Human Performance and Limitations
What the paper tests
Human performance questions ask you to recognise hypoxia, hyperventilation, decompression, fatigue, spatial disorientation, illusions and CRM failures, and to choose the safest response. The exam favours scenario reasoning over definitions.
Key concepts
- Hypoxia: slow reaction, euphoria, poor judgment; symptoms are unreliable, so use oxygen and descend.
- Hyperventilation: dizziness, tingling, chest tightness; can mimic hypoxia. Control breathing and confirm with oxygen if unsure.
- Decompression: don oxygen first, then descend; do not wait for symptoms.
- Vestibular illusions: somatogravic, somatogyral, leans and Coriolis; most dangerous in IMC or at night without visual reference.
- Visual illusions: black-hole approach, runway slope and width, autokinesis.
- Fatigue and circadian rhythm degrade vigilance; CRM includes workload sharing, monitoring and assertiveness.
Worked example
On a night go-around, the aircraft accelerates. The otoliths signal a pitch-up sensation, so the pilot may push forward and descend toward terrain. The correct response is to fly on instruments, confirm pitch attitude and climb performance, and ignore the false sensation. In deceleration, the opposite illusion may cause a pull-up.
Traps
Do not assume a pilot with hypoxia will notice it. Do not treat hyperventilation with more rapid breathing. Do not rely on vestibular senses in IMC. Do not confuse fatigue with simple sleepiness; both affect decision quality.