An Australian study over five years found there had been 23 pilot incapacitation occurrences reported per year on average in that country.
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, the Australian Transport Safety Bureau report found.
New Zealand Air Line Pilots Association president Tim Robinson said pilots trained for colleagues being incapacitated.
''Those kind of things are the exception but they do occur. We've certainly got procedures in place to deal with those and there's been a number of cases where there have been bugs and a crew member has gone down.''
He said pilots in simulators regularly trained for one going sick and the other carrying out all procedures to fly and land the plane.