Fresh analysis released by US safety officials has intensified scrutiny of China’s handling of the 2022 crash of China Eastern Airlines flight MU5735, with flight recorder data indicating that fuel to both engines was manually cut off and that the Boeing 737‑800 was then forced into a steep dive before impact.
The aircraft, carrying 123 passengers and nine crew, was flying from Kunming to Guangzhou on March 21, 2022 when it plunged from cruising altitude and crashed into a mountain in Guangxi province, killing all 132 people on board in China’s deadliest air disaster in decades.
More than four years on, the Civil Aviation Administration of China (CAAC) has yet to publish a final accident report or publicly address the cause of the jet’s sudden descent. China has previously denied that the crash was intentional and said it found no pre‑existing technical or weather issues.
In documents released in response to a freedom of information request, the US National Transportation Safety Board (NTSB) said data from the flight data recorder – one of the aircraft’s two “black boxes” – show that, while cruising at 29,000 feet, the fuel control switches for both engines moved from the “run” position to “cut‑off,” followed by a drop in engine speed.
On the 737‑800, those switches are physical controls that must be lifted and moved by hand to stop fuel flow.
The NTSB summary said there was no indication the switches were returned to the “on” position and no sign of an attempted restart before the data recording ceased when the aircraft lost electrical power during the descent. The recorder stopped at about 26,000 feet; the final seconds of the crash were not captured.
The cockpit voice recorder, which runs on a separate battery backup, continued to record and was successfully downloaded, but US officials said they provided the audio files only to the Chinese authorities and did not retain copies.
Aviation specialists quoted in international media have stressed that, while the new data strongly suggest deliberate action, the NTSB material is not a full accident report and does not itself identify who moved the controls or why.
Reporting by several outlets, including the Wall Street Journal and The Times (UK), has previously cited US officials and technical data indicating that inputs from the flight deck commanded the aircraft into its deadly dive.
The latest disclosures, based on NTSB graphs of control inputs and aircraft response, have been interpreted by some analysts as showing opposing movements on the pilots’ control columns – consistent, they say, with one pilot forcing the aircraft into a nose‑down attitude while another tried to counter it. Those interpretations have not been publicly confirmed by either the NTSB or the CAAC.
Chinese regulators have faced mounting criticism at home and abroad for their handling of the investigation and their refusal to publish a full report.
According to The Times, when the CAAC responded last year to an information request about the case, it warned that disclosure relating to the crash could, if released, “endanger national security and social stability.” China has also previously removed social media references to foreign reports suggesting the crash was deliberate.
In an update issued on the second anniversary of the disaster in 2024, the CAAC reiterated earlier interim findings that it had found no faults in the aircraft’s systems, structures or engines before take‑off and no indications of abnormal weather, radio communications or air traffic control instructions along the route.
The authority also said at the time that the flight and cabin crew all held valid licences, had sufficient rest, and passed health checks on the day of the flight – a statement that was widely seen as a response to speculation about pilot suicide.
Investigators in China are under increasing pressure from international aviation bodies to clarify their conclusions in light of the US data and earlier leaks pointing to human‑commanded inputs.
Global industry groups, including the International Air Transport Association, have criticised states that do not release full investigation findings, arguing that withholding information undermines efforts to improve safety.
The NTSB played a supporting role in the MU5735 probe because the aircraft was US‑manufactured. The US agency has emphasised that its role is limited to providing technical assistance and that responsibility for the conclusions and public reporting lies with the Chinese investigation authority.
To date, China has not provided a timeline for when, or if, a final report into the MU5735 crash will be made public.
