On March 20, the Civil Aviation Administration of China issued a report on the progress of the investigation into the flight accident of China Eastern MU5735 aircraft & ldquo;3·21”.

According to the circular, over the past year, the technical investigation team conducted a detailed inspection of the wreckage of the aircraft, determined the possible working status of the key control parts of the aircraft before landing, tested more than 100 pieces of important wreckage, and analyzed the causes of the damage.

To investigate the qualification and ability of crew members, flight operation, aircraft airworthiness maintenance, airline organization and management, etc.

Conduct investigations on air traffic control services, airport ground support, security checks and loading of passengers, luggage, cargo and mail, and the carriage of dangerous goods.

Combined with the relevant data, the final flight state of the aircraft is analyzed, and the flight simulator and real machine are used to simulate and verify.

Up to now, the technical investigation team has carried out a lot of work, such as on-site investigation, data inspection, personnel interviews, experimental analysis, and so on.The accident is very complex and rare, and the investigation is still in progress.

In this circular, Xinhua News Agency specially interviewed Shao Quan, vice dean of the School of Civil Aviation of Nanjing University of Aeronautics and Astronautics, and Gao Jun, director of the customer Service Department of China Aviation Technology Import and Export Co., Ltd., to answer relevant questions.

As for the timing of the announcement, Shao Quan pointed out thatTransport aviation accidents often have a great social impact and high public attention. It is a common requirement and practice in the international civil aviation industry to disclose information about the progress of the investigation to the public on the anniversary of the incident.

However, it needs to be emphasized that whether & ldquo; interim statement & rdquo; or & ldquo; investigation progress & rdquo;, is not the final result of the ldquo; survey & rdquo;.

Generally speaking,The investigation cycle of large transport aviation accidents is often more than one year.Mainly because of the technical complexity and uncertainty faced by the investigation, many technical doubts and difficulties need to be repeatedly demonstrated, and some key conclusions need to be verified by engineering experiments, which takes a lot of time.

Statistics show that of the more than 1000 commercial aviation accidents that have occurred in global civil aviation in the past 30 years, only 25% of the final reports have been issued within one year.

As mentioned in the report on the progress of the investigation & the ldquo; accident is very complex and extremely rare & rdquo;, Gao Jun explainedAircraft accident investigation is a complex system engineering, which usually requires comprehensive and in-depth investigation from many aspects, such as personnel qualification and operation, aircraft airworthiness, weather environment, ground support, air traffic control command, company organization and management and so on.

Judging from the current understanding, there is a great difference between this accident and the past.

The plane almost completely disintegrated after falling to the ground at high speed, and the wreckage was trivial and scattered.All these have greatly increased the difficulty of on-site search and investigation and wreckage forensics.

In accordance with the accident investigation procedureThe investigation team needs to identify all the wreckage found, conduct detailed inspection and experimental analysis of important wreckage.In order to determine the failure mechanism and the working status of the final stage, and to provide evidence for follow-up investigation and analysis, which are very complex and professional work.

Generally speaking, the workload of conducting investigations into aircraft airworthiness and maintenance mentioned in the circular is also very heavy.Generally speaking, the workload of conducting investigations into aircraft airworthiness and maintenance mentioned in the circular is also very heavy.

In addition, other aspects of the accident investigation are equally complicated, which require the investigation team to carry out rigorous, meticulous, objective and in-depth work to ensure that the final conclusions of the investigation can stand the test of history.