Brunei DCA CPL(A) Human Performance key terms

The study of how people's physical, psychological and social capabilities and limits interact with equipment, procedures and environment, aiming to optimise safety and performance rather than to blame individuals when things go wrong.

A pilot's continuous perception of relevant elements in the operating environment, comprehension of what they mean, and projection of how they will develop in the near future, underpinning sound decisions.

The coordinated use of all available resources, including crew, equipment, information and support staff, through communication, leadership, briefings and monitoring to achieve safe and efficient flight.

A framework in which crews anticipate external threats, trap or manage errors before they produce undesired aircraft states, and recover when such states occur, treating error as normal rather than exceptional.

An unintentional action or inaction, or a decision, that departs from intended or required behaviour and contributes to an undesired outcome; usually a symptom of deeper systemic weaknesses.

An error of execution in a routine, highly practised task, such as omitting a step or pressing the wrong control, typically arising from inattention or distraction rather than lack of knowledge.

An error of intention in which the plan itself is wrong, either through a rule-based misapplication of a known procedure or a knowledge-based misdiagnosis of an unfamiliar situation.

The general level of physiological and psychological activation or alertness; performance is best at a moderate level and deteriorates when arousal is too low (boredom) or too high (anxiety).

The mental and physical effort required to meet task demands within a given time; when demand exceeds capacity, performance degrades, errors rise and stress increases.

A person's response to demands perceived as exceeding their ability to cope, producing physical and psychological effects that may help short-term performance but impair judgement and health if prolonged.

A physiological state of reduced mental or physical performance capability resulting from sleep loss, extended wakefulness, circadian phase or workload, impairing alertness, reaction time and decision quality.

An approximately 24-hour internal biological cycle governing alertness, body temperature, hormone release and sleep tendency, which is synchronised mainly by daylight and disturbed by rapid time-zone crossing.

A temporary disruption of sleep, mood and performance caused by rapid travel across time zones, where the internal body clock is out of step with local day and night.

The accumulated shortfall between sleep needed and sleep obtained over successive days, which impairs alertness and performance even when the person feels adapted to it.

An inadequate supply of oxygen to body tissues, in aviation usually caused by high altitude, failure of oxygen equipment or reduced oxygen partial pressure, leading to impaired judgement and eventually unconsciousness.

The period after loss of adequate oxygen at a given altitude during which a person can still take deliberate, effective corrective action before becoming incapacitated.

Abnormally rapid or deep breathing that lowers blood carbon dioxide, causing dizziness, tingling, muscle cramps and anxiety, and which can be mistaken for hypoxia in flight.

The equivalent atmospheric pressure altitude maintained inside a pressurised aircraft cabin, typically several thousand feet, which determines the oxygen partial pressure available to occupants.

A disorder in which dissolved nitrogen forms bubbles in blood and tissues when ambient pressure falls too quickly, producing joint pain, skin, respiratory or neurological symptoms; prevented by denitrogenation and gradual exposure.

Tissue injury caused by a pressure difference between a gas-filled body cavity and the surrounding environment, commonly affecting the ears, sinuses and lungs during climb or descent.

A method of equalising middle-ear pressure by closing the mouth and nose and gently attempting to exhale, raising nasopharyngeal pressure so gas passes up the Eustachian tube during descent.

A pilot's failure to correctly perceive the aircraft's attitude, motion or position relative to the earth, often caused by misleading vestibular or visual cues in the absence of reliable outside references.

A false sensation of turning or of stopping a turn arising from the semicircular canals, especially after a sustained turn or a sudden head movement during a turn.

A false sensation of pitching up or down caused by linear acceleration or deceleration, which the otolith organs misread as a change in the direction of gravity.

The inner-ear apparatus of semicircular canals and otolith organs that senses angular and linear acceleration and head position, providing motion cues that are easily misled in flight.

A syndrome of nausea, pallor, sweating and dizziness provoked by real or apparent motion, especially when visual and vestibular signals conflict, and worsened by head movement and turbulence.

The sensory network providing information about touch, pressure, position and movement of body parts, helping a pilot feel seat pressure and control forces that contribute to attitude awareness.

A tendency for the eye to focus at a resting distance of around one metre when viewing a featureless field such as a clear sky or haze, causing distant aircraft to be overlooked.

A mistaken perception of size, distance, slope or motion caused by misleading visual cues such as runway width, terrain slope, rain or darkness, which can lead to unsafe approach decisions.

The body's ability to withstand sustained acceleration, chiefly Gz, before symptoms such as grey-out, blackout or unconsciousness occur, influenced by posture, straining and anti-G equipment.

G-induced loss of consciousness, occurring when sustained high positive G reduces blood flow to the brain, often preceded by visual symptoms and followed by a period of confusion on recovery.

The willingness to state one's position, question a decision or challenge a deviation clearly and respectfully, a core crew resource management behaviour that protects against authority gradients.

The perceived difference in power or expertise between crew members; too steep a gradient discourages challenge, while too flat a gradient can cause indecision and conflict.

The process of identifying a problem, generating and evaluating options, choosing a course of action and reviewing the outcome, ideally using structured models and crew input under time pressure.

Over-trust in automated systems that reduces monitoring and cross-checking, so that pilots may fail to notice mode changes or developing problems until they become serious.

A pilot's physical and mental suitability to fly, covering illness, medication, alcohol, fatigue and stress, and requiring honest self-assessment and adherence to regulatory medical standards.