Military Reviews Issues That Caused a Fatal 2023 Crash

The V-22 Osprey is getting a long overdue upgrade. Following the 2023 crash off the coast of Japan that killed eight Airmen, the U.S. military has decided it might be time to address the glaring issues with the tiltrotor aircraft’s drivetrain.

At the heart of these fixes is the aircraft’s notoriously complex gearbox. The Osprey’s proprotor gearbox (PRGB) is what enables the aircraft to transition between helicopter and airplane modes. Unfortunately, this same gearbox has been the root of numerous safety concerns over the years, with engineers struggling to keep up with the stresses placed on the drivetrain. The latest solutions include installing sensors to monitor for potential failures, improving the quality of steel used in key components, and redesigning the input quill assembly.

These modifications will be implemented across all V-22 variants, including those operated by the Air Force, Marine Corps, and Navy. While officials have not provided an exact timeline, the changes are expected to roll out fleet-wide in the coming months. Given the Osprey’s track record, many would argue these updates are arriving about a decade too late.

The decision to make these changes comes after a series of alarming incidents. In addition to the fatal November 2023 crash, an Air Force Osprey suffered a ‘never-before-seen’ material failure that forced an emergency landing in November 2024. That incident triggered yet another operational pause for the fleet as officials scrambled to check other aircraft for similar problems.

One of the more concerning revelations in this saga is the long-suspected issue with the steel used in the pinion gear -- the very component that failed in the deadly 2023 crash. Reports indicate that the company supplying the steel, Universal Stainless, was sued back in 2001 for allegedly producing defective aircraft materials. Now, after years of issues, the military has decided it might be a good idea to refine the steel used in these critical gearbox components.

Other improvements include the Osprey Drive System Safety and Health Instrumentation (ODSSHI), which will install vibration sensors to detect potential failures before they happen. The redesigned input quill assembly is also expected to reduce hard clutch engagements—an issue that has plagued the fleet for years, leading to at least 19 recorded incidents.

Despite these efforts, skepticism remains. The Osprey’s drivetrain has been a known weak point since its introduction, and while these upgrades might reduce some of the risks, they don’t change the fact that the aircraft’s fundamental design places enormous stress on its gearbox.

FMI: www.boeing.com/defense/v-22-osprey