Human Factors Foundations and Aviation Psychology
Why human factors matters
The aircraft is reliable; the human is the variable. Human factors study the fit between people, machines, procedures and environment. The classic SHELL model places the liveware (you) at the centre, interacting with Software (procedures, checklists, manuals), Hardware (aircraft, controls, displays), Environment (weather, noise, cabin, ATC) and other Liveware (crew, engineers, passengers). Accidents usually arise at the edges of these interfaces, not inside one block alone.
The psychological background
Understand the perceptual and cognitive building blocks: attention is limited and selective; perception is constructed from expectation, so we see what we expect; memory has a fragile short-term store and a reconstructive long-term store; motivation and personality shape risk-taking. Reason's model of error distinguishes slips and lapses (skill-based, execution failures) from mistakes (rule- and knowledge-based planning failures) and violations (deliberate departures from procedure). Swiss-cheese thinking: defences are layers, and accidents happen when holes align.
Traps in questions
Examiners like the difference between an error and a violation, and between active failures (the pilot's slip) and latent conditions (a confusing checklist or rostering pressure). Do not treat 'pilot error' as a cause; it is a starting point for asking why. Another trap: confusing the SHELL interface names, or attributing all error to laziness rather than to design and context.
Worked example
A crew selects the wrong waypoint because two names look alike on the flight-management system. This is a mistake (knowledge/rule-based) triggered by a latent design weakness in the interface. The rule of thumb: ask 'what made this error likely?' before asking 'who erred?'