Key notes — quick revision

040 Human PerformanceQuick revision

Human factors

Key fact

70% accidents human factors. GPWS biggest safety gain. Error rate 1:1000. Fault = wrong intent; Slip = wrong action. Swiss cheese = aligned holes. TEM: Threats → Errors → UAS.

Physiology

Key fact

Dalton = hypoxia. Henry = DCS. Boyle = trapped gas. Breathing controlled by CO₂. PP O₂ critical 55 mmHg @ 10,000 ft. Cardiac output = SV × HR.

Hypoxia / hyperventilation / DCS

Key fact

4 hypoxia types: hypoxic, hypaemic, stagnant, histotoxic. Stages: indifferent → compensatory → disturbance → critical. Cyanosis = hypoxia sign. Clammy + tingling = hyperventilation. DCS: bends, creeps, chokes, staggers. Dive >30 ft = 24 h wait.

Vision / vestibular

Key fact

Fovea = cones/day. Periphery = rods/night. Night adapt 40 min. Coriolis = most dangerous illusion. Leans = after undetected turn. Black hole = fly low on approach.

Fitness

Key fact

Alcohol 20 mg/100ml, 8 h min. 1 oz = +2000 ft. Smoke 1 pack = 5-8% O₂ loss. Blood donate 24 h. Illness >21 days report in writing. BMI normal 18.5-25.

CRM & sleep

Key fact

Sleep 8 h, cycle 90 min, circadian 25 h. Assertiveness aids decisions. Confirmation bias — seek disproof. Working memory ~7 items. CRM = coordination + communication.

Exam trap

Henry’s sick, Dalton’s hypoxic. Below 10k ft = think hyperventilation. Above 10k ft = think hypoxia. Joint pain = DCS not hypoxia.