Okinawa International University US military helicopter crash

The Okinawa International University US military helicopter crash (Okinawa Kokusai Daigaku Beigun herikoputā tsuiraku jiken) is an incident in which a helicopter of United States Forces Japan (United States Marine Corps) crashed into Okinawa International University in Ginowan, Okinawa Prefecture, on 13 August 2004 (Heisei 16).

Cause of the accident

The joint Japan-US accident subcommittee submitted an investigation report stating that "the cause of the accident was a maintenance error in which an important part was not fitted to a bolt connecting the tail rotor of the rotor system".

The American side explained that because a maintenance worker had failed to fit the cotter pin that should have been installed on a bolt connecting the hydraulic system to the actuator that adjusts the pitch of the helicopter's rotor blades, the bolt fell out in flight and the tail rotor became uncontrollable.

After the accident

On 12 September, about one month after the accident, a protest rally was held at Okinawa International University, the site of the accident, attended by 30,000 people according to the organisers. This was the largest since the prefectural citizens' rally protesting the Okinawa US servicemen schoolgirl rape incident, held in October 1995 (attended by 85,000 people according to the organisers).

Because of restrictions imposed by the US military immediately after the crash, a situation continued in which not only university staff and the Ginowan city authorities, but even the Ginowan City Fire Department and the Okinawa Prefectural Police, could not enter the site. For this reason, university staff have continued to protest to the US military, considering it an incident that infringed on Japan's administrative rights and the autonomy of the university. Currently, an Akagi tree burned in the accident is preserved at the crash site as a monument.

The Okinawa Prefectural Police investigated for violations of the Act on Punishment of Acts Endangering Aviation for the full 3 years of the statute of limitations, but, blocked by the barrier of the Japan-US Status of Forces Agreement, the full picture was not clarified.

On 1 August 2007, 4 people including a US Marine Corps sergeant among the crew were referred to prosecutors with their names unknown, but on 10 August the Naha District Public Prosecutors Office decided not to indict any of them.

Consultations between the two governments on the response to accidents

In this accident, problems were raised regarding matters such as investigative jurisdiction in the response after the occurrence. Following consultations between the Japanese and US governments in the Japan-US Joint Committee, on 1 April 2005 guidelines on the response of the two governments after a US military aircraft crash off-base ("Guidelines Regarding United States Military Aircraft Accidents Outside the Areas and Facilities Used by the United States Armed Forces in Japan") were drawn up. These were revised on 15 July 2019.