A military investigation has found a U.S. Marine Corps hybrid aircraft that crashed in Hawaii this year, killing two San Diego Marines, flew in sandy or dusty conditions for an extended period before its engine stalled.
The investigation found the stalled left engine put the MV-22 Osprey in an unavoidable freefall.
The airplane-and-helicopter hybrid crashed at a military base outside Honolulu in May with 21 Marines and a Navy corpsman on board.
U.S. Marine Forces, Pacific said in a statement Monday the pilots didn't violate any regulations or flight standards. But investigators say a proper risk assessment should have prompted the pilots to choose a different flight path or landing site to avoid dust or sand.
Investigators are recommending changes to help pilots make better decisions in similar situations.
Lance Cpl. Matthew J. Determan, 21, and Lance Corporal Joshua E. Barron, 24, were killed in the crash. They were deployed on USS Essex with the 15th Marine Expeditionary Unit, based at Camp Pendleton, and were in Hawaii for a week of training.
The Osprey is a tilt-rotor aircraft that can take off and land like a helicopter but flies like an airplane.
