The pilots of an inter-island flight from Honolulu to Hilo failed to respond to air traffic controllers 11 times as it overshot its destination by 15 miles while flying at an altitude of 21,000 feet.

According to air traffic control tapes obtained by TV station KGMB, a controller monitoring airspace around Maui repeatedly tried to raise the two pilots of the go! flight on Feb. 13. They are being investigated for possibly falling asleep during the 214-mile flight.

The controller was initially unable to contact the pilots of Flight 1002 when she tried to call them about 15 minutes after the plane left Honolulu.

Finally, about 32 minutes into the flight, the captain responded, and the controller said: "Air shuttle 1002, guys, I've been trying to contact you for the last 90 to 100 miles. I understand you've passed Hilo, I'm going to turn you back to the northeast bound to get you back to the Hilo airport. Is there some kind of emergency situation going on?"

"Uh no emergency situation," the captain said.

After listening to the tapes, airline analyst Peter Foreman told KGMB on Friday that it was clear something was wrong.

"By the time you get 60 miles from your destination, it's time to descend," he said. "So obviously someone was not minding the store."

The National Transportation Safety Board has said the flight had no mechanical problems, but its preliminary report reached no conclusion as to why the plane overshot Hilo International Airport. The Federal Aviation Administration is also investigating.

Go!'s parent company, Phoenix-based Mesa Air Group, grounded both pilots while the investigations continued.

The flight, which also carried 40 passengers and a flight attendant, landed safely.