A US Marine Corps Bell Boeing MV-22 struck the flight deck of an amphibious transport dock before crashing into waters off the coast of East Australia on 5 August, a US Navy document shows.
The tiltrotor launched that evening from the amphibious carrier USS Bonhomme Richard during a joint exercise with the Australian navy, carrying 26 Marines on board.
But the Osprey hit the US Navy's 25,000t-class USS Green Bay during its final approach in the Shoalwater Bay Training Area, Queensland, Australia. After the collision, the MV-22 crashed into the water, a 9 August safety report states.
The Marines declared three men on board the MV-22 dead on 7 August after calling off search rescue efforts in waters 15.6nm (18mi) off the Queensland coast.. The Green Bay and other ships rescued the other 23 Marines on board the aircraft.
The Marines have since lifted a grounding order on all aircraft in the 31st Marine Expeditionary Unit, including the MV-22s. The cause of the crash remains under investigation.
The incident is part of a rash of accidents sweeping the Marines' aviation fleet this year and stoking a spike in Class A mishaps, which incur either deaths or excessive damage. Earlier this July, a Marine Forces Reserve-operated Lockheed Martin KC-130T crashed, leaving 16 Marines dead. Twelve USMC KC-130Ts remain grounded.
Updated data from 10 August shows a Class A mishap rate of 4.56 per 100,000 flight hours to date from the beginning of Fiscal 2017, according to data posted online by the Navy Safety Center. Marine aircraft compiled a Class A mishap rate of 3.42 during the same period in fiscal 2016.