Just over four years ago, on March 21, 2022, the devastating China Eastern Boeing 737-800 crash claimed the lives of all 132 people onboard, including nine crew members and 123 passengers.

Years later, Chinese aviation authorities have still not disclosed the official cause of the plane crash, formally refusing to publish the final report in June 2025 and declaring that “disclosure may endanger national security and social stability”.

On the tragic day, China Eastern Airlines flight MU5735 suffered a catastrophic crash, as the aircraft abruptly took an almost-vertical nosedive and plummeted into a mountain in south China’s Guangxi province.

The fatal crash claimed the life of everyone on board – 132 souls lost in the blink of an eye.

The plane was scheduled to fly from the city of Kunming to the city of Guangzhou, and while the flight departed routinely with no unusual incidents reported, shortly before the craft was scheduled to start its descent, the plane entered a sudden nosedive from a cruising altitude of roughly 29,000 feet to 7,400 feet , reports the Daily Record.

Flight data shows the plane made a brief pull-up and levelled off as it climbed to 8,500 feet, before entering a second nosedive which resulted in the aircraft crashing into the side of a mountain.

All this happened in the space of approximately two minutes. According to authorities, the pilots failed to respond to repeated calls from air traffic controllers or nearby aircraft whilst the craft rapidly plummeted.

Described at the time as China’s most fatal aviation disaster in 30 years, the news stunned the world and raised concerns for the global aviation industry – and caused unimaginable devastation to the families of those that perished in the tragedy.

Two “badly damaged” Black Box flight recorders were recovered from the mountainous crash site, and according to the Civil Aviation Administration of China (CAAC), no faults or evidence of “anything abnormal” was reported before takeoff with the aircraft or engines, weather or communications.

According to the Chinese regulator, the crew held valid licences, had logged sufficient rest and passed health checks on the day of the flight. There were also no dangerous goods reported on board the craft, and no hazardous weather either.

Sun Shiying, president of China Eastern Airlines, had said in a statement at the time that all three pilots on the flight were properly licensed and in good health, saying: “Their behaviour had been good and their families were all quite harmonious.”

The same was reiterated to the Wall Street Journal (WSJ) in a statement in May that same year, with the airline adding the pilots’ health and family conditions were good and that their financial status was also in good shape.

Was the crash intentional?

According to a report published by the WSJ in May 2022, sources familiar with US officials’ initial assessment of the crash cause suggested that recovered Black Box data indicated someone intentionally crashed the plane. It was proposed that inputs to the controls were what forced the plane into the fatal nosedive.

An expert familiar with American officials’ preliminary assessment said: “The plane did what it was told to do by someone in the cockpit.”

This statement followed an analysis of the information extracted from the recordings of the damaged flight-data recorders.

Another source informed Reuters investigators were examining whether the crash could have been a “voluntary” act.

After reports surfaced suggesting the crash might have been deliberate, the CAAC issued a statement on 11 April that year claiming that the speculation had “gravely misled the public” and “interfered with the accident investigation work”.

On the one-year anniversary of the incident, the CAAS issued a sparse update report with virtually no information, describing the case as “very complex and extremely rare”.

On the two-year anniversary of the incident, the situation was almost identical, with the regulator maintaining that the crash was “very complicated and rare” whilst providing nothing substantial.

“As of June 2025, an official refusal to publish the report was recorded, citing that “disclosure may endanger national security and social stability”.

The cause behind the horrific crash remains cloaked in mystery, and four years on, the families of those who perished, as well as the global aviation industry, are still awaiting answers.