An October accident of a Japanese Self-Defense Force V-22 Osprey on Yonaguni Island was due to errors of the pilot and copilot, according to a Thursday release from the JSDF. Japanese Flights of the V-22 have resumed since the Aircraft Accident Investigation Committee.
The incident occurred when the Osprey was carrying out a medical evacuation drill as part of the U.S – Japan bilateral Keen Sword 25 exercise. The Osprey, assigned to the 108th Squadron, 1st Helicopter Wing, Transport Wing, was hovering at 11.38 a.m. at Yonaguni Garrison. While moving forward to ascend, the pilot experienced an unexpected loss of altitude and aborted the take-off and landed on a flat surface area nearby. Immediately upon touchdown on the surface, the aircraft climbed again and began shaking from side to side, causing the left nacelle to hit the ground, damaging the Osprey.
All 16 military personnel on board, which included a small number of U.S. Marines, were uninjured in the incident. The AAIC, headed by the JGSDF Vice Chief of Staff and set up on the day of the incident, conducted an investigation into the damage to the aircraft and components along with analysis of the flight data recorder (FDR) and maintenance data, the maintenance status of the aircraft involved, and interviews with related parties.
The AAIC found that no physical and external factors were involved in the accident and analysis of the Flight Data Recorder (FDR) and maintenance data found that human factors were the cause of the accident.
The JSDF said that the causes of the accident was that, firstly, the Osprey’s engine power functions which are supposed to be activated prior to hovering were not activated, specifically an interim power switch that was supposed to be turned on was not turned on due to the pilot and co-pilot being distracted by last minute changes to the Osprey’s operational plan. Japan’s Jiji Press reported that a schedule delay and the last-minute addition of one passenger were the cause of the distraction.
As a result, the Osprey failed to secure enough power for take-off with the aircraft losing altitude as it moved forward to ascend and the pilot was forced to abort take-off and land in order to avoid obstacles on the flight path. Secondly, it was found that the pilot’s poor control of the aircraft resulted in the aircraft climbing and swaying from side to side after landing, making the Osprey unstable.
The JGSDF outlined two sets of measures to be undertaken in relation to the two causes of the accident, in regard to the loss of power, the switch to activate the power would be clearly marked so it will not be overlooked, implementing additional training on pilots and co-pilots on operating procedures to be carried out before transitioning to hovering and enhancing training, including the use of simulators, on various situations and mission conditions to build up experience among Osprey flight crews.
In regard to the loss of control and stability of the Osprey, enhanced training on pilots and co-pilots will be carried out on emergency maneuvers to be undertaken in a loss of power situation, developing a specific plan and standard operating procedures for dealing with such situations and commanders to provide guidance on the planning development.
The JGSDF stated that Osprey flights will resume on Thursday with thorough measures to prevent recurrence based on the results of the investigation into this accident. The service had grounded its Ospreys following the accident, with the result that the JGSDF’s further participation of its Ospreys in the Keen Sword 25 exercise, which included a joint air assault drill with the U.S. Marine Corps, was aborted. The JGSDF operates a total of 17 Ospreys and had previously grounded its’ Osprey fleet, together with the U.S. following last year’s fatal crash of a U.S. Air Force MV-22B Osprey off Yakushima Island on Nov. 29 and resumed flight again in March this year when the U.S. cleared the Ospreys for flights again with a limited flight envelope.
Japan sees the Osprey as a key part of its island defence strategy, particularly in its southwest islands, which include the disputed Senkaku Islands claimed by China. The Osprey’s range and deployment capabilities will allow the JGSDF to rapidly deploy troops if necessary on its various small islands in the southwest, many of which lack airfields or harbors.
The operations and safety of the Osprey has been a matter of concern for the Japanese public, particularly with U.S. Ospreys in Japan staging out of bases near populated areas which results in the Ospreys overflying such areas when flying out and returning to those bases. Japan’s Ministry of Defense’s regional defense bureaus which cover areas where Ospreys operates, carries out extensive public information and explanation efforts to local authorities on Osprey operations.
The U.S. Navy ‘s CMV-22Bs of Fleet Logistics Multi-Mission Squadron (VRM) 30 “Titans” are now operating around Japan as part of Carrier Air Wing (CVW) 5 assigned to the George Washington Carrier Strike Group (CSG) based on Pentagon imagery releases on Nov.7.
