Human Factors for the AME Licence
Human Factors in AME licensing
This domain tests how maintenance engineers recognise, explain and control human performance limitations before they become maintenance error. The exam expects applied understanding: matching a scenario to a model, naming the contributing factor, and choosing the defensible barrier, not just reciting a list.
Core models and rules
- SHELL maps Liveware (the AME) against Software (procedures, manuals), Hardware (tools, aircraft), Environment and other Liveware. A mismatch at any interface raises error risk.
- Reason's Swiss cheese separates active failures (the slip, omission or wrong action) from latent conditions (poor documentation, unrealistic scheduling, inadequate training). Barriers can be technical, procedural or human.
- Dirty Dozen factors include complacency, distraction, fatigue, pressure, norms, lack of communication, teamwork, resources, knowledge, assertiveness, awareness and stress. They are prompts, not a complete taxonomy. Link each to a control.
- Error types: skill-based slips and lapses, rule-based mistakes, knowledge-based mistakes; violations are deliberate departures from procedure. Correct classification changes the fix.
Worked example
An AME signs off a task after a shift change and misses a torque value in a long job card. The active failure is an omission; latent conditions include an unclear handover, fatigue and a card that obscures the step. Blaming carelessness scores poorly. Better: improve handover, make the critical step visible, add an independent check, and manage fatigue. The reasoning must connect factor to error to barrier.
Mark-losing traps
- Calling every error a violation; violations require intent or choice.
- Listing Dirty Dozen items without explaining how they interact.
- Treating retraining as the only barrier when the system allowed the error.
- Confusing quality assurance with direct task supervision.
- Ignoring normalised deviance: repeated informal practices can become expected.
In scenarios, state the interface, the error type, the contributing factors and at least one barrier at system and individual level.