Concorde 4590
Well that's how accidents happen. In almost all cases it's a chain of unrelated events out of which it is difficult to pinpoint a unique cause. The only question here is how to weight them. I would agree that the BEA report might put too much emphasis on the titanium strip...
The metal strip would have been of no consequence (would not have been run over) if the missing spacer hadn't steered the aeroplane to the left, and eventually off the side of the runway breaking edge lights.
The tank would not have burst had it not been overfilled.
Several factors HAD to come together for the accident to happen. The metal strip is no more 'prime' than any of the others.
The tank would not have burst had it not been overfilled.
Several factors HAD to come together for the accident to happen. The metal strip is no more 'prime' than any of the others.
The missing spacer was a secondary cause but as you say there were a number of contributary factors. However, none would have hazarded the flight had the tyre not failed.
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Or the No.1 engine had not ingested a runway light or two.
Or the aircraft hadn't been rotated well below normal speed due that left tracking off the runway....
The latter two of these only played their part because the missing spacer sent the aircraft off to the left. Where it met the metal strip.
So if you want to nominate a 'prime cause' I'd point to the missing spacer.
But I'm happy not to try to pin this on any 'prime cause', but to accept that as in almost every aircraft accident, it's the combination of all of them that resulted in the tragic loss of the aircraft, those on board, and those on the ground.
As always there are many factors leading to an accident. Remove any one and the accident is likely to be averted. However any reasonable review of the known facts would point to the missing spacer as the initiating factor. Fit the spacer and the aircraft tracks the runway c/l without the tyre drag and without hitting the notorious titanium bit. Then there is a better than even chance that rotation is about normal speed and we fly away.
As always there are many factors leading to an accident. Remove any one and the accident is likely to be averted. However any reasonable review of the known facts would point to the missing spacer as the initiating factor. Fit the spacer and the aircraft tracks the runway c/l without the tyre drag and without hitting the notorious titanium bit. Then there is a better than even chance that rotation is about normal speed and we fly away.
If you have then you will see what the conclusions were. Furthermore, both AF and BA changed the tyre construction to reduce the impact of a failure and fitted Kevlar Liners to the fuel tanks.
Why would they go to that expense in order to resume operations if it was as simple as ensuring correct maintenance.
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Buster, you are moving your goal posts. You claimed the metal strip was the prime cause. I and others disagree, with the spacer (if anything) being the prime cause. Actually I'm happy not attributing a 'prime cause' as I said earlier. It took ALL the factors coming together to result in the accident. So ALL the factors that caused that accident have to be addressed, including the tyres.
Buster, you are moving your goal posts. You claimed the metal strip was the prime cause. I and others disagree, with the spacer (if anything) being the prime cause. Actually I'm happy not attributing a 'prime cause' as I said earlier. It took ALL the factors coming together to result in the accident. So ALL the factors that caused that accident have to be addressed, including the tyres.
It is quite clear that the titanium strip, having been run over at high speed was the prime cause of the catastrophic tyre failure. Had the tyre not failed IN THE WAY THAT IT DID then the other anomalies could have been managed by the aircrew.
It is really important to remember that 113 people died as a result and therefore we ought to respect the formal investigation findings, bearing in mind that the evidence was provided by subject matter experts.
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No I am not. For your information I was involved in the return to service programme following the crash and knowing what I know I completely agree with the BEA investigation and its findings.
It is quite clear that the titanium strip, having been run over at high speed was the prime cause of the catastrophic tyre failure. Had the tyre not failed IN THE WAY THAT IT DID then the other anomalies could have been managed by the aircrew.
It is quite clear that the titanium strip, having been run over at high speed was the prime cause of the catastrophic tyre failure. Had the tyre not failed IN THE WAY THAT IT DID then the other anomalies could have been managed by the aircrew.
It is really important to remember that 113 people died as a result and therefore we ought to respect the formal investigation findings, bearing in mind that the evidence was provided by subject matter experts.
Quite rightly the courts threw that one out.
The bottom line is those 113 lives are down to Air France for shoddy maintenance and even shoddier operating of a magnificent aeroplane.
I think this conversation has more than run its course.
I'll divert the conversation and go off "at an angle" as it were.
How does a missing spacer on an axle, that is perpendicular to the direction of motion, cause the wheels to track incorrectly?
How does a missing spacer on an axle, that is perpendicular to the direction of motion, cause the wheels to track incorrectly?
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The spacer held apart two collars that kept the axle in line. Its absence allowed the collars to drift to the same side and leave the axle unsupported, in this case, on the left side.
India 42, The guts of it is that the missing spacer enabled the wheels to migrate from designed positions and led to a strong left drag on the left truck by their twisting a bit left. This cost acceleration due to wheels not tracking along the longitudinal axis of the a/c and hence scrubbing a bit sideways. There was a drag induced by the necessity to steer right as well. This all cost energy and reduced performance of an a/c already over limits.
If the a/c had tracked the runway c/l there would likely have been no incident notwithstanding the huge performance discrepancies.
If the a/c had tracked the runway c/l there would likely have been no incident notwithstanding the huge performance discrepancies.
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Not only did the missing spacer, through allowing the axles to mis-track, steer the aeroplane left, but the resultant scrubbing of the tyres which were not parallel with the aircraft's direction of travel since the wheels were mis-aligned, caused extra stress and heat to the tyres which would contribute to their failure.
this accident from what we know now had NO primary cause or prime factor
it was a growing chain on the day of unconnected events and omissions errors complacency and perhaps even some arrogance
no one has mentioned that the runway was not swept for the concorde's departure which afaik was standard at CDG pre for all take offs -could you say then that was the root cause that started it all? no - course not -as other factors had already slotted into place with others lining up
one simply cannot say here that one primary item alone lead to the downing of 4590
one of the ''Titanic's'' of air travel accidents - another being KLM Pan Am Tenerife 1977 and THY DC-10
it was a growing chain on the day of unconnected events and omissions errors complacency and perhaps even some arrogance
no one has mentioned that the runway was not swept for the concorde's departure which afaik was standard at CDG pre for all take offs -could you say then that was the root cause that started it all? no - course not -as other factors had already slotted into place with others lining up
one simply cannot say here that one primary item alone lead to the downing of 4590
one of the ''Titanic's'' of air travel accidents - another being KLM Pan Am Tenerife 1977 and THY DC-10
Last edited by rog747; 30th Jan 2018 at 13:23.
And JAL 123
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Despicable.
Exactly. Like most it was a coming together of many factors - classic lining up of the holes in the cheese. The sad part is as you say, complacency and perhaps arrogance played a major role, to which I'd add a certain amount of attempted blame-deflection by AF after the tragedy.
Despicable.
Despicable.
no one has mentioned that the runway was not swept for the concorde's departure which afaik was standard at CDG pre for all take offs - could you say then that was the root cause that started it all?
no - course not - as other factors had already slotted into place with others lining up so that theory throws Busters argument right out of the water - no disrespect intended but one has to say
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There is quite a bit of mis-information on this thread.
Extracts from the BEA report:-
"The wheels were manufactured by Dunlop, and the tyres used by Air France were
manufactured by Goodyear in the United States. No retread tyres have been used since 1996."
Page 37 of the report has a diagram showing the ground track of the aircraft on the runway. This data is derived from the ground radar and as such is very accurate. It clearly shows the aircraft was tracking the centre line of the runway until after it had hit the strip. In other words, the missing spacer did not cause the aircraft to veer left....loss of thrust on the left side was the cause.
I think the report could have been more comprehensive. As already mentioned there was no investigation into the affect of the misaligned tyre running over the strip. Did that misalignment cause the tyre to fail more catastrophically than it otherwise would? We'll never know.
Extracts from the BEA report:-
"The wheels were manufactured by Dunlop, and the tyres used by Air France were
manufactured by Goodyear in the United States. No retread tyres have been used since 1996."
Page 37 of the report has a diagram showing the ground track of the aircraft on the runway. This data is derived from the ground radar and as such is very accurate. It clearly shows the aircraft was tracking the centre line of the runway until after it had hit the strip. In other words, the missing spacer did not cause the aircraft to veer left....loss of thrust on the left side was the cause.
I think the report could have been more comprehensive. As already mentioned there was no investigation into the affect of the misaligned tyre running over the strip. Did that misalignment cause the tyre to fail more catastrophically than it otherwise would? We'll never know.
There is quite a bit of mis-information on this thread.
Extracts from the BEA report:-
"The wheels were manufactured by Dunlop, and the tyres used by Air France were
manufactured by Goodyear in the United States. No retread tyres have been used since 1996."
Page 37 of the report has a diagram showing the ground track of the aircraft on the runway. This data is derived from the ground radar and as such is very accurate. It clearly shows the aircraft was tracking the centre line of the runway until after it had hit the strip. In other words, the missing spacer did not cause the aircraft to veer left....loss of thrust on the left side was the cause.
I think the report could have been more comprehensive. As already mentioned there was no investigation into the affect of the misaligned tyre running over the strip. Did that misalignment cause the tyre to fail more catastrophically than it otherwise would? We'll never know.
Extracts from the BEA report:-
"The wheels were manufactured by Dunlop, and the tyres used by Air France were
manufactured by Goodyear in the United States. No retread tyres have been used since 1996."
Page 37 of the report has a diagram showing the ground track of the aircraft on the runway. This data is derived from the ground radar and as such is very accurate. It clearly shows the aircraft was tracking the centre line of the runway until after it had hit the strip. In other words, the missing spacer did not cause the aircraft to veer left....loss of thrust on the left side was the cause.
I think the report could have been more comprehensive. As already mentioned there was no investigation into the affect of the misaligned tyre running over the strip. Did that misalignment cause the tyre to fail more catastrophically than it otherwise would? We'll never know.
I had mentioned the tyre construction because as you point out AF had used retreads in the past. During the investigation testing was carried out to demonstrate the effect of failures of various types of tyre construction.
It is correct to say that the French preferred to focus on the tyres while the UK felt that (because of the number of previous tyre failures) that fitting the Kevlar Liners to the fuel tanks would improve safety. BA were very keen to restore Concorde airworthiness as their operations had been quite profitable.
Hope this clarifies the situation.
Tabs please !
I remember reading that a number of credible witnesses who were very familiar with the airport layout commenting that there were problems well before the point at which Concorde was said to have run over the strip. IIRC, they included firemen who would not be prone to making errors and the comments related to smoke. This would be consistent with the tyres on the misaligned axle scrubbing on the tarmac. If the aircraft was still on the centreline then it begs the question of how much rudder / nose wheel input was being applied at that time.
I would disagree that there was no single factor involved. 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 would be happy to be proven wrong so go gently chaps.
I would disagree that there was no single factor involved. 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 would be happy to be proven wrong so go gently chaps.