The Federal Aviation Administration has opened an investigation into whether two go! airlines pilot fell asleep during a flight from Honolulu to Hilo last week.

Go! Flight 1002 was headed for Hilo Airport around 10 a.m. last Wednesday morning but overshot the airport by 15 miles before heading back to land safely.

FAA spokesman Ian Gregor said today that the federal agency has opened an investigation of the pilots' actions during the 29-minute flight.

"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," said FAA spokesman Ian Gregor.

Joe Bock, a spokesman for go! declined comment, saying the company is conducting its own investigation.

Gregor said the FAA plans to interview the pilots on the flight. Under FAA rules, the pilots could be subject to a warning, suspension or license revocation depending on the findings of an investigation.

A radar track of the flight provided the Web site www.flightaware.com shows that the flight remained at 21,000 feet as it flew past Hilo before returning to the airport.

Air traffic controllers, which had been tracking the plane by radar, were unable to reach the plane for 25 minutes, according to a report by KGMB-TV.

Go! is a unit of Phoenix-based Mesa Air Group, which has been a subject of complaints from its own pilots union about crew shortages and aircraft problems.

Last year, the Mesa unit of the Air Line Pilots Association protested against the company, saying the shortages were hurting morale and were impacting the company's operations.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.