The search for the downed Osprey in Japan switched from rescue to recovery this week, with Pentagon Press Secretary Air Force Brig. Gen. Pat Ryder saying the bodies of three of the eight servicemen have been recovered and three more located.

“The recovery operation will now focus on locating and recovering the remaining two airmen and aircraft debris,” he said.

The US military operates almost 500 Ospreys, with around 400 in the Marine Corps, 51 in the Air Force and 27 in the Navy.

In a statement announcing the grounding, Lt. Gen. Tony Bauernfeind, head of Air Force Special Operations Command, said the aim was to mitigate risk during the investigation.

“Preliminary investigation information indicates a potential material failure caused the mishap, but the underlying cause of the failure is unknown at this time,” he said.

“The standdown will provide time and space for a thorough investigation to determine causal factors and recommendations to ensure the Air Force CV-22 fleet returns to flight operations.”

23 were on board the Osprey that crashed in Australia in August, which was taking part in Exercise Predators Run during the incident on Melville Island, 60km off the coast from Darwin. Three US Marines were killed, while another five were taken to Darwin Hospital in critical condition.

NT Police Commissioner Michael Murphy revealed a military aircraft was deployed to help almost immediately after the Osprey went down, with further reports suggesting a CareFlight helicopter was also dispatched to the scene. The Osprey is thought to be one of two of the aircraft types flying at the time.

The Osprey has been involved in five other fatal crashes since 2012, causing 16 deaths, including an accident in California in June 2022 that saw the aircraft suffer “catastrophic, unpreventable and unanticipated mechanical failure”.