ATPL 040 Human Performance flashcards

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

SHELL model

A framework describing human factors as interfaces between Liveware (people) and Software, Hardware, Environment, and other Liveware; mismatches at these interfaces cause error.

Swiss cheese model

Reason's model in which accidents occur when holes in successive defensive layers align; holes are active failures and latent conditions in the system.

Just culture

A safety culture that treats honest error with support, at-risk behaviour with coaching, and reckless or intentional unsafe acts with sanctions, while encouraging reporting.

Latent condition

A dormant system weakness, such as poor design, inadequate training, or unclear procedures, that becomes harmful only when combined with other failures.

Time of useful consciousness

The interval after loss of oxygen during which a person can still take corrective action; it falls from about 20-30 min at 18,000 ft to seconds at 40,000 ft.

Hypoxia

Insufficient oxygen reaching body tissues; in flight it causes euphoria, impaired judgement, cyanosis, and loss of consciousness, often without the person noticing.

Hyperventilation

Overbreathing that lowers blood carbon dioxide (hypocapnia), causing cerebral vasoconstriction, dizziness, tingling, and tetany; treated by slowing breathing, not by oxygen.

Eustachian tube

The channel connecting the middle ear to the nasopharynx that equalises pressure across the eardrum; it is harder to open during descent, so squeeze is more likely.

Semicircular canals

Vestibular organs that detect angular acceleration but not steady rotation, so a prolonged coordinated turn may be perceived as straight and level.

Working memory

The limited-capacity store holding about seven items for roughly 20-30 seconds; it is easily disrupted by interruption and is central to decision-making.

Expectation bias

The tendency to perceive what one expects rather than what is actually present, a common cause of misreading instruments, clearances, or checklists.

Vigilance decrement

The decline in detection performance during prolonged, monotonous monitoring tasks, typically appearing within about 30 minutes and worsened by fatigue.

Hazardous attitudes

Five risk-prone attitudes (anti-authority, impulsivity, invulnerability, machismo, resignation) that impair judgement and can be countered by specific antidotes.

Yerkes-Dodson curve

The inverted-U relationship between arousal and performance: performance is best at moderate arousal and declines at very low or very high stress.

Circadian rhythm

The roughly 24-hour internal body clock that governs alertness, temperature, and hormone release; its lowest point is around 03:00-05:00 local time.

Sleep inertia

The temporary reduction in alertness and performance immediately after waking, especially from deep sleep or at the circadian low, lasting minutes to an hour.

Complacency

A state of reduced vigilance and self-satisfaction, often following routine or highly automated flight, that increases the chance of missed cues and errors.

Decompression sickness

Illness caused by dissolved nitrogen forming bubbles in tissues when ambient pressure falls; symptoms include joint pain, respiratory and neurological effects, treated with oxygen and recompression.

Boyle's law

At constant temperature, gas pressure times volume is constant; therefore trapped gas in body cavities expands as altitude increases and contracts during descent.

Off-centre viewing

Looking about 10-15 degrees to the side of a dim object so that its image falls on the rod-rich retina, improving detection at night.

G-LOC

G-induced loss of consciousness caused by reduced blood flow to the brain under high sustained acceleration, often preceded by grey-out or blackout.

Carbon monoxide

A colourless, odourless gas that binds haemoglobin about 200-250 times more strongly than oxygen, causing hypoxia; sources include heaters and engine exhaust.

Closed-loop communication

A communication pattern in which the receiver repeats back the instruction so the sender can confirm it was correctly heard and understood.

Authority gradient

The perceived difference in power or experience between crew members; too steep a gradient suppresses challenge, while too flat a gradient can reduce clarity.

Situational awareness

The perception of elements in the environment, comprehension of their meaning, and projection of their future state; loss often arises from fixation or failure to monitor.

Mode confusion

A state in which the crew misunderstands what the automation is doing or what mode it is in, leading to automation surprises and inappropriate actions.

Shared mental model

A common understanding among crew members of the situation, roles, plans, and tasks that allows coordinated action without explicit communication.

Threat and error management

A framework in which crews anticipate threats, trap or mitigate errors, and avoid undesired aircraft states, integrating human factors into daily operations.

Standard operating procedure

A documented, standardised method for performing a task, providing a common baseline for coordination and reducing variability between crew members.

Challenge-response checklist

A checklist format in which one crew member calls the item and the other confirms the response, ensuring both monitor and verify the action.

Safety performance indicator

A measurable parameter used to monitor the effectiveness of safety management, such as the rate of unstabilised approaches or runway incursions.

Crew resource management

Training that develops communication, leadership, teamwork, decision-making, and workload management skills to use all available resources safely.