ATPL Human Performance flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

SHEL model

A human factors framework with Software, Hardware, Environment and Liveware; the central Liveware block represents the pilot, and mismatches at each interface are where errors arise.

Swiss cheese model

Reason's model in which latent conditions and active failures line up through holes in successive defences; accidents occur when all layers are breached simultaneously.

Latent failure

A delayed, distant unsafe decision or condition created by designers, managers or regulators that lies dormant until combined with local circumstances and active failures.

Hypoxic hypoxia

Hypoxia caused by reduced alveolar oxygen partial pressure, as at altitude or with a blocked oxygen supply; blood oxygen carrying capacity is normal but saturation falls.

Time of useful consciousness

The period after loss of oxygen supply during which a pilot can still take corrective action; it falls from 5-10 min at FL300 to 15-20 s at FL500.

Decompression sickness

Nitrogen bubbles forming in tissues when ambient pressure drops too quickly after saturation at higher pressure; prevented by waiting 12-24 hours after diving before flying.

Somatogravic illusion

A false sensation of pitch-up during linear acceleration, such as on take-off or go-around, which can lead a pilot to push forward on the controls.

Barotrauma

Pressure injury to the middle ear or sinuses when the Eustachian tube or sinus ostia cannot equalise pressure during descent; treated with Valsalva and decongestants.

Hyperventilation

Excessive breathing that lowers carbon dioxide, causing cerebral vasoconstriction, dizziness, tingling and tetany; if hypoxia cannot be excluded, give 100% oxygen.

Maslow's hierarchy

A motivation model ordering needs as physiological, safety, social, esteem and self-actualisation; lower needs dominate attention until they are satisfied.

Yerkes-Dodson law

An inverted-U relationship between arousal and performance: performance peaks at moderate arousal and declines with very low or very high arousal.

Working memory

A limited store holding about 7±2 chunks for 15-30 seconds; chunking, rehearsal and clear displays help pilots retain and manipulate information.

Vigilance decrement

The decline in detection performance during prolonged monotonous monitoring, typically appearing within 20-30 minutes and worsened by fatigue and low arousal.

Hazardous attitudes

Five attitudes linked to unsafe decisions: anti-authority, impulsivity, invulnerability, macho and resignation; each is countered by a specific antidote.

Slip

An error of execution where the intention is correct but the action is performed incorrectly, often on routine well-practised tasks such as selecting the wrong switch.

Mistake

An error of intention where the plan itself is wrong, divided into rule-based mistakes (misapplied rule) and knowledge-based mistakes (wrong mental model).

Violation

A deliberate deviation from rules or procedures; it may be routine, exceptional or an act of desperation, and it differs from error because it is intentional.

Just culture

A reporting culture that consoles human error, coaches at-risk behaviour and sanctions reckless behaviour, encouraging open reporting while retaining accountability.

Threat and Error Management

A framework separating external threats, crew errors and undesired aircraft states; countermeasures are to avoid, trap and correct before consequences develop.

Signal detection theory

A model of detection in which performance depends on signal strength and the observer's criterion; a liberal criterion raises hits but also false alarms.

Perception

The interpretation of sensory information using expectation, memory and context; it can diverge from reality through illusions, bias and prior experience.

Confirmation bias

The tendency to seek and interpret information that supports an existing hypothesis while ignoring contradicting evidence, prolonging incorrect problem diagnosis.

Cognitive load

The demand placed on working memory; extraneous load from cluttered displays and unclear procedures should be reduced so that learning and performance improve.

Closed-loop communication

A sender transmits a message, the receiver repeats it back, and the sender confirms; the loop detects and corrects transmission errors.

Authority gradient

The perceived difference in power between crew members; too steep suppresses junior input, too flat causes confusion, and a consultative gradient is optimal.

PACE model

A graded assertiveness sequence: Probe, Alert, Challenge, Emergency; used when a crew member's concern is not being addressed by the other pilot.

Sterile flight deck

A rule prohibiting non-essential conversation and activity during critical phases, typically below 10,000 feet, to protect attention during high-workload periods.

DECIDE model

A decision cycle: Detect change, Estimate the need to react, Choose an outcome, Identify actions, Do the action and Evaluate the result.

Plan continuation bias

The tendency to continue with an original plan despite changing conditions that make it unsafe, often driven by get-there-itis and sunk cost.

Circadian rhythm

An internal cycle of about 24 hours controlled by the suprachiasmatic nucleus; the core temperature minimum near 03:00-05:00 marks the lowest alertness.

Sleep inertia

Reduced alertness and grogginess for 15-30 minutes after waking, especially from slow-wave sleep; allow recovery time before critical tasks.

General adaptation syndrome

Selye's three-stage response to stress: alarm, resistance and exhaustion; prolonged stress depletes coping resources and impairs performance and health.