March 21, 2022, marks the four-year anniversary of the horrific China Eastern Boeing 737-800 crash which killed all 132 people onboard, including nine crew members and 123 passengers.

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

On the fateful day, China Eastern Airlines flight MU5735 suffered a horrific crash, as the aircraft suddenly took an almost-vertical nosedive and crashed into a mountain in south China’s Guangxi province.

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

Rescuers searching for the 'black boxes' at the plane crash site(Image: Xinhua/REX/Shutterstock)

The plane was scheduled to fly from the city of Kunming to the city of Guangzhou, and although the flight took off routinely with no unusual incidents reported, shortly before the craft was scheduled to begin its descent, the plane entered a sudden nosedive from a cruising altitude of roughly 29,000 feet to 7,400 feet.

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 occurred in the matter of approximately two minutes.

According to authorities, the pilots did not respond to repeated calls from air traffic controllers or nearby planes while the craft rapidly plummeted.

Dubbed at the time as China’s most fatal aviation crash in 30 years, the news shocked the world and raised alarms for the global aviation industry — and caused indescribable devastation to the families of those that died 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 adequate rest and passed health checks on the day of the flight. There were also no dangerous goods reported on board the craft, and no dangerous weather either.

Authorities have officially refused to publish the final report which would determine the cause of the crash(Image: Vernon Yuen/Nexpher via ZUMA Press Wire/Shutterstock)

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.

According to a report published by the WSJ in May 2022, people familiar with US officials’ preliminary assessment of the cause of the crash indicated that recovered Black Box data reportedly pointed towards someone intentionally crashing the plane, as it was suggested inputs to the controls were what pushed 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.”

The statement came after an analysis of the information that was extracted from the recordings of the damaged flight-data recorders.

Another source told Reuters that investigators were looking into whether the crash could have been a “voluntary” act.

After reports of the crash possibly being deliberate surfaced, the CAAC issued a statement on April 11 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 scanty update report with virtually no information, saying the case was “very complex and extremely rare”, and on the two-year anniversary of the incident, it was virtually the same scenario, with the regulator maintaining that the crash was “very complicated and rare” while providing nothing of substance.

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

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