Two go! pilots who overshot the runway at Hilo by 15 miles have been fired.

The interisland carrier has not released the names of the pilots. Investigation into the Feb. 13 Honolulu-to-Hilo flight has focused on the possibility the pilots both fell asleep.

The plan carrying 40 passengers had to circle back to land safely at Hilo.

Mesa Air Group confirmed it has fired the pilots but has not elaborated, saying it's a personnel matter.

The Air Line Pilots Association says it has filed a grievance with the air carrier on the pilots' behalf. Union attorney John Dean said the pilots were fired 10 days ago.

A report on the National Transportation Safety Board's investigation of the incident is not expected until June.