Concorde Paris crash, questions, facts, opinions
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Concorde Paris crash, questions, facts, opinions
We already have another Tech Log thread running on the subject of "Concorde Questions", relating Concorde facts, questions, stories, anecdotes, etc.
Rather than 'dilute' that thread with the inevitable discussions and opinions on the background of the Concorde Paris crash, it seemed appropriate to start a separate thread on the subject.
The basic facts are clear enough.....
On July 25th, 2000, during take-off, Air France Concorde F-BTSC ran over a titanium strip that had dropped off a Continental DC-10 a few minutes before.
This did not just cause a tyre blowout, but totally ripped the tyre apart, throwing large enough fragments against the underside of the wing to cause a major fuel leak.
The leaking fuel caught fire, resulting (for various reasons) in a loss of power on the #1 and #2 engines.
The aircraft could not maintain height and crashed about 2 min later.
In the accident 113 people died, of which four on the ground.
CJ
Rather than 'dilute' that thread with the inevitable discussions and opinions on the background of the Concorde Paris crash, it seemed appropriate to start a separate thread on the subject.
The basic facts are clear enough.....
On July 25th, 2000, during take-off, Air France Concorde F-BTSC ran over a titanium strip that had dropped off a Continental DC-10 a few minutes before.
This did not just cause a tyre blowout, but totally ripped the tyre apart, throwing large enough fragments against the underside of the wing to cause a major fuel leak.
The leaking fuel caught fire, resulting (for various reasons) in a loss of power on the #1 and #2 engines.
The aircraft could not maintain height and crashed about 2 min later.
In the accident 113 people died, of which four on the ground.
CJ
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Hi ChristiaanJ,
Really enjoyed reading the Concorde thread.
I've seen a TV "reconstruction" about the Paris crash which suggests a "spacer" was missing from one of the bogies which made steering in a straight line with an engine failure impossible. The skid marks show the aircraft drifted very close the runway edge, and it's implied that the aircraft was forced to rotate and get airborne rather than stop and collide with another aircraft at an intersection.
Do you have any more information whether this is fact or fantasy?
Really enjoyed reading the Concorde thread.
I've seen a TV "reconstruction" about the Paris crash which suggests a "spacer" was missing from one of the bogies which made steering in a straight line with an engine failure impossible. The skid marks show the aircraft drifted very close the runway edge, and it's implied that the aircraft was forced to rotate and get airborne rather than stop and collide with another aircraft at an intersection.
Do you have any more information whether this is fact or fantasy?
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The missing spacer is a fact.
Whether it made the slightest difference, with what amounted to a dragging left main gear after the tyre blowout and a double engine failure at takeoff, is something I don't know.
CJ
strip doubt?
Air France Concorde F-BTSC ran over a titanium strip that had dropped off a Continental DC-10 a few minutes before.
After typing that I checked around, and found that stories put out by the BBC, ABC, and other news organizations report that claim being made at the opening of the February 2010 trial.
Can anyone who has seen the evidence on that point pro and con discuss their own assessment? I have not.
Strip or no strip, the tires then in use failed often enough, and the aircraft was vulnerable enough to that failure, that a serious accident would seem unduly likely to have happened within a few years unless at least one serious corrective measure had been taken (either tires much less likely to fail this way, or an aircraft with considerably reduced vulnerability).
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No Concorde tank was ever penetrated by a tyre. Really.
Early events were cause by WHEEL failures, hence the redesign of the wheel ('blue' wheels).
A piece of 'cow catcher' (water deflector) penetrated a tank following a tyre burst, this led to the modification of the 'cowcatcher'.
So this event was unique. The tank was not penetrated but was blown out from inside some distance from the point of impact.
So....not necessarily an event definitely 'likely to occur in the next few years'.
Reasons for the blowing out?? Manifold - and subject to some conjecture, but it was not possible to replicate the event in testing when the fuel system was configured as per flight manual.
Early events were cause by WHEEL failures, hence the redesign of the wheel ('blue' wheels).
A piece of 'cow catcher' (water deflector) penetrated a tank following a tyre burst, this led to the modification of the 'cowcatcher'.
So this event was unique. The tank was not penetrated but was blown out from inside some distance from the point of impact.
So....not necessarily an event definitely 'likely to occur in the next few years'.
Reasons for the blowing out?? Manifold - and subject to some conjecture, but it was not possible to replicate the event in testing when the fuel system was configured as per flight manual.
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I'm sure I speak for all Concorde fans when I report that seeing the news on TV about the crash that day was one of the saddest moments in avaiation history (only outdone by the 9/11 events the next year)
Long live that magnificent white bird. None of us will ever forget the sheer majesty and marvel that was Concorde...
Long live that magnificent white bird. None of us will ever forget the sheer majesty and marvel that was Concorde...
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Different Opinions
On the other - truly brilliant - Concorde thread, there was a comment made which indicated to me that those contributing to the thread, i.e. those that had either flown or maintained Concorde, had a different theory or opinion to that of the official crash report? Or have I mis-interpreted?
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Hi,
Many answers at the questions are in the record of the trial (by the investigation experts and also the people who conceived the Concorde)
This is the complete record of the trial as reported by the passengers association (FENVAC) who followed the trial
Warning :
This is a pdf in french language
PROCES-CONCORDE-RAPPORT_FENVAC.zip - 4shared.com - online file sharing and storage - download
Many answers at the questions are in the record of the trial (by the investigation experts and also the people who conceived the Concorde)
This is the complete record of the trial as reported by the passengers association (FENVAC) who followed the trial
Warning :
This is a pdf in french language
PROCES-CONCORDE-RAPPORT_FENVAC.zip - 4shared.com - online file sharing and storage - download
EXWOK
Just trying to clarify my understanding of what you have said
Putting aside the previous (to the crash) incidents what, where and how did the fuel tank penetration in the crash occur?
It was my understanding that the rubber tread from the tyre struck the tank setting up a hydraulic shockwave (full tank) which reverberated back and progressed a minute fracture in the aluminum to a square foot blown out hole. This rather large piece of the tank wall was recovered from the runway.
If you have something different from my understanding would you describe it?
No Concorde tank was ever penetrated by a tyre. Really.
Early events were cause by WHEEL failures, hence the redesign of the wheel ('blue' wheels).
A piece of 'cow catcher' (water deflector) penetrated a tank following a tyre burst, this led to the modification of the 'cowcatcher'.
So this event was unique. The tank was not penetrated but was blown out from inside some distance from the point of impact.
So....not necessarily an event definitely 'likely to occur in the next few years'.
Reasons for the blowing out?? Manifold - and subject to some conjecture, but it was not possible to replicate the event in testing when the fuel system was configured as per flight manual.
Early events were cause by WHEEL failures, hence the redesign of the wheel ('blue' wheels).
A piece of 'cow catcher' (water deflector) penetrated a tank following a tyre burst, this led to the modification of the 'cowcatcher'.
So this event was unique. The tank was not penetrated but was blown out from inside some distance from the point of impact.
So....not necessarily an event definitely 'likely to occur in the next few years'.
Reasons for the blowing out?? Manifold - and subject to some conjecture, but it was not possible to replicate the event in testing when the fuel system was configured as per flight manual.
Putting aside the previous (to the crash) incidents what, where and how did the fuel tank penetration in the crash occur?
It was my understanding that the rubber tread from the tyre struck the tank setting up a hydraulic shockwave (full tank) which reverberated back and progressed a minute fracture in the aluminum to a square foot blown out hole. This rather large piece of the tank wall was recovered from the runway.
If you have something different from my understanding would you describe it?
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My thoughts
Hi,
As person who follows PPRUNE but does not post often I have a question regarding the crash.
On one of the TV programmes I have viewed about the crash it was stated that the fuel poured out of the tank and was ignited by a damaged electrical cable that was creating sparks. I have one issue with this, watching another programme (air crash investigation) about TWA800 a demonstration was made that proved jet fuel did not ignite if a match (bit more than a spark) was dropped into it. If the fuel was heated to 53 degrees and a match was dropped in the fuel ignited.
My point being what did ignite the fuel that was leaking from the tank on Concorde? Was the fuel in Concorde indeed warm enough to become volitile?
RIP those who perished.
for a video of the fuel ignition demo click this link and got 7min 30 seconds
YouTube - air crash TWA flight 800 part 4
As person who follows PPRUNE but does not post often I have a question regarding the crash.
On one of the TV programmes I have viewed about the crash it was stated that the fuel poured out of the tank and was ignited by a damaged electrical cable that was creating sparks. I have one issue with this, watching another programme (air crash investigation) about TWA800 a demonstration was made that proved jet fuel did not ignite if a match (bit more than a spark) was dropped into it. If the fuel was heated to 53 degrees and a match was dropped in the fuel ignited.
My point being what did ignite the fuel that was leaking from the tank on Concorde? Was the fuel in Concorde indeed warm enough to become volitile?
RIP those who perished.
for a video of the fuel ignition demo click this link and got 7min 30 seconds
YouTube - air crash TWA flight 800 part 4
Last edited by d747; 9th Sep 2010 at 12:58.
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There were firefighters who witnessed the take off. They reported seeing flames form the Concorde some distance short of where the strip of metal was found. This info came from a Discovery channel show I think. Anyone else see that show? Very sad day.
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d747
I think you make a good point - as I understand it JETA1 will only ignite if it is a heated vapour - or atomised. It is difficult to understand how fuel flowing out of a hole that large would be either a vapour or atomised 
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d747
I think you will find when an aircraft is flying at 200mph or more as this Concorde was, any fuel leak will atomise especially around the edges of the flow and could be ignited . This is why when dumping fuel, all sorts of precautions are taking to prevent the stream igniting.
From what I remember about fuel fires is that, it is the fumes that burn not the fluid, and perhaps in the TWA case it is at 53 degs [ F 0r C ?] that fuel starts to vapourize sufficently to give, above the fluid, a fuel/air mixture that will ignite given a spark source
I think you will find when an aircraft is flying at 200mph or more as this Concorde was, any fuel leak will atomise especially around the edges of the flow and could be ignited . This is why when dumping fuel, all sorts of precautions are taking to prevent the stream igniting.
From what I remember about fuel fires is that, it is the fumes that burn not the fluid, and perhaps in the TWA case it is at 53 degs [ F 0r C ?] that fuel starts to vapourize sufficently to give, above the fluid, a fuel/air mixture that will ignite given a spark source
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On the other - truly brilliant - Concorde thread, there was a comment made which indicated to me that those contributing to the thread, i.e. those that had either flown or maintained Concorde, had a different theory or opinion to that of the official crash report? Or have I mis-interpreted?
Let's not forget that, as with virtually all crashes
- the final report will try to establish a "probable cause" and the most plausible theory for what happened,
- we are dealing with a chain of events, and not with a single event one can point at and say unequivocally : "that's the cause".
So it's normal, that there are different opinions and theories.
The BEA (with the judiciary breathing down their necks....) did make an effort to come up with the best and most plausible answers. Some of those answers were theories, because the evidence had been destroyed by the crash itself, and hence it was impossible to prove whether those answers were right or wrong.
So yes, in Concorde circles there were certainly differences of opinion, and different theories, some equally plausible, but equally unprovable.
Also, let's not forget the judicial enquiry had less to do with establishing the most probably cause and more with determining who was going to pay the bill......
CJ
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The "match in a pool of Jet A1" demo doesn't really have much to do with the matter (and with a big pool on boiling hot tarmac in the July sun, it won't be me tossing the match).
And we're not talking about "a spark", we're talking about fuel droplets swirling around in the undercarriage bay and being ignited by arcing, not sparking, from the 115V brake fan wiring.
In my experience, 115V is enough for a nasty arc...
CJ
And we're not talking about "a spark", we're talking about fuel droplets swirling around in the undercarriage bay and being ignited by arcing, not sparking, from the 115V brake fan wiring.
In my experience, 115V is enough for a nasty arc...
CJ
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There is a two hour documentry on this that is playing on cable TV.
During the show, there are lots of theories given by British pilots, and British engeeners, etc. on why the bird crashed. These include, the metal Ti strip, the tire design, the missing wheel spacer, the fuel tank design, overweight condition, early engine shut off, wind direction, fuel pumped from the back to the front tanks, etc.
My view would be that it is a combination of factors but, given the history of shreaded tires, it seems irresponsible to not have modifed the fleet to include kevlar reinforced fuel tanks.
I never understood why these ships were built if breaking the speed of sound causes huge sonic booms which meant they could not fly over land at speed. It seems the fleet was doomed as a commercial venture from the start.
Is there any news on the status of the French trial? I thought it was a 4 month trial that started in February 2010.
During the show, there are lots of theories given by British pilots, and British engeeners, etc. on why the bird crashed. These include, the metal Ti strip, the tire design, the missing wheel spacer, the fuel tank design, overweight condition, early engine shut off, wind direction, fuel pumped from the back to the front tanks, etc.
My view would be that it is a combination of factors but, given the history of shreaded tires, it seems irresponsible to not have modifed the fleet to include kevlar reinforced fuel tanks.
I never understood why these ships were built if breaking the speed of sound causes huge sonic booms which meant they could not fly over land at speed. It seems the fleet was doomed as a commercial venture from the start.
Is there any news on the status of the French trial? I thought it was a 4 month trial that started in February 2010.