Well David L nailed it, I was involved within the BA
Concorde Engineering operation at the time, so saw it all up close.
We really were stumped by how a FOD incident, could lead to such a destructive chain of events.
FOD issues were known, in the early days, some bad incidents, including that notorious one to an AF
aircraft in 1979, led to a range of design and procedure changes, (including new tyres), that prevented a repetition of severe ones.
The notion, popular in the media, that nothing was done, is an outright lie.
An aircraft operating in Concordes unique envelope, with it's design, was always going to be more FOD damage prone, that was always understood too.
In 1993, a BA
Concorde (G-BOAB), had a double burst, that blew the spray deflector off, it being buried in the wing.
This led to a retaining strap being fitted, the deflector had meant to shatter on any impact, it did not in this instance, hence the changes.
This would be the last major FOD incident before the AF
Small wonder that at first, this was suspected as being maybe a cause in the AF4590 crash, since AF
had not fitted the retaining strap, they did not have to, the authorities never made it mandatory.
When this was eliminated as a cause, the confusion grew.
We knew what Concorde tyre bursts could do, this crash seemed way beyond that.
In time, what David L mentioned came to light, it was certainly a bizarre chain of tragic events, that could not have been foreseen.
But, the offending FOD, part of the DC-10 thrust reverser assembly, was meant to be made of aluminium, for some reason, after servicing at Bedek Aviation, one made of titanium was fitted, this was the FOD.
This is a much harder material, it was not crushed by the weight of the aircraft running over it, only distorted, it damn thing acted like a knife, slashing the tyre in a way unseen in ANY related event with FOD, in the whole history of civil and military jet aviation.
There have long been fears about 'illegal parts' being made of inferior, less durable materials, here a crash was caused by one that was the opposite, who'd have thought it?
Had this FOD been of the correct material, you still might well have seen a tyre burst, but it would have not acted in the same manner on the tyre, if it had burst, the debris would have been much smaller, lighter, damage might still have been done, but a small fuel leak would not have led to the whole chain of events that downed F-BTSC.
The fuel gushed out of F-BTSC's damaged tank at an enormous rate, aside from all the effects of the aircraft itself, this rate of loss lowered the flash-point.
These revelations in spring 2001, altered the whole return to flight programme, the number of tank liners to be fitted, (a very difficult job), was much reduced, then Michelin unveiled their NZG tyre, a step change in tyre design, an adaptation of a design already in the works then for A380 and A340-500/600.
Knowing then, what was not known 6 months before, the fitment of NZG's would have sufficed, in pure technical terms, but the rest of the effort was well underway.
Reflecting back now, I really think there was another cause to the early bad incidents, ultimately too for AF4590.
There were so few Concordes in service, that the usual operational experience enjoyed by other types, took much, much longer to grow. All airliners in service, rack up Airworthiness Directives, Service Bulletins, based on operational experiences, including safety related ones, it just did not happen at the usual rate for Concorde, which was also far from a normal airliner. Others soon have tens of, then hundreds of airframes in service, all those different operators, racking up all those hrs and cycles, with incidents/issues leading to mods, mandated changes.
This could never happen with Concorde, after the early incidents often cited, the BA
grew in number, both operators increased the flying rate, but serious incidents reduced.
But all the while, we were out on a limb here, no one else had operated a SST before as well.
I do recall however, some incidents where a tyre burst started a chain of events that led to aircraft being lost, IIRC, two involved B727's in the 70's and 80's, one or two involved DC-8's.
This account of the return to flight, touches on many of the issues, it uses extensive sources from within, is a very comprehensive account, it was written in late 2002.
[Edited 2007-12-22 09:24:17]