Safety Analysis for the Civil Aircraft Emergency Door Based on Latent Failure and Multi-failure Mode Coupling

Abstract

The emergency door on the wing of a civil aircraft has particularity,and its fault is somewhat concealed,so it is particularly important to analyze its safety reasonably.The evaluation and selection principles of the latent failure of the emergency door are defined,and the exposure time of the latent failure is considered in the solution procedure of the failure probability of the bottom event.The fault tree of accidental opening of emergency door in flight is established.The bottom event of“the latch axis movement being not in place caused by tolerance accumulation”,which is generally constructed,is considered as the mechanism movement not being in place caused by the joint action of tolerance accumulation and structural wear.The modeling technology of fault tree bottom event is refined,and its safety is analyzed.The results of reliability analysis before and after fault tree refinement are compared.The results show that the refined fault tree is more in line with the engineering practice,and the reliability analysis result of emergency door is more accurate.

Keywords

• latent failure
• emergency door
• safety
• multi-failure mode
• reliability