Human Performance and Limitations
This domain links physiology and psychology to flight safety. Begin with the senses used in flight: vision, hearing, and the vestibular system. Understand how the eye adapts to darkness, why off-centre viewing improves night vision, and how spatial disorientation arises when vestibular cues conflict with instruments. Know the illusions - somatogravic, somatogyral, and the leans - and the correct response: trust the instruments.
Hypoxia is a core topic. Distinguish hypoxic, hypaemic, stagnant, and histotoxic hypoxia, and know the signs, the time of useful consciousness at altitude, and the role of supplemental oxygen. Study decompression sickness and the effects of trapped gas.
Fatigue, stress, and workload affect judgement. Learn the symptoms of fatigue and the countermeasures, plus the concept of the hazardous attitudes and how to counter each with a antidote thought. Crew resource management principles - communication, assertiveness, situational awareness, and decision-making - appear frequently.
Worked example
A pilot in a climb without oxygen notices euphoria and tingling. The question asks the first action. Reasoning from hypoxia physiology, the answer is to descend and use oxygen, not to continue and monitor.
Traps include confusing hypoxia types, misidentifying illusions, and choosing a passive response where an active correction is required.