Brunei DCA CPL(A) 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 human factors framework describing Software, Hardware, Environment and Liveware, with the human at the centre; mismatches at the Liveware boundary are the main source of error.

Swiss cheese model

Reason's model in which latent organisational conditions and active front-line failures align like holes in cheese slices to breach defences and allow an accident.

Dalton's law

The total pressure of a gas mixture equals the sum of the partial pressures of its components; alveolar oxygen partial pressure therefore falls as altitude increases.

Boyle's law

At constant temperature, the volume of a gas is inversely proportional to its pressure, so trapped gas expands on ascent and contracts on descent.

Henry's law

The amount of gas dissolved in a liquid is proportional to the partial pressure of that gas above the liquid, which underlies nitrogen loading and decompression sickness.

Empty-field myopia

In a featureless sky or sea the eye relaxes to a near focus of about one metre, making distant aircraft appear larger and closer than they are.

Somatogravic illusion

Linear acceleration is misperceived by the otolith organs as a pitch-up, so acceleration feels like a climb and deceleration feels like a descent.

Coriolis illusion

A head movement during a sustained turn stimulates the semicircular canals in an unexpected plane, producing a violent tumbling sensation and disorientation.

Time of useful consciousness

The period after loss of oxygen during which a pilot can still take corrective action; about 3-5 minutes at 25,000 ft and 30-60 seconds at 35,000 ft.

Hypoxic hypoxia

A reduction in alveolar oxygen partial pressure at altitude that lowers arterial oxygen saturation and impairs brain function.

Hyperventilation

Rapid deep breathing that lowers arterial carbon dioxide, causing cerebral vasoconstriction, dizziness, tingling and carpopedal spasm.

Type II decompression sickness

The serious form of DCS involving neurological, respiratory or cardiovascular symptoms such as chokes or paralysis, requiring urgent oxygen and hyperbaric treatment.

Middle-ear barotrauma

Pain and hearing loss on descent when the Eustachian tube cannot equalise middle-ear pressure with cabin pressure; prevented by early and frequent equalisation.

Anti-G straining manoeuvre

Tensing the legs, abdomen and gluteal muscles while performing a forced exhalation against a partially closed glottis to raise blood pressure and resist +Gz.

G-LOC

G-induced loss of consciousness caused by insufficient cerebral blood pressure under sustained +Gz, often preceded by grey-out and black-out.

The leans

A false sensation of banking in the opposite direction after an undetected bank is corrected, which can prompt an incorrect control input.

Graveyard spiral

A descending spiral that develops when a prolonged unnoticed bank is maintained, with increasing bank and loss of altitude unless instruments are used.

Circadian rhythm

An approximately 24-hour internal cycle entrained by light, with alertness lowest around 02:00-06:00 and 14:00-16:00.

Sleep inertia

Temporary grogginess and reduced performance after waking, worst after slow-wave sleep and lasting roughly 15-30 minutes.

Yerkes-Dodson law

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

Workload

The relationship between task demands and the operator's capacity; overload causes tunnelling and omission, while underload causes boredom and vigilance failure.

Threat and error management

A framework in which crews anticipate and avoid threats, trap and mitigate errors, and recover from undesired aircraft states.

Two-challenge rule

A crew resource management practice allowing any crew member to question a decision twice and requiring a response before the action proceeds.

DECIDE model

A decision-making model: Detect the change, Estimate its effect, Choose an outcome, Identify actions, Do the best action, Evaluate the result.

IMSAFE checklist

A fitness-to-fly checklist covering Illness, Medication, Stress, Alcohol, Fatigue and Emotion or Eating before flight.

Situational awareness

The perception of elements in the environment, comprehension of their meaning, and projection of their status into the near future.

Automation bias

Over-trust in automated systems that leads pilots to accept incorrect automation outputs and reduce their own monitoring and cross-checking.

Grey-out

Loss of peripheral vision and colour under increasing +Gz as retinal blood flow falls, preceding black-out and loss of consciousness.

Rapid decompression

A sudden loss of cabin pressure causing fogging, a temperature drop and noise, with a shorter time of useful consciousness than slow decompression.

Black-hole approach

A night approach with no ground reference in which the runway appears higher than it is, leading the pilot to fly a lower-than-normal approach.

Autokinesis

A stationary light in a dark featureless sky appears to move because of small eye movements; the pilot should not chase it.

Carbon monoxide poisoning

Carbon monoxide binds haemoglobin far more strongly than oxygen, causing headache and confusion without cyanosis; treat with 100% oxygen and land.