It has been more than 72 hours since the accident of China Eastern Airlines, and the search and rescue operation is still ongoing. On Wednesday (23rd), the cockpit voice recorder in the two black boxes of the crashed passenger plane MU5735 was recovered at the scene. Wang Yanan, editor-in-chief of Aviation Knowledge magazine, estimates that it will take about 10 to 15 days to obtain the preliminary analysis report of the black box, but it may take longer to form the final conclusion of the accident investigation report. Internal media once reported on Friday (25th) that another black box, the flight data recorder, was found at the crash site on the same day, but subsequent corrections have not been found.
Zhu Tao, director of the Aviation Safety Office of the Civil Aviation Administration of China, said that the first black box found was the cockpit voice recorder, which was sent to Beijing for decoding and analysis that night, and it was not ruled out that the storage memory was damaged. The flight data recorder lasts for about 25 hours and records about 1,000 parameters in detail, including important parameters such as altitude, speed, heading, pitch angle, roll angle, vertical speed, and crew operations such as the throttle.
Guo Qing, an associate professor at the School of Aeronautics at Northwestern Polytechnical University, said that the time required to interpret the black box depends on the degree of damage, which may be days or months. Shu Ping, director of the Aviation Safety Research Institute of the China Academy of Civil Aviation Science and Technology and director-general of the Aviation Safety Committee of the China Aviation Association, said that if the black box is in good condition, it will generally be sent to the laboratory of a civil aviation professional institution designated by the government for decoding analysis; If it is more serious, it must be sent to the original manufacturer of the equipment for repair.
It is understood that most of the sound in the cabin is recorded by the cockpit voice recorder by the traditional tape method. As long as it is not completely damaged, it can be at least partially interpreted. Guo Qing also pointed out that although the black box is an important source of clues to determine the aircraft accident, even if it cannot be recovered, the cause of the crash can be determined by investigating the aircraft maintenance records, the pilot’s psychological status, other crew members and other auxiliary means.