Report on the progress of the investigation of the flight accident of MU5735 aircraft of China Eastern Airlines on March 21.

    On March 21, 2022, China Eastern Airlines Yunnan Co., Ltd. Boeing 737-800 (registration number B-1791) carried out a scheduled passenger flight from Kunming Changshui Airport to Guangzhou Baiyun Airport. At 13: 16, the plane took off from Kunming Changshui Airport. After 64 minutes, it deviated from the cruising altitude of 8,900 meters and quickly descended. It crashed near Moguang Village, Langnan Town, tengxian, Wuzhou City, Guangxi Zhuang Autonomous Region. All 123 passengers and 9 crew members on board were killed.

    The Civil Aviation Administration of China, in conjunction with relevant departments, conducted a technical investigation on this accident in accordance with the China Civil Aviation Regulations "Provisions on Technical Investigation of Civil Aircraft Accidents" (CCAR-395) and the relevant provisions of Annex 13 of the Convention on International Civil Aviation. The main progress is as follows:

    First, the search, identification and analysis of the wreckage. Organize the search for physical evidence of the wreckage, identify the main wreckage, take photos to collect evidence, mark the location of discovery, and make a map of the location of the wreckage; Conduct special technical investigation on aircraft structure, flight control system, engine and other wreckage, and analyze the attitude of the aircraft before falling to the ground and the possible working state of key control components; Send the engine parts, control system parts and other important wrecks to the laboratory for analysis to determine the cause of damage.

    Two, flight operation and aircraft airworthiness. Investigate the crew members’ technical status, health status and actual performance; Investigate the release plan, load balance, performance calculation, operation monitoring and crew preparation of the incident flight; Investigate the company’s safety management, training management, personnel qualification management, maintenance management and other organizational management; Investigate the implementation of aircraft airworthiness instructions and service notices, the maintenance of routes and scheduled inspections, and the maintenance of faults; Investigate and analyze the fuel filling and fuel quality of the incident flight; Integrate monitoring data, video recording, etc., and analyze the flight state of the aircraft in the final stage; Repair the damaged recorder and analyze the obtained data.

    Third, the flight security situation. To investigate the qualifications of security personnel and the working conditions of facilities and equipment at the take-off airport; Investigate the routine inspection and maintenance of runways, taxiways, taxiways and apron pavements used by the incident flights; Investigate the qualifications of air traffic controllers, communication, navigation and monitoring equipment, air traffic control automation system, air traffic control command process and air route weather conditions; Investigate the basic information, security inspection and loading of passengers, luggage, goods and mail; Check the dangerous goods carrying information of the incident flight and the dangerous goods training of the crew and related support personnel.

    After investigation, the flight crew and cabin crew of the incident flight held valid licenses and certificates, and the flight, duty and rest time met the requirements. The physical examination before the flight on that day was qualified, and the crew qualification and configuration met the requirements; The airworthiness certificate of the incident aircraft is valid, and the qualifications of relevant maintenance personnel meet the requirements; No faults or abnormal conditions were found in the aircraft system, fuselage structure and engine before take-off, and no faults were reserved; The qualification of relevant operation support personnel on the day of departure airport meets the requirements, the facilities and equipment work normally, and the operation and operation conform to the working procedures; The qualification of relevant air traffic controllers meets the requirements, the communication, navigation and monitoring equipment works normally, there is no abnormality in radio communication and control command before the incident, and there is no dangerous weather report in the airspace and flight altitude of the aircraft at the time of the incident; The flight of the incident met the requirements, there was no cargo mail declared as dangerous goods, and there was no evidence that there were dangerous goods in the cargo mail and luggage.

    Subsequently, the technical investigation team will continue to carry out experimental verification and cause analysis, and release relevant information in a timely manner according to the progress of the investigation.