Human Performance and Limitations
The body in flight
Understand hypoxia - insufficient oxygen reaching the tissues - and its insidious onset above roughly 10,000 ft cabin altitude, with euphoria, tingling, poor judgement and cyanosis. Hyperventilation produces similar tingling and dizziness but is treated by slowing the breathing rate, whereas hypoxia requires oxygen or descent; if in doubt, treat it as hypoxia. Learn the gas laws that explain trapped-gas expansion and decompression sickness, carbon monoxide poisoning from the cabin heater, and the effects of alcohol, medication, fatigue and circadian rhythm.
Perception
Spatial disorientation is a major killer: the somatogravic illusion during acceleration makes you believe you are climbing, the leans follow a slow roll, and a black-hole approach at night puts you too low. Vision matters too - cones for detail and colour, rods for night vision, and the fovea effectively blind in darkness - so use off-centre viewing and dim cockpit lighting.
Decision making
Know the IMSAFE checklist, the DECIDE model, and the SHELL and Reason 'Swiss cheese' models of error. Questions test whether you accept that errors are normal, that judgement is trainable, and that steep authority gradients suppress the challenge that prevents accidents.
Common traps
Confusing hyperventilation with hypoxia; assuming you will notice your own hypoxia; and treating stress as always harmful, when moderate arousal improves performance.
Rule of thumb
Allow about 30 minutes for full dark adaptation, avoid white light, and scan 5–10° off-centre to detect dim objects at night.