Combined with the above materials, talk about why the black box is called the witness of the air crash.

After the air crash, when people come to the scene to rescue, they always look for one thing, that is, the black box called the "witness" of the air crash.

(2) The black box is a special electronic recording instrument for aircraft, and the other is a flight data recorder. It can record altitude, speed, heading, climb rate, descent rate, acceleration, fuel consumption, landing gear retraction, Greenwich Mean Time, as well as flight parameters such as aircraft system working conditions and engine working parameters. The other is the cockpit voice recorder. It is actually a radio call recorder, which can record all kinds of calls on the plane. When necessary, the black box can provide investigators with the operation of various systems and various conversations of the crew before the plane accident, providing a basis for accident analysis.

(3) The black box shell is made of thick steel plate and multiple layers of heat insulation and impact-proof materials, which can withstand 30 minutes of barbecue in the flame of 1 100 degrees Celsius, 5 minutes of extrusion of 2 tons of heavy objects, and months of immersion in gasoline, engine oil, batteries, acid solution and seawater. In short, it can be safe and sound under many harsh conditions.

Actually, the black box is not black. In order to make it easy for people to find it, it was painted bright orange. Perhaps people think that the information stored in it is of great significance to the identification of aircraft accidents, so they use such a very mysterious name-"black box".