Human Performance and Limitations
What the exam tests
Human Performance and Limitations covers hypoxia, hyperventilation, spatial disorientation, fatigue, stress, vision, hearing, decision-making, and crew resource management in single-pilot and multi-crew operations.
Core rules
- Hypoxia symptoms include euphoria, impaired judgement, headache, and cyanosis. Time of useful consciousness falls rapidly above FL350.
- Hyperventilation produces dizziness, tingling, and muscle spasms; symptoms overlap with hypoxia. Treat suspected hypoxia with 100% oxygen and a descent, not faster breathing.
- Somatogravic illusion occurs during acceleration, such as a night take-off, and creates a false pitch-up sensation; the pilot may push forward and descend.
- The black-hole approach occurs at night over featureless terrain or water; the runway appears higher than it is, leading to a low approach.
- IMSAFE is a pre-flight self-check: Illness, Medication, Stress, Alcohol, Fatigue, Emotion.
Worked example
On a dark night over water, a pilot on final sees the runway lights but no horizon. The approach feels high, so the pilot lowers the nose. The result is a dangerously low approach. The correct action is to fly the PAPI or VASI and instrument glideslope, cross-check altitude and sink rate, and ignore the false visual picture.
Traps
Do not treat hyperventilation with more rapid breathing. Do not rely on feelings of pitch attitude at night or in cloud. Do not continue after a fatigue or illness check that fails IMSAFE.