On the occasion of the fourth anniversary of the China Eastern Airlines Flight 5735 (MU5735) crash, the Civil Aviation Administration of China has yet to release the annual progress report on the investigation into the crash, contrary to international practice.
On March 21, 2022, the MU5735 flight from Kunming to Guangzhou, operated with a Boeing 737-800 aircraft, suddenly nosedived in mid-flight, almost vertically crashing to the ground, resulting in the deaths of all 132 people on board (123 passengers and 9 crew members).
The Civil Aviation Administration of China previously issued a brief initial notification stating no structural or system failures were found with the aircraft, the engines were functioning normally, there were no dangerous goods onboard, and no issues were detected with the crew’s qualifications or health. The report mentioned that the black box had been located and initial analysis had commenced, but did not disclose technical details or the cause of the accident.
According to the International Civil Aviation Organization (ICAO) requirements, if the final investigation report of a flight accident cannot be completed within 12 months, annual updates on the investigation progress must be made public.
However, since 2024, the China Civil Aviation Administration has not released any annual updates on the MU5735 accident. On March 20, 2024, the administration stated that no faults or anomalies were found in the aircraft’s systems, structure, or engines. On May 19, 2025, in response to a government information disclosure request, the administration decided not to make the mid-year investigation report public, citing potential risks to “national security and social stability”.
Some sources quoted by US media indicated that flight data suggested the aircraft may have been deliberately operated to nosedive, citing reasons such as lack of distress signals, multiple unsuccessful control calls, and flaps/gear not deployed (unlike for an emergency landing).
The International Air Transport Organization has consistently emphasized the importance of transparent reporting to enhance safety, warning that failure to do so could hinder global aviation safety improvement efforts and prevent similar accidents from recurring.
The Germanwings Flight 9525 crash shares similarities with the China Eastern Airlines MU5735, as both incidents possibly involve human factors (the pilots).
The Germanwings Flight 9525 crash in 2015 prompted reforms in cockpit safety and pilot screening rules worldwide. The regular passenger flight from Barcelona, Spain, to Dusseldorf, Germany, crashed in the French Alps on March 24, 2015. Investigators concluded that the co-pilot intentionally caused the crash, resulting in the deaths of all 150 people on board.
The French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) publicly stated within days that the co-pilot deliberately crashed the plane, disclosed partial audio contents from the black box recordings within weeks, and released a full final report approximately a year later.
The black box recordings revealed that the captain was locked out of the cockpit, and the co-pilot deliberately descended the aircraft. Medical and psychological data that were made public showed that the co-pilot had a history of depression and had concealed his health condition.
Subsequently, multiple airlines globally adjusted regulations, implementing the “two-person cockpit rule”, requiring at least two people to be present in the cockpit at all times. Airlines also strengthened medical and psychological evaluations and enhanced monitoring systems for pilot mental health. Discussions on medical privacy and public safety were institutionalized.
However, as the reasons behind the MU5735 crash remain undisclosed to this day, the aviation industry has been unable to learn from this tragedy to prevent similar accidents from occurring again.