Aeromedical Factors and Decision Making
The Aeromedical Factors and Decision Making domain tests whether you can recognize when your body or your attitude is the biggest threat to the flight, and whether you will act on that recognition.
Flight physiology
Hypoxia comes from insufficient oxygen and shows as euphoria, tingling, headache, and poor judgment; the response is supplemental oxygen and descent. Hyperventilation produces similar dizziness but with rapid breathing and tingling in the hands, so slow the rate. Carbon monoxide from the cabin heater is odorless and brings headache and drowsiness; shut off the heater, open vents, and land. Spatial disorientation, especially a black-hole approach at night, is defeated by reference to instruments and a stabilized approach. Fatigue, dehydration, and stress degrade judgment long before they are obvious.
Medical certification and self-grounding
A third-class medical is required. It is valid for 60 calendar months if you are under 40 and 24 calendar months if you are 40 or older. Alcohol: no flying within 8 hours of a drink, never with a blood alcohol of 0.04 or higher, and never while impaired. Any prescription or over-the-counter medication that warns against driving or operating machinery grounds you until you know its effect; check with an aviation medical examiner.
Decision making
Use IMSAFE before every flight: Illness, Medication, Stress, Alcohol, Fatigue, Eating. Use PA VE for the flight as a whole: Pilot, Aircraft, enVironment, External pressures. The five hazardous attitudes - anti-authority, impulsivity, invulnerability, macho, resignation - each has an antidote: follow the rules, slow down, it could happen to me, taking chances is foolish, I am not helpless.
Worked example
You slept four hours, took a sedating antihistamine, and a friend is waiting at the airport. IMSAFE fails on Illness/Medication and Fatigue; the urge to launch anyway is impulsivity, and the antidote is to slow down and not go. No amount of flight planning fixes a pilot who should not be flying.
Traps
Believing the eight-hour rule is the whole alcohol regulation. Assuming nonprescription drugs are automatically safe. Confusing hyperventilation with hypoxia. Treating a valid medical certificate as proof of fitness for today's flight.