[Explanation] A black box of the crashed passenger plane of China Eastern Airlines was discovered on March 23. At present, the black box has arrived in Beijing, and technical experts are deciphering it.
[Explanation] What is a black box?
What information is stored in the black box?
Is it possible to restore the flight status of the aircraft?
On March 24, Guo Qing, an associate professor at the School of Aeronautics of Northwestern Polytechnical University, answered several key questions about the black box.
[Concurrent] Guo Qing, Associate Professor, School of Aeronautics, Northwestern Polytechnical University
The black box is a relatively important flight data recorder of the aircraft. It can be retrieved to check the most real (status) of the aircraft. There are generally two such devices, one is called the flight data recorder, and the other is A cabin sound recorder called the cockpit.
[Explanation] Guo Qing introduced that the black box is generally square or cylindrical. In order to reduce the impact and improve its survivability, it is usually placed at the tail of the aircraft.
In addition, the black box shell is made of steel plate and thermal insulation material, which can withstand the impact of gravitational acceleration of more than 100G and the high temperature of 1100°C.
[Explanation] On the evening of the 23rd, Zhu Tao, director of the Aviation Safety Office of the Civil Aviation Administration, disclosed to the public that the first black box of the crashed passenger plane of China Eastern Airlines had been found, and its appearance was severely damaged. The initial judgment was that it was a cockpit voice recorder.
[Concurrent] Guo Qing, Associate Professor, School of Aeronautics, Northwestern Polytechnical University
The one I found is the cabin sound recorder, which records the sound inside the cabin, and the other is called the flight data recorder, which records the flight speed of the aircraft, including some of its altitude and other information.
[Commentary] Guo Qing said that although the first black box has been found, it is not easy to find another black box because the attitude and speed of the plane at the moment before the crash are difficult to judge.
[Concurrent] Guo Qing, Associate Professor, School of Aeronautics, Northwestern Polytechnical University
The black box must be found as soon as possible, because as its own power is consumed, the signal it sends will gradually become weaker. Generally, such a window period is at least 30 days or more, or even more than 40 days.
[Explanation] How long does it take to decipher the black box?
Guo Qing said that it depends on the degree of damage to the black box.
[Concurrent] Guo Qing, Associate Professor, School of Aeronautics, Northwestern Polytechnical University
If the damage is low, it could be very quickly, maybe a few days, if the damage is high, maybe a month or even months.
[Commentary] Guo Qing introduced that the black box is an important source of clues for judging an aircraft accident. If it is not found or cannot be recovered, the cause of the crash can also be determined by auxiliary means such as investigating the aircraft's maintenance records, the pilot's psychological status, and other crew members. .
Reporter Liu Chao reports from Beijing
Responsible editor: [Li Yuxin]