The Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR) (popularly known as ‘black box’) of the Mi-17V5 chopper of the Indian Air Force that crashed with Chief of Defence Staff Bipin Rawat, his wife Madhulika Rawat and 12 defence personnel on board at Kattery in the Nilgiris were recovered.
Prelims, GS-III: Science and Technology
Dimensions of the Article:
- What is a Black box?
- About the way in which Black Boxes work and help in investigation
What is a Black box?
- A black box, technically known as an Electronic Flight Data Recorder, is an orange-coloured heavily protected recording device placed in a flight. It is used to investigate the details of the events immediately preceding an accident.
- Australian Scientist David Warren was the first to build a FDR/CVR prototype in 1958.
- Black boxes are also used in vehicles other than planes like railways, cars etc.
- Black Boxes are compulsory on any commercial flight or corporate jet where they are usually kept in the tail of an aircraft, where they are more likely to survive a crash.
About the way in which Black Boxes work and help in investigation
- The flight data recorder (FDR) of the Black Box – records the information about a flight and help reconstruct the events leading to an aircraft accident. It records more than 80 different types of information such as altitude, airspeed, flight heading, vertical acceleration, pitch, roll, autopilot status etc.
- The cockpit voice recorder (CVR) records radio transmissions and other sounds in the cockpit such as conversations between the pilots and engine noises.
- It usually takes at least 10-15 days to analyse the data recovered from the black boxes. Meanwhile the investigators will be looking for other clues such as taking accounts from air traffic control personnel and recordings of the conversation between ATC and the pilot’s moments before the crash.
How do the black boxes survive the crash?
- The recording devices are stored inside a unit that is generally made out of strong substances such as steel or titanium and are also insulated from factors such as extreme heat, cold or wetness.
- To protect these black boxes, they are equipped towards the tail end of the aircraft – where usually the impact of a crash is the least. There have been cases where planes have crashed into water bodies.
- To make black boxes discoverable in situations where they are under water, they are equipped with a beacon that sends out ultrasound signals for 30 days. However, in certain cases – like the Malaysian Airlines MH370 flight – the recorders aren’t found despite all the redundancies.
-Source: The Hindu