Flight Data Recorder

While the search of black box is going on for the recently crashed flight in Mangalore, where 158 people got killed, I had curiosity, why this blackbox so important? I retrieved some information as follows.

Black Box in a flight, aka Flight Data Recorder (FDR) holds a store of data often crucial to air crash investigators looking to find the cause od a disaster or accident.

Why are they placed at the rear of the aircraft?

Putting them in the back of the aircraaft increases their chance of survival. The precise location of a black box depends on the individual plane. Typically, the tail of the aircraft is the last portion of the aircraft to impact.

How it is built?

Using three layers of materials, the crash survivable memory units (CSMU) in a solid state Black box insulates and protects the stack of memory boards that store the digitised information. To make sure CSMUs are strong they are subject to rigororous tests like crash impact, pin drop, static crush, fire test, deep sea submersion, salt water submersion & fluid immmersion etc.

What is the history?

One of the earliest and proven attempts at a data recorder was made by Francois Hussenot and Paul Beaudouin in1939 at the Marignane flight test center, France, with their type HB flight recorder. This was an essantially photograph based device, because record was made on a scrolling eight meters long by 88 mm wide photographic film. After its evolution, in 1960, after the crashof an aircraft at Mackay, the inquiry judge strongly recommended that flight recorders be installed in all airlines Ustralia the be came the first country in teh world to make cockpit-voice recording compulsory.

Source: DNA