Incapacitation of a pilot due to the effects of a medical
condition or a physiological impairment represents a serious
potential threat to flight safety. The purpose of this research
project was to investigate the prevalence, type, nature and
significance of in-flight medical conditions and incapacitation
events occurring in civil aviation. A search of the Australian
Transport Safety Bureau's accident and incident database was
conducted for medical conditions and incapacitation events between
1 January 1975 and 31 March 2006. There were 98 occurrences in
which the pilot of the aircraft was incapacitated for medical or
physiological reasons (16 accidents, one serious incident and 81
incidents). Such events accounted for only 0.6 of a percentage
point of all the occurrences listed in the Australian Transport
Safety Bureau's database. The majority of the events occurred in
airline operations, with private flying the next most common (22.4
per cent of events). In 10 occurrences (10.2 per cent), the outcome
of the event was a fatal accident. All of these accidents involved
single-pilot operations, and in the majority of cases, heart attack
was the most common cause. The majority (21 per cent) of in-flight
medical and incapacitation events in Australian civil pilots for
the study period were due to acute gastrointestinal illness
(usually food poisoning), a finding consistent with other published
studies. The next most common cause was exposure to toxic smoke and
fumes on board the aircraft, of which 25 per cent were due to
carbon monoxide. The results of this study demonstrate that the
risk of a pilot suffering from an in-flight medical condition or
incapacitation event is low. However, if the pilot suffers a heart
attack the risk of a fatal accident occurring increases. The
aeromedical certification process must keep pace with the evolving
nature of modern medical science to ensure that the risk of
in-flight incapacitation remains low.