Investigators found that the “catastrophic” failure of a gearbox, compounded by pilot actions, caused an Osprey military aircraft to crash off the coast of Japan last year, killing all eight personnel onboard, the U.S. Air Force said Thursday.
The CV-22 Osprey’s crash on Nov. 29 was the fourth in a string of fatal Osprey crashes over the past two years that have killed 20 service members. The latest incident caused a monthslong grounding of the military’s 400-strong fleet and spurred a major safety investigation into the craft’s unique design.
In the report released Thursday and obtained by the Associated Press, investigators said they’d determined that a pinion gear inside the Osprey’s proprotor gearbox had cracked about 40 minutes into an otherwise routine training flight out of Yokota Air Base.
