Description:
ASRS maintenance reports from 1996 through 2000 (n = 937) were subjected to posterior probability analysis to determine the probability of causal factors leading to a specific maintenance‐related event. Unintentional release of an unairworthy aircraft into revenue service was found to be the most frequent maintenance‐related event (40 per cent). The top three maintenance errors leading to such an event were improper documentation (33 per cent), improper installation (27 per cent), and sign‐off of work not performed (13 per cent). The probabilities of certain causal factors responsible for each of the maintenance errors were as follows: (a) For documentation errors – lack of awareness (22 per cent), poor procedures (15 per cent), and lack of training (4 per cent); (b) For improper installation – complacency (21 per cent), lack of awareness (21 per cent), and poor procedures (15 per cent); and (c) For sign‐off of work not performed – maintenance management (27 per cent), complacency (21 per cent), and poor procedures (14 per cent).