A go! airliner overshot Hilo International Airport by 15 miles last week, and the Federal Aviation Administration is investigating whether the pilots were sleeping.
"We're investigating whether the pilot and co-pilot of a Feb. 13 go! airlines flight fell asleep while the plane was in the air between Honolulu and Hilo," FAA spokesman Ian Gregor said.
Midmorning Flight 1002 drifted off course during the 214-mile trip and had to turn back to get to the airport on the Big Island. The flight landed safely.
Air traffic controllers tracking the plane by radar were unable to contract the cockpit for 25 minutes, according to a report by KGMB-TV.
Mesa Air Group, the parent company of go!, is cooperating fully with the FAA, said Paul Skellon, vice president of communications. He said the company would not comment further until the investigation was complete.
If the pilots did fall asleep while the plane was on autopilot, FAA rules carry penalties ranging from a warning letter to license suspension or revocation.
Mesa launched go! in June 2006. It is the state's fourth largest carrier, flying 50-seat Bombardier CRJ-200 aircraft.