The U.S. Air Force said Wednesday it had canceled its Ospreys fleet due to safety concerns, and the move will affect the tilt-rotor aircraft in Japan.
The command's public affairs director Rebecca Heyse said that the Air Force Special Operations Command ordered a safety shut down of its CV-22 fleet on Tuesday due to an increase in safety incidents.
The safety issues that are linked to a malfunctioning clutch inside a gearbox affect the transfer of drive from the engine to the propeller rotor, according to defense-focused U.S. media outlets.
In the coming days, the command will work with industry partners and others to understand the issue and develop risk control measures to mitigate the likelihood of catastrophic outcomes.
A U.S. Air Force official said that the move does affect those CV-22 stationed in Japan.
There have been four incidents involving the clutch problem during the flight since 2017 with two of them occurring in the past six weeks, it said. No one was injured in the incidents.
Ospreys, which take off and land like a helicopter, but cruise like a plane, have a patchy record of accidents and mishaps in Japan and abroad.
U.S. forces in Japan have deployed 24 MV-22 s at U.S. Marine Corps Air Station Futenma in the southern prefecture of Okinawa, and more than five CV 22 s at Yokota Air Base in the suburbs of Tokyo. MV 22 is a variant used by the Marines and CV 22 is used by the Air Force.