More than four years after a Boeing 737-800 jetliner plummeted from an altitude of 29,000 feet and crashed into a mountain in southern China, killing all 132 people on board, newly released data appears to show that someone in the cockpit intentionally cut off the fuel supply.
It was China’s deadliest air disaster in decades, but the Civil Aviation Administration of China (CAAC) has not addressed critical questions about what caused China Eastern Airlines flight MU5735 to take a deadly nose dive in a remote area of Guangxi in March 2022.
Data released by the National Transportation Safety Board (NTSB) in response to a Freedom of Information request shows that the fuel switches on both engines shut off simultaneously before the Boeing 737-800 fell from the sky.
The data was taken from the plane’s flight data recorder (one of two so-called “black boxes” that record all relevant operational information), which was recovered from the wreckage and sent to the NTSB’s laboratory in Washington, D.C., for analysis (NTSB involvement due to Boeing being a US aircraft manufacturer).
“While cruising at an altitude of 29,000 feet, the fuel switches on both engines were found to have moved from the run position to the cutoff position. Following the fuel switch movement, engine speed decreased,” the NTSB report states.
A commercial aircraft fuel switch is a physical control device that regulates the flow of fuel to the engine. On the 737, the pilot must pull up on the switch before moving it from the drive position to the cutoff position.
“This data clearly shows that the fuel switch was manually placed in the off position shortly before the crash,” CNN aviation safety analyst David Soucy said.
“There is no evidence that the switch was returned to the on position, indicating that there was no attempt to restart the engine,” he added. “If the switch was accidentally turned off, the pilot would have tried to turn it back on.”
The flight data recorder stopped recording when the plane’s generators lost power at 26,000 feet, and the final moments of the crash were not captured, the report said. The cockpit voice recorder (another “black box” on the plane) continued recording via battery backup.
U.S. investigators managed to obtain four audio recordings from the damaged cockpit recorder and sent them to CAAC, but the NTSB said it does not have a copy of the audio files.
CNN has reached out to CAAC and China Eastern Airlines for comment. The CAAC had previously denied that the crash was intentional.
However, previous reports indicate that someone in the cockpit intentionally crashed the plane.
The Wall Street Journal reported in May 2022, citing people familiar with the rover, that information extracted from the plane’s damaged flight data recorder showed that commands entered by humans into the control system led the plane into a dangerous dive.
The newspaper quoted a person familiar with U.S. officials’ preliminary assessment as saying, “The plane carried out what someone in the cockpit told it to do.”
The newspaper said at the time that U.S. officials involved in the investigation were focusing on the actions of the pilot, adding that someone else on board the plane may have entered the cockpit and intentionally caused the crash.
CAAC had previously issued a denial due to speculation about the pilot’s suicide. The CAAC said in a preliminary report that the flight and flight attendants had valid licenses, that the flight attendants were well-rested and that they passed a medical examination on the day of the flight.
China has not released an update on its investigation in 2024, but CAAC released a statement on the second anniversary of the crash, reiterating its earlier findings that no problems were found with the aircraft, crew or weather conditions.
The statement said no malfunctions or abnormalities were found in the aircraft’s systems, structure or engines prior to takeoff. CAAC said there were no abnormalities in radio communications or air traffic control commands prior to the crash, and there were no reports of hazardous weather in the aircraft’s airspace or flight route.
China has faced public criticism for not releasing a final report into the fatal crash, with some questioning why investigating authorities did not release the “black box” information.
On March 21, 2022, a Boeing 737 was flying from Kunming to Guangzhou in the southwest when it lost contact with air traffic control over Wuzhou. There were 123 passengers and 9 crew members on board.
