Concorde 4590

[booke23]

Originally Posted by B Fraser

It was a multitude of failures to follow SOPs. I post here under my own name so please forgive me for calling a spade a spade but the elephant in the room here would appear to be operating culture.

I agree to a large extent. I was disappointed that the report did not probe the culture within the airline. There were also human factors lessons to be learnt
with regards to aircraft maintenance.....reading between the lines in the report, that undercarriage was reassembled incorrectly on a night shift (not the first or last time a serious maintenance error happened in the middle of the night).

However you have to ask.......if the aircraft was at MTOW (not over it), took off with the spacer in place the No 2 engine wasn't shut down.....would the outcome have been different? (btw the tank that ruptured wasn't overfilled according to the report)

Well the tyre would almost certainly still have burst. If it shed 4.5kg of rubber up against the tank it would still have ruptured and caught fire. If engine 2 hadn't been shut down it would have flamed out anyway as engine 1 did. So they may have flown a little bit further but the outcome would have been the same.

[B Fraser]

The chap who gave the presentation I attended mentioned that some of the runway lighting debris was ingested by the #1 engine. I'm not sure how he knew this but as he was a BA skipper, I trust his account. Perhaps if the spacer had been fitted and the strip of titanium was positioned so it still hit the tyre, would the aircraft have veered by the same degree and not hit the edge lighting ? We will never know.

[Buster15]

Originally Posted by booke23

However you have to ask.......if the aircraft was at MTOW (not over it), took off with the spacer in place the No 2 engine wasn't shut down.....would the outcome have been different? (btw the tank that ruptured wasn't overfilled according to the report)

Well the tyre would almost certainly still have burst. If it shed 4.5kg of rubber up against the tank it would still have ruptured and caught fire. If engine 2 hadn't been shut down it would have flamed out anyway as engine 1 did. So they may have flown a little bit further but the outcome would have been the same.

They were also quite unlucky in that the tyre debris was thrown up at speed and impacted the underside of the wing very close to a junction between a thicker and thinner (machined) section. The fuel pressure pulse then fractured the skin at that junction. Had it impacted at a slightly different location it is possible that the wing skin may not have failed OR lead to a smaller leak.

All this discussion about the crash must not detract from the stunningly brilliant technical achievement that was Concorde.

[booke23]

You are quite right about the tyre debris.......To cause tank rupture it probably had to hit the tank within quite a small range of angles......a more glancing blow would not have had the energy to cause major damage. It could have flown off the tyre at any angle, yet it happened to impact the wing square on and rupture it.

If you tried to replicate it in a lab, you'd probably have to do it a couple of dozen times before you got a piece to hit the wing and cause damage. Of course these type of freak happenings are often the root of many disasters.

Originally Posted by Buster15

All this discussion about the crash must not detract from the stunningly brilliant technical achievement that was Concorde.

Absolutely.....in my view, one of the best aircraft mankind has ever made. I still can't quite believe one crashed.

[B Fraser]

Originally Posted by Buster15

They were also quite unlucky in that the tyre debris was thrown up at speed and impacted the underside of the wing very close to a junction between a thicker and thinner (machined) section. The fuel pressure pulse then fractured the skin at that junction.

I think it is well documented that the tank did not rupture at that point. The absence of an air gap in the tank due to intentional overfilling caused conditions where a shock wave could pass through the fuel, blowing out a hole far from the point of debris impact. Another violation of a SOP, another hole in the Swiss cheese.

[Shaggy Sheep Driver]

Quite so, The rupture of the tank was FROM THE INSIDE OUT, not the outside in, by an overpressure caused by there being insufficient gap of compressible air at the top of the tank to absorb that overpressure in the incomprehensible fuel, the initial cause of which was a big bit of tyre hitting (but not puncturing) the underside of the tank.

[Feathers McGraw]

It's also worth pointing out that according to John Hutchinson fuel was being transferred forward from the rear fuselage tank during the take off roll, this is apparently not permitted. The reason was that the CoG was too far aft, not helped by that extra baggage. In addition because rearwards transfer is needed for acceleration with centre of lift movement it was important to get the fuel out of the fuselage tank for that reason too otherwise there would be no space to move fuel back once climbing towards Mach 1.

Something not often mentioned is that the longer CDG-JFK route imposed a fuel penalty on Air France Concordes and perhaps that could have led to a culture of adding extra fuel which became a habit and was not questioned.

[flyboyike]

Originally Posted by booke23

The aircraft was also overweight by 0.7 - 1.2 tonnes, which it pretty shocking practice from a national carrier IMHO.

You're kidding, right?

[booke23]

Originally Posted by flyboyike

You're kidding, right?

Afraid not. 19 bags were put on the aircraft without appearing on the load sheet. And of the 2 tonnes of taxi fuel loaded, only half was used before take off. The investigation couldn't determine the exact overweight figure, but it was somewhere in the 0.7 - 1.2 tonne range........probably closer to the 1.2 tonne figure, given the nature of the pax (joining an extended duration cruise).

[B Fraser]

Those bags are said to have been loaded in the rear hold which didn't help the CoG. A further 10 bags were left behind. The status of each bag is not immediately clear however the accepted number of bags loaded that were not on the load sheet is 19.

The document at the link below shows that right rudder was being applied progressively during the take off run. The key data is about 1/3 down the page showing larger lateral accelerations from 100kts onwards. This could be consistent with the hypothesis that the missing spacer was affecting performance prior to the tyre burst event and reliable witness statements that smoke was seen far earlier than the fire. I can't see any reference to the spacer in the report but I have not read it in great detail

https://www.bea.aero/docspa/2000/f-s...sc000725pa.htm

[Buster15]

Originally Posted by B Fraser

The document at the link below shows that right rudder was being applied progressively during the take off run. The key data is about 1/3 down the page showing larger lateral accelerations from 100kts onwards. This could be consistent with the hypothesis that the missing spacer was affecting performance prior to the tyre burst event and reliable witness statements that smoke was seen far earlier than the fire. I can't see any reference to the spacer in the report but I have not read it in great detail

https://www.bea.aero/docspa/2000/f-s...sc000725pa.htm

Fraser. Page 155 of the BEA Report states that (words to the effect) the analysis carried out shows that the absence of the Spacer had no affect on the aircraft crash.

[B Fraser]

Thanks Buster, I was looking for references using keywords but can't find any in the preliminary report. The subject is as you say covered in the final report from P.148 onwards at https://www.bea.aero/uploads/tx_elyd...-sc000725a.pdf

[Concours77]

Is the chronic lateral and increasing port side trend charged to a specific finding?

It seems to me that if FOD is portrayed as the cause, its location on the runway has much to do with this left drift. Absent leftward Bias, does the Titanium strip come into play? At all?

[Shaggy Sheep Driver]

Knowing how - ahem - 'unbiased' the French are when it comes to attributing blame (like their despicable attempt to blame the entire tragedy on a maintenance engineer at Continental, which the courts rightly threw out) I prefer BA Concorde Captain Hutchinson's take on the spacer issue and the evidence of unbiased witnesses to which the report gives little heed, above the complete dismissal the BEA report gives it.

That is simply not tenable IMO.

[pulse1]

I prefer BA Concorde Captain Hutchinson's take on the spacer issue and the evidence of unbiased witnesses to which the report gives little heed, above the complete dismissal the BEA report gives it.

According to the series of lectures given by the ex BA Concorde flight engineer, one of the best witnesses was the captain of Mitterrand's Airbus which was holding to cross the runway. Apparently he witnessed that there were signs of fire before the Concorde reached the metal strip. His testimony was not included.

[B Fraser]

The same goes for the airport fireman who noted smoke coming from somewhere consistent with the bogie.

[booke23]

Originally Posted by pulse1

Apparently he witnessed that there were signs of fire before the Concorde reached the metal strip.

This thread is in danger of descending into a farce of conspiracy theories. (if it hasn't already).

[Buster15]

Originally Posted by booke23

This thread is in danger of descending into a farce of conspiracy theories. (if it hasn't already).

Agreed. Some people seem to believe that because the crash investigation was carried out by the French BEA that the report was biased in favour of AF and ignored vital information. Technical information was requested from and supplied by a range of specialists including Airbus UK and RR.
Quite how anybody watching the takeoff could accurately know and remember where the strip was on the runway when the aircraft was travelling at speed is open to question.

[Shaggy Sheep Driver]

Originally Posted by Buster15

Agreed. Some people seem to believe that because the crash investigation was carried out by the French BEA that the report was biased in favour of AF and ignored vital information.

It was and apparently it did. Is it a 'conspiracy theory' that following the publication of the BEA report AF tried to lay the entire blame at the door of a Continental Airlines maintenance engineer, a despicable try-on thrown out by the courts?

You only have to look at how that Concorde was being operated to understand the serious inadequacies of that airline. And of course they almost lost another Concorde shortly after it was restored to service when the FE mis-handled a fuel leak and the aeroplane narrowly avoided dead sticking into the North Atlantic when if landed on fumes at its nearest landfall, Halifax Nova Scotia.

No wonder they stopped operating it shortly afterwards, and shortly after that French politicking ended the BA operation as well. They were never going to allow the worlds only supersonic airliner, an Anglo-French aeroplane, to be operated by the British alone.

[atakacs]

Originally Posted by pulse1

According to the series of lectures given by the ex BA Concorde flight engineer, one of the best witnesses was the captain of Mitterrand's Airbus which was holding to cross the runway. Apparently he witnessed that there were signs of fire before the Concorde reached the metal strip. His testimony was not included.

Firstly it was president Chirac.
Secondly from their position they could obviously not see what caused the tire to shred. All there was too see was a dangerously off track burning Concorde passing uncomfortably close