Why the ATSB did this research
Occasionally pilots become incapacitated during flight. Incapacitations can arise from different reasons. They include the development of an acute medical condition, changes in environmental conditions during the flight, or the effects of a pre-existing medical condition. The effect of incapacitation on a pilot can be restricting their flight duties for the remainder of the flight, or for single-pilot operations, a collision with terrain.
This research report documents pilot incapacitation occurrences in high capacity air transport, low capacity air transport, and general aviation to help educate industry about the causes and risks associated with inflight pilot incapacitation.
What the ATSB found
In the past 5 years, there have been 23 pilot incapacitation occurrences reported per year on average. Nearly 75 per cent of the incapacitation occurrences happened in high capacity air transport operations (about 1 in every 34,000 flights), with the main cause being gastrointestinal illness, followed by laser strikes. In the majority of the occurrences reported, the incapacitation was severe enough for the pilot to be removed from duty for the remainder of the flight. With multi-pilot crews in high capacity operations, these occurrences usually had minimal effect on the flight.
Low capacity air transport and general aviation had fewer occurrences with a wider variation of causes of incapacitation. These ranged from environmental causes, such as hypoxia, to medical conditions, such as heart attack. Furthermore, 70 per cent of pilot incapacitation occurrences in general aviation had an effect on flight operations, namely return to departure aerodrome or collision with terrain.
This report highlights that pilot incapacitation can occur in any operation type, albeit rarely. In high capacity air transport operations, the practice of ensuring all pilots on the same flight eat different meals prior to and during the flight has been an effective defence preventing all pilots on the same flight becoming incapacitated at the same time. Providing pilots with training in dealing with incapacitation events has been effective for when these events do occur. Pilots are also encouraged to report laser strikes to police and the Office of Transport Security. In low capacity air transport operations, providing emergency training to non-flight crew, such as aeromedical nurses, is an important defence in case of pilot incapacitation. Finally, in general aviation, pilots are reminded to assess their fitness prior to flight. Assessment of fitness includes being aware of any illness or external pressures they may be experiencing.