A pilot flying from Devonport, Tasmania to nearby King Island has fallen asleep and missed his destination by almost 50kms.
The Australian Transport Safety Bureau (ATSB) is investigating the Vortex Air freight flight on November 8.
"The issue became apparent when air traffic control was unable to contact the pilot in-flight, and the aircraft travelled past the intended destination point while operating on autopilot," a statement from Vortex-Air said.
“Vortex Air takes the safety of our passengers, crew and pilots extremely seriously and always abide by all safety procedures.
“This is an extremely rare occurrence.”
The pilot was the only person on board at the time of the flight.
Vortex Air also confirmed the pilot continued to fly that day.