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Concorde question

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Concorde question

Old 7th Sep 2010, 14:34
  #261 (permalink)  
 
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Brit312 ---- that reminds me....

On the two prototypes, the AFCS controller was located on the centre pedestal, and had two big rotary multiposition switches to select the autopilot/flight director modes, plus the autopilot, flight director and autothrottle engage switches.

On the preproduction and production aircraft, the design was totally changed and became the big box with rows of pushbuttons and little handwheels, to set things like altitude and speed, that one now sees at the top centre of the instrument panel, just under the windscreen and above the engine instruments.

It was not until years and years later that I had an occasion to visit a VC-10 cockpit .... to discover how similar the VC-10 AFCS controller was to the prototype Concorde one.
No wonder... both were made by Elliott.

CJ
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Old 7th Sep 2010, 16:55
  #262 (permalink)  
 
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Brit312

...In fact quite a bit was transferred from previous aircraft designs to Concorde...

Indeed; I've heard it said that the Concorde nose & visor selector lever:
Concorde Nose & Visor Selector Lever | Airliners.net
came out of the spare parts box, it certainly looks similar to the Bristol Britannia flap selector lever (rear right hand corner of centre console):
Britannia Flap Selector Lever | Airliners.net

Best Regards

Bellerophon
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Old 7th Sep 2010, 17:54
  #263 (permalink)  
 
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Bellerophon

The Britannia and now you are talking about the love of my life and yes I do remember the story of the nose and visor selector, but we have forgotten the most abvious. Where do you think they got the idea for the conrol column from

Concorde
Photos: Aerospatiale-BAC Concorde 102 Aircraft Pictures | Airliners.net

Some other great aircraft

Photos: Bristol 175 Britannia 253F Aircraft Pictures | Airliners.net


Now must stop deviating from the topic
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Old 7th Sep 2010, 19:45
  #264 (permalink)  
 
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Harryman,

I stand corrected! Many thanks for the pressure vs temperature correction. I will digest your formula another day, but for now I will turn towards Hertfordshire and bow

(I'm from Watford originally anyway)
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Old 8th Sep 2010, 02:02
  #265 (permalink)  
 
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Originally Posted by Brit312
Now must stop deviating from the topic
No, no, no, no, no! It is this info that makes this thread so special. We can Google to find out many of the tech specs but it is the personal recollections, anecdotes like this that are not known and must never be forgotten.

If it relates to Condorde then it IS on topic. Keep the titbits coming......please.
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Old 8th Sep 2010, 02:27
  #266 (permalink)  
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As we've observed in the past, often the most attractive aspects of PPRuNe threads are the digressions.

Similarly to the thoughts of many others, I have been following this thread with great interest.

Please do keep up the good work.
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Old 8th Sep 2010, 04:50
  #267 (permalink)  
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Thanks again M2Dude, since we're into details, prior to the accident did BA and AF use different tyres ?


For some reason I thought that BA used Dunlop and AF Michelin.


I think they both changed to the new design Michelin after the accident, can you offer any more info on this tyre ?


I believe it's design was part of the changes for recertification ?


Any other info on the changes incorporated afther the accident would be welcome.
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Old 8th Sep 2010, 05:52
  #268 (permalink)  
 
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As per a previous post of mine, I've uploaded a takeoff and landing from JFK - LHR, including the very minor blip on roll from JFK and the 1990mph on the Marilake.


YouTube - uvs040403 002 3
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Old 8th Sep 2010, 07:13
  #269 (permalink)  
 
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Stilton -

Pre-accident I think we did use different tyres than AF. I also recall that BA elected to not use retreaded tyres while AF did, but am not 100% on that.

A pivotal part of the return to service was the Michelin 'NZG' tyre. (Near-Zero-Growth).

The tyres on Conc were incredibly hard-worked, partly because of the speed and partly because they took the full weight of the a/c throughout take-off (a conventional wing is producing a fair bit of lift prior to rotate - concorde produces none of note).

A LOT of energy is stored in a heavy tyre rotating this fast, so a burst can shed debris at great velocity.

The make-up of the NZG meant that it contained the expansion caused by rotation better (so less stored energy in the carcass), and had a far more robust and damage-tolerant structure. The videos of the destructive testing compared with the original tyres is frankly amazing.

The tyre was being developed by Michelin for the A380, I believe, and the principle was adopted for new Concorde tyres. In my opinion, this was the contribution which ensured we got back in the air.
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Old 8th Sep 2010, 08:20
  #270 (permalink)  
 
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Stilton
prior to the accident did BA and AF use different tyres ?
For some reason I thought that BA used Dunlop and AF Michelin.
Prior to the Gonez disaster BA used DUNLOP tyres for both the main and nose landing gear. As EXWOK quite rightly states BA did not use retreads (although I recall these were tried in the very first few years of service). After the disaster Dunlop were approached regarding the development of an improved tyre for Concorde, but declined, and so BA went along with the superb Michelin NZG design. BA subsequently also changed the nose gear tyre to Michelin. A final modification was the curious decision to remove the steel cord that the British alone had fitted to their main gear water deflectors. This cord was fitted as a modification in the the early 1990's, it's purpose being that if a tyre burst occured, the water deflecor was held together in one piece, and would not fragment, with the resulting structuaral damage. After this modification was embodied there were no further cases of ANY BA aircraft having skin puncture as the result of a tyre failure. (Having said all this, it would not have been of any benefit at all in Paris).
EXWOKS explanation of the mechanics of why the Concorde tyre had such an incredibly stressful and vulnerable life, as well as the design makeup of the NZG tyre is as usual 100% correct; a high speed, very high pressure tyre bearing virtually the entire weight of the aircraft right up to the point of rotation.
EXWOK
The tyre was being developed by Michelin for the A380, I believe, and the principle was adopted for new Concorde tyres.
It was as you say being developed for the A380. As well as all the well known benifits, this tyre lasted roughly twice as long as the original article, a further testament to this incredible design.
In my opinion, this was the contribution which ensured we got back in the air.
Oh yes, you are 100% on the ball here EXWOK. I remember hearing that the CAA was even considering 'de-mandating' the tank liner modification, as the new tyre alone was enough to prevent any chance at all of any potential fuel tank rupture. I don't want to spoil the nature of this wonderful thread by discussing the why's and wherefores of the Paris disaster (most of us 'here' have our own opinions about what really happened and why). What we do know that if there had been any case of a high speed falure of an NZG tyre, the airframe would have been safe from damage.

Dude
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Old 8th Sep 2010, 10:04
  #271 (permalink)  
 
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Ohhh.. and bits of Concorde on other aircraft etc:
The emergency generator (and generator control unit) were license built replicas of the units fitted to the F4K and F4M.
The air intake void (Pv) pressure sensor, built by Garrett Aireseach, was used in another 'case' as an inlet pressure sensor on the F14.
Carbon wheel brakes, pioneered on Concorde are now used by just about every modern commercial AND military aircraft. (Although originally trialled on a VC10 in a single brake installation).
(Already bleated on about Airbus pinching our audio warning tones etc).
The Triplex 10-20 glass, developed for and used on the visor panels were used in the automotive industry for many years to come.
I'm sure that there is stacks more.....

Dude
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Old 8th Sep 2010, 10:13
  #272 (permalink)  
 
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Paris Disaster

"most of us 'here' have our own opinions about what really happened and why"

I for one would like to hear these opinions, especially if they differ from the official report and/or the documentaries that have followed.
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Old 8th Sep 2010, 10:17
  #273 (permalink)  
 
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M2Dude

I think it's a space saving issue TURIN, I'm not even sure if 'our' telescopic strut arrangement was any lighter. (The Concorde solution was also somewhat more elegant don't you think)?
Elegant indeed.
We used to convince the weekend visitors to TBB that it was actually the retraction jack.
I feel so ashamed.
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Old 8th Sep 2010, 10:27
  #274 (permalink)  
 
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Originally Posted by bizdev View Post
"most of us 'here' have our own opinions about what really happened and why"
I for one would like to hear these opinions, especially if they differ from the official report and/or the documentaries that have followed.
bizdev,
So far this thread has been about facts, and stories and anecdotes about Concorde.
While the accident is certainly a subject worth discussing, I've seen enough forum threads on the subject to know they invariably end up with many opinions, but very few facts.
So may I respectfully suggest that, rather than diluting this thread, you open a new one ?

CJ
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Old 8th Sep 2010, 10:44
  #275 (permalink)  
 
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Agreed, let's not spoil this thread

Dude
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Old 8th Sep 2010, 10:50
  #276 (permalink)  
 
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Yep, agreed.
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Old 8th Sep 2010, 12:11
  #277 (permalink)  
 
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I agree with that. This thread is so good because everyone involved either designed,operated or flew her; together with onlookers such as myself who are grateful that you are all willing to share your unique experiences. If we get on to the crash we will have all the people with other agendas posting here.
Regards
Nick
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Old 8th Sep 2010, 12:13
  #278 (permalink)  
 
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This thread has had me re-watching every Concorde video of note on Youtube over the past few weeks.
What an exceptional, emotion inducing aircraft. Designed by exceptional people with drive, passion and vision, maintained by exceptional engineers and crewed by the very best of the best.

My question, if I may? I noticed a tail skid in many videos. Did Concorde ever have a need for it?

Bellerophon, Brit312, ChristiaanJ, EXWOK, , M2dude, et al, you are all legends in my mind.
Thank you all for your very real contribution to the history of Mankind.
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Old 8th Sep 2010, 13:04
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Originally Posted by AC Busted View Post
My question, if I may?
Of course! That's what this thread is about !
I noticed a tail skid in many videos. Did Concorde ever have a need for it?
Two answers.

Only the first three Concordes (001, 002 and 01) had a real tail skid (coated with hardwood, IIRC, to prvent sparks).
From aircraft 02 onwards, the skid was replaced by two small wheels, that look as if they've come off a Spitfire....

To understand why it's there, look at a drawing of a side view of Concorde.
If a Concorde overrotates at take-off, or lands with the nose too high, the first things that would have touched the ground are the exhaust nozzles / thrust reverser buckets. The tail skid/wheels are there to prevent that.

As to the need for it...
"Tailstrikes" were rare, but they did happen.
Now I don't remember offhand whether it was already mentioned here or somewhere else, but more often than not those tail wheels were not much good, and got shoved back into the tail, with the reverser buckets still hitting the ground : there are photos of repairs to the buckets to prove it !

CJ
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Old 8th Sep 2010, 14:22
  #280 (permalink)  
 
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..........which was one reason it was so important to touch down with the wings level - even a very small angle of bank could result in bucket contact as they translated to the reverse position. It was a surprise coming to Concorde to find it was even more restrictive than the 747 in this respect.
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