The shell of the black box has a very thick steel plate and many layers of adiabatic impact protection material, usually installed in the tail of the aircraft in the most secure parts. It can survive many harsh conditions. The international aviation agency has imposed even stricter standards, and the recording medium has been improved from magnetic tape to a static storage recorder that can withstand greater impacts, similar to a memory chip in a computer, to prevent the black box from being damaged in a crash.
The "black box" was invented in 1958 by a Melbourne engineer in 1908, the year of the first U.S. military aircraft accident. Since then, as flight accidents continue to occur, there is a need for an instrument to remember the cause of the accident process. During World War II, the flight recorder was used on military airplanes and later on civilian airplanes. The reason why the flight recorder is called "black box" can be traced back to 1954, when all the electronic instruments in the aircraft were placed in the size and shape of the uniform black box.
Because of the rapid development of modern electronic technology, for airplanes, people began to advocate the direct wireless transmission of data signals to the ground and record, and no longer use the flight recorder, so the name of the future black box will return to the ground. For example, automobile data black box. 1987 (scalpel incident over the Barents Sea), a military aircraft over Norway exploded, the plane crashed and the pilot was killed. Norwegian authorities rushed to the scene of the crash and identified it as a military reconnaissance plane of a major power from the wreckage of the plane and the body of the pilot. Norway protested to a major power, which denied it. Later, Norway found the black box on the plane, and analyzed the data recorded from the black box to reveal the truth. The Soviet Union had to admit its mistake in the face of ironclad evidence.
"Black box" is a common name, its real name is very common: flight data recorder. It is an instrument that stores information about an airplane's flight so that it can be played back by a replay device when it is needed to understand the flight later.
In a box with a magnetic recording device, it can record what the pilot says, the pilot's off-board communications and flight data in real time. Generally in the aircraft accident 30 minutes before the various information, it can be retained. This makes it convenient to analyze the failure afterwards. The earliest use of black box is military aircraft. 1908, the United States occurred the first military aircraft accident. Later, as flight accidents increased, there was an urgent need for an instrument to study the causes of accidents. In World War II, flight recorders were officially used on military airplanes. After the war, it began to be used on civilian airplanes. In the early days, the recording method was backward, using mechanical recording method, recorded on photographic paper. It was only after the invention of the magnetic recording method that it became convenient and reliable.
The black box is a solid shell, rectangular, equal to four or five bricks together. Internal net is some electrical devices,
Yichun passenger black box [1]
essentially a transceiver. In the aircraft flight process, it can be collected by the in-flight sensors of a variety of information received in a timely manner, and automatically converted into the corresponding digital signals continuously for the record; when the aircraft crash, relying on the black box emergency locator transmitter automatically in all directions to send out a specific frequency (for example, 37.5 kilohertz), similar to heartbeat like a regular radio signals, "declares
Black box transmitter automatically transmits radio signals in all directions at a specific frequency (e.g. 37.5 kilohertz), similar to a regular heartbeat, to "announce" the location of the black box, so that the searchers can trace back the waves.
The black boxes are actually painted a bright orange-red color. This bright, conspicuous color, as well as the reflective conditions on the outside of the recorders, allow accident investigators to locate the recorders very quickly after a plane crash, especially if the plane crashes on water.
According to European standards, the black box must be able to withstand an impact force of 2.25 tons and remain undamaged for 10 hours at a temperature of 1,100 degrees Celsius. To meet the above standards. The black box is usually made of iron metal and some high-performance heat-resistant materials. Has a strong resistance to fire, pressure, shock vibration, seawater (or kerosene) immersion, anti-magnetic interference and other capabilities, even if the aircraft has been completely damaged black box in the record data can also be well preserved.
Types
There are two types of black boxes installed on most passenger and military airplanes. [2] One is known as the aircraft data recorder (FDR) black box, specializing in recording a variety of data in flight, such as flight time, speed, altitude, aircraft rudder deflection, engine speed, temperature, etc., *** there are more than 30 kinds of data, and can be accumulated to record 25 hours. Before takeoff, as long as the switch of the black box is turned on, all the above data will be included in the black box during the flight. Once there is an air disaster, the entire accident process of flight parameters can be found from the black box, people will know the cause of the airplane crash. Another kind of black box called pilot language recorder (CVR), like a tape recorder, it is placed in the cockpit and cockpit speakers, recorded between the pilot and the pilot and the cockpit passengers, hijackers and air hostesses of the speech, it records the time of about 2 hours, after recording, it will be rewound automatically from the beginning of the record, if an air crash, the previous two hours will be retained in full, and continues to signal until the power goes out (the recorder provides enough power to signal for 30 days).
With the rapid development of science and technology, the black box is also constantly updated. 1960s introduced the black box (FDR) can only record 5 parameters, the error is large. 70s began to use digital recording tape, can write down more than 100 parameters, save the last 25 hours of flight data. 90s after the emergence of integrated circuit memory, like the memory stick in the computer, can record 2 hours of CVR sound. record 2 hours of CVR sound and 25 hours of FDR flight data, greatly improving the accuracy of air crash analysis. On each airplane, there are usually two black boxes, their scientific names are called "flight data recorder" and "cabin voice recorder". The former mainly records all kinds of flight data of the airplane. The cabin voice recorder mainly records the crew and ground personnel calls, conversations between the crew and the cockpit sound (including the sound of the aircraft engine operation) and so on.