The Navy and Air Force were given clearance to resume flying their grounded V-22 Ospreys as long as new guidelines are followed on how inspections are conducted on the controversial tilt-rotor aircraft's gearbox.
The military temporarily grounded some Osprey on Dec. 9 after a near crash in New Mexico in November, the Navy Times reported Friday. The Marines soon resumed Osprey flights, but the Navy and Air Force kept them idled longer while they further reviewed for what was causing metal components to fail.
Naval Air Systems Command, or NAVAIR, issued a bulletin to the fleet Friday morning ordering crews to verify how many hours each aircraft's proprotor gearbox had flown, according to the Times. If the gearbox meets or exceeds a certain number of flight hours — NAVAIR did not disclose how many because of operational security concerns — the aircraft can resume flying under limitations issued in March.
But if the gearbox is found to have fewer flight hours, the aircraft will have to fly under a new and stricter set of limitations, Air Force Special Operations Command Spokeswoman Lt. Col. Becky Heyse told Defense News. Heyse said some Ospreys kept flying to conduct necessary operations.
The crash of an Air Force CV-22 Osprey near Japan in November 2023 that killed all eight airmen on board was caused by a cracked gear, which had impurities called inclusions that weakened the metal, according to the Times. Similar metal weaknesses might have also caused the near crash last month near Cannon Air Force Base on the New Mexico-Texas border.
Four Osprey crashes have claimed the lives of 20 U.S. airmen since March 2022. Osprey manufacturer Bell is working with the V-22 Joint Program Office to upgrade some of the aircraft's gears to make those weakening impurities less common, the Times reported.
Studies of the Osprey revealed when impurities cause gear cracks, Heyse said it typically happens in their early life. Once they have flown a certain number of hours and are "broken in," she said they are less likely to crack, and the military is more confident in them. That is why the Ospreys under the flight hour threshold must adhere to the more conservative restrictions, she said.
The stricter guidelines for those Ospreys will stay in place until their gearboxes are upgraded, or they exceed the flight-hour threshold, NAVAIR said.
The military declined to say how many Ospreys are affected by these changes, and what their additional flight restrictions are, for security reasons, the Times reported. The Marine Corps has 350 Ospreys in its fleet. The Air Force has about 52 and the Navy has roughly 30.