Human Factors in Aircraft Maintenance
A survey designed to identify safety issues in maintenance, with a particular emphasis on human factors, were distributed to Licensed Aircraft Maintenance Engineers (LAMES) in Australia.
As a result the Australian Transport Safety Bureau has provided the following analysis, conclusions and recommendations.
Table 1. Outcome of Safety Occurrences
|System operated unsafely during maintenance||18%||7%|
|Incomplete installation, all parts present||8%||9%|
|Person contacted hazard||7%||9%|
|Vehicle or equipment contacted aircraft||7%||1%|
|Incorrect assembly or orientation||6%||11%|
|Material left in aircraft||4%||5%|
|Part damaged during repair||4%||2%|
|Panel or cap not closed||3%||3%|
|Incorrect equipment/part installed||3%||4%|
|Part not installed||3%||6%|
|Required servicing not performed||3%||4%|
|Degradation not found||3%||5%|
Table 2. Occurrences Factors
|Unsafe Acts in Occurrences||Airline||Non-airline|
|Trip or fumble||9%||11%|
|Failure to check||6%||2%|
|Failure to see||5%||6%|
|Lack of equipment||8%||3%|
Definitions of Occurrence Outcomes
- System operated unsafely during maintenance
- Activating an aircraft system such as flaps or thrust reversers when it was not safe to do so, either because personnel or equipment were in the vicinity, or the system was not properly prepared for activation.
- Towing event
- A safety occurrence which occurred while an aircraft was under tow.
- Incomplete installation, all parts present
- Although all necessary parts were present, the installation procedure had not been completed. For example, a connection may have been left ‘finger tight’ rather than torqued.
- Person contacted hazard
- A worker came into contact with a hazard which caused, or had the potential to cause injury. Includes electric shocks, falls and exposure to aircraft fluids or other chemicals.
- Vehicle or equipment contacted aircraft
- A stationary aircraft was contacted by a vehicle or maintenance equipment such as stairs or moveable stands.
- Incorrect assembly or orientation
- A component was installed or assembled incorrectly.
- Material left in aircraft
- A maintenance related item such as a tool was inadvertently left behind by a maintenance worker.
The Australian Transport Safety Bureau considers that the issues identified in the survey are not specific to Australia but will be of use to safety agencies around the world, and has identified a number of recommendations: 
- the need for refresher training for aircraft maintenance engineers
- the need to remove barriers which discourage aircraft maintenance engineers from reporting incidents
- the need for fatigue management programs
- human factors training for management and engineers, and
- program to address aircraft maintenance engineers concerning memory lapses, pressure, fatigue and coordination difficulties.