Steve Nichols
The truth behind the cause of the Concorde tragedy may rest with the two "black boxes" that have now been recovered from the crash site. Transcripts of part of the conversation between the pilot and the air traffic controller are available showing the _Cockpit Voice Recorder (CVR) was recovered intact.
Both the bright orange Flight Data Recorder (FDR) and (CVR) are being analysed, probably by the DGAC - the French equivalent of the US NTSB - or Air France. The airline is thought to have the equipment needed to analyse the data.
Both boxes are known to be damaged, although this does not mean their data are unreadable. The units are made of hardened stainless steel and built to withstand 1,000g decelerations and temperatures of up to 1,0000C. Both boxes were older, tape-based units. The FDR is known to be about 15 years old and was probably manufactured by Sundstrand, now part of the Honeywell organisation after the AlliedSignal merger. The CVR is thought to be of a similar age and possibly manufactured by a company that now forms part of L3 Communications, although the company declines to comment. Frank Daly, Honeywell's president, Commercial Electronic Systems, says the FDR is "pretty surviveable". "Our records show that this wasn't the original FDR fitted to Concorde," he says. "It is about 15 years old, but was recently overhauled as part of the aircraft's D-Check. "As an older, tape-based unit it doesn't record as many parameters as a modern sold-state unit, but Air France is a pretty contemporary company so we expect it has more than the basic 11 parameters required when the aircraft was built."
Daly is sure that the FDR will give details of the engine temperatures prior to the crash. "From what we have seen this could be crucial in determining what was going on in the number two engine," says Daly.
In the US, the FAA requires airlines to record a minimum of 11-29 parameters depending upon the type of aircraft. All aircraft manufactured after August 2002 will be required to be fitted with FDRs that can record at least 88 parameters, although some modern solid-state units can keep track of up to 700. A modern solid-state FDR can withstand at least 3,400g - the equivalent of stopping in 45cm (18in) from 640km/h (400mph) and a crushing force of 5,000 lbs (22kN).
Source: Flight Daily News
