Osprey V-22s head for Japan despite 'design flaw' fears

Shortcomings in the helicopter function of the Bell-Boeing V-22 Osprey tilt-rotor aircraft make it "precarious", a rotorcraft expert has warned.

"As an airplane it's quite safe, but its helicopter role is always very precarious," Dr Arthur Rivolo told IHS Jane's in early July. "The shortcomings of the V-22 have to do with the design of the aircraft."

Rivolo was speaking as the US Department of Defense pressed ahead with plans to base 12 MV-22s at Marine Corps Air Station Futenma in Okinawa prefecture in Japan despite local opposition.

The Ospreys are en route to Marine Corps Iwakuni Air Station in Yamaguchi prefecture, where they will be reassembled before being moved to Okinawa in August at the earliest to replace 12 Boeing Vertol CH-46 helicopters.

But two accidents this year involving Ospreys have mobilised opposition to their deployment on the southern island. In April, two marines were killed in an MV-22 crash in Morocco that occurred while the pilot was moving the rotors from an upright position to forward; in June, a US Air Force (USAF) CV-22 Osprey crashed in Florida, injuring five crew.