Often, after an air disaster, we hear about the black box in the news. The black box does not play any part in making an aircraft fly but it serves an important function. It is basically an electronic device used by investigators to discover the cause of a crash and may be, prevent others.

Why do Aircrafts Have a Black Box?
Why do Aircrafts Have a Black Box? [Illustration by Shiju George]

The black box can be inserted or removed from an aircraft. In a passenger aircraft there are actually two black boxes. One contains the flight data-recorder and the other, the cockpit-voice recorder.

The flight data-recorder registers the aircraft’s speed, direction, altitude and other important information throughout the flight. The cockpit-voice recorder has a small cassette tape in it. This tape runs continuously like that in an answering machine. It has an endless loop of tape, which keeps recording each and every message. However, depending upon the capacity of the tape, one can retrieve messages in the previous 30 or 60 minutes.

Illustration of a flight recorder (black box) in customary bright orange
Illustration of a flight recorder (black box) in customary bright orange

Both the recorders are placed in the cockpit of the plane.

In order to protect the recorders, they are kept separately. These recorders are enclosed inside a crash-proof and fireproof metal shell. The interesting part is that although the flight recorder is called a ‘black box’ it is always painted bright yellow or orange!

What! A black box is actually yellow you ask? The answer is simple – it is easier to find a brightly coloured item in wreckage when everything around you is black, charred from the fire.

Although the flight recorder is called a 'black box' it is always painted bright yellow or orange!
Although the flight recorder is called a ‘black box’ it is always painted bright yellow or orange!

Then why call it a black box?

The term ‘black box’ is not just confined to an aircraft. Any device that is not essential for the functioning of a system is termed a black box.

So now, don’t get puzzled if the futuristic car of tomorrow has an orange or yellow box under the seat or in the dashboard!