Page 14 - Module 9 Look Inside

Recommended further reading: CAP 562 Civil Aircraft Airworthiness Information and
Procedures (CAAIP).
http://publicapps.caa.co.uk/modalapplication.aspx?appid=11&mode=detail&id=92

Human performance and limitations

The intention of this subsection is to provide an overview of those key physical and mental
human performance characteristics which are likely to affect an aircraft maintenance engineer in
his working environment, such as his vision, hearing, information processing, attention and
perception, memory, judgment and decision making.

Just as certain mechanical components used in aircraft maintenance engineering have
limitations, engineers themselves have certain capabilities and limitations that must be
considered when looking at the maintenance engineering ‘system’. For instance, rivets used to
attach aluminium skin to a fuselage can withstand forces that act to pull them apart. It is clear
that that these rivets will eventually fail if enough force is applied to them. While the precise
range of human capabilities and limitations might not be as well-defined as the performance
range of mechanical or electrical components, the same principles apply in that human
performance is likely to degrade and eventually ‘fail’ under certain conditions (e.g. stress).

Mechanical components in aircraft can, on occasion, suffer catastrophic failures. Man, can also
fail to function properly in certain situations. Physically, humans become fatigued, are affected
by the cold, can break bones in workplace accidents, etc. Mentally, humans can make errors,
have limited perceptual powers, can exhibit poor judgment due to lack of skills and knowledge,
etc. In addition, unlike mechanical components, human performance is also affected by social
and emotional factors. Therefore, failure by aircraft maintenance engineers can also be to the
detriment of aircraft safety.

The aircraft engineer is the central part of the aircraft maintenance system. It is therefore very
useful to have an understanding of how various parts of his body and mental processes function
and how performance limitations can influence his effectiveness at work.

Total Training Support Ltd 2-7 Issue 2 – January 2016
© Copyright 2016 Module 9.2 Human Performance and

Limitation