WASHINGTON (Reuters) – A U.S. military Osprey aircraft that crashed off the coast of Japan in November, killing all eight crew members, was caused by a gearbox failure and the pilot’s decision-making contributed, a U.S. Air Force investigation released on Thursday said.
The U.S. military grounded its fleet of V-22 Ospreys for several months after the fatal crash during a routine training mission on Nov. 29 off Yakushima Island, about 1,040 kilometers (650 miles) southwest of Tokyo. “The accident was caused by a catastrophic failure of the left rotor gearbox,” the investigation said. “The decision-making was causal, prolonging the accident sequence.” It said the crew had no sense of urgency when they received warnings in the aircraft. The Osprey pilot had been advised to “land as soon as possible” when the aircraft was still close to mainland Japan and could have diverted to several closer airports. The pilot continued to fly at 8,000 feet above sea level, the investigation said, even though it would have been wiser to fly below the clouds.
Although the deployment of Ospreys in Japan has faced opposition in the past, the Japanese government said it accepts the report’s findings and believes further accidents can be prevented.
“We have stressed at all levels between Japan and the United States that ensuring flight safety is the top priority, and we intend to continue cooperating with them to ensure this safety,” Chief Cabinet Secretary Yoshimasa Hayashi said at a regular news conference on Friday.
According to Boeing (NYSE:BA), which makes the Osprey along with Textron’s Bell Helicopter unit (NYSE:BH), at least 400 multirole Ospreys have been delivered, and they are used primarily by the U.S. Air Force, Marine Corps and Navy in Japan and elsewhere. The U.S. Navy’s aircraft carrier, the USS Carl Vinson, deployed to Japan, relies on them to deliver some supplies and personnel.
According to the Flight Safety Foundation, at least 50 people have been killed in crashes while the aircraft was in operation or testing. More than 20 of these deaths occurred after the V-22 entered service in 2007.