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Originally Posted by CliveL
(Post 7585858)
Yes, but not in the phase where there was appreciable aircraft sideslip
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Hi
My position is to foreclose all positions except the true one...:ok: So basically I am looking at everything that is visible, and reported, to see if anything is left out.... Did you have a chance to view the runway photo of the carbon trail/kero stain? Because if BEA are referring to the tyre marks prior to burst, these must be visible, are they the ones showing two trails of dark rubber, interrupted in a seemingly consistent way? i feel a resistance in the force; one hopes I am not too annoying. |
Please help me out here - is that different to the kind of sideslip referred to on p153-154? Fig 73 looks at the effect of malalignment of a bogie with the aircraft following a straight line path. Note how the RH gear is still lined up with the aircraft track. The French version of the report describes this state as ripé which is simply slip. If the aircraft as a whole was angularly displaced relative to its track the RH gear would also be showing slip. That is what I mean by sideslip and the French term would be dérapage. Once again confusion from English translations! |
Anyone know why BEA did not translate Appendix 6 mentioned up-thread?
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Hi Lyman
If as you ask we leave aside the titanium strip and instead assume that there was an engine failure(not caused by FOD) then if I understand correctly you are of a view that the missing spacer will cause a shimmy which makes the FE think that he must shut down the engine immediately. Then the loss of that engine results in the plane not being able to climb away safely and so we end up with the same tragic outcome. Now we have an engine failure then in this hypothetical case, the reason for the failure would have to be investigated and also the possibility that the engine was switched of because of the failure must also be considered. So there are a lot of new things that have to be considered. I presume (correct me if am wrong) that you think the FE would not have shut down the engine just based on the shimmy, but he would also need to have other indications of failure. Unfortunately for your hypothesis to have any chance of being proved, we would need to know exactly what the FE was thinking as the accident unfolded. Having read CliveL's helpful posts and considering what you have said I am still of the view that the report gives us the best overview of the accident. |
So. I will offer an evidence for oscillation in the early roll.
Note the paired deposits of rubber through the stain and beyond. The two men are standing directly on each individual mark. Four tyres are making two trails, as they would do. They are soaked in kerosene, which has a marked affinity for synthetic rubber. It wets and remains wet. This helps the marks' visibility. We see that in between pairs of black deposit, there is a portion of skid free concrete. This is the time when the four tyres are aligned with the a/c motion. the following pair of black skid mark is their misalignment with the aircraft, and the four tyres are skidding in kerosene wetted Elastomer. due to lousy traction, there is no net effect on heading. The truck then rebounds, returns through the zone of alignment, and deposition of rubber stops, until the truck continues into the misalignment, deposits black, and repeats, disappearing into the soot stained photo. The oscillation is relatively harmonious, by symmetry of the paired deposits. Work for you? |
Hi Lyman
Thank you for posting your opinion on the photographs concerning the tyre marks. Whilst I accept that the photos are evidence and don't doubt for one moment that you are convinced by your argument but your convection can't change your opinion into evidence. Therefore am unable to accept your conclusions drawn from the photographs as evidence. So that is why it does not work for me. |
Lyman,
Forgive me for being thick but what b*y picture are you talking about? I can't seem to find anything in the BEA report that has two men standing on tyre marks. |
Sorry.....
Was Continental Responsible For the Concorde Crash? « Heritage Concorde the "other runway pic." rgds. |
If you're referring to the second wide-angle shot where there are several vehicles and men on the runway, the very bottom of that picture shows the stain from the fuel spilled when the tank burst. The picture itself is taken roughly in the direction of the takeoff roll from just prior to the unburnt spillage.
Correct me if I'm wrong, but if the tyre burst preceded the fuel leak, would it not be reasonable to conclude that no tyre or debris markings in that photo were made prior to the tyre burst? [For reference, this picture I'm referring to is Fig. 74 on the report, p.160. I must confess my initial impression was that the resolution was not sufficiently high to determine tyre and rubber debris markings with much accuracy. Additionally, determining the nature of marks within the soot is made difficult, as it appears one of the ground vehicles has inadvertently driven through the soot trail.] |
Lyman
Thanks, I've got it. It is fact the same picture as Fig 74 in the BEA report, which I missed.. It looks to me that Fig 24 of the BEA report was taken from just about where the two men are standing together in the picture you are using, but being much closer to the action it shows much more clearly the tyre imprints and tracks. I recommend looking carefully at that Fig 24 because although you can see the obvious cyclic imprint of the flapping remnants of the tyre if you run a ruler over the line of imprints there is no evidence of lateral oscillations whatsoever that I can see. |
Originally Posted by Lyman
(Post 7585981)
Sorry.....
Was Continental Responsible For the Concorde Crash? « Heritage Concorde the "other runway pic." This link made me understand why we were in disagreement a bit earlier, on a specific point: We simply didn't look at the same picture. ;)
Originally Posted by AlphaZuluRomeo
(Post 7584246)
Originally Posted by Lyman
(Post 7584220)
The runway pictures that show carbon deposition are aerial, long distance, no?
But it's not the pic I was thinking about: Please, do not get stuck on the one page of Heritage Concorde, and refer yourself to BEA's richer final report, § 1.12.1.8 Tyre tracks, you'll find some other pics, that are neither aerial, nor long distance, nor blurry. :) And as Clive said:
Originally Posted by CliveL
(Post 7586186)
I recommend looking carefully at that Fig 24 because although you can see the obvious cyclic imprint of the flapping remnants of the tyre if you run a ruler over the line of imprints there is no evidence of lateral oscillations whatsoever that I can see.
Originally Posted by Feathers McGraw
(Post 7585904)
Anyone know why BEA did not translate Appendix 6 mentioned up-thread?
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20 juillet 1979 : après l’accident de Washington, le BEA, dans une note confidentielle faisait le constat suivant quant à la gravité des conséquences possibles d’une destruction de pneumatique : risque d’incendie, avarie grave de moteur, impossibilité de relevage du train d’atterrissage.
25 juillet 2000 : crash du Concorde F-BTSC suite à l’éclatement d’un pneumatique qui avait provoqué un feu important sous la voilure gauche, une perte de poussée des réacteurs 1 et 2 et l’impossibilité de relevage du train d’atterrissage 29 août 2000 : Les certificats de navigabilité des Concorde sont suspendus par le BEA à cause du risque lié aux destructions de pneumatiques. Ce jour-là, devant les caméras télé, le patron du BEA persuade les médias du monde entier qu’il vient de découvrir le problème. « Nous avons déterminé que le risque d’éclatement d’un pneu pouvait provoquer des dégâts aussi extraordinaires en aussi peu de temps » « C’est ça le point important » martèle t’il pour que l’auditoire perçoive bien le message… July 20, 1979: Washington after the accident, the BEA, in a confidential note made the following statement about the seriousness of the possible consequences of a tire destruction: fire, severe damage to the engine, unable to lift the landing gear. July 25, 2000: Crash of the Concorde F-BTSC following the bursting of a tire which caused a large fire under the left wing, loss of engine thrust 1 and 2 and the impossibility of raising the landing gear August 29, 2000: The Concorde airworthiness certificates are suspended by the BEA because of the risk of destruction of tires. That day, before the TV cameras, the boss of BEA persuaded the media of the world that he has just discovered the problem. "We have determined that the risk of a blowout could cause damage as extraordinary as little time" "That's the important thing" he insists so the audience perceives the message well |
@jcj:
Could you humour me and tell me the sources you're quoting there? As pointed out up-thread, in the wake of the '79 Dulles incident a modification was made to prevent tyres failing in the same way (in this case by improper inflation). In other instances of tyre failures where the cause was investigated, more modifications were made. It's commonly (and erroneously) reported that little or nothing was done to prevent tyre failures between the '79 incident and the loss of F-BTSC, but the fact is that modification work was ongoing and procedures put in place several times in the intervening years to minimise risk (for example, forbidding use of re-tread tyres, BA's deflector modification and the extra inflation monitoring equipment mentioned above). All these modifications and procedures, along with the dates they were implemented, are listed in the BEA report on F-BTSC. Additionally, every prior incident of tyre failure that led to fuel tank damage consisted of debris directly piercing the fuel tank from outside, causing either no significant fuel leakage or minor leakage that presented practically no risk of ignition. The fuel tank damage due to fluid compression happened for the first and only time on F-BTSC. Arguably this should have been considered before, but it was a little-known phenomenon at the time. |
Hi Doze.
In that laudable defence of tyre performance, did you 'forget' to include the years tyre incidents/failures were simply not reported? |
I wouldn't characterise it as a "defence", simply a statement of fact. If you could enlighten me as to any evidence you have of tyre-related problems not being reported, that would help.
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Could you humour me and tell me the sources you're quoting there? The source is the Concorde trial notes For the video .. the source is obvious All this merely shows that the BEA sometimes exercise intellectual dishonesty .. no more .. no less BEA (in the video) cites reasons for ground the Concorde BEA cited the same reasons long before in a confidential memo .. but had not decided to ground the Concorde (why confidential .. and why not make a recommendation for ground the Concorde ? ) The BEA's note in 1979 shows that the accident was foreseeable ... but in fact (in 2000) .. it's show to the public that Gonesse accident is a surprise .. it was not foreseeable (they discovered the reasons by primary investigations after the crash) .. nobody could imagine that .. etc. .. |
The note was confidential, the fix made as a result of it was not. No intellectual dishonesty, just the way things worked in the '70s I suspect.
There was no talk of grounding until 2000 because the failure mode was a new one, and more severe than anyone (including the NTSB and AAIB, who had investigated more tyre incidents than BEA) had predicted. |
Hi,
DozyWanabee The note was confidential, the fix made as a result of it was not What fix ? .. better tires ? .. this was no good results .. tires continued to have problems Why not the Kevlar fix ? (like made after Gonesse) |
This information is all there if you go back over the last few pages of the thread. The public investigation of the Dulles incident would have been handled by the NTSB, not the BEA. In essence, the BEA were simply backing up in private what the NTSB determined in public.
The fix was a device which detected improper tyre inflation (the root cause of the Dulles incident) and fed that information back to the flight deck. The damage to the fuel tank was external and not sufficient to cause fire, very different from the F-BTSC damage which was caused by compression of the tank causing it to burst outwards. This was unforeseen by all. The Kevlar lining was designed to prevent that kind of damage, not the kind that occurred at Dulles. In fact the Kevlar lining was not strictly required, providing instead a level of redundancy - the post-2000 tyre design would have been enough on its own to get the AOC reinstated. |
just the way things worked in the '70s I suspect 2010 procès Concorde Question (Me Rappaport - avocat) A quel moment a été envisagé le risque incendie à la suite d’un éclatement de pneu ? Answer (Mr Arslanian - directeur BEA) A l’étude des évènements, nous n’avons pas relevé de risque incendie Note confidentielle de Mr Guillevic (BEA) 1979 Quelque soient les résultats des investigations en cour,l'incident de Washington et les incidents antérieurs mettent en lumière la gravité des conséquences possibles d'un éclatement de pneu: risque d'incendie par écoulement hydraulique ou de carburant sur des éléments du train surchauffés ou en combustion ,avarie grave de moteur,impossibilité de relevage du train d'atterrissage et limitation des possibilités de freinage et évidement combinaison de deux ou plusieurs de ces effet possibles 2010 Concorde trial Question (Me Rappaport-lawyer) At what time was considered the fire risk following a burst tire? Answer (Mr Arslanian BEA director) After study of the events , we found no fire risk Confidential note Mr Guillevic (BEA) 1979 Whatever the results of the investigation in progess, the Washington incident and previous incidents highlight the seriousness of the possible consequences of a burst tire: fire hazard from hydraulic flow or fuel elements of the gear overheated or burning, severe damage to the engine, the impossibility of lifting gear and limiting the braking ability , combination of two or more of these possible effect |
It's possible M. Arslanian never saw the 1979 memo prior to the 2000 accident, it being 21 years old by then. More importantly the 1979 memo is clearly referring to an investigation in progress (presumably by the NTSB) that was later completed and published resulting in modifications that were thought to minimise or remedy the risks from a burst tyre. He's well within his rights to say what he's saying because the modifications to equipment and procedures over the intervening years were expected to have all but eliminated the risk of fire from a tyre burst.
I should have pointed out in my previous post that all Concorde tyre debris-related incidents between 1979 and early 2000 resulted in the same type of external piercing damage which was not considered to present a significant fire hazard. I reiterate - the one and only time the damage caused a burst from inside and a significant fuel leak was the F-BTSC accident. To borrow a phrase from Bill Clinton, "There's no 'there' there". |
Asked to give her opinion of Oakland, California, Gertrude Stein famously said : "There's no there there..."
Asked a question by Monica Lewinsky, Bill Clinton famously said: "There it is.." Dozy, you know as much about AF tyres as you do Americana... .....not very much |
Correction on Clinton accepted (although the phrase was used by the presiding judge over the "Judicial Watch" lawsuit against the Clinton Administration). If you'd like to point out where I'm wrong on the other matters, I'm happy to hear it. Supporting evidence preferred.
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Air France ceased reporting tyre incidents for some years between Dulles and Gonesse. My search function does not work. Show us your objectivity and assist me. It is in this thread.
For truth..... |
Once and once only will I be your monkey (no offence, but while I'm all for objectivity and truth I'm still suspicious of being played for a fool).
Using both the search function and a visual check of all occurrences of the word "tyre" or "tire" (for our transatlantic cousins) I can find no post referring to AF not reporting tyre failures. Outside of the fact that it would be extremely difficult to do so because such incidents are required to be reported by regulations, I have to conclude that if such a post ever existed it was retracted, or it was misread. The closest thing I can find is AZR's post early in the thread which states his opinion:
Originally Posted by AlphaZuluRomeo
(Post 7552554)
Indeed, I think AF/French authorities in general took "too lightly" some issues with the plane (namely: tyres, and the Michelin NZG fitted for the return to flight were an excellent thing).
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Confidential note Mr Guillevic (BEA) 1979 Whatever the results of the investigation in progess, the Washington incident and previous incidents highlight the seriousness of the possible consequences of a burst tire: fire hazard from hydraulic flow or fuel elements of the gear overheated or burning, severe damage to the engine, the impossibility of lifting gear and limiting the braking ability , combination of two or more of these possible effect This should be read in conjunction with section 1.16.4.2 of the BEA report which describes the results of that investigation and the modifications that were applied as a result. |
jcjeant,
We have established facts, here. 1/ The BEA wrote a confidential memo. 2/ Lessons from '79 did not prevent Gonesse. You're linking those two facts into a theory that makes you (almost?) accusing people back in '79 to have said: "let it crash, it doesn't matter". :ooh: Really? :ugh: Can't you imagine other theories? Or do you choose not to mention them because they do not correspond to a certain (preconceived?) idea you might have? Let's try again, shall we? ;) 1/ The BEA wrote a confidential memo. Yes. Question is: why?
2/ Lessons from '79 did not prevent Gonesse. Indeed. But this undeniable fact has too often been distorted into "nothing was done" or something like that. This distortion is wrong: Fixes were implemented after Washington'79 and other tyres events, before the 2000 crash, and this was already stated numerous times in this very thread (among others). Those fixes were aimed at correcting/solving the issue with the tyres. They didn't succeed (enough). But we can only say that with hindsight. Washington'79 and Gonesse were different events regarding the importance of the fuel leak (hence the importance and destroying capabilities of the consecutive fire). And the difference is not a little one, see my #59. Conclusion: I have no difficulty imagining the political leaders of the time (IIRC the issue had risen to the presidency) decide to remain discreet and try to control the information made public. With our current mindset, we can find it "weird" or even suspect. But when we remember the time and conditions ... it does not seem so suspect anymore, IMO. Even if we wouldn't accept such things anymore: the world has changed! But the fact that discretion was required does not automatically means that the people advocating for that discretion were refusing to fix the issue at hand. := I cannot imagine, OTOH, that people (from BEA, DGAC, AF, French gov...) were convinced that there still was a great risk of accident after the fixes were implemented. I cannot imagine they have deliberately limited the range of the fixes, that would have meant they didn't care if a Concorde took fire and crashed later. |
AZR
I cannot imagine, OTOH, that people (from BEA, DGAC, AF, French gov...) were convinced that there still was a great risk of accident after the fixes were implemented Is the fixes were the solution to the risks confidentially described in 1979 ? Fixes were implemented after Washington'79 and other tyres events, before the 2000 crash, and this was already stated numerous times in this very thread (among others). The fact is, whether these were the good fixes to the potential risks Is that all risks have been taken into account to determine the solutions to bring ? Or is that some risks have been set aside by the use of comforting statistics ? |
The fact is, whether these were the good fixes to the potential risks Is that all risks have been taken into account to determine the solutions to bring ? Or is that some risks have been set aside by the use of comforting statistics ? The relevant parts of that section state: Risk of fire. Based on the data about the leak in the accident, the study concluded that the risk of fire was limited, considering: o that the size of the penetrations and the rate of flow of the leak are sufficiently low; o that ignition cannot be caused by rubber or metal debris penetrating the tank; o that the fuel leaks from tanks 6 and 7 follow the flow under the wing and remain generally parallel to the aircraft axis without meeting areas of separation and thus dissipate via the wing trailing edge .The secondary nozzle’s temperature is too low to ignite the fuel; o that fuel from leaks in tanks 5 and 8 may accumulate in the landing gear well. Only the electrical circuits in this compartment constitute a possible source of ignition; o that ignition of the fuel on contact with hot brakes would not definitely occur, bearing in mind the average temperature reached by the brakes; o that in case of penetration of the tanks forward of the air intakes, leaks would be limited (due to the limited size of the debris taken into consideration) and could only enter the engine at a very low speed (after landing) and at a high thrust level Most of the solutions then proposed were in fact put into effect and were the subject of Airworthiness Directives: • AD of 14/01/8, applied from 21/01/81, calling for the installation of a system for detection of main landing gear tyre under-inflation. An improved version of this system was then applied by AD on May 15 1982, • AD of 14/01/81, applied on 21/01/81, calling for improvements in protection in the normal braking hydraulic system, • AD of 5/05/82, applied on 15/05/82, defining an inspection procedure for the main landing gear tyres and wheels before each takeoff, • AD of 5/05/82, applied on 15/05/82, calling for the installation of new reinforced wheels in order to limit damage in case of contact with the ground and for new reinforced tyres capable of bearing twice the normal load (the regulations require one and a half times). As a result of studies carried out on the risks of damage from pieces of tyre and on trials performed at the CEAT in 1980 to justify the integrity of the structure in case of direct penetration, it was concluded that it was not necessary to install protection for the underside of the wings. 1.16.4.2.2 Other Events All of the tank penetrations that occurred after the Washington event involved aircraft operated by British Airways. It should be noted that after the modifications carried out after this event, tank penetrations following a tyre burst were caused only by secondary debris. In most cases, this debris came from the destruction of equipment located in the landing gear area, probably dislodged by pieces of damaged tyre. The parts in question include the water deflector and the gear door latch. |
Not only for Concorde had the tyres' explosion possible various issues. DGAC was already in the glue of absolute SOPs theory to limit captain's autority and destroy SNPL and other French Pilots Unions. DGAC was not able to let the Captain reject T/O after V1 in case of tyre explosion. LFPG had the best firemen in France, would they had to extinguish the plane fire on the RWY 08 and not in Gonesse they could save lifes.:}
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I'm afraid I fail to see your point, RH... :confused:
I'm convinced things should (must) change @ DGAC (perhaps change is already on the way, at last I hope so) but that's not the point. DGAC was not able to let the Captain reject T/O after V1 in case of tyre explosion. Why would DGAC (alone?) change that? I'm not sure that advocating for an exception (a derogation, once again?) is such a good idea. LFPG had the best firemen in France, would they had to extinguish the plane fire on the RWY 08 and not in Gonesse they could save lifes. The figures were impressive (74 kt or 115 kt) (the entire § is quoted in my post #138). And there is the cargo zone 1,200m after the threshold, with parkings & buildings. I understand from the report that Concorde overruning would not have created a situation with better chances of survival. The exact wording is: These figures show that an aborted takeoff would have led to a runway excursion at such a speed that, taking into account the fire, the result would probably have been catastrophic for the aircraft and its occupants. |
OT// bad news for Continental
One of their main lawyer just die
Google*Traduction Note that UK = Brittany .... :rolleyes: La disparition de l |
Jc - knew to much about Christiane?
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