Human Performance and Limitations
What you must know
Study hypoxia (hypoxic, hypemic, stagnant, histotoxic), time of useful consciousness, hyperventilation, and the effects of altitude. Learn spatial disorientation and sensory illusions: somatogravic, somatogyral, leans, black-hole approach, and vestibular vs visual cues. Understand fatigue, circadian rhythm, sleep debt, and the danger of continuing a duty day beyond limits. Study stress, workload, situational awareness, decision making (DECIDE, FORDEC), crew resource management, communication, and the sterile cockpit concept. Learn vision (rods and cones, dark adaptation, empty-field myopia), hearing and noise, and decompression sickness.
Traps
Questions confuse hypoxia symptoms with hyperventilation (both cause dizziness and tingling - treat with 100% oxygen and controlled breathing). Another trap: the somatogravic illusion makes a pilot think the aircraft is pitching up during acceleration, leading to a push-over. Also, alcohol, medication, and self-medication rules: the pilot must not fly under the influence and must consult an AME.
Worked example
On a rapid decompression at FL350, time of useful consciousness is roughly 30–60 seconds. The correct action sequence is: don oxygen mask first, then descend, then communicate. Mask first is always the answer.
Rule of thumb
When in doubt, oxygen first, then descend, then talk. Never trust your senses in IMC - trust the instruments.