Human Performance and Limitations
Scope
Human Performance and Limitations tests hypoxia, hyperventilation, carbon monoxide, fatigue, stress, spatial disorientation, visual illusions, and aeronautical decision making. The exam wants you to recognize a degraded pilot before it becomes an accident.
Core concepts
- Hypoxia: insufficient oxygen to tissues; early signs include euphoria, poor judgement, and headache. Use supplemental oxygen when required and descend.
- Hyperventilation: rapid breathing lowers CO2; symptoms can mimic hypoxia. Slow the breathing rate and treat suspected hypoxia seriously.
- Carbon monoxide is odourless; suspect it with cabin heat use, headache, or drowsiness. Open vents and land.
- Spatial disorientation: trust the instruments, especially in cloud or at night; do not rely on body sensations.
- Fatigue and stress narrow attention and slow decisions; use a personal checklist and diversion/landing option.
Worked example
On a night final over dark water, the runway appears too high, so the pilot pushes the nose down. Reasoning: the black-hole illusion makes a runway with no ground reference appear higher than it is; pushing down risks an undershoot. The correct action is to fly instruments and a stabilized approach, using VASI/PAPI if available, and not chase the illusion.
Traps
Assuming hypoxia always causes a dramatic gasp; euphoria can hide it. Confusing hyperventilation with hypoxia and ignoring CO. Believing you can overcome spatial disorientation by feeling the attitude. Fatigue is not fixed by caffeine.