E-Paper
China plane crash: Explained - What is airplane's black box?
Black box is a recording device used by aviation investigators to analyse the events leading to the air mishap
A black box from the China Eastern Airline flight that crashed in south China's Guangxi was recovered on Monday. The flight recorders are crucial to probe why the flight MU5735 nosedived before ramming into a hillside, leaving 123 passengers and nine crew members dead.
Black box is a recording device used by aviation investigators to analyse the events leading to the air mishap . Here are five important things to know about the black boxes.
> Black boxes are of the size of shoe boxes, fit inside the aircraft to record in-flight information. The data can be used in the event of an incident or accident. They are actually known as flight recorders. Australia was the first country to make black boxes mandatory in its airplanes.
>Unlike its name, a black box is of fluorescent orange in colour to be clearly visible among the debris from a crash site. Actually the term was coined during the Second World War, coinciding with the development of radio and other electronic navigation aids in aircraft flown by the British and other Allied powers. These recorders were kept in non-reflective black boxes.
> Commercial aircraft have two black boxes fit on either side of the back of the aircraft. The cockpit voice recorder (CVR) records pilot conversations, announcements from the cockpit of the aircraft. The second is flight data recorder (FDR) which lists hundreds of flight details such as the plane altitude, temperature speed etc. The two devices may be combined in a single unit.
> The total length of CVR recording is two hours and the FDR is 25 hours. To record data in extreme situations, the black boxes resist extreme temperatures in case of fire and being submerged as deep as 6,000 metres into the water.
> In case the plane crashes into the water, an underwater beacon will send out pulses which can be detected by an audio equipment. But if the aircraft crashes on land, the locator beacons will not send the signals.
