Sensitivity analysis for aviation insecure event using Monte-Carlo method under uncertain conditions

To solve the problem of sensitivity analysis of aviation insecure events under uncertain conditions, this paper proposes the aviation safety index and its sensitivity measurement based on the Bow-tie model. Taking the tire burst accident as an example, we calculate the aviation safety index, the global sensitivity for basic event and its local sensitivity for distribution parameters using Monte-Carlo method. According to the simulation results of the tire burst accident, both types of sensitivity indexes vary with the increasing flight hour, and the most significant change appears during 500-600 h, but with the same order of index importance. The type of basic events is the main factor affecting sensitivity, for the sensitivity of electronic events is far less than the mechanical events. In the uniform type of basic events, the mean time before failure is not the leading factor affecting the sensitivity, which has a close relationship with the failure transferring logic. The results of this example demonstrate that the safety index descends with the flight hour, and the focus for improving aviation safety is to pay attention to accident caused by aviation components failures in 500-600 h. The importance of sensitivity will not change with the flight hour, and the key of preventing aviation accident is to improve the degree of reliability for basic events with a higher sensitivity.