Incident Overview
While climbing en route from Bettles to Fort Yukon on a firefighting mission, the aircraft experienced a right engine fire that escalated into an explosion. The captain ordered the four firefighters and the copilot to evacuate the cabin, leaving the captain as the sole occupant on board. The captain then attempted an emergency landing on a sandbar located near the Kayokuk River.
Rescue and Damage
All six occupants were subsequently rescued. The aircraft sustained damage that rendered it beyond repair.
Probable Cause and Contributing Factors
The official investigation determined the probable cause to be a powerplant failure for undetermined reasons. Contributing factors reported included a fire in the engine, inadequate maintenance and inspection, loose gravel, sandy terrain, forced landing off airport on land, an unknown internal fire in the right engine, and an unfeathered propeller.