ATPL Human Factors 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 model showing Software, Hardware, Environment and Liveware; the central human interacts with each, and the liveware-liveware interface is the most critical.

Swiss-cheese model

Reason's accident model in which defensive layers contain holes; an accident occurs when holes in successive layers align, allowing a hazard to pass through all defences.

Dirty dozen

Twelve common human-factor precursors to error: communication, complacency, knowledge, distraction, teamwork, fatigue, resources, pressure, assertiveness, stress, awareness and norms.

Safety culture

The shared values and behaviours of an organisation regarding safety, comprising reporting, just, flexible and learning cultures that support open hazard reporting.

Dalton's law

The total pressure of a gas mixture equals the sum of the partial pressures of its components; at altitude, reduced ambient pressure lowers oxygen partial pressure.

Henry's law

The amount of gas dissolved in a liquid is proportional to its partial pressure; rapid decompression releases dissolved nitrogen, causing decompression sickness.

Time of useful consciousness

The period after loss of cabin pressure during which a pilot can still take effective corrective action; it shortens markedly as altitude increases.

Hypoxic hypoxia

Hypoxia caused by reduced oxygen availability to the lungs, as at altitude or with a blocked oxygen supply, lowering arterial oxygen saturation.

Somatogravic illusion

A false sensation of pitching up during forward acceleration, caused by the otolith organs responding to linear acceleration as if it were a gravity change.

Hyperventilation

Excessive breathing that lowers arterial carbon dioxide, causing dizziness, tingling and cramps; treatment is controlled breathing and, if in doubt, oxygen.

Circadian rhythm

The roughly 24-hour internal biological cycle regulating sleep, alertness and body temperature; disruption by shift work or time-zone crossing degrades performance.

Yerkes-Dodson law

Performance improves with arousal up to an optimum and then declines; the optimum is lower for complex tasks and higher for simple tasks.

Maslow's hierarchy

A motivational model ordering needs from physiological and safety through belonging, esteem and self-actualisation; unmet lower needs dominate attention.

Hazardous attitudes

Five attitudes - anti-authority, impulsivity, invulnerability, machismo and resignation - that increase risk; each has a specific antidote thought.

Defence mechanisms

Unconscious psychological strategies such as denial or rationalisation that protect self-esteem but can hide a developing problem from the pilot.

Slip

An error of execution in which the intention is correct but the action is performed incorrectly, often during routine, highly practised tasks.

Mistake

An error of intention in which the plan itself is wrong, arising from faulty rule application or inadequate knowledge rather than from faulty execution.

Latent condition

A dormant organisational or design weakness, such as poor procedures or inadequate training, that can combine with active failures to cause an accident.

Just culture

A safety culture that consoles human error, coaches at-risk behaviour and sanctions reckless behaviour, encouraging reporting without fear of punishment.

Vigilance decrement

The decline in the ability to detect rare signals over time during prolonged monotonous monitoring, a form of underload-related performance loss.

Workload

The proportion of a person's limited mental resources demanded by a task; when demand exceeds capacity, errors and task shedding occur.

Automation complacency

Over-reliance on automated systems that reduces active monitoring, so the crew may fail to detect mode changes or system failures.

Task shedding

Under overload, the deliberate or unconscious dropping of lower-priority tasks to protect performance of the most critical task.

Short-term memory

A limited store holding about seven items for 15-30 seconds; information is lost unless rehearsed or encoded into long-term memory.

Selective attention

The process of focusing on relevant cues while filtering out irrelevant ones; it can cause a pilot to miss unexpected but important signals.

Situation awareness

Three levels: perception of elements in the environment, comprehension of their meaning, and projection of their future status.

DECIDE model

A decision-making framework: Detect change, Estimate need to react, Choose outcome, Identify actions, Do the action, Evaluate the results.

Closed-loop communication

A communication protocol in which the sender transmits, the receiver reads back, and the sender confirms, ensuring accurate reception of the message.

Authority gradient

The perceived power difference between captain and crew; too steep suppresses input, too flat can weaken decisive command.

Assertiveness

The ability to state a concern clearly and persistently until it is acknowledged, without aggression or passivity, supporting safe crew coordination.

Threat and Error Management

A framework in which crews identify threats, anticipate and trap errors, and manage undesired aircraft states to maintain safety margins.

LOSA

Line Operations Safety Audit: structured observation of normal flights to identify threats and errors and to measure the effectiveness of CRM.