The U.S. Air Force said Thursday it has recovered the flight data recorder from its Osprey aircraft that crashed off a southwestern Japan island in late November, and analysis of the records is expected to take several weeks.

The recorder, also known as a black box, and other critical equipment for the ongoing investigation of the fatal accident will be sent to laboratories for data retrieval, according to the Air Force Special Operations Command.

The Air Force's CV-22 Osprey crashed off Yakushima Island on Nov. 29 during a routine exercise, killing all eight on board the tilt-rotor aircraft.

File photo taken in September 2018 shows a CV-22 Osprey aircraft at the U.S. military's Yokota Air Base in the western suburbs of Tokyo. (Kyodo) 

Japanese authorities confirmed in late December that wreckage from the Osprey, including the black box, had been pulled out of the sea and arrived at Marine Corps Air Station Iwakuni.

The U.S. command said the vast majority of the wreckage has been at the base to be inspected as part of the ongoing probe.

In Japan, a major U.S. treaty ally, concerns over the safety of the aircraft, known for a number of mishaps and fatal crashes, have rekindled.

The crash was the deadliest involving U.S.-made Ospreys, which take off like helicopters but fly much faster, like airplanes, since their combat debut in 2007.

Following a series of requests from Japan, the U.S. military has suspended all of its Osprey flights worldwide after determining that the accident may have been due to a malfunction.

The bodies of seven airmen have been recovered, with the command saying efforts to find the eighth crew member are ongoing, and there are no updates to the Osprey stand-down.

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