ATPL Human Factors (CAA) 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 is the pilot, and mismatches at these interfaces are where errors arise.

Dirty Dozen

Twelve common error precursors: fatigue, complacency, lack of knowledge, distraction, lack of teamwork, lack of resources, pressure, lack of assertiveness, stress, lack of awareness, norms and lack of communication.

Swiss cheese model

Reason's model in which accidents occur when holes in successive defensive layers line up; defences, not individual blame, are the target of safety improvement.

Time of useful consciousness

The time after loss of oxygen supply during which a pilot can still take corrective action; roughly 3-5 minutes at FL300 and 15-20 seconds at FL430.

Hyperventilation

Overbreathing that lowers blood CO2, causing tingling, dizziness and muscle spasm; treated by slowing breathing and rebreathing, and distinguished from hypoxia by symptoms and response to oxygen.

Somatogravic illusion

A false sensation of climbing during acceleration, or of descending during deceleration, caused by linear acceleration stimulating the otolith organs; rely on instruments.

Decompression sickness

Nitrogen bubbles forming after rapid decompression, causing joint pain, skin mottling and neurological signs; treated with 100% oxygen and descent to sea level.

Working memory

A limited-capacity store holding about seven items for roughly 20-30 seconds; clearances should be written down and read back to avoid loss.

Vigilance decrement

The decline in detection performance during prolonged monitoring of a low-event task; counter with active scanning, breaks and varied tasks.

Black-hole approach

A night approach over dark terrain with no visual horizon, causing a too-low approach; countered with instrument references and PAPI or VASI guidance.

Slip versus lapse

A slip is a correct intention executed incorrectly, such as the wrong switch; a lapse is a forgotten action, such as missing a checklist item.

Threat and Error Management

A framework in which threats are external events, errors are crew actions, and the aim is to anticipate, trap and recover before consequences develop.

Just culture

A safety culture that treats human error non-punitively while still addressing reckless or intentional violations, encouraging reporting and learning.

Plan continuation bias

The tendency to continue an original plan despite changing cues; countered by setting explicit abort criteria before flight.

DECIDE model

A structured decision model: Detect, Estimate, Choose, Identify, Do and Evaluate; useful for in-flight decisions under time pressure.

Risk matrix

A tool combining probability and severity of harm to rank risk; only risk that is understood and mitigated should be accepted.

Authority gradient

The perceived power difference between captain and first officer; a steep gradient suppresses challenge and is reduced by a speak-up culture.

Closed-loop communication

A message is sent, received, read back and confirmed; this confirms understanding and reduces ambiguity in crew and ATC exchanges.

Sterile cockpit

A rule prohibiting non-essential activity and conversation during critical phases such as taxi, takeoff and approach, to reduce distraction.

Automation complacency

Over-trust in automation that reduces monitoring; countered by active questioning of what the system is doing, why, and what happens next.

Mode confusion

A pilot misunderstanding which automation mode is active; countered by monitoring the flight mode annunciator and verbal callouts.

Automation bias

The tendency to accept automated advice over one's own judgement; cross-check with raw data and independent sources.

Yerkes-Dodson law

Performance peaks at moderate arousal; too low arousal causes boredom and too high arousal causes narrowing of attention and errors.

Situational awareness

Endsley's three levels: perception of elements, comprehension of their meaning, and projection of future status; lost through fixation and distraction.

Workload

Mental and physical demand relative to capacity; overload causes errors and underload causes complacency, so an optimal load is the aim.

Circadian rhythm

An internal roughly 24-hour clock; alertness dips around 03:00-05:00 and 14:00-16:00, and desynchronises with time-zone travel.

Acute versus chronic fatigue

Acute fatigue is short-term and recovers with sleep; chronic fatigue accumulates over days and requires extended rest to resolve.

Jet lag

Desynchronisation of the circadian clock after time-zone travel; eastward travel is usually harder, and adaptation takes about one day per zone.

Flight and duty time limits

Regulatory maximum duty, minimum rest and cumulative limits; they are a minimum safety floor, not a target to be used fully.

Stress response

A physiological and psychological reaction to demands exceeding resources; some stress aids performance, but excessive stress narrows attention and increases errors.

Coping strategies

Problem-focused coping addresses the source of stress, while emotion-focused coping manages feelings; denial and press-on behaviour are maladaptive.

Critical incident stress

Psychological reaction after a traumatic event that can impair performance; managed with peer support and professional help, not self-medication.