Part-66 Module 9 key terms

The study of how people interact with their work, covering physical, psychological and social influences, with the aim of optimising performance, safety and well-being in aviation maintenance.

A model showing that performance depends on the fit between Software (procedures, manuals), Hardware (tools, aircraft), Environment (physical and social) and Liveware (people), with Liveware at the centre.

The shared attitudes, beliefs and behaviours in an organisation that determine how seriously safety is treated, including willingness to report, to learn and to challenge unsafe practice.

A reporting environment in which honest errors are not punished but reckless or deliberate violations are, so that staff report mistakes and near-misses without fear.

A shortage of oxygen reaching body tissues, causing impaired judgement, euphoria, headache and eventual loss of consciousness; relevant to unpressurised aircraft and to oxygen equipment handling.

A false perception of body position or motion relative to the earth, occurring when visual cues are absent or misleading and the inner ear gives conflicting information.

The process by which the brain interprets sensory information; expectations, habit and past experience can distort it, leading to misread instruments, labels or defects.

The ability to concentrate on relevant information while ignoring distractions; vigilance, the sustained form of attention, declines over time, especially in monotonous inspection or monitoring work.

A limited store holding a small amount of information for only a few seconds; forgetting steps held only in short-term memory is a common source of maintenance lapses.

The mental sequence of sensing, perceiving, deciding and responding through which a person deals with information; limited capacity at each stage explains errors under high workload.

A person's physical and psychological response to demands perceived as exceeding their ability to cope; brief stress may sharpen performance but prolonged stress impairs judgement, memory and health.

A state of reduced physical and mental capability caused by prolonged effort, insufficient sleep or a disrupted body clock; it slows reactions, impairs judgement and raises error rates.

The internal body clock that regulates alertness, body temperature and sleep over roughly 24 hours; disruption by night shifts or time-zone changes degrades performance.

Working rotas outside normal daytime hours, which disturbs sleep and circadian rhythms and can lead to chronic fatigue, reduced alertness and higher error rates.

The influence of colleagues' expectations and behaviour on an individual's decisions; it can support safe practice but can also push people into taking shortcuts.

An unwritten standard of behaviour accepted within a team; norms can either support compliance and reporting or normalise unsafe shortcuts and poor practice.

The way a person guides and influences a team; effective leaders set clear standards, encourage reporting and make sure that safety concerns are acted upon.

Coordinated cooperation in which members share goals, information and responsibilities so that the combined result is safer and better than individual effort alone.

The ability to state clearly and respectfully one's own position, concerns or needs without aggression or submission, which is essential for challenging unsafe instructions.

A communication technique in which the receiver repeats a verbal instruction back to the sender so that it is confirmed as heard and understood correctly.

The structured transfer of task status, outstanding work and safety-relevant information from one shift to the next, ideally face-to-face and supported by written records.

Factors such as noise, language differences, jargon, assumptions and interrupted messages that prevent information from being transmitted or understood correctly.

An unintended action in which a correct intention is carried out incorrectly, for example pressing the wrong switch or transposing digits; typically a skill-based error.

A memory-based error involving the omission of a step or the forgetting of an intention, common when a task is interrupted or highly routine.

An error arising from a wrong intention or faulty plan, usually caused by inadequate knowledge or misjudging the situation; includes rule-based and knowledge-based mistakes.

A deliberate deviation from a rule or procedure; it may be routine, becoming accepted practice, or exceptional and situation-driven, and in either case it erodes safety margins.

A model of accident causation in which each layer of defence has weaknesses shown as holes; an accident happens only when holes in successive layers line up.

Twelve commonly cited precursors of maintenance error, including complacency, fatigue, pressure, distraction, lack of communication, knowledge, teamwork, resources, assertiveness and awareness, stress and norms.

A weakness hidden in the system, such as poor design, inadequate procedures or a management decision, whose effects may appear much later and far from its origin.

Unwanted sound that can mask speech and warnings and cause annoyance, fatigue and hearing damage; controls include reducing the source, limiting exposure time and wearing hearing protection.

The level and quality of light in a workplace; too little light or excessive glare causes eye strain, fatigue and missed defects during inspection and fine work.

The mental and physical effort a task demands; overload causes rushed or omitted steps while underload lowers vigilance, so both extremes must be managed.

Breaking a job down into its steps, information needs, decisions and hazards so that procedures, training and risk controls can be matched to human capabilities.

Identifying hazards, judging how likely and how severe the resulting harm could be, and putting controls in place to reduce the risk to an acceptable level.

Personal protective equipment such as goggles, gloves, ear defenders and safety footwear worn to reduce exposure to hazards; it is the last line of defence after other controls.

Foreign object debris: loose items such as tools, swarf, fasteners or rubbish left in or around an aircraft, which can jam controls, damage engines or injure personnel.

Lifting, lowering, pushing, pulling or carrying loads by hand or bodily force; poor technique or excessive weight causes back and limb injuries, so aids and correct posture are used.

A document supplied with a chemical that lists its hazards, handling, storage, protective measures and first-aid actions, used to plan safe use in the workplace.