The crash involved a Boeing 737 operated by China Eastern Airlines, which plunged into a hillside, killing all 132 people on board. It remains the country’s deadliest aviation disaster in decades.
According to the NTSB findings, fuel control switches for both engines were moved to the “cut-off” position while the aircraft was cruising at approximately 8,839 metres (29,000 feet). The report states that engine speeds dropped shortly after the switches were activated, effectively shutting down fuel supply mid-flight.
The data was retrieved from one of the aircraft’s “black boxes,” which had been recovered from the crash site and analyzed at the NTSB laboratory in Washington, DC. The findings support a theory that the crash may have been intentional, though no final conclusion has been officially confirmed.
The flight, identified as MU5735, departed from Kunming and was scheduled to land in Guangzhou. After more than an hour in the air, the aircraft suddenly entered a rapid descent. Flight tracking data from Flightradar24 showed the plane dropping thousands of metres in under three minutes.
At its cruising altitude of around 29,100 feet, the aircraft descended to about 9,075 feet within just over two minutes. The final recorded data indicated the flight ended at 14:22 local time at an altitude of roughly 3,225 feet.
Investigations into the crash have been led by the Civil Aviation Administration of China (CAA), with assistance from the NTSB due to the aircraft being manufactured in the United States. Authorities initially considered multiple possibilities, including pilot error, technical failure, structural issues, or deliberate action.
Shortly after the crash, officials said they had no clear assessment of the cause. Air traffic controllers reportedly attempted to contact the aircraft multiple times during its descent but received no response.
The CAA has maintained that the flight crew were properly licensed, well-rested, and medically fit on the day of the incident. It has also previously rejected speculation that the crash was the result of pilot suicide, warning that such claims could mislead the public and disrupt the investigation.
China has yet to release a final report on the crash, citing concerns over national security and social stability. The delay has drawn criticism, as questions surrounding the cause of the tragedy remain unresolved.
Air accidents are relatively rare in China, where aviation safety standards have improved significantly in recent years.