THE AIRPLANE'S ENGINE FAILED SHORTLY AFTER THE FLIGHT'S DEPARTURE FROM THE AIRPORT. THE POST ACCIDENT INSPECTION OF THE ENGINE REVEALED A SURFACE ORIGINATED FATIGUE CRACK IN THE CRANKSHAFT AT THE NUMBER TWO CRANKCHEEK. AT THE TIME OF THE MISHAP, THE ENGINE HAD ACCRUED A TOTAL OF 86 HOURS SINCE OVERHAUL BY THE OPERATOR. THE PILOT COMMENTED TO ALASKA STATE POLICE PERSONNEL THAT HE HAD SUFFICIENT ALTITUDE TO LAND THE AIRPLANE ON THE AIRSTRIP.