IMSAFE — Self-Fitness Check

Even with a valid medical certificate under EASA Part-MED, MED.A.020 applies: the pilot must not exercise privileges as soon as they notice signs of decreased medical fitness, effects of medication, drugs, or alcohol. IMSAFE is the established checklist (FAA-H-8083-25B Chapter 2 Aeronautical Decision-Making).

I — Illness

Cold, fever, nausea, diarrhoea, migraine, acute pain → do not fly. Even harmless infections increase pressure-equalisation problems (see [[dekompressionskrankheit-bends]]), concentration deficits, and hypoxia susceptibility.

Body core temperature — performance effect

Mental performance is closely linked to body core temperature (normal: about 36.5–37.5 °C). Even small deviations measurably reduce cognitive performance:

Consequence: with fever ≥ 38 °C or unclear hypothermia (e.g. after long exposure in cold cockpit) → self-ground.

M — Medication

Antihistamines, sleep aids, opioids, sedatives, many cold remedies are not flight-compatible. Rule of thumb: on first use at least 5 half-lives clear before flying; consult an AME (aeromedical examiner) if uncertain. OTC medications count too — e.g. diphenhydramine (Bonadoxin / sleep aid) causes sedation.

Even prescription drugs without a fresh prescription (self-medicated, OTC) require AME advice before flying — the effect on cognition and reaction is often underestimated.

S — Stress

Professional pressure, family problems, financial worries reduce attention and workload reserve (see [[stress]]). Acute stressful events (death, separation) are a "self-ground" indication.

A — Alcohol

EASA Part-MED Subpart B prohibits exercising privileges under influence. ICAO Annex 1 §1.2.7 requires at least 8 h between last consumption and duty start; many authorities add a maximum BAC (e.g. FAA: 0.04 %). Bottle-to-throttle 8 h is the minimum; after significant amounts even 24 h is too short due to residual effects on the vestibular system and sleep architecture. See [[drogen-und-alkohol]].

F — Fatigue

Acute fatigue (sleep deficit <6 h) and chronic fatigue reduce reaction time similar to alcohol; Dawson & Reid (1997) showed 17 h awake equivalent to 0.05 % BAC. Long journey to the airfield, very early start, hard work day → check carefully.

E — Emotion / Eating

Acute emotional load (anger, grief) narrows focus and promotes tunnel thinking. Eating: hypoglycaemia from skipped meals or dehydration measurably worsens cognition — see [[ernaehrung-fluessigkeit-rauchen]].

Lifestyle risk factors — background conditions

Certain lifestyle conditions raise long-term risk of flight-relevant diseases:

→ These factors are not acutely day-fitness-deciding, but long-term relevant for maintaining the medical certificate and the pilot career.

Practical application

IMSAFE belongs before every flight — before weather, before performance, before mass & balance. It is a self-ground decision; no one but the pilot can make it.