CAA NZ AME Human Factors key terms

The study of how people's physical, psychological and social capabilities and limits affect their work with machines, procedures and each other, applied to reduce error and improve safety.

A framework showing that accidents arise at the interfaces between Software, Hardware, Environment and the Liveware (people) at the centre, rather than from any single element alone.

The human element in the SHEL model, including its physical size, sensory limits, psychological needs and social relationships, and the fit between people and other system elements.

Twelve commonly cited error-inducing conditions in maintenance, such as fatigue, pressure, distraction, lack of communication, complacency and lack of knowledge, used as a training checklist.

An action or inaction that deviates from what was intended or required, or a planned action that fails to achieve its intended outcome, regardless of whether harm results.

A deliberate deviation from a rule, procedure or regulation, often driven by perceived pressure, convenience or normalised practice, distinguished from unintentional error.

An error of execution where a correctly intended action is carried out incorrectly, typically a lapse of attention during a routine, well-learned task such as fitting the wrong fastener.

An error of omission or memory failure, where a planned action is forgotten or a step is skipped, often during routine tasks or after an interruption.

An error of intention or planning where the action proceeds as intended but the plan itself is wrong, such as selecting the wrong procedure or misdiagnosing a fault.

Highly practised, largely automatic performance of routine tasks carried out with little conscious attention, making it fast and efficient but vulnerable to slips and lapses.

Performance guided by stored if-then rules and familiar procedures, where the person recognises a situation and applies a known solution, vulnerable to choosing the wrong rule.

Slow, effortful performance used in novel or unclear situations, relying on reasoning and mental models rather than stored routines, and most prone to planning mistakes.

A person's accurate perception of what is happening around them, comprehension of what it means, and projection of how it will develop in the near future.

Self-satisfaction and reduced vigilance arising when performance has become reliable, leading people to assume all is well and to skip checks or overlook warning signs.

The gradual acceptance of small departures from correct practice because they appear to cause no harm, until unsafe behaviour becomes the accepted norm within a team.

A physiological state of reduced mental or physical performance caused by sleep loss, long duty periods, circadian disruption or workload, impairing alertness, memory and reaction time.

The body's roughly 24-hour internal cycle governing sleepiness, alertness and temperature, which shift work and night duty can desynchronise, causing performance lows at certain hours.

A person's response to demands they perceive as exceeding their resources, which at low levels can aid performance but at high or prolonged levels degrades judgement and coordination.

The general level of physiological and psychological activation, where performance is poor when arousal is very low or very high and best at a moderate level.

The ability to sustain attention over time to detect rare or subtle signals, such as defects during inspection, which declines with fatigue, monotony and time on task.

The mental and physical effort required to meet task demands, which can be too high causing overload and error, or too low causing boredom and reduced attention.

Any internal or external event that draws attention away from the task in hand, such as interruptions, noise or personal worries, increasing the chance of skipped steps.

A perceived demand to complete work faster or with fewer resources than normal, which can push people to cut corners, rush and make errors or violations.

The exchange of information between people such that the intended meaning is understood, requiring clear language, confirmation and feedback, especially at shift handover.

The transfer of responsibility and task status between outgoing and incoming personnel, a high-risk point where incomplete or ambiguous information can lead to maintenance error.

The willingness to state one's own concerns, needs or safety information clearly and respectfully, without either aggression or passive withdrawal, especially to senior colleagues.

The perceived difference in power or status between team members, where a steep gradient discourages junior people from speaking up about concerns or errors.

Coordinated effort in which members share goals, monitor each other's actions, back each other up and adapt roles as needed to maintain safe and effective performance.

The shared values, attitudes and behaviours of an organisation regarding safety, reflected in reporting, learning, just treatment of error and management commitment.

A fair approach to error that distinguishes honest mistakes and system-induced slips from reckless or intentional violations, encouraging reporting without fear of blame.

A formal organisational framework for managing safety, including hazard identification, risk assessment, occurrence reporting, investigation and continuous improvement of controls.

The process of identifying hazards and judging the likelihood and severity of harm, so that controls can be prioritised and applied before an event occurs.

A condition, object or activity with the potential to cause harm or damage, which becomes a risk only when combined with a means of exposure or a triggering event.

The accurate recording of inspections, repairs, part numbers and certification details, which underpins traceability, task continuity and legal release of an aircraft to service.

A person's internal representation of how a system works, used to interpret cues and predict behaviour; inaccurate or outdated models lead to misdiagnosis and mistakes.

The tendency to seek, notice and interpret information that supports an existing belief, such as a suspected fault, while ignoring evidence that contradicts it.

A second person independently verifying a critical action, measurement or part selection, used to catch slips and mistakes before they affect the aircraft.