For more than four years, the final moments of China Eastern Flight 5735 remained shrouded in secrecy, with few clues to a baffling descent from 29,000 feet that left no survivors.
Now, new data from the Boeing 737 suggests the crash was no accident. The plane’s fatal dive was a deliberate act initiated from within the cockpit, aviation experts say, following what appears to have been a struggle for control of the aircraft.
The plane, which was operated by highly experienced pilots, had been traveling from Kunming, in southwestern China, to Guangzhou when it plunged almost vertically into a hillside, driving pieces of the aircraft as deep as 60 feet into the earth.
The report by the National Transportation Safety Board shows that the dive began when a pilot or pilots pressed the cutoff levers — essentially, fuel switches — for both engines on the plane mid-flight, according to Jeff Guzzetti, a former accident investigator for the Federal Aviation Administration and the N.T.S.B.
Pressing down the two levers simultaneously stopped fuel flow to the engines and shut them down, Mr. Guzzetti said.
Almost immediately, data from the cockpit controls show, the plane entered a terrifying dive and spun in at least one 360-degree roll, Mr. Guzzetti said. The data shows that control wheels in the cockpit — one each in front of the captain and first officer — were turned to produce that roll, Mr. Guzzetti said. (The control wheels on a plane are a little like the steering wheels in a car, but they cause the plane to bank.)
