ExSp33db1rd, data about the wheels & tyres of F-BTSC are publicly available in the final report §1.6.2.5:
How do you explain the clean transverse cut about 32 centimetres long in the tyre, then? (*)
How do you explain that black elastomer (whoose spectral analysis showed similar to Concorde's tyre rubber) was found in the rivets holes of the strip? (**)

(*) Final report, §1.12.1.2 (with photo):
(**) Final report, §1.16.6.4:
Perhaps :) I'm still not interested.

May I also remind you that the BEA was in charge of the technical, not the AAIB? Hence, even with full access, the AAIB would not have conducted its own analysis to "cross-check" everything the BEA would have said. You may show little confidence about the BEA, but AAIB doesn't seem to share the extend of your concern about that. That's enough for me, I must say :)

Quote:
"the parts [pieces of tyre] found at Slab 152 level (a piece measuring 100 x 33 cm and weighing about 4.5 kg) and that found at Slab 180 level fitted together. Visual inspection revealed a transverse cut about 32 centimetres long."

This is the maddening thing about BEA. The two pieces 'fitted' together means they were lined up manually. It does not mean that they 'fit together'. Nor does it mean the seam was such that these were two adjoining pieces of a larger section. The deficit that separates these two pieces of tyre is the length overall of the Titanium?

But then there is this:

"The spectra of these marks and deposits are similar to the Concorde tyre.".....BEA

Does that mean that the elastomeric deposits were similar also to the Goodyear tyres on the DC-10? Also similar to other Goodyear fod on the runway from neither DC-10 or Concorde? The strip is remarkably clean of deep scratches one would expect from a scraping on concrete beneath a 200 ton aircraft.....

Did the Titanium contact the Concorde's tyres only? Or both the Concorde and the Continental DC-10? Or ONLY the Douglas?

To slash the sidewall of tyre number two is counterintuitive, since it presupposes that the Titanium strip was airborne before hitting the lead tyre. More likely would be that the strip, if airborne, would have contacted a following tyre, having been launched by passage of the lead.

AZR: (thanks)

Quote:
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.


That's nice, but rather optimistic. Looking at the photo of Tyre 2, one notices the complete lack of siping on the tire's carcass. The other tyres have siping. Also, the failed tyre has all the tread scrubbed off to the fabric. This is notable, since it is indicative of a patent failure in a Recapped carcass, where the additive layer of elastomer is vulcanized to the remaining elastomer of the carcass. This precludes an embed in the fabric of the carcass, meaning there is no DualPhase adhesion of the additional material, something that of course makes the re-cycled tyre substandard, and a hazard.

Similarly, there is evidence in the photo of a classic separation of a recap bond on the sidewall. The tyre may indeed be an original manufacture, but the evidence is at least suspicious. Did the spectral analysis eliminate the presence of recap material, which is indeed different from OEM? Did it confirm that the material in the Titanium rivet void matches the sidewall (original) of tyre #2?

A shop that wil leave a critical component of a truck on the shop floor may well refit a retread, in a "pinch".

And a shop that will replace an ablative Aluminum strip with a haphazard Titanium lashup, the same. Neither aircraft was airworthy, by definition.

IMHO....

Well the report is full of AAIB negative comments ...
Concerned .. but must express a diplomatic manner given the constraints of political relations between countries (not forget that the BEA is a french governement body)
It's to note that the AAIB complain (between other things) about the fact that they could see the metal strip for a very short time only .. ie .. they could not make any serious analysis of the (most important) element that ( from BEA report) triggered the accident
But "maybe" they had the right to examine at long .. other scrap metal .. etc ...
Weird ins't it ?

To note that between the Continental DC-10 and the Concorde .. another plane had taking off ...

Really? You did look at the picture included in the report (as shown by another part of your post). I cannot then understand how you came to your conclusion that "It does not mean that they 'fit together'". :confused:
They fit. I see that on the pic.

Lost from the DC-10 right hand engine, I cannot imagine how the strip would have made contact with any tyre of the same DC-10. Geometry. Speed. That sort of things.

About the 747 (only aircraft on the RWY between the DC-10 and Concorde), I don't know if the spectra would have been same as Concorde or not.
What I do know, however, is that no tyre problem was reported on that aircraft.
What I do imagine is that Continental would have seeked to prove it was not Concorde rubber on the strip. I'm not aware they did that (nor try to). Are you?


Huh? Where does that come from? The transverse cut is on the tread of the tyre. The strip was not magically airborne. The tyre from wheel #2 (i.e. front right tyre of the left hand main landing gear) rolled on the strip, and was cut.
See also §1.16.5 "Tyre destruction Mechanism" with experimentations conducted (pictures provided, there too).

I fail to notice that. Quite the contrary, in fact. Tyre 2 was not new (37 cycles old). But it doesn't show a complete lack of siping either. Comparing to picture 4, page 25, or pictures 48, 49 and 50, pages 99 & 102 makes me say: "it looks normal, from the siping PoV". :)

Yeah, sure. What does that hypothesis imply? Nothing much: simply falsificate the papers about that tyre (date of purchase, date of installation on the plane), hide the invoices/workshop who did the retreading, and make false GoodYear invoices for new tyres. :=
Big bad Frenchies, huh? :E
Take care, in case AF or GoodYear decide a recent irish exemple is to be followed ;)


What's weird? Are you implying the BEA lied, and made falsificated material proofs? How is that even possible with the strip under the (too strict, we already covered that) control of the judicial that the AAIB, and you, and me did regret?
If you're going that way, well it's your choice. May I then adress to you the same piece of advice I just gave to Lyman? :)

Dave Reid
Four days prior to the accident the left hand undercarriage bogie was removed for maintenance. When it was refitted a spacer was left out.
The initial accident report took great pains to say the missing spacer had absolutely no relevance to the crash.
Other experts disagree and say that the missing spacer led directly to the tyre failure.

Most of the information I have on this came from a series of lectures given by an ex Concorde Flight Engineer ( perhaps he is already taking part in this discussion). According to him, one of the factors which made the possible misalignment of the bogie more critical was the ridge across the runway as it passed from the sterile runway onto the main runway. If this is true, presumably being over weight and down wind, encouraged the pilots to use this part of the runway or maybe they would have done this anyway.

There is indeed disagreement. But that's rather different from your original assertion:

Where is the evidence for your "probably" and "more likely" ?

Hi Dalek,

It was the final report, not an initial one. Agreed that it "took great pains" (or made a detailled analysis, as I would have written it) about that point.

I've seen disagreements on that point too, and I cannot imagine the spacer having "no use at all": why was is there in the first place, then? ;)
But, do you have a link/ref to something substantial about that?
So far, I'm "only" aware of:
- general public intented TV broadcasts, with most "experts" being not so experts in fact, and some real experts having no time to really explain their points;
- polemic blogs, usually animated/promoted by people well known to have an agenda (against AF most of the time, or against other french organisations such as DGAC, BEA...).

I'm looking for an honest and documented analysis about that point, by an expert (not only in name). Without it, we have no ground to refute the final report saying, after a detailled/pusblished analysis, that the absence of the spacer didn't change the trajectory of the plane nor the state of its tyres on july 25, 2000 (or on flights that preceded the accident (but after the bogie replacement work).

[edit] Thanks, pulse1, wrote my post before reading yours. That's a start :) Were there docs published after those lectures?
And I think I see who you're talking about. ;)

Shortly after the Concorde crash, there were various photographs published on websites, possibly somewhere in a thread on here, one of which showed crescent-shaped tyre marks allegedly on the runway, allegedly caused by a squittering bogie (like a supermarket trolley with a bad castor wheel). Was that indeed linked to the Concorde, or positively eliminated from any involvement?

Does anybody have a link to the picture and various comments at the time?

chrisN
I guess this is this ?
Was Continental Responsible For the Concorde Crash? « Heritage Concorde

What I had in mind was referred to in post 33 at:
http://www.pprune.org/rumours-news/2...article-2.html .

"The photographs of the tarmac clearly show that after the tyre deflated, the gear was oscillating either side of centre, which was, in my opinion, caused by the missing spacer and the (now) unbalanced bogie. I really cannot think of any other explanation as to why an aircraft with one engine out should be in danger of leaving the runway."



But the actual picture I have seen is not visible there, and embedded links no longer work.

Chris
The site in jcjeant's link is very slow in delivering information. I dd see the picture of the tire marks leading to the runway light this evening.

Machinbird, the pics in jcjeant's link are the same provided by the BEA in its final report.

jcjeant, thanks for the link, I read it yesterday night :)
I still fail to be convinded, I must say. I'm at work, will explain in details later, but mostly it is because the parts presenting "alternative" theories (relative to the official one from the BEA) seem incantatory rather than based on facts (the facts themselves, included as reported by the BEA, being sometimes - and when it matters - contradictory with said theories, whatever their logic & value).

If one kowtows to the popular opinion, one would never question. Any alternate theory involves countering accepted (though perhaps questionable) conclusions.

The French treat an accident scene as a crime scene. Fine. Well then, was the Metal strip photographed in situ? What is the genesis of the convenient hook shape that allowed the strip to present in the vertical to the oncoming Goodyear? How did the offensive element migrate well left of the center line to intercept a tyre that was already left of said line? And that strip having originated on the right side of the donor aircraft? What of the telltale rubber deposits well in front of the spilled fuel? Why a triple when dual represented a preferred skid?

The last three years of my construction career was spent in working with French principals. There is a cultural flavor to the stubborn and precipitous need the French had for assigning "Blame" prior to any extensive forensics. It is obsessive, almost precognitive, and unnerving to associates.

More synthetic rubber comments to follow.

Is there some way of seeing G-BOAF at Filton from the public road?

Heritage Concorde saysthat it can be viewed from a road name “Concorde Way” which is located at the rear of the Cribbs Cause Way Shopping Centre. From Google Maps it looks looks like it's close to a road but not sure if it's a public road:

Concorde Way, Bristol BS2, United Kingdom - Google Maps

I remember going to see Concorde testing at Filton when I was a kid. Would love to go back and see her now, even from a distance.

Certainly! :D
Let's not extend that to the point of countering established facts, will we please? Because if facts don't matter, then we're not being serious about aviation safety, we're being serious about personnal beliefs. ;)

Let's try, once again:

Questionable conclusions from the BEA report:
A1- the titanium strip was the only & direct root cause for the sequence of events that led to the crash;
A2- the missing spacer had no influence to the crash;
A3- the too early #2 engine shut-down had no influence;
A4- the too early rotation (as per references speeds) had no influence to the crash;
A5- the overweight had no influence to the crash;
A6- the rearwind had no influence to the crash;

All those conclusions are indeed questionable, and may be seen as aimed to protect AF from liability, indeed (at last: they had this effect).

Questionable conclusions from third parties:
B1a- the titanium strip had no influence to the crash;
(or)
B1b- the titanium strip cannot be seen as the only root cause of the crash;
B2- the missing spacer had an influence, and was a causal factor of the crash;
B3- the too early #2 engine shut-down had a direct influence to the crash;
B4- the fuel tanks were overfilled and that had an influence to the crash;

Those are questionable because they contradict the report (hence they must be fact-checked), and because they may be seen as aimed to protect a third party (namely: Continental) from liability.

Now, all those have already been discussed numerous times.
Allow me to make a résumé (in french in the text ;)) of my point, without being going to far sidetracked into other (interesting nonetheless) discussions.

Scenario:

• B1a is rejected: All evidences show indeed that the #2 tyre blow up when rolling on the strip. BEA, AAIB, judicial and every informed/serious third party analysists are OK with that established fact.
• As a first consequence, a major fuel leak occured. B4 is rejected because the overfilling of the tanks (as per procedures) concerned the tanks 1, 2, 3 and 4, but not the tank 5 which suffered the leak. This tank was not overfilled, it was filled.
• As a second consequence, a fire started (because of an electric arc or because of reheat: there is a disagreement on the cause). Let's stick to the established fact that the fire was present, as BEA, AAIB, judicial and every informed/serious third party analysists are OK with that (not counting anyone able to look at a picture).
• The extent of the fire had in turn two main consequences:
  • Loss of thrust on engines 1 & 2. It is unclear if the #2 would have produced any significant thrust if it had not been shut down too early, but B3 cannot be ruled out with certainty: Perhaps the #2 engine would have been able to generate useful thrust.
  • Significant damages to the left wing and left control surfaces of the aircraft. Those damages were increasing with the time. They was no way to stop them from increasing, unless being able to extinct the fire (which was not possible).
• Those damages ultimately led - in conjonction with the too low thrust - to the loss of control of the aircraft and to its crash.

Analysis:
Now, my point is that even with the hypothesis of enough thrust being available (i.e. #2 engine not shut down and physically able to produce significant thrust despite the fire, which is far from certain and certainly not an established fact), the thing is the fire damages to the aircraft itself would have been "enough" to make the aircraft uncontrollable => loss of control => crash.
What would maybe have changed is the exact time (hence location) of the LOC, therefore the plane would have crashed elsewhere than at "La Patte d'Oie" of Gonesse. But il would have crashed anyway.
In this way, A2, B2, A5, A6 are irrelevant, whatever their reality or their importance about what they show about AF (non)adherence to procedures.

And if we were to stretch things a bit more? What if the plane had been able to reach & land - not crash, land - at Le Bourget, that was not so far away? Then I think there would have been (massive/total) casualties anyway because of weight, speed, some brake power lost (damages to the U/C), and fire engulfing the plane when it would have stopped.

Hence I don't think it would have been able to "make it" in any way once it had rolled on the strip.
A1 surely is a bit of a stretch, and aimed to protect AF, but it seems the court finally saw better and didn't forget to blame AF too. That's good. A1 is wrong.
B1b is most certainly true: the inherent fragility of Concorde to blown tyres/fuel/electrics interactions was known since a long time. With hindsight, it is now an established fact that the corrective actions that were undertaken since '79 were too feeble to protect the aircraft from that risk.

Conclusion, part 1: All parties involved in the operation and certification of Concorde (in France and UK at last, and perhaps we should add the NTSB/FAA too because of the location of Washington) can be seen as sharing (to some degree it is) the responsibility of letting Concorde fly to its fateful fate in July 2000. I'm not a lawyer, I won't try to assess the sharing of that global responsability, except to say - before being crucified - than I agree that the share/responsability of AF seems greater than the share/responsability of BA.
Conclusion, part 2: As I wrote earlier that, if a BA aircraft had rolled on the strip, it would also crashed too (even with the equation better operated=able to stay airborne longer, there is no equivalent to Le Bourget near Heathrow, I believe?).

Hi AZR, and thankyou for your well reasoned posts.

Here..

"Conclusion, part 2: As I wrote earlier that, if a BA aircraft had rolled on the strip, it would also crashed too (even with the equation better operated=able to stay airborne longer, there is no equivalent to Le Bourget near Heathrow, I believe?)."

I am not so sure....at all.

You neglect one important thing. With an intact and complete undercarriage, the BA Concorde would most likely not have adventured into the weeds, wiped out a light, and caused a long tail wind driven roll to urge the Captain to rotate immediately. Captain may have rejected the TO, though that is a stretch. Had he done so, he would have decelerated straight ahead, on tarmac, with likely an overrun. Off runway, and directionally challenged, the French Captain had to launch, or face disintegration on dirt. Because he was lacking a standoff spacer.


With an intact axle, at #2 tyre rupture, the forward truck would have maintained separation of tyres 1 and 2, allowing a smooth recovery of track. On BTSC, the #2 wheel migrated left the full 16 centimeters, towards the wheel of #1. Without the spacer, the ruptured tyre would certainly drift on the axle, nothing stopping it. This would have completely altered the carriage geometry, creating an intense out of balance condition, and enormous side loads on the tyres, pulling the a/c to the left.

I say the BA Concorde survives, though perhaps not without fatalities, had there been a similar fire.

Hi Lyman,

I didn't neglect anything: See my "analysis" paragraph where A2 & B2 (i.e. the missing spacer, hence the not complete U/C) are quoted. Regarding the "intact" U/C... well, one tyre blown by the strip, it's no more intact.
My point is that rolling on the strip was enough to start the leak & fire.
And the fire itself was enough to crash the plane.

The drift to the weeds, the wiped out light, and the early rotation (whatever their cause(s)) are irrelevant, here, as they would have no influence on the fire and its structural consequences:
Fire => Serious & quickly worsening damages to wing & surfaces => aircraft uncontrollable => loss of control before it had time to land anywhere => crash inevitable.
Even on a perfectly balanced airplane, taking off straight on the centerline (which a BA Concorde would not be, because part if not most/all of the drift to the left was due to loss of thrust following engine surges/FoD ingestion, spacer or not spacer - see my MP).

-----

Now, you imagine an RTO.
First, I don't think an RTO after V1 is likely to have occured at BA. :ooh:
Not without hindsight, as it would have been a violation of procedures := (that even AF didn't do ;))

But what if it did occur? BEA did the maths, for the CDG runway, I suppose the conclusions would have been roughly equivalent @ LHR or elsewhere:

The sole difference I can see re: a BA Concorde would be thrust reversers, on 4 engines and not 3. It remains unclear if the #2 (or the #1 for that matter) would have been able to produce any significant thrust (reversed or not) particularly in a decceleration phase (more hot gases injested). Even if we imagine all 4 reversers OK, the aircraft would still overrun at significant speed (even if less than calculated by the BEA above), and the conclusion still stands: overrun + massive fire = catastrophic results.

According to (many) BA FEs I've spoken to, it's extremely unlikely the tanks would have been overfilled on any BA departure, therefore there'd be some air space above the fuel to get compressed and absorb the hydraulic shock of the base of the tank being clouted by a piece of tyre, therefore no torrent of fuel pouring out the bottom of the wing, therefore a controllable 'incident' at worst, rather than a total disaster.

And that's ignoring the other AF factors (spacer, downwind, overweight, no.2, etc).

Not conclusive of course, but it is food for thought.

Once again:
I think it was not uncommon for BA to fill (not overfill) the #5 tank.

If you have data which suggest/prove otherwise, please feel free to share them :)

Bonjour AZR...

Given that the accident crash has been discussed at such length, it is predictable that complete agreement will be elusive. Impasse is not unfriendly, or need not be.

* "Between leaving the maintenance hangar and the fateful flight of July 25 the Concorde flew two round trip flights to New York and back.* In that time after each gear retraction the right hand shear bush began to slide down into the gap left by the missing spacer.* By the day of the accident the shear bush had moved a full seven inches out of alignment to the point where the two washers were almost touching.* The movement of the shear bush allowed the beam and wheels to wobble up to three degrees in any direction."

.......From "Heritage CONCORDE"

So therefore.....

The accident takeoff was the fifth since return to service. At Rotate speeds approaching 300 miles per hour, the stresses are formidable, so.....

It is my belief the problematic landing gear issue was at the very least contributory, definitely not "irrelevant".


re the "Transverse Cut". I would be looking for evidence of Zinc Chromate from the strip's painted (primered) surface, and remnants of Red Applicating mastic.

The site of deposition? The "cut" area of the tyre tread separating the two recovered oval pieces of tire tread surface. Evidence of elastomer (tyre material) was identified on the Titanium strip itself, there is no reason that the tyre remnants would be free of applied materials from the metal shard.

I am sure it is in the report, and my cursory review missed it. For me, evidence of Red Mastic and paint primer on the tyre pieces would be absolutely conclusive of rupture due to Continental's shoddy shop work on the DC-10.

merci beaucoup

It's generally accepted by all parties that the deviation from centreline was caused by the sheer amount of thrust asymmetry caused by the starboard engines functioning normally with reheat and the port engines being impeded/damaged by the fuel fire. The missing spacer may have had an effect, but even if correctly fitted it is *extremely* unlikely to have changed the outcome beyond losing control at a marginally higher altitude.

Such a gain in altitude might have altered the location of the crash, but the controls would still have been destroyed by the fire (the existence of which is irrelevant to the spacer) at the same rate - there's simply no way they could have made Le Bourget and landed safely with that kind of damage.

Oh, but I've no problem with that. :)
Indeed, we differ on the spacer. Neither of us has conclusive evidences, and both scenarii are possible/sensible. I hope not to give the impression of being unfriendly here. :)

I can also agree with that. Not a problem.
I didn't say it's irrelevant per se. I said it's irrelevant in the scenario I presented (and which is by no means a personal one).
I notice you "forgot" to answer about that scenario. Too bad, it was the only point I really stressed. Should I take it that you agree with me here, then? :)


Well, I disagree, and I could think of a number of reasons. Relative hardness of materials involved, for example. ;)
If you have no counter-proof, you may "just" admit it, say "I don't know" (*) instead of asking for a complementary proof that we know doesn't exist.
As you said yourself, impasse is not unfriendly, or need not be. :)
OTOH, trying to "noyer le poisson" could be seen as unfriendly. ;)

(*) I tried to do that at lenght earlier in the topic, and I'm not hurt for having done that.

Hi AZR

negative on the Poissons, Monsieur...

Ici.....

Quote:
"there is no reason that the tyre remnants would be free of applied materials from the metal shard"

Well, I disagree, and I could think of a number of reasons. Relative hardness of materials involved, for example.

if My interest was required to be objective I would not stop once I had found elastomer on and in the Titanium strip. I would continue and seek to find deposition of Alkyd and epoxy mastic on the rubber pieces. Did BEA? (it is exceedingly unlikely Titanium would be found on the rubber :) ). But NOT impossible, since remnants of grinding might be bound in the primer, or mastic!

"If you have no counter-proof, you may "just" admit it, say "I don't know" (*) instead of asking for a complementary proof that we know doesn't exist."

I missed this, does this mean you believe no proof one way or the other exists?
Do you think they sought such evidence?

1. They must have, if only to cement further their theory of "transverse cut".

2. They did not report the results of their Gas chromatography/electro phoresis?

3. They did report, and I missed it?

4. There was no such deposition?

5. If none, they missed a chance to cement Continental's 'guilt'?

6. If foreign material was identified, and not reported, they are incompetent?

I have no bias here, my enjoyment is in the discussion, especially with a bright and patient person such as you :D

Hi

When I cut meat with a knife, I think findind bits or traces (juice) of meat on the knife is proof enough that the knife was used. Especially when there is no other meat in the neighborhood that could have been cut by this knife, and when I learn that the bits/traces found on the knife were analysed, and found consistant with the two parts of meat in my plate.
I don't have to find bits of knife on the meat to be convinced.
In fact, finding bits of knife (or knife's coating) on my meat would worry me. :p


Thanks for saying that, Sir :)

AZR...

My friend, your 'knife' is coated with chemicals that are made from petroleum, and the meat is made from naturally occurring proteins, and fats. That there could be commingling is a virtual certainty.

The rubber in the tire is a product of organic chemistry, the mastic is composed of basic chemicals found in the same lab, and the paint alkyd resin. If the Titanium 'knife' has been ground at the bench, it may have donated ground Titanium to the applied paint.

There was elastomeric debris covering the runway, that is the nature of runways.

BEA said only that the elastomer on the Titanium was consistent with Goodyear rubber, not that it was proof that the Titanium had entered the carcass of BTSC's tyre. With possible proof available, the forensics are untried and the result is insufficent, unsatisfactory.

I think a test should have been done, rather than being so easily satisfied that Titanium from CAL sliced the tyre.

It suggests satisfaction at a low threshold, that a preconceived theory was proved by the presence of material that is found all over the runway, as well as in the GoodYear #2.

Were the tyre remnants rubber only, or complete through and through sections of the tyre to include fabric?

See you next time?

Hi Dozy....

You write...

By what mechanism were the port engines impeded, or damaged, by fire?

But that's the limit of forensic science right now. Just as it is in criminal murder trials, the furthest the evidence can be taken is that the "wounds" are consistent with having been caused by the object in question (unless a portion broke away inside the "wound" and can be physically matched up). Further speculative conclusions may be drawn, but they will not be legally admissible as evidence.

Several tests *were* done as part of the investigation and the results from every test supported the conclusion.

Not true. In accident investigation the theories are derived from the evidence, not the other way around. The BEA applied due diligence in trying to prove or disprove the sequence of events that led to the evidence with which they were confronted.

I remember reporting of this case very well, and it was at least weeks following the accident before the possible role of the titanium strip was publicised. As usual the press published a lot of incorrect information in the rush for an exclusive story - one of the most repeated was the allegation that there was a 747 with then-President Chirac on board nearby. I still see this repeated in articles today but it was never true.

The latter. They simulated the wheel and tyre behaviour with and without the missing spacer and the loads were never sufficient to precipitate catastrophic failure of the tyre.

The outcome of this legal process simply stated (correctly in my opinion, as criminal law and accident investigation should not mix except in significant extenuating circumstances) that Continental should not be held *criminally* liable for the unorthodox repair of the titanium strip - it does not alter the facts of the case itself.

The fire heated the air in front of the intakes to a temperature that was outside the normal operating range. This caused both engines to surge during the take-off roll, from which engine one eventually (briefly - once airborne) recovered, but engine two did not.

Makes sense......

May I rule out convection? So radiative. Were starboard engines affected? I would think so. By what amount?

You are defending French rules of evidence, above. Manslaughter demands "beyond a reasonable doubt" in the USA. Had I been the Titanium gearhead charged, I would have wanted all procedures exhausted.qa

The procedures I discuss above are not new. GC has geen around for decades, all that is required is a solution of tyre, and the 'unknowns'.

No, the starboard engines were not affected because the fire was well away from the intakes of those engines. Convection causes heated gases to travel upwards and sink as they cool. In the case of the port engines, hot gases from the fire were being sucked straight into the intakes - no time for the convective process to be established.

I am doing no such thing - I've stated several times that I believe the continental legal process following aviation accidents to be counter-productive in many ways. Criminal procedure on the continent differs from that of the US and the UK in that the supposition is of guilt, and that guilt must be disproven rather the other way around.

There's no doubt in this case that the mechanic overstepped his bounds and performed a repair job that he didn't fully understand - even though he probably thought he was doing no harm (see also the mechanic who used the wrong window bolts leading to separation and decompression on BA5390). I don't believe criminal negligence is an appropriate description of what he did - the issue was and is far more complex.

In this case there was no need - the tyre remnants were reassembled and the initiating point of damage was conclusively proven to be consistent with the titanium strip. They ran theoretical and physical reconstructions over and over again and the results of those experiments proved (beyond reasonable doubt) that the failure of the tyre was initiated due to contact with the titanium strip. No other failure mode matched either the debris pattern as was found on the runway, or the velocities required to breach the fuel tank.

All newspaper articles confirm that Jacques Chirac was aboard the plane with his wife
He was back from Japan (G7 meeting)
Centre de Documentation G8
If you have a press article release or any other document that proves otherwise (contradicted by Jacques Chirac .. etc. ..) they are welcome
http://www.pprune.org/rumours-news/1...ed-chirac.html
Eléments d
Crash Concorde 'almost killed Chirac' | Mail Online
Le Figaro - France : Concorde*: Continental Airlines joue son va-tout
| The Sun |News
Chirac a assisté au crash en direct - Libération
CONCORDE: Anatomy Of A Disaster [Archive] - David Icke's Official Forums
Concorde : enqute sur un incroyable crash - L'EXPRESS

@jcj:

All those articles used the same source, which turned out to be incorrect.

See here (from #219 for the next couple of pages):
http://www.pprune.org/rumours-news/4...-crash-11.html

The only AF 747 in the vicinity was vacating runway 26L and M. Chirac was categorically *not* on board. It makes for a juicy, emotive story though - which is probably why it was repeated so much without proper verification.

[EDIT : Friendly word of advice - it's not advisable to link to the David Icke forums if you want your point to be taken seriously. Unless of course you subscribe to the theory that most if not all world leaders are in fact shape-shifting lizard aliens intent on enslaving the planet! ]

DozyWanabee
http://www.pprune.org/6111388-post205.html
A310 (official aircraft) for go and return from Japan ?
Poor Chirac ...... :)
Joke ?
I'm waiting a denial of the presence of Chirac aboard the 747 .... from a independent source
So far I find nothing ....

Why should he deny it? He was all over the international press within hours of the event - do you think that if he were an eyewitness or somehow directly connected that he would not have mentioned or confirmed it?

Aside from the fact that I know there was only one source for the claim, other things that make me suspicious include the fact that the reports do not agree on the airline the supposed 747 belonged to (some say AF, others JAL), as well as the fact that none agree on how close F-BTSC came to the supposed 747. As I said before - variations on the story include F-BTSC passing within 7m, 70m or 7 yards(!) of the alleged Chirac 747, the alleged 747 itself either on the runway and exiting, at a holding point or *actually crossing the runway across F-BTSC's path*. Some even have Chirac himself "looking on in horror" as the flaming Concorde passed by.

This is my first post on this topic. To establish myself, I put in over fifty years in aircraft maintenance in positions from mechanic to vice president and I managed Quality Control as well.

The controversy over whether the missing spacer contributed to the accident is impossible to settle. It does show a shocking lack of adherence to process and poor quality control at Air France. Work of this nature in the USA is mandated as a "Required Inspection" which is a warning sign to the Inspector. I believe the British used a “Double Inspection” to ensure compliance. What failed here is not fully explained. I might also add, I found the cavalier attitude toward an overweight takeoff and in a downwind direction disturbing. The corporate safety culture apparently failed all around.

The titanium repair spacer from the DC-10 engine was apparently not installed in accordance with the Structural Repair Manual (SRM). Continental also is at fault for shoddy work.

All these aside, the bigger issue is the failure of the relevant regulatory agencies and the manufacturer to prevent the chain of events caused by a tire failure. As an example, early on in the B727 history there were some tire failures that punctured the composite material tank access plates on the bottom of the wing in the gear area. I seem to remember Boeing Service Bulletins and an Airworthiness Directive mandating their replacement with metal tank access plates to prevent puncture. Every time we purchased a used B727 we had to check to see the AD was complied with to get the aircraft on our certificate.

After Concorde suffered a major tank rupture at Dulles, what regulatory action was taken? Apparently there were tire improvements. But tire failures continued. Every single tire failure was a roll of the dice as to where the shrapnel would go. It took the CDG crash to finally come up with some measure of protection which I believe was lining the tank bottom with Mylar fabric material. It took all those years from Dulles to CDG to drive the point home that the aircraft was vulnerable to a simple tire failure.

Lord knows I have seen many tire failures. Early on it was a B720 that wiped most of the hydraulics off the strut, a B747 that damaged the horizontal stabilizer (the mechanics on duty never thought to look back there until I told them to take a peek). I have seen landing gear doors badly damaged, etc, all of these from failed tires that threw pieces or chunks or even entire recaps but they didn't bring the aircraft down.

The real cause of the crash was the failure of the regulators and the manufacturer to take definitive corrective action to prevent a repeat of the Dulles tank rupture. If it was impossible to do so, then the aircraft certificate of airworthiness should have been pulled. The Concorde was a magnificent flying machine but it had a fatal Achilles Heel. They had adequate warning at Dulles, they should have taken action.

A now retired member of the Concorde flight crew told me that the engine problems were down to one engine (can't recall which one) ingesting runway lighting debris and the adjacent engine ingesting neat fuel which was interpreted as a second failure on the flight deck. The ingress of fuel into the engine was a transient condition and full power would have been available after it had sorted itself out. Once both engines had been rolled back, Concorde was then on the back of the drag curve. Had power been maintained and the ruptured tank had fully drained, there may have been a better chance of a survivable outcome but it's a purely academic discussion.

The flame front could not advance faster than the airflow so it begs the question what ignited the fuel ? It was thought that damage in the wheel well caused electrical arcing which by some means of a disrupted airflow in that area, ignited the fuel. The reheats are thought not to have been the source due to the airflow speed being greater than the speed of flame front advancement.

Either way, it was a very dark day in aviation and has revealed once again the consequences of lax attitudes to process.

Very well said B Fraser :

".....and has revealed once again the consequences of lax attitudes to process."


Some times all the holes in the Swiss cheese line up, and an accident is the result.

As professionals, we most do our utmost to keep these holes out of alignment.

As a fare paying passenger, I ask that the holes are found and filled in.

Hi Lyman,

I've quoted a number of sources, established facts and so on.
I'm convinced of the role of the strip. So is the BEA, the AAIB, and a number of other detailed analysis.

You have doubts? Fair enough, you're entitled to that. :)

But I you want me (or anyone) to share those doubts, you don't need to ask for "more proof".
You need to demonstrate, first, that what we consider as proof is not good enough. And you need to do that with more than "just" your doubts and convictions, because you're "fighting" material evidences.

That's not easy. And by the way, I'm perfectly happy with you having doubts about the strip. I'm not a lawyer, I don't think PPRuNe is a court either.
I suggest we put that point at rest until your doubts are backed by either hard evidence, of a logical demonstration able to counter all of the evidences/conclusions of the final report.


Now, the matter in discussion when you joined this thread, the point I was trying to make is this one:
BA Concorde was not more immune to tyres events leading to damage to the wing/tanks/electric that AF Concorde. Basically, they were the same aircraft, even if operating procedures differed (in definition or in the quality of their execution).
Therefore, it was the right decision to ground both fleets until the tyres were replaced by NZG ones (resistant to blow-up IIRC) and a kevlar liner fitted inside the fuel tanks.

Even if you think BTSC didn't roll on the strip (or have doubts about it), you surely agree with the above? I mean, the strip was one FOD, there was no way to ensure that never such an aggressive FOD will find its way to Concorde's tyres, with the potential catastrophic consequences we're all aware of since july 2000 (or since '79 or any other tyre incident since, depending your view).


Calculations were made about that (and other theories) here if you're interested.
Short answer is: the tank would not have fully drained before the aircraft was rendered uncontrollable by fire damage to the wing & elevons.

AZR

"Even if you think BTSC didn't roll on the strip (or have doubts about it), you surely agree with the above? I mean, the strip was one FOD, there was no way to ensure that never such an aggressive FOD will find its way to Concorde's tyres, with the potential catastrophic consequences we're all aware of since july 2000 (or since '79 or any other tyre incident since, depending your view)."

There are several ways to see this, my preference is to agree with you.....

Any patent vulnerability to disaster requires mitigation, in a sane and honest way. My perspective is that the Concorde was especially vulnerable to tyre issues. Likewise, as a unique design, she had other vulnerabilities exclusive to her mission. Air France purposely avoided their most basic responsibilities. Evidence? Continuing with the use of recycled tyres well past the first disintegration of the installed problem......

stuckgear broaches what I expect is the nucleus of the discussion.

BTSC was overweight......substantially

She was without a required part in her left bogie....unconscionable

Regardless, she pushed back, and initiated a Take Off on the 'wrong' runway.

What follows in the take off is the genesis of a spirited discussion, and Legal action.

All of it MOOT......

Characteristically, partisans focus on the irrelevant and inconsequential, in a practiced way, to distract and confuse the course of Aviation as it relates to duty of care, fundamental safety, and honestly derived profit.

The Court has decided the evidence is not sufficient for criminal retribution, as regards the errant metal shard.

Works perfectly well for me.......

Tip of hat to you, sir...... :ok: