The Department of Defense announced Wednesday that it was grounding all of its Osprey V-22 helicopters, a week after eight Air Force Special Operations Command service members were killed in a crash of the vehicle off the coast of Japan.
The grounding includes all Osprey V-22 vehicles used by the Navy, the Air Force and the Marine Corps.
A preliminary investigation of last week’s crash indicated that a materiel failure was the cause of the crash, not human error, but the investigation is ongoing.
The Osprey has been involved in several recent fatal accidents. Thirteen American service members have been killed in four Osprey crashes in the past two years,
Three U.S. Marines were killed and eight others were injured following an Osprey crash on an Australian island in August, according to The Associated Press.
Last year, five Marines died when an Osprey crashed in the desert in California. In March 2022, four Marines died in a crash in Norway.
The U.S.-made Osprey is a hybrid aircraft that takes off and lands like a helicopter but can rotate its propellers forward and cruise much faster, more like an airplane, during flight.
Lt. Gen. Tony Bauernfeind, head of Air Force Special Operations Command, directed the standdown “to mitigate risk while the investigation continues,” the command said in a statement. “Preliminary investigation information indicates a potential materiel failure caused the mishap, but the underlying cause of the failure is unknown at this time.”
In a separate notice, Naval Air Systems Command said it was grounding all Ospreys. The command is responsible for the Navy and Marine Corps variants of the Osprey.
Air Force Special Operations Command has 51 Ospreys, the U.S. Marine Corps flies as many as 400 and the U.S. Navy operates 27.
The Air Force said it was unknown how long the aircraft would be grounded. It said the standdown was expected to remain in place until the investigation into the latest crash is concluded.