New data has shown that Chinese authorities allegedly knew within weeks that a pilot had deliberately brought down a passenger jet in a catastrophic crash that killed all 132 people on board.
Fresh details published by the US National Transportation Safety Board (NTSB) appear to confirm long-running suspicions that China Eastern Airlines Flight 5735 was intentionally crashed into mountains in Guangxi province in March 2022.
The Boeing 737 had been cruising between Kunming and Guangzhou when both engines were manually shut down, the autopilot was disengaged, and the aircraft was forced into a steep nosedive, according to the US findings.
Data extracted from the flight recorders showed a terrifying struggle inside the cockpit, with two pilots reportedly fighting over the controls as the jet plunged towards the ground.
The NTSB said: ‘It was found that while cruising at 29,000ft, the fuel switches on both engines moved from the run position to the cut-off position. Engine speeds decreased after the fuel switch movement.’
Graphs released by the American agency showed opposing movements on the pilot's control yokes, indicating one crew member was attempting to recover the aircraft while another continued forcing it into a dive.
Video captured from the ground showed the plane plunging almost vertically from the sky.
No distress call was made by the crew, and no emergency transponder code was transmitted before the impact.
The Chinese passenger jet, which smashed into a mountain in 2022 killing all 132 people on board, was deliberately crashed, investigators believe
The plane crash site in Tengxian County, south China's Guangxi Zhuang Autonomous Region, March 21, 2022
Workers search through debris at the China Eastern flight crash site in Tengxian County, March 24, 2022
The disaster has become one of the most politically sensitive aviation cases in modern Chinese history, with Beijing being accused of suppressing information amid mounting international pressure for transparency.
Last year, China's Civil Aviation Administration warned that any further 'disclosure [about the crash] may, if released, endanger national security and social stability'.
The NTSB has been asked to decode the aircraft's black boxes after the crash and sent its findings to Chinese authorities just two weeks after the recorders were recovered in 2022.
Extracts were only released publicly this week after a Chinese citizen submitted a freedom of information request in the United States.
The agency said the flight data recorder stopped after around 90 seconds because of a power failure, although the battery-powered cockpit voice recorder continued operating.
The NTSB said it no longer holds a copy of the audio after transmitting it to Beijing.
Chinese investigators have repeatedly stated in previous updates that the aircraft's systems appeared to be functioning normally before the crash.
Just two months after the disaster, however, a US investigator told The Wall Street Journal that 'the plane did what it was told to do by someone in the cockpit'.
References to the report were later scrubbed from Chinese social media.
Three pilots were on the flight deck at the time of the crash - Captain Yang Hongda, 32, first officer Zhang Zhengping, 59, and trainee second officer Ni Gongtao, 27.
Speculation in China has focused heavily on Zhang, one of the airline's senior pilots, who had reportedly recently lost his captain's rank.
No official conclusion identifying responsibility has ever been published.
Rescue workers speculated that the fire resulting from the crash had 'totally incinerated' the passengers and their belongings, before causing damage to the surrounding forest
Rescuers are pictured searching for the black boxes at a plane crash site in Tengxian County, south China's Guangxi Zhuang Autonomous Region, March 22, 2022
The crash has renewed scrutiny of suspected pilot murder-suicides in commercial aviation, a phenomenon linked to several of the world's deadliest air disasters in recent years.
The most infamous case remains the 2015 Germanwings tragedy, when co-pilot Andreas Lubitz deliberately flew an Airbus into the French Alps, killing all 150 people on board.
Deliberate pilot action has also long been considered a leading theory behind the disappearance of Malaysia Airlines Flight MH370, which vanished in 2014 with 239 people aboard after veering dramatically off course with no radio communication.
More recently, investigators examining the crash of Air India Flight 171 in Ahmedabad, which killed 241 people after take-off for London last year, are facing intense scrutiny amid disputes over whether cockpit actions played a role.
In March, the International Air Transport Association criticised countries that fail to release crash findings promptly.
Its director-general Willie Walsh said: ‘Anything less than 100 per cent compliance short-changes everyone on opportunities to improve.’