Human Performance and Limitations
The human in the loop
Human performance questions test your understanding of physiology and psychology in flight. Know hypoxia: its onset with altitude, the insidious nature of symptoms, and the value of supplemental oxygen. Understand hyperventilation and how it can mimic hypoxia, and the role of the pressurisation system in preventing both.
Spatial disorientation
Know the vestibular illusions: the leans, somatogravic illusion (false climb sensation on acceleration), and somatogyral (false rotation). The remedy is to trust instruments, not sensations. Candidates should understand why visual illusions on approach, such as a black hole approach or a narrower-than-usual runway, cause low or high approaches.
Fatigue and stress
Know the difference between acute and chronic fatigue, and the effect of circadian rhythm on performance. Understand that stress narrows attention and that workload management, prioritisation, and communication are core crew resource management skills.
Traps
- Assuming hypoxia always produces obvious symptoms; it often produces euphoria and impaired judgement first.
- Confusing hyperventilation (which lowers CO2 and can cause tingling and dizziness) with hypoxia.
- Believing you can overcome spatial disorientation by feel; you cannot.
- Forgetting that fatigue degrades judgement before it degrades skill.
Worked example
If a pilot feels euphoric and has tingling fingers at altitude, suspect hyperventilation and slow the breathing rate; if symptoms persist, treat as hypoxia and use oxygen. The distinguishing clue is the tingling and the absence of cyanosis.