11 Human Factors, CRM & TEM

What is the practical TEM chain of threat → error → undesired aircraft state?

A threat increases operational complexity; an error is crew action or inaction that leads away from intentions or expectations; an undesired aircraft state (UAS) is a resulting aircraft position, condition or configuration that reduces safety margins.

What is the primary objective of Threat and Error Management?

Anticipate and manage threats, trap errors before they create consequences, and recover promptly from undesired aircraft states.

What is the difference between an anticipated and an unexpected threat?

Anticipated threats can be identified during planning or briefing; unexpected threats emerge without sufficient warning and require recognition and adaptation.

Does the occurrence of an error necessarily mean the operation has become unsafe?

No. Safety depends strongly on whether the error is detected, trapped and corrected before it produces an undesired aircraft state.

What should take priority once an undesired aircraft state has developed?

Recover the aircraft to a safe state before analysing why the error occurred.

What is the difference between a slip/lapse and a mistake?

A slip or lapse is an execution or memory failure despite a correct plan; a mistake results from an incorrect plan, judgement or understanding.

How is a violation different from an error?

A violation is an intentional deviation from a rule or procedure; an error is not an intentional departure.

What are the three practical levels of situational awareness?

Perceive what is happening, understand what it means, and anticipate what is likely to happen next.

What is shared situational awareness?

A sufficiently common understanding among crew members of the aircraft state, environment, plan, threats and likely next events.

Why is verbalising a developing threat useful even when both pilots can see it?

It aligns mental models and makes subsequent monitoring and decision-making more effective.

What is attention tunnelling?

Excessive concentration on one task or cue while relevant information elsewhere is missed.

What is fixation?

Continuing to focus on a problem, hypothesis or course of action despite evidence that attention should shift elsewhere.

What is confirmation bias?

Seeking or interpreting information in a way that supports an existing belief while discounting contradictory evidence.

What is plan-continuation bias?

The tendency to continue with the original plan despite changing conditions that increasingly favour another course of action.

How can a crew reduce confirmation and plan-continuation bias?

Actively search for disconfirming evidence, reassess at predefined decision points and explicitly discuss viable alternatives.

Why are monitoring and cross-checking active tasks rather than passive observation?

The monitoring pilot must compare actual aircraft state and trajectory with the intended state and intervene when deviations develop.

What should the PM monitor during high-workload phases beyond checklist completion?

Flight path, energy state, automation modes, clearances, configuration, threats and the PF’s actions.

Why should deviations be called early rather than waiting to see whether they correct themselves?

Early intervention requires smaller corrections and prevents normal deviations from developing into undesired aircraft states.

What is the purpose of standard callouts?

To create predictable triggers for shared awareness, cross-checking and intervention.

What is an authority gradient?

The interpersonal difference in perceived authority between crew members that can influence willingness to challenge or contribute.

Why can both an excessively steep and an excessively flat authority gradient be hazardous?

Too steep suppresses challenge and information flow; too flat can weaken leadership, role clarity and timely decision-making.

What does effective assertiveness look like in the cockpit?

State the concern clearly, explain the risk when useful, propose or request action and escalate if the safety issue remains unresolved.

What is graded assertiveness?

Escalating communication from inquiry or concern to an explicit challenge and, if necessary, decisive intervention as the threat becomes more urgent.

What is closed-loop communication?

A message is sent, acknowledged or repeated by the receiver, and the sender confirms that the intended information was correctly understood.

Why are assumptions particularly hazardous in multi-crew operations?

One crew member may believe information, intentions or responsibilities are shared when the other has a different mental model.

What is effective delegation under high workload?

Assign clear tasks to available resources while the person with primary responsibility retains overall awareness and verifies critical results.

Why should crews ask for help early?

Additional capacity is most useful before workload becomes saturation and situational awareness begins to deteriorate.

What is task saturation?

Workload exceeds available cognitive capacity, causing prioritisation, monitoring and decision quality to deteriorate.

What is the practical response to excessive workload?

Prioritise, simplify, use automation appropriately, delegate, delay non-essential tasks and protect flight-path control.

Why is “aviate, navigate, communicate” still useful in highly automated aircraft?

It protects the hierarchy of priorities when workload or abnormal situations threaten to draw attention away from aircraft control.

Why can interruptions cause disproportionate errors?

They break working memory and task sequence, making omissions or duplicated actions more likely when the original task is resumed.

What is a useful defence after an interruption during a procedure?

Deliberately identify where the procedure was interrupted and re-establish the correct point before continuing.

What is automation complacency?

Reduced vigilance because the crew assumes automation will continue to operate correctly.

What is automation overreliance?

Depending on automation beyond its capabilities or continuing to use it when simpler/manual control would provide better situational awareness.

What is the best response when automation increases rather than decreases confusion?

Reduce the level of automation until the aircraft response is clearly understood and controlled.

What is the difference between surprise and startle?

Surprise is an unexpected mismatch between expectation and reality; startle is the immediate physiological and cognitive reaction to a sudden threatening stimulus.

How can startle impair pilot performance?

It can temporarily narrow attention, disrupt working memory, delay action and provoke inappropriate or excessive responses.

What is the key response to startle in an aircraft upset or abnormal event?

Maintain or regain aircraft control, recognise the actual situation, avoid impulsive action and then apply the appropriate procedure.

What does resilience mean in CRM?

The ability to recognise changing conditions, adapt effectively, recover from disruption and restore safe operation.

Why can excessive stress degrade performance?

It narrows attention, reduces working-memory capacity and flexibility, and can impair judgement and communication.

Can very low workload also reduce performance?

Yes. Underload can reduce vigilance and increase complacency, missed cues and delayed detection of changes.

What are the main operational effects of fatigue?

Reduced vigilance, slower reaction, impaired judgement, poorer memory, weaker monitoring and increased susceptibility to errors.

Why is subjective alertness an unreliable measure of fatigue?

People may underestimate their own impairment, particularly after prolonged wakefulness or repeated sleep restriction.

What is sleep debt?

The cumulative performance impairment resulting from insufficient restorative sleep over time.

Why can circadian rhythm impair performance even after apparently adequate rest?

Human alertness varies biologically with time of day, producing predictable periods of reduced performance independent of recent workload.

What is a microsleep?

A brief involuntary episode of sleep or loss of effective attention, potentially lasting only seconds but sufficient to miss critical information.

Why is caffeine not a substitute for sleep?

It can temporarily improve alertness but does not restore the cognitive and physiological functions provided by adequate sleep.

Why is hypoxia particularly dangerous from a human-factors perspective?

It can impair judgement, attention and coordination before the affected person recognises their own impairment.

Why is relying on subjective symptoms a poor defence against hypoxia?

Hypoxia itself reduces the ability to recognise and correctly interpret those symptoms.

Why are vestibular sensations unreliable when external visual references are absent?

The inner ear primarily senses changes in motion rather than sustained motion and can create convincing false sensations of attitude or acceleration.

What is the somatogravic illusion?

Rapid linear acceleration can be perceived as excessive nose-up attitude, while deceleration can be perceived as nose-down.

What is the fundamental defence against spatial disorientation in IMC?

Trust and cross-check reliable flight instruments rather than bodily sensations.

How can an unusually narrow or wide runway affect visual approach perception?

A narrow runway may create the illusion of being too high; a wide runway may create the illusion of being too low.

How can runway slope affect visual approach perception?

An upsloping runway may create an impression of being high; a downsloping runway may create an impression of being low.

What is a black-hole approach illusion?

At night with few surrounding visual cues, a pilot may perceive the aircraft as higher than it really is and unintentionally fly a low approach.

What is the key defence against visual approach illusions?

Cross-check visual perception against objective vertical-path and flight-instrument information.