Medical fitness

040 Human PerformanceChapter 7

Pilots must meet medical standards and report conditions that affect fitness. Lifestyle choices directly affect hypoxia tolerance and performance.

Reporting to the authority

Situation	Action
Hospital >12 h	Seek AME advice
Surgery / invasive procedure	Seek AME advice
Regular medication or correcting lenses	Seek AME advice
Significant injury / illness >21 days	Must advise authority in writing
Pregnancy	Must advise authority in writing

Key fact

Blood donation — no fly 24 hours (increased hypoxia susceptibility). Bone marrow donation — 48 hours. Local anaesthetic — 12 h; general anaesthetic — 48 h.

Alcohol

Key fact

EASA limit: 20 mg alcohol per 100 ml blood. Minimum 8 hours bottle-to-throttle (often “12 h if in doubt”). 0.05% blood alcohol — coordination begins to fail.

Key fact

Metabolism ≈ 1 unit (15 mg/100 ml) per hour by liver. 1 ounce alcohol ≈ +2,000 ft physiological altitude (histotoxic hypoxia). Alcohol does not promote barotrauma but degrades REM sleep, judgement, G-tolerance, and causes spatial disorientation.

Exam trap

Weekly limits often cited: 28 units (M) / 21 units (F) — damaging threshold. Never rely on packaging alone for aircrew drug guidance.

Smoking

Key fact

Nicotine — addictive. Tar — carcinogen, heart disease. 1 pack/day ≈ 5–8% reduction in O₂ transport (CO poisoning) — equivalent to raising physiological altitude 4,000–5,000 ft when flying at 10,000 ft.

Drugs & medication

Key fact

Antibiotics — infections. Antihistamines — allergies (may cause drowsiness). Analgesics — pain. Anti-hypertensives — high BP. Always consult AME before flying on medication.

Key fact

Caffeine — limit 250–300 mg/day for aircrew; >200 mg may reduce performance (tremor, tachycardia). 1 cup ≈ 75 mg. Breakfast ≈ 25% of daily caloric intake.

Health & fitness

Formula — BMI

BMI = mass (kg) / height (m)²
Normal: 18.5–25 | Overweight: 25–30 | Obese: >30

Key fact

Diabetes — Type 1 insulin-dependent typically permanent unfit; Type 2 may be temporary. Hypoglycaemia — headache, lack of concentration; eat regular balanced meals/snacks.

Key fact

Exercise recommendation: double resting heart rate for 20 min, 3× per week. Hyperthermia acclimatisation to hot climate ≈ 14 days. Hypothermia — shivering stops, amnesia at severe stages.

Incapacitation

Key fact

Insidious (subtle) incapacitation is most dangerous. Takeover if: 2 failures to respond, or 1 failure + SOP deviation.

Key fact

Distinguish stroke (blood supply cut off), fit (electrical brain disturbance), faint (reduced O₂ to brain from low BP).

Radiation & environment

Key fact

Cosmic radiation increases with altitude, latitude, and exposure time. Records required above 49,000 ft. Ozone toxic; negligible below 40,000 ft in cabin; converters remove it from bleed air. Cabin RH often 5–15% (certification minimum ~30%, optimum 40–60%).

Key fact

After depressurisation: oxygen mask on FIRST, then descend to 10,000 ft or MSA.