Human Factors in Airline Maintenance: A Study of Incident Reports


Maintenance incidents contribute to a significant proportion of worldwide commercial jet accidents, yet until recently, little was known of the nature of maintenance incidents and the factors which promote them.

In face-to-face interviews, maintenance technicians were asked to report examples of maintenance incidents which they had experienced first-hand. Eighty-six incident reports were recorded.

Human factors were involved in most of the reported incidents, with workers on duty between the hours of 0200 and 0400 having a greater chance of having an incident than workers on duty at other times of the 24-hour clock. The frequency of incidents increased as the shift progressed up to the second-last hour, after which the frequency of incidents diminished.

For those incidents which had the potential to affect the airworthiness of an aircraft, difficulties with procedures emerged as the most significant factor. This included misunderstandings and ignorance of procedures.

For those incidents which had the potential to affect the health and safety of workers, difficulties with tools and equipment emerged as the most frequent factor.

The majority of the human errors involved in incidents were rule-based mistakes, many relat-ed to mistaken assumptions. Absent-minded slips and lapses were involved in approximately one-third of the incidents.

The final section of the report contains suggested safety actions, intended firstly to reduce the frequency of human error and maintenance incidents and secondly, to reduce the conse-quences of any such errors which do occur.

Type: Research and Analysis Report
Publication date: 14 June 1997
ISBN: 0 642 25639 X
Last update 07 April 2014
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