Human Performance and Limitations
Human Performance and Limitations
This domain tests pilot physiology, perception and decision-making: hypoxia, hyperventilation, carbon monoxide, spatial disorientation, fatigue, stress and hazardous attitudes. Questions often ask what you would notice and what you should do first.
Core rules
- Hypoxia: reduced oxygen. Early signs include euphoria, tingling, light-headedness and impaired judgment. Use supplemental oxygen above 10,000 ft when required, and descend if symptoms appear.
- Hyperventilation: rapid breathing lowers carbon dioxide; symptoms can resemble hypoxia. Breathe slower and deeper; if symptoms persist, treat as hypoxia.
- Carbon monoxide: odourless; suspicion arises from headache, dizziness and drowsiness with cabin heat on. Shut off the heater, open vents and land.
- Spatial disorientation: trust the instruments, not your sensations, in cloud or at night.
- Fatigue and stress: degrade scan, radio work and decision-making. Use personal minimums and recognise hazardous attitudes such as invulnerability and get-there-it is.
Worked example
On a dark-night approach over water, the runway has no surrounding lights. You feel low and nose-down, but the altimeter and glidepath indicator show you are on profile. This is a black-hole approach illusion; continue on instruments and the visual glidepath, and do not “correct” by pulling up or pushing over based on sensation alone.
Traps that cost marks
Assuming hyperventilation is always harmless, ignoring CO symptoms because the cabin smells normal, and trusting a false horizon are common errors. “I can handle it” is a hazardous attitude, not a plan.