The Marine Corps MV-22 Ospreys stationed on Okinawa remained operational Aug.7 as U.S. and Australian navy vessels attempted to recover wreckage of a downed tiltrotor off the east coast of Australia.

On Aug. 5, an Osprey clipped the edge of the USS Green Bay while trying to land on the San Antonio-class amphibious transport dock. The aircraft – which can takeoff, land and hover like a helicopter and fly at speeds and altitude of a fixed-wing airplane – plunged into the Pacific Ocean with 26 U.S. military personnel on board. All but three of the Osprey’s occupants were recovered safely from the water.

Osprey mishap

The circumstances of the mishap are currently under investigation. As of Monday afternoon, the Marine Corps had not grounded its fleet of two dozen Osprey’s based at Marine Corps Air Station Futenma on Okinawa. Japanese Defense Minister Itsunori Onodera, who took the post on Aug. 3, reportedly voiced concerns about the safety of MV-22 operations at the base, which sits amidst a crowded city.

The Navy called off its search for the remaining three Marines on Sunday, Aug. 6. Operations have now shifted to recovery efforts. The next-of-kin for the three missing Marines have been notified, according to the Marine Corps.

“The transition comes after teams led continuous sustained search efforts supported by aircraft and ships,” 3rd Marine Expeditionary Force (MEF) said in a statement. “As the sea state permits, recovery efforts will be conducted to further search, assess and survey the area, in coordination and with assistance from the Australian Defence Force. Recovery and salvage operations can take several months to complete, but can be extended based on several environmental factors.”

Royal Australian Navy survey ship HMAS Melville arrived in Shoalwater Bay where the mishap occurred overnight Sunday. Shortly after commencing survey operations in the area, the submerged aircraft was located, according to a statement from Australian Minister of Defense Marise Payne.

“The crew of HMAS Melville and our divers will conduct remotely operated underwater vehicle operations beginning this evening,” Payne said in the statement released Aug. 7. “These operations will further survey the aircraft as a prerequisite for diving operations.”

Australian dive team members finalized planning in conjunction with the U.S. Marine Corps and U.S. Navy aboard USS Bonhomme Richard (LHD 6), 3rd MEF said. The dive team plans to commence recovery operations using a remote operating vehicle this evening. The location of the MV-22 was detected on Aug. 6 by Melville using its hydrographic capabilities.

“I want to thank the Australian Defence Force, and the crew of the HMAS Melville in particular, for their assistance in the search and recovery effort of our MV-22 that went down off the coast of Australia,” said III MEF Commander Lt. Gen. Lawrence Nicholson‎. “They volunteered their help before we could even ask, demonstrating their friendship and value as international partners. The crew of the Melville and its assets have been invaluable in the recovery effort.”

The Osprey has a reputation for mishaps because a spate of fatal crashes early in it service history. As more of the aircraft have entered service – Air Force Special Operations Command operates its own version while the Navy is buying the tiltrotors to perform aerial resupply on aircraft carriers – its safety rating has become one of the best of any military aircraft.

Still, operation of the aircraft on Okinawa has been contentious with residents who fear the complex machines flying over their homes. In Dec. 2016, an MV-22B attempted a precautionary emergency landing on land but suffered a hard landing in shallow water off the Okinawa Coast. The five Marines aboard were evacuated with some injuries.

The Marine Corps has had a tragic few weeks of aviation mishaps. On July 10, a KC-130T crashed during a logistics flight from Cherry Point, N.C. to El Centro, Calif., killing all 15 Marines and one sailor aboard.

According to the Naval Safety Center (NSC), the Marine Corps has experienced eight Class-A mishaps in fiscal 2017 through July 13. A Class-A mishap is one that involves a fatality. That gives fiscal 2017 the 30th best aviation mishap rate in history through July, according to the NSC. At this pace, fiscal 2017 would end the year as the 29th best year ever.