The Pentagon said Friday it would start shipping 24 hybrid aircraft to Japan next month but would not fly them until final results of crash investigations confirmed for Tokyo that the helicopter-plane is safe.
The Marine Corps' MV-22 tilt-rotor troop transport's troubled past has stirred safety concerns and protests on Okinawa, the southern Japanese island where the Pentagon intends to deploy it as part of a streamlined U.S. military presence.
Long-running friction involving Okinawa has complicated the Obama administration's plans to boost the U.S. military presence in the Asia-Pacific after 10 years of land wars in Iraq and Afghanistan.
"In recognition of the remaining concerns of the Japanese government about the safety of the aircraft," the Defense Department will refrain from flights until final investigation results are presented to the Japanese government "and the safety of flight operations is confirmed," a Pentagon statement said.
The Pentagon said it anticipated presenting the results in August. In the meantime, Japan will be the only place worldwide where such flights will be suspended, including over the continental United States.
The aircraft, a revolutionary design, are to be shipped initially to Iwakuni, the only U.S. Marine Corps air station in the main Japanese islands, for unloading in late July.
Twelve are to go this year and another 12 next year, said Major Cathy Wilkinson, a Pentagon spokeswoman. They are to be based at the Marine Corps Air Station Futenma, long a focus of local resentment over noise, safety and crime concerns.
The V-22 Osprey swivels, or tilts, two 38-foot rotors on its wing tips to take off and land like a helicopter and fly forward with the speed and range of an airplane.
Built by Bell Helicopter Textron and Boeing Co, it is designed to transport 24 fully equipped Marines and has been used in Iraq and Afghanistan.
A combined total of 30 people, including 26 Marines, were killed in test flights or training accidents from 1991 through 2000 during the aircraft's development.
Only weeks after word emerged of plans to deploy to Okinawa, a V-22 crashed during a training mission in Morocco in April, killing two Marines.
Earlier this month, a Special Operations Command CV-22 Osprey crashed at Eglin Air Force Base in Florida, injuring five servicemembers.
Despite these mishaps, the Osprey has been one of the safest rotorcraft in the U.S. military since it went into service in 2007, according to Richard Whittle, author of The Dream Machine: The Untold History of the Notorious V-22 Osprey.
The Defense Department said it had provided preliminary findings from investigations of the two latest crashes at Tokyo's request.
Based on the preliminary conclusions that the aircraft remains safe, and in close coordination with the Japanese government, the department said it had decided to move forward with the shipment.
Tokyo was formally notified on Thursday of a planned fleet upgrade that would replace aging CH-46 helicopters with the Osprey, which the Marine Corps formally designates MV-22 and the Air Force CV-22.
The Pentagon said the MV-22 aircraft had an excellent safety record based on more than 115,000 flight hours including combat, humanitarian assistance, training and test and evaluation missions.
Basing the Osprey in Okinawa will strengthen significantly U.S. ability to provide for the defense of Japan, perform humanitarian assistance and disaster relief operations and fulfill other alliance roles, it said.
The United States and Japan announced in April a revised agreement on the footprint in Okinawa that would shift 9,000 Marines from there to Guam and elsewhere in the Asia-Pacific, including Hawaii and Australia.
Okinawa was occupied by the United States from 1945 to 1972. It accounts for less than 1 percent of Japan's soil but hosts three-quarters of the U.S. military facilities in the country by land area.
(Reporting By Jim Wolf; Editing by Sofina Mirza-Reid)