(Crash of China Eastern Airlines plane) A black box of the crashed passenger plane of China Eastern Airlines has been found: how long does it take to decipher the black box?
China News Agency, Beijing, March 23 (Reporter Liu Liang) On the 23rd, important progress was made in the search for the crash of the China Eastern Airlines passenger plane.
According to the "3.21" China Eastern Airlines MU5735 aircraft flight accident National Emergency Response Headquarters reported on the 23rd, a black box of China Eastern Airlines MU5735 flight has been found on the 23rd.
Although the official is currently not sure whether the black box is a data recorder (FDR) or a cockpit voice recorder (CVR), and another black box is still being searched, this undoubtedly gives the outside world a glimmer of hope.
The black box, also known as the "flight recorder", is an important carrier installed on the passenger plane to record the flight information of the passenger plane.
In many airliner accidents, finding the black box often means one step closer to the "truth".
Guo Qing, an associate professor at the School of Aeronautics at Northwestern Polytechnical University, pointed out in an interview with a reporter from China News Agency that there are generally two flight recorders installed on passenger planes. One is an aircraft data recorder, which is responsible for recording flight speed, altitude, time, engine speed, Data such as the deflection angle of the rudder surface of the aircraft; the other is the cockpit voice recorder, which is responsible for recording the calls between the aircraft and the ground, the conversations of the staff, and various sounds in the cabin.
"The black box can provide investigators with the flight situation of the aircraft in the period before the crash. It is an important source of evidence for accident analysis and a source of data for making correct judgments about the accident." Guo Qing said.
He pointed out that in order to withstand the violent impact and high-temperature burning flames of a plane crash, the outer shell of the black box usually has a very thick steel plate and multiple layers of shock-proof thermal insulation materials, which can withstand high temperature, gravitational impact, and deep water pressure.
In the category of general passenger aircraft, the "black box" performance indicators of different types of aircraft are basically the same.
As for the black boxes that have been found, he said that the interpretation time of the black boxes depends on the seriousness of the crash of the plane, which may be several days or several months.
The black box is generally interpreted by a professional civil aviation accident investigation agency, involving multiple forces.
According to the International Civil Aviation Convention and the relevant investigation regulations of civil aircraft incidents, the accident investigation generally includes the country where the accident occurred, the country where the aircraft was designed, the country of manufacture, the country of operation and the country of registration.
At present, the search for another black box is also critical.
When talking about whether there is a time window for finding the black box, Guo Qing said that the main function of the black box is to provide multiple data records of the aircraft, not the positioning function, so its positioning function is not strong, usually just sending out pulse signals, and the time Limited, but generally more than 30 days.
"The faster the search for the black box is, the better. Over time, the strength of the signal emitted by the black box will gradually weaken with the consumption of electricity. The longer the time, the more difficult it is to search for the black box." Guo Qing said.
He also pointed out that the crash site of the China Eastern Airlines plane was in a mountainous area with complex terrain and dense jungles. The size of the black box of a Boeing 737 aircraft is usually about 60 cm x 20 cm x 20 cm. In a mountainous area with dense forests, a size similar to a small express carton was found. It is very difficult to find the black box of the aircraft, and it is difficult to judge the attitude and speed of the aircraft at the moment before the crash, which also brings difficulties to the search for the black box.
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