Dhaka: Data from China Eastern Airlines Flight 5735's flight data recorder (FDR) has revealed that deliberate cockpit actions caused the Boeing 737-800 to plunge into a mountainside in southern China on March 21, 2022, killing all 132 people on board.

The National Transportation Safety Board (NTSB) released the documents on May 1, following a Freedom of Information Act (FOIA) request made in January by a Chinese citizen.

The released materials include the FDR contents, email correspondence between the NTSB and China's Civil Aviation Administration of China (CAAC), and a July 2022 data download report.

According to the FDR data, 23 seconds before recording ceased, the fuel control switches for both engines were simultaneously moved to the cut-off position, effectively shutting both engines down. The autopilot was immediately disengaged.

Approximately three seconds later, one of the cockpit's yokes was violently pushed forward. However, the FDR did not indicate which yoke was actually pushed.

The 737 then entered a steep dive. Data indicated that somebody was continuously controlling the yoke throughout the descent. Fluctuating inputs from the ailerons further suggested that at least one individual was actively attempting to recover the aircraft.

The FDR stopped recording at around 26,000 feet, 23 seconds after the fuel control switches were cut off, probably due to the loss of electrical power caused by the engine shutdowns. The recorder was not equipped with a backup battery.

The NTSB noted that in 2022, FDR data was provided to China following the accident. The agency also stated that the cockpit voice recorder (CVR) data had similarly been handed over to Chinese authorities and that it had not retained a copy of that recording.

Flight 5735 was operating a scheduled passenger service from Kunming Changshui International Airport to Guangzhou Baiyun International Airport. The aircraft, registered B-1791, carried 123 passengers and nine crew members, none of whom survived.

The crash near Wuzhou, in the Guangxi region, was among the deadliest aviation disasters in China in decades and triggered an extensive joint investigation between Chinese and American aviation authorities.

The latest findings have reignited debate over cockpit safety protocols and the transparency of China's aviation accident investigation process, as official Chinese authorities have yet to release a final report on the cause of the crash.