WASHINGTON: The Marine Corps will brief its roughly 850 MV-22 Osprey pilots and air crew on the “extraordinary set of circumstances” that caused the fatal crash of an Osprey in Morocco on April 11 and will revise its training and flight manuals to prevent future such mishaps, Lt. Gen. Robert Schmidle, deputy commandant for aviation, said.

“They will all be briefed on this so that they all understand exactly what occurred and what caused this to happen,” Schmidle said this afternoon at a Pentagon news conference. Afterward, the Marine Corps released a redacted 27-page summary of the findings of a Judge Advocate General Manual (JAGMAN) investigation of the accident, a copy of which was obtained in advance by Breaking Defense and reported on in detail here Thursday. “I am committed to doing all that I can to keep this kind of mishap from occurring again.”

Just how Japanese protesters, who claim the Osprey is unsafe, will react to Schmidle’s announcement is difficult to predict. The US recently deployed a dozen Ospreys there. Japanese defense officials are clearly committed to flying the plane in Japanese airspace. Satoshi Morimoto, Japan’s defense minister, flew from the Pentagon on Aug. 3 in a V-22.

“The recommendations and the changes that we’re making will be in place here very soon,” Schmidle said. “This is a big deal to us. We take this mishap very, very seriously.”

The Marines will add simulations of the accident to computerized flight simulators used to train pilots and will study what changes might be made in academic training of MV-22 aviators to prevent similar accidents. “You can expect to see us do things right away to mitigate this,” he said.

“There was nothing mechanical with the airplane that caused this to occur,” Schmidle said. “We believe that it is a solid and safe airplane.”

The MV-22B from Marine Medium Tiltrotor Squadron 261 (VMM-261) went down 15 seconds after taking off like a helicopter from an austere landing zone in coastal Morocco, where the crew had just delivered a dozen Marines taking part in an exercise with the Moroccan military.

The JAGMAN report confirmed that, as Breaking Defense reported July 9, the pilot put the helicopter-airplane hybrid into a hover, then executed a 180 degree turn that put the wind at the aircraft’s rear. At the same time, the pilot allowed the aircraft’s nose to pitch downward 5 degrees and lowered the angle of the nacelles that hold the Osprey’s rotors further than permitted by the MV-22B’s flight manual. The Osprey is called a “tiltrotor” because it swivels two wingtip rotors upward to fly like a helicopter and forward to fly like an airplane. With the nacelles that far forward and the nose down, the Osprey’s center of gravity shifted forward as well, Schmidle said. Combined with the tail wind, that left the control stick with too little “authority” to bring the nose back up and the Osprey plunged into the ground nose first.

The two pilots survived with serious injuries. Two crew chiefs, Cpl. Robby A. Reyes and Cpl. Derek A. Kerns — each of whom was standing as the Osprey took off, attached to the aircraft only by a thick tether — were killed.

“We grieve with the families,” Schmidle said during the press conference.

The pilot, whose name hasn’t been released, could have avoided the accident by continuing to fly the Osprey in helicopter mode until it gained enough forward airspeed to both escape the tailwind and get enough wind flowing over its wings to fly like an airplane, Schmidle said. “Unfortunately, the pilot didn’t recognize that at the time,” he added.

Schmidle declined to use the term “pilot error” to describe the cause of the crash, saying there are “a whole series of things that go into causing an accident.” The two pilots, however, could face disciplinary action, such as loss or curtailment of flight privileges, after the accident is reviewed by a Field Flight Performance Board that has yet to start its work, he said.

The JAGMAN report recommended no disciplinary action be taken.