United States Air Force CV-22 Crash

A United States Air Force CV-22B Osprey of the 21st Special Operations Squadron crashed into the sea off Yakushima, in Kagoshima Prefecture, during a routine training mission, killing all eight airmen aboard. The accident investigation attributed the crash to a catastrophic failure of the left-hand proprotor gearbox, most likely initiated by a crack in a high-speed pinion gear, and also faulted the crew's response to repeated chip-burn warnings and the decision to press on toward a more distant airfield. The loss led to a grounding of the entire United States V-22 fleet that lasted several months.