How many black boxes are there? How many black boxes are there on the plane?

Lead: As we all know, in the event of an air crash, there is little chance of escape. After the air crash, everyone's attention will be focused on finding the black box. So, Bian Xiao will chat with his friends today. How many black boxes are there? How many black boxes are there on the plane? The following small series will share with you, hoping to help friends in need.

How many black boxes are there?

black box

There are generally two black boxes, and each plane generally has two black boxes. Their scientific names are "flight data recorder" and "cabin voice recorder" respectively.

Black boxes usually include cockpit voice recorders and flight data recorders. The black box is orange, not black, so it is easy to find.

The cockpit voice recorder is installed at the back of the cargo hold of the aircraft. It starts recording when the plane is powered on and stops recording when the plane is powered off. It can record the sound of four channels: the captain's channel, the co-pilot channel, the standby channel and the environment channel, and the recording time is about two to three hours.

The flight data recorder is installed at the rear of the engine room. It starts recording when the engine starts and stops recording after the engine stops. The recording time is about 25 hours, and the recording parameters are about 1000, such as the altitude, speed, heading, pitch angle, roll angle, vertical speed of the aircraft, steering wheel lever, throttle and other important parameters of the crew.

The cockpit voice recorder can record the sound of headphones, microphones and cockpit environment of different channels on all three audio control panels. The recorder is located in the aft cargo hold. From the first increase of engine lubricating oil pressure, the recorder records with 120 minutes or 30 minutes continuous cycle tape until the last engine car finishes 5 minutes later.

Black box diagram

The flight data recorder is located above the ceiling in the back kitchen. In the history of 737, there were many types of FDR, and the parameters collected ranged from 8 to hundreds, and the duration ranged from 30 minutes to hundreds of hours. Most FDR starts recording at the moment when engine oil pressure appears.

Later, Digital Roosevelt used 1/4 inches wide and 450 feet long magnetic tape to record data. The latest solid-state FDR stores the recorded data in the memory chip.

737-3/4/500 FDR can record 25 hours of data. Its protective box includes aluminum inner shell, constant temperature protective shell, stainless steel outer shell and stainless steel dust cover. This enables it to withstand the extrusion force of 20,000 pounds in each axial direction and provide impact protection of 65,438+000 g5 milliseconds. The thermostatic protective shell can keep its core components at a safe temperature. It also has an underwater positioning device that can continuously send signals underwater for at least 30 days.

The FDR of the crashed aircraft model 737NG is similar to the above description, but it can withstand the impact of 3400G, the water pressure of 20000 feet and the high temperature of 1 100℃ for 30 minutes.

Black box picture

The structure of black box

Generally speaking, the structure of a black box includes the following parts:

1

Memory chip

All the stored information such as sound and flight data are stored in the core memory chip, so this is the core of the whole black box;

2

Thermal insulation and isolation layer

These two layers of materials are wrapped around the periphery of the memory chip, which plays a role in fire prevention and waterproof. According to the regulations, the memory stick should be able to withstand the high temperature of 1090 degrees Celsius for half an hour, and it can still be soaked in 6000 meters deep water. For example, in the history of the air France flight 447 crash, the black box slept for two years at a depth of several kilometers, and finally the deep-sea robot was salvaged and rediscovered;

three

top hat

This layer of material will wrap the insulation layer, isolation layer and the memory chip inside, and it is made of titanium steel, which can resist external impact. According to the requirements, the whole storage unit should be able to withstand the impact of 100G gravity15s, so the strength of the titanium steel shell is very high.

four

Peripheral mechanism

Including circuit excuses, power supply devices, underwater positioning, etc. The existence of power supply device and underwater positioning can make the black box continuously emit radio signals within 30 days, which is convenient for rescuers to locate the black box.

Relevant suggestions

Where is Wu Tong tengxian? Where is Wu Tong tengxian?

What's the weather like in tengxian? What's the weather like in tengxian?

What are the latitude and longitude coordinates of tengxian and tengxian in Guangxi?

Which city does Wuzhou City in Guangxi belong to?

When does the black box start? When does the black box start working?