Why Do Aircraft Maintenance Engineers Commit Errors?

Sofema Aviation Services (www.sassofia.com) provides an overview of the issues and challenges.

Knowledge Related Errors

As a “Group” aircraft maintenance engineering staff have a strong belief in their self-determination, unfortunately, this can often become a pre-cursor to a maintenance error.

Example – Where maintenance staff is not aware that their knowledge has been superseded in a particular circumstance – For example where a referenced technical procedure has been changed, but not positively communicated.

Maintenance Errors linked to Documentation

Typical errors which are linked documentation break down into two areas:

a) Failure to use the documentation

Essentially performing the task without reference to the applicable maintenance DATA

b) Issues with the content of the documentation

Paying insufficient attention to the technical content and committing an error

For example, they perform what is essentially a familiar action, but it is performed incorrectly or they fall back and rely on their own knowledge, instead of seeking clarification or additional technical guidance from appropriate documentation.

When providing anonymous feedback maintenance staff have confirmed they have at times:

a) Performed a task using an alternate (their own) procedure


b) Performed a task in a way that did not conform to the formal procedures.

Contributing factors related to incorrectly performing a task

a) Information not understandable,

b) Information incorrect,

c) Information not enough,

d) Information not used and

e) Information unavailable

f) Missing procedural steps

g) An incorrect sequence of steps

h) Inadequate procedures for inspection and troubleshooting

i) Incorrect technical information or Drawings / Diagrams

Document Deficiency as a Precursor

Investigation revealed the following errors committed by Maintenance Personnel:

a) Failure to read/follow

b) Information Missing or Lost and not retrieved

c) Error / Omission during Inspection

d) Documentation or Log Book Error

Maintenance Engineers deliberately not following procedures because they are believed to be

a) Inaccurate

b) Out of Date

c) Not Workable in Practice

d) Make the task harder

e) Overly Restrictive

f) Too time-consuming

g) Not possible to complete the task in time if done I.A.W the Task Procedure

h) I know a better way!

i) The procedure not easily understood or relevant information difficult to find within the procedure

The Primary Reasons that Maintenance Engineers deviate from Standard Procedures can be summarised as follows

1/ If I followed the job to the letter, the job would not get done.

2/ I was not aware that this procedure exists.

3/ I prefer to rely on my own skills and experience.

4/ I know the procedure so do not need to look up the technical information

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