CAMP FOSTER — An independent investigation by Japan’s Ministry of Defense has confirmed the findings of a U.S. Air Force probe that blamed human error for an Osprey crash in Florida in June.

The report, released Tuesday, was the second Osprey accident review by the ministry, following an investigation into the April fatal crash of an MV-22 in Morocco, which also was attributed to crew error.

It appears to bring Japan a step closer to giving approval for the Marine Corps’ helicopter-plane hybrids to begin flying here. There was no immediate indication, however, on when a final decision might come. Since their arrival in July, 12 MV-22 Ospreys have been waiting at Marine Corps Air Station Iwakuni on mainland Japan for deployment to Okinawa.

Defense Minister Satoshi Morimoto traveled to Okinawa on Tuesday and was scheduled to visit Iwakuni on Wednesday to discuss the report’s findings and the aircraft’s safety.

“I do not believe that these two reports suffice for assuring the safety of the aircraft,” Morimoto said. “Therefore, we will continue talks with the United States on how to secure safe operations of the aircraft in Japan.”

In response to public concerns about the aircraft’s safety record following two crashes this year, the United States has said the Ospreys will remain grounded here until Japan is assured of their safety.

Japan sent two investigation teams to the United States to conduct independent analysis of the accidents. The latest report concluded the Florida crash was caused by the copilot’s failure to keep his aircraft out of the propeller wake of another Osprey.

“It is considered that the accident was largely due to human factors,” the report said.

A possible contributing factor was the lack of a clear description in the Osprey operating manual about the impact of wake turbulence.

“There is no mechanical factor found attributable to the accident,” the report concluded.

The U.S. has announced plans to deploy Ospreys to Marine Corps Air Station Futenma on Okinawa in October to replace Vietnam-era Sea Knight helicopters. An anti-Osprey rally Sunday drew tens of thousands of protesters at a park near the air station.

sumidac@pstripes.osd.mil