Tag Archives: cockpit voice recorder

Black Box

How Black Box Works.?

Black Box
Black Box

Whenever an air crash happens, the investigators use this box to get to know how the accident happened. This box is the “Black Box”, inside which lies the much needed clues and it is the key to understand the air crash.


Dr. David Waren was the inventor of the Black Box. Australia is the first mandatory country to use the black box. It is sometimes called as the Flight Data Recorder but nicknamed as “Black Box” by the media.

Despite the name ‘Black Box’, these boxes aren’t black. They are painted bright orange for easy and high visibility. They do not help when the plane is in the air. Their work starts only at the time of air crash.

In all commercial airplanes there are two black boxes present. One is the Flight Data Recorder and other is the Cockpit Voice Recorder. Both are located at the rear of the aircraft.


The Flight Data Recorder (FDR) is a digital computer that records aircraft performance such as the planes air speed, engine setting, wing movement and altitude. The Foil Oscillographic Recorder inside the FDR helps in recording the various parameters of the aircraft before the crash. It also records the pilot’s input to various devices, the information sent to any electronic system.


The Cockpit Voice Recorder (CVR) is another black box which records all the conversations of the crew members and any other sounds, for example the beep sounds of the instruments inside the cockpit. It uses microphone to record all those radio communications, conversations, ambient noise and every other stuff when pilot deals with, during emergency situation.

The black box used today is more complex than the black box used in the olden days. The olden day’s black box recorded only the basic information such as the airspeed and altitude of the plane in magnetic tapes. But the aircraft used in today’s aircraft captures the basic information along with the wing movement, engine setting and conversations made in the cockpit using microchips.


What makes these black boxes unique is the ability to survive in anything and in any kind of environment. They are designed to withstand the high pressure and temperature. The battery works for 30 days and they can be detected two miles away.

The Underwater Locater Beacon (ULB) inside the black box helps in locating its position after the crash. The black boxes are usually placed in the tail section of the aircraft, so that they are more likely to survive at the time of collision.

It nearly took two years to find out the black box of the Atlantic Flight that went into Atlantic in 2009. The black box of the recently missing Malaysian Airline Flight MH 370 is missing and yet to be found. There hasn’t been any signal from the ULB, only if the signal is found, the box will be unveiled.

I suggest that there should be some improvements made in the Black Box, such as the ability to float in water so that it will be helpful to determine its position when the ULB is not working.

Hope some changes will be made in future in these investigation boxes.