Human Performance and Limitations (Desempenho e Limitações Humanas)
This domain examines how the human body and mind behave in flight and how to manage their limits. Core concepts include hypoxia (hypoxic, hypemic, stagnant, histotoxic), hyperventilation and its similarity to hypoxia, spatial disorientation and the vestibular illusions (somatogravic, somatogyral, and the leans), and the effects of fatigue, stress, and dehydration. You must understand vision in flight - the role of the fovea and peripheral vision, night vision and the 30-minute dark adaptation, and the danger of empty-field myopia. Also know the effects of carbon monoxide, alcohol, and medications, and the IMSAFE checklist for fitness to fly.
Question traps often blur the distinction between hypoxia and hyperventilation, which share symptoms like dizziness and tingling but require opposite responses - hypoxia needs oxygen and descent, hyperventilation needs slowed breathing. Another trap is the somatogravic illusion: acceleration is misread as a climb, prompting a dangerous nose-down push on takeoff. Candidates also misjudge how quickly alcohol and fatigue impair judgment, or forget that CO poisoning produces a cherry-red complexion only late. Spatial disorientation questions expect you to trust the instruments, not your sensations.
Rule of thumb: "In IMC, believe the instruments, not your body." Worked example: on a dark night departure, a rapid acceleration creates a somatogravic illusion of pitching up, so the pilot instinctively lowers the nose - the correct action is to cross-check the attitude indicator and maintain the climb attitude.