Gearbox Failure, Pilot Decision to Keep Flying Blamed for Japan CV-22 Crash, Says Air Force Probe | Aviation

The U.S. Air Force’s Accident Investigation Report says that the CV-22 crash could have been prevented had the crew decided to land earlier and at a closer airfield.

The Nov. 29, 2023 crash of the CV-22B of the U.S. Air Force Special Operations Command off the coast of Yakushima in Japan, that killed eight American personnel, was owing to “catastrophic failure” in one of the aircraft’s PRGBs (Prop Rotor Gearboxes), the Aircraft Accident Investigation Board has found. Previous reports, including here at The Aviationist, had noted that, while a recurring “hard clutch engagement” had been a cause behind previous accidents, investigators had determined a different “parts failure” for this time around.

A few months ago, some officials identified off the records the gearbox as the culprit part (the ‘what’), and were examining “why” and how it failed. This aspect currently remains unclear, but more light has been shed on the manner in which the gearbox failed and what transpired in the cockpit.

From Dec. 6, 2023, through May 30, 2024, the AAIB conducted interviews, perused maintenance logs, flight recorder data, briefing materials, and inspection of aircraft wreckage. The…