The pilot is part of the aircraft system — and the part that fails most often.
Most accidents trace back to human factors, not broken machines. As PIC you assess your own fitness as carefully as you assess the aircraft and weather. The good news: nearly every aeromedical hazard is preventable with awareness and an honest self-check.
| Factor | What happens | Pilot action |
|---|---|---|
| Hypoxia | Too little oxygen reaching the body/brain; judgment and vision degrade, often without the pilot noticing. | Descend; use supplemental oxygen when required by altitude/regulation. |
| Hyperventilation | Over-breathing (often from stress) blows off CO₂; tingling, lightheadedness, anxiety. | Slow the breathing rate; talk aloud; symptoms reverse quickly. |
| Carbon monoxide | CO from exhaust binds hemoglobin; headache, drowsiness — a faulty heater is a classic source. | Fresh air, shut off heater, land; consider a CO detector. |
| Dehydration & fatigue | Reduce alertness and reaction time; fatigue mimics impairment. | Hydrate, rest, and don't fly tired. |
Curated reference clip — “Aeromedical Factors,” ERAU SpecialVFR / Embry-Riddle Aeronautical University (YouTube). Embedded with the creator's player; we don't host or alter it. General aeromedical content applies across category/class.
Without a clear visual horizon — at night, over water, or in reduced visibility — your inner ear can convincingly lie about attitude. This is spatial disorientation, and for a VFR pilot it is deadly. The defense is to avoid degraded-visual conditions and, if you encounter them, to trust the instruments over your sensations. Also respect vision physiology: the eyes take time to adapt to darkness, and there is a night blind spot — scan, don't stare.
| Letter | Ask yourself |
|---|---|
| Illness | Am I sick — even a cold that affects pressure equalization or focus? |
| Medication | Am I on anything that could impair me? When in doubt, don't fly. |
| Stress | Is life stress occupying mental bandwidth I need for flying? |
| Alcohol | Bottle-to-throttle and blood-alcohol limits met, with margin? (14 CFR 91.17.) |
| Fatigue | Am I rested, or pushing through tiredness? |
| Emotion / Eating | Am I emotionally settled, hydrated, and fed? |
The FAA names five hazardous attitudes — anti-authority, impulsivity, invulnerability, macho, and resignation — each with a mental antidote. The most common real-world trap is get-there-itis (mission completion bias): pressing into worsening weather or fatigue because you want to arrive. Naming the pressure out loud is the first step to defeating it.
Aeromedical material lives in the FAA's Pilot's Handbook of Aeronautical Knowledge and the AIM, not the Helicopter Flying Handbook.
📄 FAA Pilot's Handbook of Aeronautical Knowledge — “Aeromedical Factors” chapter 📄 AIM Chapter 8 — Medical Facts for Pilots 📄 14 CFR 91.17 — Alcohol & drugs