Bell-Boeing CV-22B Osprey crash near East China Sea off Yakushima, Kagoshima, Japan

The CV-22B suffered a catastrophic failure of the proprotor gearbox, the left nacelle caught fire, and the aircraft rolled inverted and came down in the East China Sea off Yakushima, killing all eight crew. The accident investigation board traced the failure to cracking in a high speed planetary pinion gear, a failure mode with no precedent in the fleet, and also found that the pilot had continued the flight after chip burner warnings rather than landing. The accident led to a worldwide grounding of the type.