V-22s cleared to fly following operational pause, with restrictions on newest parts of the fleet

WASHINGTON — Naval Air Systems Command today is clearing the V-22 Osprey fleets to continue operations following a pause put in place earlier this month, albeit with some restrictions on how the newest parts of the fleet can operate.

NAVAIR, the Navy’s primary agency for procuring aircraft as well as determining their airworthiness, said in a statement that it has issued a fleet bulletin directing that V-22 Ospreys be inspected prior to their next flight to “verify flight hours on each Proprotor Gearbox (PRGB).”

“Aircraft with PRGBs that currently meets or exceeds a predetermined flight-hour threshold will resume flights in accordance with controls instituted in the March 2024 interim flight clearance (IFC),” according to the statement.

“A new IFC, containing additional risk mitigation controls, has been issued to address aircraft with PRGBs below the flight-hour threshold. These controls will remain in place until the aircraft’s PRGBs are upgraded, or the predetermined threshold is exceeded,” the statement continued.

NAVAIR oversees the V-22 Joint Program Office which delivers Osprey variants to the US Navy, Air Force, Marine Corps as well as international customers. The agency declined to publish details concerning the flight-hour threshold, number of aircraft affected or additional controls, citing operational security concerns.

However, a source with knowledge of the program said that the issue stems from “inclusions” in the metal of the gearbox, common small faults that inevitably occur during the metallurgy of producing the parts for both commercial and military vehicles. The NAVAIR analysis found that these inclusions led to cracks in previous V-22 incidents — but that if the cracks don’t occur early in the part’s lifespan, the inclusions won’t present problems down the road.

In other words, if the part is going to fail, it will fail early in the lifespan of the V-22. As a result, newer V-22s will be operating under safety guidance until they hit a certain number of hours, the source said, at which point they will be able to fly normal operations.

Those restrictions are built around how much time it takes to get a V-22 onto the ground safely, the source said, noting it largely means crews need to plan out their flight path and be aware of their altitude during operations in case they need to make an emergency landing, the source said. Those requirements likely won’t impact operations over land but are likely to have greater impacts during sea-based operations.

“NAVAIR remains committed to transparency and safety regarding all V-22 operations. The V-22 plays an integral role in supporting our nation’s defense. Returning these vital assets to flight is critical to supporting our nation’s interests,” the statement said.

The Pentagon opted to pause certain V-22 operations earlier this month following what it called a “precautionary landing” by an Air Force Osprey, which did not result in any injuries. That incident, and now this subsequent return to flight, is the latest in a string of incidents the Osprey fleet has faced in recent years as the Defense Department has grappled with a variety of technical issues.

A fatal MV-22 Osprey crash that killed five Marines in June 2022 was blamed on the gearbox, with the department working with industry to design and field a new “proprotor gearbox input quill assembly that mitigates the unintentional clutch disengagements and hard clutch engagement events,” according to a 2023 statement.

All three services were then directed to replace the gearbox input quill assemblies after an undisclosed “predetermined flight hour threshold,” which the service at the time said “reduces the likelihood of a hard clutch engagement occurring by 99 percent, based on the data.”

Since that June 2022 incident, the Osprey has been on a roller coaster of restrictions, shutdowns and returns to flight.

In August 2022, Breaking Defense first reported that the Air Force was grounding its CV-22 fleet over safety concerns with the clutch of the aircraft. At the time, the Marine Corps did not follow suit, instead insisting their pilots could compensate for the issue and had been doing so for some time. While the Air Force returned to flight weeks later, the issue re-emerged and a Pentagon-wide grounding across a “subset” of the Navy, Air Force and Marine V-22 models was instituted in February 2023.