It's surprising that she stayed in service as long she did. Even with the fuel tank revamping and anti collision avoidance system installations it was evident she was way too long in the tooth. Hardly a week went by that I did not hear Speedbird 1 or 2 calling up Shanwick or Gander on HF ssb for lower flight levels as the air intake doors had problems. The passenger cabin was hardly more comfortable than that of a Dash 8 but the prestige and service was unrivalled and just listening on T2 spectators roof at Heathrow to the Olympus engine whine on taxying or the roar on take-off from R27 after she jumped the long queue will never be surpassed or seen again.:hmm:

Her resurrection is nigh!

No it ain't mates, she died and is dead!

But how and why she died will live on forever, and though I admire the cut and thrust of the PPRuNe contributors, I feel that the subject has died, and all that should have or not have been done by those in all forms of control can be argued until the cows come home (in whatever Grassy Valley), the outcome has already been determined by the justice (injustice?) system.

We can no more make a "silk purse" from a "sow's ear" than could the actors of the day replay and correct their final act(s) from their graves. R.I.P.

The Concorde a Sow's Ear? Wash ya mouth out with pork fat! :p

Hi SLFinAZ,

I agree that we got (with my comments in [brackets]):
- sworn testimonies by highly respectable & trained people, [that I never saw quoted in extenso (if you have a reference, I'm interested), except for one ATC who said IIRC (TV show) he was not looking towards Concorde when she began her T/O roll];
- sworn testimonies by certainly also respectable people, [but not trained in any way, for exemple the foreman seen in the TV parallel inquiries];
- all those people were situated, at the time of the accident, relatively far from the aircraft [making it difficult to jaudge distances];
- the "step" on the runway that could have played a role "before the strip" [but I can't remember any evidence or even precise/factual hypothesis about that].

Now, on the "other side", we also got:
- no single hard evidence of fire (or any other arising problem) before the blown tyre/fuel leak event;
- no satisfying scenario able to explain where/why a fire would have been present before the strip/tyre/leak event (not even the missing spacer, see quote below);
- evidence (damaged concrete) of the tyre blowning up at the time when & place where the final report said it occured;
- evidences of the fuel leak beginning at the time when & place where the final report said it occured;
- evidences of this fuel leak taking fire shorlty afterwards;
- correlation of all those with the FDR traces;
- correlation of all those with the CVR recordings;
- correlation between those events and the TWR ATC message "Concorde, vous avez des flammes derrière vous".

The lack of precision of eyewitnesses is relatively common, if we're to believe what professionals experienced in working with witnesses say on the topic.
My conclusion is, then, that without meaning the slightest disrespect to sworn and/or professional witnesses, their testimonies must be somehow incorrect/not enough precise.

Quote from B. Sieker (op. cit. in my #160): The report makes a point of recording that there was no sign of abnormality in the taxying and takeoff run up to the point of tyre destruction. There was no shimmy, no deviation from track, the brake temperatures were equal RHS and LHS, and the longitudinal acceleration was consistent with the TO mass and ambient conditions. Let us accept that ensemble as evidence that any bogie misalignment due to the missing spacer became a potential problem only after the destruction of the tyre.

I think you can have some answers to your questions about references in the minutes of the trial:
2 « février « 2010 « Procès du crash du CONCORDE

SLF

Retrospective knowledge is wonderful. We now know that once the exploding tyre or titanium strip had caused a fire on that scale, a controlled crash landing was impossible.

It is unlikely that the crew knew this until the final couple of seconds before impact.

Carrying out an emergency drill (engine shutdown) before the aircraft is at safe height and speed smacks of poor airmanship. Or at least it was on any of the aircraft I have been on.

Thanks jcjeant, but there is "only" Me METZNER PoV there.
I see no testimonies. Should I look at other pages? I will try to find something better suited on that blog, but it may require some time.

As a lawyer in court, Me METZNER had a clear and open agenda.
I've no problem with that, but I'm not interested in discussing his PoV, nor am I ready to take it into account for an analysis :)

EDIT
Disregard, my bad and so on (about the bold part) the testimonies are "simply" available in the Appendix 6 of the BEA final report. Will re-read that.

dalek you know no such thing. We can certainly agree that the catastrophic nature of the event made any type of controlled crash landing highly improbable. Can you tell me with 100% absolute certainty that a flight deck crew of aviators the caliber of Alfred Haynes and Dennis Fitch might not have accomplished a miracle?

We need to look no farther then the annals of any nations military aviation to find incidents of planes and/or people surviving catastrophic damage. The sad truth is that while events doomed the air-frame the specific cause of the crash was flight crew error.

How is it OK to argue that without the titanium strip none of the other deficiencies really matter yet dismiss the actual cause of the crash (FE's incorrect response). I'll use UA 232 as my argument. Had a less qualified flight crew destabilized the aircraft resulting in a high altitude loss of control and crash...many of you would be arguing the design flaws of the DC-10 as the root cause and dismissing the upset...since the plane was clearly doomed.

Yet more people lived then died that day. At the end of the day it's not really over till the aviator can no longer aviate. In this case the weakest link on the flight deck removed any opportunity for survival at a time when the plane was still capable of controlled flight.

With respect, I would like to invite interested people to view the photograph in the Heritage link.

The shimmy is obvious. the trail of rubber has a cycle roughly the circumference of the tyres, and an excursion from center of close to one foot. That suggests the out of balance condition of the right side of the portside bogie contributed to the skid.

That means the ruptured tyre is contributory. Also note the dark scrub of the #2 tyre in roughly the same cycle as the bogie's oscillatory condition... That suggests the tyre was essentially still on the wheel, with the ruptured deficit causing severe drag.

A bogie with a blowout will not shimmy like that. Period. Can we surmise the bogie stated to shimmy at brakes release? Yes, I would say, yes.

Now, given the state of the bogie's wobble, I can suggest that as speed increased, it worsened. The vibration would have reached substantial effect in the cockpit (imo), and now we come to #2 engine cut.

Did FE have evidence to cut the engine? Of course. What was the nature of the evidence to hand to cause FE to take such a remarkable action? Temps? Tower? (ATC) "..derriere vous...."

I submit that FE associated the extreme portside bogie vibration with engine failure....

At 120 mph, the bogie would wobble seven times (right, left) EACH SECOND.

I estimate the weight of the bogie at approximately 2000 pounds.

I urge all objective people to see the photographic image, and decide if they can see the scalloped trail of rubber left by the 1 and 3 tyres.

At the runway light, the a/c was travelling closer to 250mph.

In many ways the damage sustained by Concorde F-BVFC in the June, 1979 incident at Dulles was probably as severe if not worse than that sustained by sister ship F-BTSC on that fateful flight in July of 2000.

Probably (IMO) the most telling comment based entirely on factual observation vs informed speculation.

If the image I reference is not fake, I submit the out of line track of the tyres is a matter concluded by factual observation.

with all due respect....

SLF

Yes, I see that, I thought you were addressing my point re: shimmy.

Add to your (below) comment...

The dispatcher was also made aware of a technical issue with the new aircraft, F-BTSC, when his computer indicated that the thrust reverser on the number two engine was inoperative due to an issue with the secondary nozzle.* The aircraft could be safely operated in this condition but the issue would reduce the aircraft’s maximum operating weight by 2.5%.

That is roughly 5000 pounds. For performance, did the aircrew subtract that from maximum allowable TOW?

I completely agree: that the tyre burst is indisputable, its mechanism of failure is less important than the history of similar events, and the utter lack of mitigation that followed Dulles. The complete disregard for safety given the dozens of incidents is inexcusable. In that context, the Titanium strip takes on a more subtle role, that of scapegoat....

Lyman, we are discussing different issues. My point is that regardless of the cause of the tyre failure the damage incurred in the two incidents is similar and the Dulles incident actually had potentially greater damage to the air frame...

Further....

While the condition experienced was highly unusual and not something for which any crew had been trained to deal with the crew failed to follow one of the most basic responsibilities of a pilot. No matter what happens, no matter how many alarm bells or warning are going off, your chief responsibility is to fly the airplane. An engine fire can be dealt with, but only after a stable climbout has been achieved. By shutting the #2 engine down the crew eliminated any available margin that might have kept the aircraft in the air long enough to reach Le Bourget.

After reviewing the 3 firemen testimonies (and a waiting captain's), I note 2 things:

First, even if the 3 firemen were in the same room, they don't give the same exact same location/timing for the events.
Example: event "blake smoke like a tyre exploding" at around S6 or S5 for two of the firemen, while the third didn't see the black smoke, but only the beginning of the fire, around S5, with first a small flame at the rear of the engine (different from the reheat), then the big flame everybody saw later.

Nevertheless, they were close enough (not like the foreman I remembered from a TV show) and their descriptions are precise enough to come to the conclusion that it seems the "black smoke" event took place at or shortly before the "first apparent trace of destroyed tyre" located between W7 and W6 on the appendix12.
Indeed "around S5" and "shortly after W7" are close enough - or were, in 2000, now the taxiway have different names.

Also noteworthy is the confusion in some TV shows when they said that witnesses had said the fire had begun a long distance (wasn't 1 km quoted?) before the strip. Yep. That is before where the strip was finally found. Not before where the strip probably was when Concorde rolled over it. I really have no difficulty to imagine the strip being swept along the trajectory of the aircraft, as its 200 tons rolled over it... but it seems that notion eludes some people anyway.

Second, many people said the BEA just "disregarded" the testimonies of the firemen. Not so, as seen above.
And quite not, when we read in extenso the appendix6. We understand then that the fact that the BEA was so keen to say the fire may have begun at the rear of the engines (by opposition to the second theory of the ignition in the U/C bay, which is the only one the AAIB considers valid) is somehow directly related to the testimonies of the firemen, which were trusted (as they should be) regarding the sequence of events (first this, then that: we human are good for that; not so when it came to precisely locate (in the space or time) this or that).

AZR

BTSC took off with an inop Thrust reverser on #2. It was legal, but reduced her max op weight by 2.5%.

It is not possible to know what FE was acting on, but if #2 was problematic, even in his thought only.......

Something triggered his desperate attempt to cage the #2 engine.

What do you make of the "black smoke" re: the "tyre burst"?

I would associate black smoke with unburned (neat) fuel out the nozzle?

"Can you tell me with 100% absolute certainty that a flight deck crew of aviators the caliber of Alfred Haynes and Dennis Fitch might not have accomplished a miracle?

We need to look no farther then the annals of any nations military aviation to find incidents of planes and/or people surviving catastrophic damage. The sad truth is that while events doomed the air-frame the specific cause of the crash was flight crew error.

How is it OK to argue that without the titanium strip none of the other deficiencies really matter yet dismiss the actual cause of the crash (FE's incorrect response). I'll use UA 232 as my argument. Had a less qualified flight crew destabilized the aircraft resulting in a high altitude loss of control and crash...many of you would be arguing the design flaws of the DC-10 as the root cause and dismissing the upset...since the plane was clearly doomed."

SLFinAZ the UA 232 is a red herring as it's no way comparable with this incident.
Firstly it happened at altitude and secondly they had an extra qualified pilot travelling on the flight. So the time they had to deal with the problem was considerably greater than the Concorde crew. That in no way takes away from the skill and expertise of the UA 232 crew. Yes the design flaws of the DC10 were the root cause of that incident.
To blame the late FE for the crash is simplistic and flawed and to expect any flight crew to be able to perform "miracles" is preposterous.
If you read my earlier post I clearly state that whilst the other deficiencies had no direct bearing on the crash, it does not mean that action should not be taken to correct them. The crash would have happened with or without the deficiencies.
Can I tell you with 100% certainty that the UA 232 crew would not have saved the day. They are human so I doubt that they can perform "miracles". The best people to answer that question would be the UA 232 crew. In fact this line of argument is better suited to the pub as it resembles the typical pub discussion comparing sporting teams of different eras, whilst fun it has no value in this case.

No, the reverser motor (cause of inop) was replaced before departure, by request of the crew after the plane change (BTSC was the reserve aircraft for that day).

No, the testimonies (in french) are pretty clear. Black (puff of) smoke, located at/near the U/C, not at/near the nozzle.
Shortly after that, fire begun with a small flame at first (said the firefighters). Then, the big flame we all saw with, then, black smoke (yes again), this time from uncomplete burn of the leaked kerozen. But there is no confusion possible for a french reader.

Again I'm sorry but your comment is completely incorrect. Under no circumstances is it appropriate to shut down the #2 engine below 400 ft regardless of circumstances. UA 232 is in no way a red herring but an indication of what is possible under extreme circumstances.

The shut down of #2 engine directly contributed to the specific circumstances of the crash. Had the engine been left on in accordance with specific SOPs that clearly state that no engine (even if on fire) is to be shut down below 400 ft a different specific outcome would have emerged.

This does not mean a different final outcome but we'll never know, what we do know with 100% certainty is that the FE's flawed decision robbed the captain of any chance to successfully control the "landing".

This seems to go back to the numerous 447 threads that all go beyond a basic lack of airmanship. At the end of the day that plane crashed entirely due to a lack of basic piloting skills. Neither individual was even remotely qualified to be in the pointy end of a commercial airliner.

Yes I have really difficulty to imagine the strip being swept along the trajectory (over such a large distance) of the aircraft ...
It is a concept that escapes me completely .. seems some"magic" at work there .. :)

Agreed until there... :)

... but I agree no more here:
- as per SOPs, the #2 engine would have most certainly been shut down once in flight & above 400ft;
- hence any landing attempt would have been on 3 engines "only", which is abnormal but certainly not "without a chance".

What is the definition of "such a large distance" for you?
I'm fond of Harry Potter, but not so fond of magic regarding aviation safety.

If the Titanium had slashed and punctured cross tread, it is quite possible it stayed with the carcass for a time. Evidence of the transverse slash is shown in the runway photo I reference from Heritage Concorde. If that is the case, that the black deposit is from the cut, then we know that piece of tyre was retained at least up to that point. I think the fuel stain is prior to the loss of directional control to left. Thus suggesting the tyre rupture was not initially responsible for the off runway excursion, imho.

Once the two "flaps" of tread parted, the Titanium obviously was released.

Why would a tyre rupture cause such extreme yaw? I do not think that it did.

SLFinAz I still stand by comment that the UA 232 flight is a Red Herring. I do agree with you when you say the engine should have not been shut down below 400ft, but because something shouldn't be done doesn't automatically mean that it must be the primary cause of the accident. For you to convince me that you view is worthy of consideration you will have to refute the findings of the BEA.
There are many theories being put forward in this thread and for them to have any credence they must be backed up by verifiable facts. Quoting Heritage Concorde, newspapers or other forums do not pass that test. You can belive what you want but that does not entitle you to overlook the vast body of evidence that has been tested by a far more rigorous body than this forum. Nor does trying to claim that the accident investigation is trying to hid the truth. In fact to be blunt this thread reads very like all others where people claim that there is a conspiracy in place.

Nick Thomas

Would you consider viewing the runway photography of the skid marks and making a comment?

I see evidence of oscillatory movement about the bogie's horizontal plane.

For me, with some experience in vehicular investigation, the marks show a distinct wobble, such that a rate and distance of displacement can be readily discerned. Given the expected ground speed of the bogie, a cycles per second can be ascertained.

There is also evidence of tread crush, the siping width varies in concert with this cyclical action. This is indicative of side loading, or "scrub".


Will you please comment? Thanks.

I know the pic is from other than BEA, but it is intriguing, and I believe it is genuine.

Hi Lyman
I am not an accident investigator so am unable to draw conclusions from those photographs. From reading this thread I know you think they are important and that is your right so to do. My view is that there are two opposing views represented on this thread. One in it many guises doesn't accept the BAE report and will spare no effort in promoting their theories. The other (of which am a member) take the view that out of the available information present, the BAE report is the most useful in understanding what happened.

Where I do agree with those who don't accept the report or parts of it, is that the many other failures brought to the fore after this sad crash should be addressed but that doesn't mean that they actually caused the crash. In other words am of the view that even if all these points had been addressed before the incident the crash would have still occurred with the same awful outcome.

From previous conversations with you on this forum(when you were know as Bearfoil) I respect that you are trying to establish the truth. My path towards getting a better understanding of this tragic event is a different one to yours and therefore for me looking at the photographs you mention, will be of little value, as I am not expert enough to draw conclusions from them. The other reason am disinclined to view them is that it would mean that in order to be fair I should carefully study all the other evidence presented here that questions the report.

In science when something new is postulated it normally undergoes a peer review and if that is favourable it is then included in the body of scientific knowledge. Of course over time this theory will again be tested and if then found wanting the body of scientific knowledge will be revised to accept this new development. Why do I mention this. Well for my understanding of this incident to be increased or changed, then the BAE report will have to be challenged by another body of similar standing. As I have said earlier I am not an expert in this field and I therefore have to trust those who are considered to be so. I presume that other people posting here will not agree with my last point but may I suggest that in questioning the report you must have considerable confidence in your ability to understand third hand a very complex accident

No Lyman, I'm sorry but this pic is from page 64 of the final report; there are other pics from the runway in pages before and after that. ;)
All those pics show places where Concorde was after the destruction of the tyre from wheel #2. Hence I fail to see where you're heading to? :confused:

As previously quoted:
I would also take this opportunity to say that I fully agree with Nick Thomas' excellent last two posts #222 & #224 just above. :D
Well said, Sir, and tip of the hat to you. :ok:

Nick Thomas, AZR...

Thanks to you both. Your input is most helpful.

Briefly, I conclude the bogie is rotating about its horizontal plane as a result of a missing stand-off spacer. I do so because the tires are tracking irregularly in a plane which would ordinarily not be active.

Yes the marks were deposited after the rupture. The artifact that describes the shape of the tread cut suggests the tire was still reasonably intact at the site of the strip's insult.

If this contravenes BEA material, I think it worthy of mention..

So there we are.

A very enlightening discussion, and again, thank you.

Cheers :ok:

Hi Lyman,

I'm sorry, I don't understand this :confused:

Sure! If, it would :)
But I don't think this contravenes BEA conclusions. As for the material (=the picture ??), as previously stated it is from BEA.

Hello AZR,

pls allowe me one question,would the concorde have hit the strip if the spacer had been in place ?

Thank you

All other things being the same, yes it would have.

From what I've read regarding accident investigation, if physical evidence and eyewitness evidence diverge, then it is standard procedure to consider the physical evidence as more reliable, as eyewitness evidence has been proven to be one of the less reliable sources - dependent as it is on human perception and psychology.

The missing spacer is unlikely to have altered trajectory prior to contact with the metal strip, it would simply have had a very marginal effect on acceleration (and possibly a barely-perceptible level of vibration) given the sheer amount of thrust-to-weight involved.

At the risk of re-stating the obvious, no amount of errors on AF's part (of which there were undoubtedly several) would be sufficient to negate the errors made by CO. Mistakes made by both organisations must be combined and considered as a whole (and indeed the BEA report always reflected this).

Lyman

As you requested, I looked at that picture very carefully, and yes, there is evidence of a shimmy-like oscillation in that part of the track. However, I also looked at the other pictures in the BEA report (which is the source of the Heritage picture) and I could not see any evidence of similar oscillations when the aircraft was on the tarmac.

So I have some questions for you ..

I am no expert on shimmy, but I do know that it depends on a critical relationship of feedback between tyre forces and gear structure. The tyre force/slip characteristics would change substantially when the gear moved from tarmac to grass, so why are you sure that shimmy was present throughout all the TO? The BEA certainly didn't think so. Could shimmy be present only in the grass-bound part of the roll?

By the time the FE called the #2 engine failure and fire warning and then shut down #2 the aircraft had been airborne for several seconds. There would have been no shimmy once airborne, so why do you think it such an important factor in his decision to shut down #2? Why would it trump the engine failure and fire warnings? [The debate as to whether he should have shut down at that time is another matter]

At the time when the aircraft passed over that region (97611.5 on the BEA datum) it was at about 203 kts and had an AoA of 9 deg. One second later it lifted off, still at 203 kts but with an AoA of 11 deg. At the time we are discussing then about 80% of the weight was being carried by the wing so only 10% was on the LH gear. Since any forces transmitted to the airframe must depend on ground reaction and slip why do you think that the gear had a important effect at this point?

Shimmy, as I understand it, is a cyclical rotation of the wheels about the main leg. Again at the time we are talking about, the aircraft sideslip was 3 deg. Allowing for +/- 3 deg oscillation because of the missing spacer that would mean the wheels oscillating between zero and 6 deg would it not? Why would the time they were at less than 3 deg not offset the time they were at more? Or in other words, why should shimmy change the average force?

I notice that in your argument you do not mention the sideforce generated by the tyres. Have you any reason to neglect that contribution? I would think it a bigger effect than the drag and what is more it would have been acting behind the CG and giving a moment to restore the aircraft towards the centreline.

CliveL

I am most grateful for your response. To start...

"I notice that in your argument you do not mention the sideforce generated by the tyres. Have you any reason to neglect that contribution? I would think it a bigger effect than the drag and what is more it would have been acting behind the CG and giving a moment to restore the aircraft towards the centreline."

Let us begin with brake release. First off, a skidding tyre has less authority to affect direction. If skidding from the start, the left bogie is having less effect on direction than the right. That means the a/c will tend right, and may explain the Captain's initial left ruddering. (with four healthy engines))

For the record, I would suggest that as a whole, asymmetrical thrust had far more to do with track than tyres. If the left bogie had one tyre out of line, the bogie as an entirety would have less authority for directional control than the right bogie. Notice the tire marks on the picture showing roll prior to kero stain?
Only the left side?

This is suggestive of misalignment of left bogie. Notice also the straight track. This suggests that the misalignment is well managed. After the tank rupture, and fire, the bogie has less to do with track than thrust inequalities, imo.

You make a good point re: weight on wheels at the runway light image. The skid marks are light, narrow, and show the wing carries the a/c here. They also show more emphatically the stresses on the tyres from the outset. Free of most weight, they shimmy and wobble more readily.

I am interested in discussing the rest of your post. I'll leave at this point for you to respond if you wish.

Again, thank you

Another very important factor to bear in mind is that unlike with most powered ground transportation, where the motive power of the engine is transmitted to the ground *through* the wheels and tyres, an aircraft's thrust is independent of the wheels, which serve only to maintain heading and not to transmit propulsion mechanically (at least in a direct sense). An unbalanced wheel on a drive axle will therefore have a considerably greater effect on ability to control direction than a similar imbalance on a non-driven axle.

The lateral trajectory of the aircraft shows no abnormal signs of instability prior to contact with the metal strip, so it can therefore be concluded that the guidance of the correctly-fitted wheels along with the force of the forward thrust were more than capable of overriding any instability that the wheel with the missing spacer might have caused.

It is also therefore reasonable to conclude that the veer to the left coinciding with the strip contact was at least largely caused by a combination of the forces involved in loss of the tyre, loss of thrust from the port engines due to hot gases and the loss of grip caused subsequent to the tyre's destruction.

Another thing to bear in mind with the eyewitness testimony is the simple difference in perception that can be caused by the difference in speed of light vs. speed of sound. In general eyewitness testimony will tend to report perception of fire or visible evidence of explosion before any audible abnormality, and this is generally regarded to be because of the speed of light vs. sound perception. The firemen in this case may well have seen the fire before they heard anything abnormal with the takeoff (such as unusual engine noise or even the sound of a tyre failure) for this very reason.

Concorde engines didn't all spool up at the same speed (3 + 1 iirc) so this was normal.

I guess I should have specified that I meant conditions after the tyre was demolished. The BEA report (18.2.3.3) deals with the situation before that and all the evidence presented there says that the missing spacer and consequent freedom of bogie to yaw had no effect on the trajectory in that phase. I know no better.

I'm wholly with you there :ok:

Quote from CliveL:
"By the time the FE called the #2 engine failure and fire warning and then shut down #2 the aircraft had been airborne for several seconds. There would have been no shimmy once airborne, so why do you think it such an important factor in his decision to shut down #2?"

I think Lyman is arguing that violent vibration caused by main-wheel shimmy may have influenced the F/E's decision to shut down engine #2, even though the a/c was still getting airborne. While the root cause of any shimmy would be removed once the wheels left the ground, my experience suggests significant vibration might continue until the auto-brakes have stopped wheel rotation. I don't know what criterion is required on Concorde for autobrake, but it's likely to be near the start of an active gear-retraction sequence. In this case, as we all know, gear-door damage led to the selection of gear UP being refused or aborted by the retraction system at some stage in the sequence. Perhaps you or others can comment.

Having said that, I'm not aware of any evidence to support Bearfoil's intuition.

Indeed - this was discussed in detail on the old thread here:

And some further detail on startup at pushback here:

Something I recall from the time I was reading these discussions was that during critical phases the FE would have been watching the engine instrumentation like a hawk, and given that the takeoff run was proceeding relatively normally prior to strip contact it would be far more likely that abnormalities in that instrumentation would have been the trigger for engine shutdown rather than a split-second increase in vibration. All evidence suggests that the crew thought they were dealing with an engine fire and had little time (or inclination) to determine its cause in the short time between strip contact and impact.

Dozy

That's a trap I fell into also - it wasn't a wheel with a missing spacer it was the bogie pivot, so all four wheels on that bogie were affected.

But let me draw your attention to the comment in the BEA report (18.2.3.3 again)

This is (presumably) the reason why the pre-burst trajectory was not affected.
Easy to see that if vertical loads on the bearing predominate the 'slack' will be taken up by the axle moving to the top of the female part not to the rear which would produce a yaw.

That was indeed so, but #4 was spooled up with the others at 60 kts and the left rudder input from the FDR trace was at 100 kts - no obvious reason for it either.

Hi Chris,

Nice to see you back again :)

I'll buy that! (at least as a contributory cause). I don't know of course, but I wouldn't bet against auto-brake being NBG along with a lot of other functions.

Cheers for that Clive - interesting stuff!

Us engineers are pre-disposed to be concerned with "why" in that situation, however is it not likely to be the case that a line pilot would simply correct as necessary and worry about the "why" once airborne? After all, the possibility exists that it may simply be an unexpected lateral gust...

Regarding Chris's very salient point, I have to ponder just how significant such vibration would be compared to that which might be expected from a damaged engine as suggested by the warning systems. To my mind this is reinforced considerably by the fact that a trained Concorde flight crew would be acutely aware of just how critical engine problems are during that phase of flight and prioritised that problem almost instantly.

There was damn all wind in any direction ....

But engine 2 had no real internal damage - in fact the BEA report says specifically that the internal state was not such as would cause surge. Equally there is no mention of any engine failures that might give rise to a genuine fire warning from flames inside the nacelle.