Black box or flight data recorder, mounted in the tail of an aircraft, is one of the most important gadgets that is used to reconstruct the events leading to a plane crash.
The term "Black Box", however, is a misnomer as its colour is orange. This is done for easier location after a crash. It is found in the rear part of a plane, considered the most crash-survivable portion.
Flight data recorder (FDR) is enclosed in steel and surrounded by multiple layers of insulation so that it remains protected against crash, fire, and extreme climatic conditions.
It records actual flight conditions, including altitude, airspeed, heading, vertical acceleration and aircraft pitch.
Another device cockpit voice recorder (CVR) records radio transmissions and sounds in the cockpit, such as the pilot's voices and engine noises.
David Warren of Aeronautical Research Laboratories in Melbourne is credited with the invention of the Black Box in 1953. The purpose was to help identify the reasons for a plane crash, by recording any clues in the flight crew's conversation. They were painted bright red or orange to make them easier to find after a crash.
In 1960, Australia became the first country to make flight recorders mandatory in aircraft.
According to Directorate General of Civil Aviation (DGCA) rules, from January 1, 2005, it is required of all aircraft including helicopter in India to carry a CVR and FDR for recording digital communications with Air Traffic Service (ATS).
CVR is installed in the aircraft for recording aural environment on the flight deck during flight time for the purpose of accident/incident prevention and investigation.
If recorded on the flight data recorder, the digital communication shall be readily correlatable to the cockpit voice recorder recording.