Australian authorities are investigating an incident which saw a flight continuing past its destination - because the pilot was sleeping in the cockpit.
It happened on November 8 on a chartered flight between Devonport on mainland Tasmania and nearby King Island.
A statement from the Australian Transport Safety Bureau (ATSB) says the pilot of the Piper PA-31 operated by Vortex Air fell asleep when the flight reached cruising altitude and flew 46km past his intended destination.
As part of the investigation, the ATSB will be reviewing operational procedures and interviewing the pilot.
A 2013 study by the British Airline Pilots Association found that 56 percent of pilots admitted to falling asleep while flying, and 29 percent of those said they awoke to find their co-pilots were also asleep.
A final report on the Tasmanian incident is expected in March 2019.