Human Factors: Basic Concepts
What the domain covers
Human factors studies the fit between people and the aviation system: the machine, the procedures, the environment and the organisation. Candidates must know the SHELL model (Software, Hardware, Environment, Liveware), the distinction between flight-deck centred and system-centred views, and the shift from a blame culture to a safety culture. Understand the 'dirty dozen' only as a broad checklist of maintenance and operational hazards, not as a rigid list to memorise verbatim.
Concepts to master
- Person-machine interface: controls, displays, workload and error tolerance.
- Liveware-Liveware edge: the most error-prone interface in SHELL, because it involves communication and teamwork.
- Regulatory context: ICAO Annex 1 and Annex 6 place human factors and CRM training requirements on operators.
- Statistics trap: human error is a factor in the majority of accidents, but questions often ask for the single most common causal category (often decision or judgement failures, not skill failures).
Question traps
Watch for absolutes such as 'human error is the cause of all accidents' (false) and for confusion between 'error' (an action) and 'violation' (a deliberate deviation). Also distinguish prevention strategies: design, training and regulation.
Worked example / rule of thumb
A question describes an engineer using an unapproved tool because the correct one is locked away. Ask: is this an error or a violation? The deliberate choice makes it a violation, driven by the organisational Software (procedures) and Environment (tool availability). Rule of thumb: when a question mentions 'deliberate' or 'chose to', suspect violation; when it mentions 'unintended' or 'misread', suspect error.