I have offered possible approaches to glean some understanding of the affect of tyre rupture, and my suggestions have been ignored.
Not ignored – maybe not agreed with or understood, but not ignored as evidenced by the number of responses you get
Likewise, an attempt to quantify would be based on data supplied from BEA, data I believe is lacking in sufficiency.
There is quite a lot of data in the BEA report that could be used in a quantitative way if one was so inclined.
It is BEA who proffered the photography, and begged the work, then did not perform it. Neglectful.
Or did not report it, which is not quite the same thing.
It was BEA who did not provide the chemical analysis of the rubber that may have proven the Titanium had been present in the tyre's carcass. In neglecting even the attempt to prove conclusively the strip was involved, they demean the discipline itself. Lazy.
But the BEA report stated
black marks were noted on the outer side of the strip and black elastomer debris was found jammed in one of the rivets. The spectra of these marks and deposits are similar to the Concorde tyre.
I don’t know what sort of chemical analysis you had in mind, but for me a spectral analysis of the material counts as a valid chemical analysis.
It was BEA that neglected elimination of material other than Titanium as the cause of tyre rupture, Cowcatcher/mount?
Are you now suggesting that the water deflectors somehow failed and got caught under the tyre? If so, how do you explain the curved failure on the tyre and the fact that the water deflectors were made of frangible material?
Was the area of the truck's mount inspected/analysed by BEA for abnormal wear? The landing gear had travelled several miles carrying two hundred tons, was the spacer's saddle worn?
Again I say yes, witnessed by their remarks...
The condition of the various pieces (shear rings, bronze bearings, seals) show that the inner shear ring had moved from its position incrementally during the last few flights. The marks indicate that the mechanism was operational although the shear ring was no longer in its position on the bronze bearings of the shock absorber and bogie.
The exact chronology of this displacement is, however, difficult to determine since the ring was not new and certainly bore marks related to its previous usage. The only marks observed on the mechanical parts correspond to movements in the vertical plane alone or to normal oscillations of the bogie.
Has anyone found an opinion on why the Captain's rudders were not planted full right? And held?
Yep! Just take a look at the figure presented in section 1.16.13.2.
By the time he got to the point you are discussing he was 2 deg off runway heading but heading back to the runway centreline (heading 270 against the runway’s 268). In addition the lateral acceleration at the cockpit had dropped to essentially zero. The aircraft was way above Vmcg even at the point of engine thrust loss, so why would he think he needed more drag producing rudder?
The report can be described in many terms. Exhaustive is not one such term.
Not many would agree with you there.
There is no reason to assume the shimmy was established in consistent fashion at any time, except for the three arcs of tread deposit we see. It could have been extremely irregular.
OK, so we can eliminate shimmy as a factor anywhere except where you found it after the aircraft left the tarmac?
An admission. I have not found the reference to shimmy in the Report. Therefore I do not know BEA's conclusions. I'm extrapolating on evidence I see, and read elsewhere and in the BEA work.
But the BEA report did contain a reference to shimmy
The Concorde landing gear manufacturer indicated that no cases of landing gear bogie shimmy had been reported. Examination of the parts revealed no such phenomenon.
Furthermore, the tyre marks left by tyre No 2 showed no signs of vibration or instability.
Therefore, the side load is left, and LEFT.....no balancing side load right. This demonstrates that at least in the area of the photographic evidence, the net load is constantly left. This means a bogie that is tracking well left of the longitudinal axis of the airframe.
Actually no, it doesn’t show any such thing, because the aircraft longitudinal axis was itself inclined to the aircraft path (sideslip).
Let me try another scenario on you.
The inclination of the bogie beam to the ‘normal’ setting would have been dependent on the balance of vertical and horizontal forces as BEA stated. Statically that would put the contact point at “12 o’clock” in the bearing housing., but again as the BEA state, the gear would be inclined to the vertical (camber). When rolling with intact tyres there would be no sideforce and the horizontal forces would be limited to the rolling friction – about 2~3% of the vertical forces. Not enough, I suggest, to move the contact point very far from 12.00.
It all changes after the tyre burst and loss of thrust. Now the horizontal force on each tyre is predominantly sideforce which would be proportional to ground reaction and tyre slip. When the aircraft started to diverge left under the action of asymmetric thrust the tyres became subject to right sideslip. When gear and tyres are intact this slip would produce forces pushing the aircraft left towards the runway edge and, because they act behind the CG, they would also make a small contribution to the yawing moment trying to return the aircraft to its original heading.
However, with the combination of a burst tyre and a sloppy bearing, the asymmetric side loads (two wheels aft, only one forward) would drive the bogie out of alignment in a sense to reduce the effective slip on the tyres to zero. In other words, if sideslip were numerically below the play in the bogie bearing the tyres would not be producing any side load at all!
So far as I can see, the aircraft was above this 2.75 deg limit for only a very short period between 97608 and 97613, which of course spans the time period at which you noticed shimmy, hence you can detect side load at that time.
This loss of sideforce would have reduced the lateral acceleration to the left (and runway edge) but would also have reduced the restoring yawing moment. But as argued above, the pilot had, and used enough rudder authority to bring the aircraft back towards the runway centreline.
Now factor in that the wing was carrying an increasing amount of lift in this period.
All of which of course begs the question as to whether this lateral displacement had any real consequences on the final outcome. My answer to that would be no, it didn’t, because when push comes to shove it was the failure to achieve a safe flying speed that mattered, and that was due to loss of engine thrust in a critical flight phase.