Human Factors in Aircraft Maintenance
The dirty dozen, properly understood
Human Factors questions test whether you can name the mechanism, not just the label. The classic twelve are: lack of communication, complacency, lack of knowledge, distraction, lack of teamwork, fatigue, lack of resources, pressure, lack of assertiveness, stress, lack of awareness and norms. For each, be ready to give a maintenance example and a countermeasure. Complacency after years on the same task is countered by independent inspection and by deliberately re-reading the task card; fatigue is countered by duty limits, rest and reporting; norms ("everyone signs it off that way") are the hardest, countered by a just culture and visible standards.
Error models
Understand the Swiss cheese model (latent conditions in organisation, supervision and preconditions line up with active failures), SHEL (Software, Hardware, Environment, Liveware interfaces) and the error types: slip (right intention, wrong execution), lapse (forgotten step), mistake (wrong intention) and violation (deliberate deviation). Note that most maintenance errors are omissions and wrong-component/installation errors, and that shift handover and duplicate inspection are the highest-value defences.
Traps
Questions blur stress (arousal) with pressure (deadline/management), and blur just culture with blame-free culture. Just culture still holds people accountable for reckless acts. Also watch questions on circadian rhythm and sleep debt: the answer is usually the one that reduces night-shift fatigue through planned naps and rotation, not willpower.
Worked rule of thumb
For any scenario, ask: Was this a slip, lapse, mistake or violation, and which barrier failed? The option that names the correct barrier beats the option that names the correct feeling.