Clinical aspects of inflight incapacitations in commercial aviation

Sudden incapacitations can affect a pilot and even a whole crew during a flight, preventing them from performing their task in complete safety. In some cases, they could even cause an accident. Our study examines the causes of sudden in-flight incapacitation in Air France pilots and flight engineers from 1968-88. Ten cases were reported out of a population of 1,800 cockpit crew, each flying an average of 600 h/year. These incapacitations were due to cardiac disorders (1 atrial fibrillation, 1 sinus tachycardia), epileptic attacks (2 generalized seizures), duodenal hemorrhages (2 cases), infection (1 case of severe vertigo due to viral labyrinthitis), metabolic disorders (1 case of hypoglycemia), and sometimes disorders affecting the whole crew (1 case of hypoxia due to a pressurization deficiency, 1 case of CO2 intoxication caused by the inadequate packaging of a container refrigerated in dry ice). Seven times out of ten, incapacitations occurred during cruising, twice during approach, and once on the ground before starting up, with closed doors (CO2 intoxication). Two of these incapacitations led to flight diversions. None of them caused an accident. In this series, incapacitations of a cardiac nature were rarer and less serious than those caused by gastrointestinal or neurological disorders. Prevention is based on detection during systematic medical check-ups, and on crews being trained to recognize subtle incapacitations early and to ensure that the flight continues safely when such a case occurs.