Part-66 Module 9 flashcards

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

SHELL model

Framework describing human factors as the interaction of Liveware (people) with Software, Hardware, Environment and other Liveware; mismatches at these interfaces cause error.

Dirty Dozen

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

Short-term memory capacity

Working memory holds about seven plus or minus two items for 15–30 seconds; unrehearsed information is lost, so procedures must not overload it.

Dark adaptation

Full dark adaptation takes about 20–30 minutes as rod sensitivity increases; sudden bright light resets adaptation, so avoid white light at night.

Hypoxia at altitude

Above about 10,000 ft oxygen saturation falls; after decompression at FL350, time of useful consciousness is roughly 30–60 seconds.

Circadian low

Core body temperature and alertness reach a minimum around 03:00–05:00 body time, raising error risk on night shifts.

Groupthink

A mode of thinking in which the desire for harmony suppresses dissent, producing poor decisions; counter it with independent evaluation and a devil's advocate.

Authority gradient

The perceived power difference between leader and team; too steep discourages challenge, too flat blurs command, so assertiveness training balances it.

Crew Resource Management

Training in communication, teamwork, leadership and decision-making that helps crews use all available resources safely; it originated after human-error accidents.

Inverted-U stress relationship

Performance rises with moderate arousal but falls when stress is too low or too high; complex tasks tolerate less arousal than simple ones.

Fatigue effects

Fatigue slows reaction time, reduces vigilance and impairs memory and judgement; it cannot be overcome by motivation alone.

Alcohol impairment

Alcohol impairs psychomotor performance, judgement and vigilance; effects persist after blood levels fall and compound fatigue.

Motivation and performance

Motivation drives effort and performance; excessive motivation can over-arouse and impair fine psychomotor control.

EU noise action levels

EU exposure limits: lower action level 80 dB(A), upper action level 85 dB(A), exposure limit 87 dB(A) over eight hours; hearing protection is required above these.

Lighting levels

Recommended illuminance is about 300–500 lux for normal work and 750 lux or more for detailed inspection; glare and shadows impair performance.

Thermal comfort range

Optimal workplace temperature is roughly 20–24 °C with 30–60% relative humidity; heat and cold degrade vigilance and dexterity.

Vibration exposure

Hand-arm vibration can cause white finger; whole-body vibration impairs vision and comfort; exposure should be limited and tools damped.

Vigilance decrement

Sustained attention to monotonous tasks declines after about 20–30 minutes, increasing missed signals; breaks and task variety reduce the decrement.

Ergonomics

Fitting tasks and equipment to human capabilities; correct working height, posture and reach reduce musculoskeletal injury and error.

Manual handling

Lift close to the body with a straight back and bent knees; use mechanical aids where possible and assess load, distance and repetition.

Feedback in communication

The receiver's confirmation that a message was received and understood; without feedback, communication is incomplete and error risk rises.

Assertiveness

The ability to state concerns clearly and respectfully, especially to authority; it is essential for challenging unsafe decisions.

Standard phraseology

Agreed words and formats that reduce ambiguity; slang and deviations increase misunderstanding, particularly with non-native speakers.

Active listening

Concentrating fully, paraphrasing and confirming understanding; filters such as expectation, noise and bias distort messages.

Swiss cheese model

Reason's model: accidents occur when holes in successive defences-organisational, supervisory and unsafe acts-align.

Slip

A skill-based error where the action is not what was intended, often due to attention failure, such as pressing the wrong switch.

Lapse

A skill-based error involving memory failure, such as forgetting a step or an intention; common in routine, highly practised tasks.

Mistake

A rule-based or knowledge-based error where the intention is wrong even if execution is correct; usually caused by misdiagnosis or bad rules.

Violation

A deliberate deviation from rules or procedures; types include routine, situational, exceptional and sabotage, often normalised by workplace culture.

FOD

Foreign object debris can damage aircraft and equipment; control it by clean-as-you-go, tool control and pre-close inspections.

PPE

Personal protective equipment is the last line of defence; it must be suitable, maintained, correctly fitted and used.

COSHH

Control of Substances Hazardous to Health: assess risks, prevent or control exposure, use ventilation and PPE, monitor exposure and train workers.