Two black boxes of China Eastern Airlines MU5735 have been found. What about the on-site search? How long does it take to decipher the black box? What challenges did the accident investigation encounter? On the channel news 1+ 1 broadcast on the evening of 28th, Bai interviewed Li Yong, the key authoritative expert of "3.21"China Eastern Airlines MU5735 aircraft flight accident technical investigation team and director of the Aviation Safety Office of the Civil Aviation Administration of China.
How damaged are the two black boxes? Will it affect the root cause and data collection? At this stage, the two black boxes have already been sent to the technical professional laboratory and the corresponding decoding work has been carried out. Li Yong introduced in detail that everything is normal. The decoding work of the black box only needs to plug in the switching power supply and connect the special decoding mechanical equipment, so that the data information can be downloaded for free, and the pressure can be relieved and loaded. If the black box is intact, the whole process will take about three or four hours.
However, the two black boxes were seriously damaged. The black box we see at this stage is actually the data storage of the memory chip. Because its surface is resistant to falling, it has been left out in the cold, and the base of the black box has long since disappeared. Therefore, after the black box is brought back to the laboratory, it must be inspected in detail and cleaned, such as drying or even dismantling. If there is something wrong with the processing chip, it is likely that it needs to be repaired later. At this stage, it seems that the time required for decoding is still impossible.
The black box has been found, why are you still looking for it? Li Yong showed that the wreckage of the plane is also crucial for the investigation of safety accidents. Finding a large number of aircraft wreckage and knowing their distribution is conducive to mastering the landing attitude and collision angle of the aircraft. There may be some key direct evidence hidden in the remains, such as the position of control surface, engine output power and other information, which can be checked with the information of flight data monitoring software in the future. In addition, the collection and analysis of relevant videos and interviews with witnesses also help to clarify the attitude and perspective of the plane before it crashed.
How long will the accident investigation take? Li Yong introduced in detail that civil aircraft accident investigation is a very complicated engineering project, which must be thoroughly and comprehensively analyzed from the aspects of aircraft trial maintenance, navigation operation, air traffic control, temperature and natural environment. Only then can we gradually peel off and reel off cocoons, and when necessary, we need a lot of experimental certification work from institutions to verify our ideas. Generally speaking, a typical international aviation accident investigation usually takes more than 2 years.
Li Yong said that according to the information at this stage, the investigation of this safety accident also encountered three major challenges: the plane suddenly dropped from the relative height of constant speed cruise without warning, and the air traffic control unit did not receive any distress information or abnormal information fed back by all generator sets; The collision at the scene is very strong, and the remains are very scattered and widely distributed. It is difficult to investigate and collect evidence according to the remains in the middle and late stages. The terrain of the site is extreme, and the collision address is in the canyon area. Long-term precipitation immersion leads to very muddy land resources, which also causes many difficulties for inspectors.
Li Yong said that the investigation will take some time, but in any case, he and his friends will do their best to find out the truth as soon as possible and give an account to the country, social development and relatives of the victims.