using AHP and DEMATEL for evaluating and determining their importance was used. In this case, AHP determines the effects of factors on helicopter crash and DEMATEL method determines the effects of factors on each other. For this purpose, a questionnaire (comparison matrix) was distributed among some experts. The statistical population included all employees in technical areas, standards, design bureau, and technologies development. In this regard, a kind of survey has been performed with 15 experts in this field. After data collection and data analyses by using the proposed methods, the most important criteria in helicopter accidents was the standards of training and the less important one was related to repetitive and boring nature of these jobs. The other human factors such as fatigue, personal problems, and lack of resource including accessories and components have an equal importance. This study was an applied research adopting a correlational method and survey design.