Flight data recorder information released by the U.S. National Transportation Safety Board confirms what many aviation investigators long suspected: someone in the cockpit of China Eastern Flight MU5735 deliberately shut off both engines before the aircraft plunged into a hillside in Guangxi Province on 21 March 2022, killing all 132 people on board. According to the FDR data, approximately 23 seconds before recording stopped, the fuel control switches for both engines were moved to the cut-off position. Both engines shut down. The autopilot disengaged immediately afterward. About three seconds later, one of the cockpit yokes was pushed violently forward. The Boeing 737-800 went into a near-vertical dive and hit the ground at over 500 mph.

What the Data Shows

On a Boeing 737, the fuel control switches are located on the centre pedestal between the two pilots. Moving them to the cut-off position requires a deliberate physical action — they cannot move accidentally. Both switches can be moved together with one hand. The sequence recorded by the flight data recorder is unambiguous in its mechanics: engines were deliberately shut down, the automatic flight systems disengaged, and the control column was pushed forward with force. The aircraft then accelerated into the ground in a trajectory consistent with a controlled descent — not a stall, not a structural failure, not a system malfunction. What the data does not tell us is who moved the switches, or why. The cockpit voice recorder was recovered but its contents have not been publicly released by Chinese authorities.

China’s Silence

The Civil Aviation Administration of China (CAAC) is the official investigator. Under ICAO rules, the state of occurrence must publish a final accident report — or at minimum, regular updates. China has done neither. The last publicly available update from CAAC was issued in 2024, and it contained no conclusions about the cause. The NTSB participated in the investigation as the representative of the state of manufacture (the 737 was built in the United States). The data now surfacing comes from NTSB’s own records, not from any Chinese release. Chinese authorities have cited “national security” concerns for withholding the cockpit voice recorder transcript and their final analysis. International aviation safety experts have been sharply critical of this silence. Without a published final report, the global aviation community cannot learn from the event — which is the entire purpose of accident investigation under the Chicago Convention.

Important Caveats

Aviation specialists stress that while the flight data strongly suggests deliberate action, the released material is not a complete accident report. It does not identify which pilot made the inputs. It does not establish motive. It does not rule out every conceivable scenario in which the fuel switches could have been moved (though no plausible accidental mechanism has been proposed by any analyst). The distinction between “the data shows X happened” and “person Y did X for reason Z” is legally and morally significant. A full investigation — including CVR analysis, crew background investigation, and forensic examination — is needed to cross that bridge. That investigation exists. It has simply never been published.

ICAO Changes the Rules

Partly in response to the MU5735 investigation stalemate, ICAO approved amendments to Annex 13 in March 2026 — the first major revision to the international accident investigation framework in years. The new rules address conflicts of interest, mandate unrestricted access to evidence, and provide mechanisms for delegating investigations to independent bodies when the investigating state cannot or will not complete the work. Amendment 20 takes effect in November 2028. Whether it would have changed the outcome of the MU5735 investigation is debatable. What is certain is that 132 families are still waiting for an official answer — more than four years after their loved ones boarded a routine domestic flight that never arrived.

Sources: CNN, AeroTime, Simple Flying, View from the Wing, ICAO