Both engines were shut off and there was a cockpit struggle before a China Eastern Airlines jet slammed into a mountain in 2022 and killed all 132 people aboard, newly released data released by American investigators suggests.
In response to a public records request, the National Transportation Safety Board released a report recently on what the Boeing 737-800’s flight data recorder revealed. The NTSB became involved in the Chinese investigation because the plane and engines were made by American companies and the US investigators are regarded as the world’s leading experts on analysing black boxes after a crash.
The report offers the best explanation yet about what caused the crash and confirms news stories at the time suggesting the crew may have played a role after Chinese investigators said they did not immediately find a problem with the plane.
Aviation safety experts agree that the data shows the fuel to both engines was cut off and someone sent the plane into a nosedive and a 360-degree roll, but it does not conclusively show exactly what happened because the Civil Aviation Administration of China has yet to release its final report than four years later. International standards call for investigators to strive to release their report by roughly a year after a crash.
The NTSB report was released May 1.
LIKELY INTENTIONAL FUEL CUT
By design the fuel levers in a 737 cannot be easily bumped or shut off inadvertently — someone has to pull them out to release them before they will move. John Cox, CEO of Safety Operating Systems, said the levers lock into place, so it’s likely that someone deliberately moved them both to the cutoff position.
The data ended while the plane was still at 26,000 feet of altitude after the flight recorder and all the plane’s hydraulic systems lost power, but the report of the 12 minutes before that suggests what happened.
The cockpit voice recorder, which continued working because it had a battery backup, could also help shed light, but the NTSB did not release a transcript of what it found on those recordings. It is up to Chinese authorities to release those details.
Jeff Guzzetti, who formerly investigated crashes for the NTSB and the Federal Aviation Administration, said the flight data suggests a struggle and the crash could have been a pilot suicide. There have been a number of previous instances of that, including a Germanwings flight that crashed into the French Alps in 2015, killing everyone aboard.
“Typically when you want to roll an airplane, it’s a smooth movement of the control wheel in one direction. But here you have it moving back and forth, back and forth, as if someone is trying to counter the initial movement of the roll,” Guzzetti said. “So it’s not conclusive, but it sure has the earmarks of a struggle in the cockpit.”