Posts about: "Toulouse" [Posts: 25 Pages: 2]

From the thousands of hours of windtunnel tests, test flying with aircraft like the Mirage IV, HP 115, BAC221, etc. etc. they already had a pretty close idea of how the aircraft was going to fly.
IIRC, Andr\xe9 Turcat remarked after the first flight of 001 it flew pretty well like the simulator, or if anything somewhat better!

There were two development simulators, one at Toulouse and one at Filton, that were used by the test pilots and by the engineers. These were "tweaked" whenever more data became availble before the first flights, and then updated with flight test data.
For airline crew training , two new simulators were built in the early seventies, again one in Toulouse (later moved to CDG) and one in Filton.
In the best Concorde style, they were designed and built by two different firms....

I don't believe anything of the development simulators has survived.
As you will know, the "cab" of the British Airways Filton simulator was salvaged and taken to Brooklands, where it's now slowly being brought back to life.
The Air France simulator at CDG, minus motion system and video display, was taken back to Toulouse, where it's slowly being restored, to go on display in the planned Museum at Toulouse.

CJ

db737,

I remember Jerry White, who did his Concorde training in Toulouse. He was a great bloke and and a good pilot. If you see him again send him by best wishes from the Brit F/E in Toulouse

What a fascinating read, thanks to all guys contributing to it.

The fact that the Conc still fascinates so many people after so many years is the best prove of its uniqueness. Never flown on one, but having brought clients to it I remember a time where we parked right under the nose of an AF example at CDG with our tiny Cheyenne. The Pax was lead from our airplane up the stairs and off they went. (1989ish, I was a wet as a fish F/O then) Queing in Heathrow a few years later I couldn't hear my KingAirs engines for quite a while when the guys opened up and fired the cans. Fond memories and still the most graceful airplane I saw in my life.
I still use the opportunity to see the 2 examples at the museum at Le Bourget when there. Having seen a documentary on the first flights in Toulouse and Filton I had a trip to Filton a few days later and sitting in the air field ops Landrover was sort of a time travel.

We had the pleasure to have ex FE\xb4s and an ex Capt. as trainers at FlightSafety in Farnborough. Very nice blokes and I should add, very capable and knowledgable guys. One can see why they were on the sharp end.

Sorry that I cant ask a good question right now, just had to get my thanks off my chest!

My long (eternal?) love affair with Concorde probably started, like with so many other people (at least those ancient enough to remember) on March 2nd 1969. I was at home at my mum's house on leave from the RAF, (I really was a funny hairy little 'erk') when the live TV coverage, in glorious black and white, showed the first prototype 001 taking to the air in Toulouse. Raymond Baxter's classic commentary understatement of 'she flies, Concorde flies', combined with the sight of this sleek white aircraft, trailing a cloud of thick black exhaust smoke, taking to the air for the first time. (The prototype aircraft in my view looked a little ungainly compared to the pre-production and production babies, and the -22R engines fitted to the original aircraft was a real coal burner). And as far as TV went, it was quite a year; While on night shift at RAF Lyneham I got to watch the live feed of the first Apollo moon landing too.
The next stage in my love affair was in 1970, when this same hairy little 'erk' heard this roar in the sky over Swindon while shopping and saw the British prototype 002 with its accompanying Canberra chase plane flying very low, straight over the top of Debenhams; my jaw dropped as I stared at this amazing (but rather loud) spectacle unfolding right in front of my eyes.
The die was cast I guess for me in 1972. I was on the ramp at RAF Lyneham, chatting to a visiting USAF C-141 crew. "do ya ever get 'the Concorde' flyin' anywhere near hear ?" asked one of the pilots. I was about to tell him that sometimes on occasion we get a brief glimpse, when the pre-production aircraft 101 flew straight over the top of us. Now these USAF guys just stood there in awe, their eyes popping out like organ stops, and I just figured that this amazingly on cue spectacle just had to be a sign. When I left the RAF two years later I joined BAC at Filton and Fairford engaged on the production and flight testing side of Concorde, leaving there for BA at the end of July 1977. (The story goes that I was delivered to BA a week after G-BOAE as part of a surplus, auxiliary spares package ).
So that's my personal Concorde love affair, it started in 1969 and continues to this day, forty one years later. GOD I AM OLD!!

Dude

My "Concorde Story" really started around April 1968.

I'd only just finished my aeronautical enginering studies and had already been sending CVs all over the place... when I received a letter from the French firm (SFENA) that was building the French half of the Concorde automatic flight control system, to meet them for an interview : they needed a "flight test support engineer" to take care of their equipment in the UK (Fairford and Filton).

"No experience needed".... since everything in Concorde was new anyway....
My engineering degree, which included a fair amount of electronics, was considered enough... I could learn the rest "on the job".
What clinched the deal at the time was that I was aleady pretty well bilingual Dutch/English, and spoke enough French to get by, whereas in those days most of the French engineers in the firm had very little if any English.

So Dec. 1st, 1968, I moved to Paris, after delivering wife and new-born daughter to mother-in-law in London.
Some nine months of intensive study followed, before my move to Fairford and my first encounter with Concorde 002.

During my "indoctrination", the firm thought it would be a good idea to at least have a personal look at what I was going to work on, and also meet my 'counterparts' at Toulouse I was to be in continuous contact with.
So, sometime end January 1969, only a few weeks before the first flight of 001, I first set eyes on a real Concorde, still buzzing with final preparations.
With all our stuff being in the "pointy end", that's where we went, of course, and I spent half an hour or so in the left hand seat getting familiar with the cockpit lay-out and "our" systems..... the same seat where Andr\xe9 Turcat would be sitting a few weeks later during the first flight.

After that came five years of Concorde at Fairford and Filton, until the development flight test support largely came to an end, and was taken over by our 'product support' department, and I returned to France.

In my case, I wouldn't yet have called it a "love affair" in those days, more an intensively satisfying job.
It was really not until afterwards, that I started to regard those "Concorde days" as the best time of my professional career, and that I started to realise she'd gotten "under my skin".

And I can call myself lucky.... I've "met" 002 again 35 years after last seeing her in the Fairford hangar.
And I've also sat again in that self-same left-hand seat on 001, more than 40 years after that first time.
And I've had the chance of flying once on Concorde, even if in the end she retired just before I did.

landlady is right. We were there, at the right time, and the right place.
I think that says it all.

CJ

nomorecatering asked: M2dude answered:
The BA simulator, now at Brooklands, is a long story.
For various reasons, only the simulator 'cab' could be salvaged. It was taken to Brooklands to be used as a static exhibit of what the Concorde cockpit looked like.
It was only well after its arrival at Brooklands that people started to think about bringing it back to life.... a huge piece of work, since about all that was left was the 'cab' itself, with the instruments and controls... the computers and interface circuits, needed to make them work, were all gone.
A team of volunteers, a simulator firm and university students have now brought it back to a state where it can be 'flown'. Even if not everything works yet, ex-Concorde pilots who've 'flown' it were already full of praise.
As to the visuals, the original visual system was taken back by BA, since it was recent and the same as used on other BA simulators.
It's been replaced by a specialised video projector and a wide screen, which appears quite satisfactory, although I 've heard rumours about plans to replace it with a three-projector system.

The story of the Air France simulator, that was located at CDG, is very different.
After the end-of-service it was moved almost in its entirety to Toulouse (Airbus), minus only the visual display system and the motion platform.
A small team of volunteers (mostly Airbus engineers) are slowly bringing that one 'back to life' as well, but (contrary to Brooklands) using most of the original electronics.
The intention is to have it ready for display (and use) at the Toulouse 'A\xe9roscopia' museum, which hopefully will open within a few years.
Unfortunately, until then the sim is not accessible to the public, since it's inside one of the Airbus site buildings.
And no, of course that one isn't certified either....

One small bit of trivia... the BA and AF simulators were NOT built by the same firm. The BA one was built by, IIRC, Singer-Redifon, and the French one by LMT.
Today that's a pity, really, because the Brooklands and Toulouse teams have very little technical information they can exchange.

Oh and, yes, I've visited and sat in both of them, but so far I haven't flown either of them yet.

CJ

OK, I see others have already posted answers.
I've carefully avoided looking at them, but I'll might as well plug in mine now.

My personal problem is that I was involved in the very earliest days, before the aircraft went into service, and then in the last days and afterwards...
So the questions dealing with the in-service period are totally outside my field of experience... all I can do is guess, in case I saw the answers somewhere.

1) How many Concorde airframes were built?
Twenty-two.
Two static-test airframes.
- One at Toulouse, for purely static tests, and tests such as vibration and flutter.
- One at Farnborough, for the long-duration thermal fatigue tests.
(A few bits and pieces of the Farnborough test specimen have survived, and can still be seen at the Brooklands museum).
Two prototypes (001 and 002)
Two pre-production aircraft (01 and 02)
Two production aircraft used for certification, that never entered service (201 - F-WTSB and 202 - G-BBDG)
Fourteen production aircraft, seven that served with British Airways, seven that served with Air France.

2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.
Not a clue as to the full list.
- Bahrain, obviously.
- JFK.
- IAD (not sure if that's rated as regular, or only incidental)
- Dallas (with Braniff)
- Barbados (of course, right until the end)
- Sngapore (with Singapore Airlines, and G-BOAD in Singapore Airlines colours on one side)
- Sydney (again no idea if that rated as a regular flight or only a few tries)

3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).
Not a clue either. Vague memory of about 10:00 am which gave you a full working day in New York.

4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?)..
Never flew on them, never had to deal with them.
BA174 comes to mind from the depths of my memory, in that case BA003 would have been BA176?

5) There were no less than FORTY SIX fuel pumps on Concorde. What was the breakdown for these? (Clue; don't forget the scavenge pump )
M2dude, I did AFCS, not the fuel system. I believe you, but without pulling out some diagrams I honestly have NO idea.
I expect each tank had at least two pumps, which gets me up to 26.
Then there were a few emergency pumps for the trim tanks, and I suppose each engine had additional pumps associated with it.
Still nowhere near the 46 I need to find.....

6) What airframe had the only TOTALLY unique shape?
That would have been my old friend, 01 (G-AXDN), first pre-production aircraft, now at Duxford.
It was the first Concorde with the new transparent visor, but it still had the short tail that characterised the prototypes.
It was 02 (F-WTSA), the first French pre-production aircraft, that was close to the final shape of the production aircraft.

7) This one is particularly aimed at ChristiaanJ. What was the total number of gyros on the aircraft?
Good question.... never counted them all. But I'll try a guess.
First a nice one, the SFENA Emergency Standby Artificial Horizon (made by the firm I worked for).
Ran off the Emergency Battery Bus via a small independent inverter.
And if that failed too, it would still run reliably for several minutes on its own inertia.
Next, the rate gyros used by the autostabilisation system ; these measured the angular rate of the aircraft along the three main axes, pitch, roll and yaw.
There were six, three each for the two autostab systems.
Now the rest....
Each IMU (inertial measurement unit, part of the inertial naviagation system) had three gyros.
With three INS on board, that would make nine.
Much as I try, I can't remember other ones, so I'll look forward to the final answer.
I can imagine the weather radar using an additional gyro for stabilisation, but I never went there.

8) How many wheel brakes?
Unless this is a trick question, I would say eight, for each of the main gear wheels.
The nose gear did not have any brakes - unless there were some small ones to stop the wheels rotating after retraction of the gear, but not used during landing.

9) What Mach number was automatic engine variable intake control enabled?
No idea.
Mach 1.0 or thereabouts is my personal guess only.

10) Above each bank of engine instruments were three lights, a blue, a green and an amber. What did they each signify?
I know that they each monitored the status of one of the engines, because it was too complex for the pilots to fully monitor all the parameters of all four engines in the short time between start-of-roll and V1... they had too many other things to do.
But I don't remember what each light meant, would have to look it up in the manual.

11) At what airfied were the first BA crew base training details held?
No idea.
Was it Brize Norton, or Casablanca?

12) What LHR runways did Concorde use for landing and take-off? (Trick question, not as obvious as it might seem).
No idea.
Vague memory of it being systematically the North runway for noise issues.

13) What operator had serious plans to operate Concorde from SNN to JFK in the early 1980's?
No idea.

14) What development aircraft did not exceed Mach 2 until fifteen months after her maiden flight?
I would expect the obvious answer to be 002.
Working up from first flight to Mach 2 was a slow and laborious process, and in the end it was 001 that both flew first, and also went to Mach 2 first.
I don't think any of the other aircraft took that long.

A I said, I tried to answer all questions "off the top of my head", without looking at any other sources.

CJ

That one is sadly rotting away in the Ailes Anciennes aircraft museum storage area exposed to the Toulouse weather...


Left Upper Wing Skin


Right hand passenger window, rear fuselage


Seat tracks, forward cabin looking aft

At least it was in 2008, maybe it has been scrapped in favor of the A350 production line by now.

OK guys, here are the answers. If you disagree about any of them then fire away, the old memory certainly 'aint perfect.
As many of you have guessed, there were 22: The 14 production airframes, the 2 production series development aircraft (201 & 202), the 2 pre-production airframes (101 & 102) and the 2 prototypes 001 & 002. PLUS, the major fatigue test specimen at the RAE Farnborough and the static test specimen at CEAT in Toulouse. The CEAT tests actually tested the wing to destruction; I seem to remember it was something like a 200% overload before the wing failed at the root. And great but rather sad pictures VOLUME , never seen these before.
OK, from MY memory , we have: London LHR (duhhh!!), Bahrein BAH, Singapore SIN, New York JFK, Washington IAD, Dallas DFW, Miami MIA, Toronto YYZ, Barbados BGI, and Riyadh RUH. As well as charters being ommited, so are some of the special 'surprise' shuttle appearances that Concorde would make, substituting a subsonic to and from destinations such as Manchester and Edinburgh.
11:15
The BA193 and BA 195.
OK, there were 12 engine feed pumps (3 per engine) 8 main transfer tank pumps (2 each for the transfer tanks 5, 6, 7 & 8), 4 'A' tank pumps (2 each for 5A & 7A), 8 trim-transfer tank pumps (2 electric pumps each for tanks 9, 10 & 11 PLUS 2 hydraulically driven pumps for tank 9), 4 electric engine start pumps (there was a single electric start pump per engine that delivered fuel to it's own dedicated start atomiser in the combustion chamber. The pump automatically ran when the engine HP valve was set to OPEN and would continue running for 30 seconds after the DEBOW switch was returned to the 'normal' position), 4 engine first stage pumps (a single mechanically driven pump per engine), 4 second stage pumps (a single pneumatically driven pump, sometimes termed 'the turbopump, per engine. This would cut out at around 20,000'), our scavenge tank pump (triggered automatically when there was 7 US gallons in the tank; pumping it back into tank 2. This pump was identical to an 'A' tank transfer pump), and FINALLY, a single de-air pump for tank 10. The pump would drive the fuel through a mesh, removing air bubbles from the fuel. Tank 11 used the L/H trim pump for de-air (similar principle)and would be switched on during take-off. This is why the tank 5 trim inlet valve being set to over-ride OPEN would result in the tank being highly pressurised in the case of the Gonesse disaster; the pump would obviously pressurise the L/H trim gallery and any tank on that side with an open inlet valve!!!
G-AXDN, aircraft 101. (A production wing, fuselage, droop nose and intakes, but with the short tail section and secondary nozzles of the prototypes.
Ready ChristiaanJ? There were 18....Yes, the single SFENA standby horizon, 9 INS gyros (one per X,Y and Z platform in each of the 3 INUs), 8 autostab' rate gyros (one per axis for each of the 2 autostab' computers PLUS a monitor gyro for the pitch axis). The radar by the way used attitude signals from the INS.
9. One per main wheel plus the single 'in flight braking' nose wheel brake.
Mach 0.7!!! Between this and Mach 1.26 the intake surfaces were positioned as a function of engine N1 if the engine was shut down for any reason. (Otherwise of course the intake surfaces were fully up). You needed a sub idle N1 of 57% and below for all this to happen, and it was to assist relight performance and reduce buffet. Between Mach 1.26 and 1.32 the ramps were driven down slightly to about 5%, full supersonic scheduling itself commencing at Mach 1.32.
Already brilliantly answered by Brit312 (as well as the FSLabs diagram). Yep, Geen GO, T/O monitor armed, fuel flow and P7 at or above datum, A/C on ground, reverse not selected and CON light not on. Amber CON (Reheat selected and not detected, N1 OK or reverse selected and primary nozzle (Aj) not at minimum. Blue REV; steady buckets at reverse, flashing buckets in transit.
Fairford, followed by Brize Norton, and then a host of airfields from Prestwick and Shannon to Chateauroux.
OK, probably no surprises now:
Landing - 27L & R, 9L & R (prior to LHR mag' deviation update were 28L & R & 10L & R) together with 23/05.
Take off - 27L (28L), 9R (10R) and 9L. (10L never happened as take offs on this runway only occurred in 2003).
It was FedEx, they planned to operate two stripped out aircraft, leased from BA, between Shannon and JFK as high value parcel carriers. The idea was that parcels would be flown in from all over Europe by small FedEx feeder aircraft and the parcels transferred to Concorde which would then speed on to JFK in around 2 1/2 hours. It never happened because of a combination of economics appraisal by FedEx and BA deciding that it could would not release the aircraft anyway.
A/C 101, G-AXDN first flew on 17th December 1971 with FIXED INTAKES!! (101 was going to be the launch vehicle for the new digital intake control system, but the 'boxes' were still being designed). This placed an operating limit of Mach 1.5 on the aircraft, limiting her ability with such a restricted flight envelope. She returned to Filton in late 1972 for installation of the system, as well as the new Olympus 593-602 engine. (The engine, very similar to the production Mk 610 version, used a quite revolutionary annular combustion chamber, and eliminated at a stroke the thick smoke exhaust that had up to then been Concorde's unwanted visual signiture). The aircraft flew more or less smokeless on 15 March 1973, achieving Mach 2 soon afterwards. As ChristiaanJ pointed out, the British prototype 002 had a similar gap, actually significantly higher, of 19 months. (The French aircraft 001 had an even longer gap of some 20 months).

I hope you guys had fun with this one, regards to all

Dude

I'd never seen those either.... I was convinced the static test speciment had been scrapped a very long time ago.
The entire collection of "Ailes Anciennes Toulouse" has been moved to a different location only very recently... one can merely hope that at least some of the bits and pieces of "0001" have survived...
Maybe VOLUME can tell us more?

CJ

Sorry, no. Haven\xb4t been there for more than a year and at that time it was just clear that they have to move due to the A350 FAL, but the details were not decided.
Found one more picture...

Sad to see this masterpiece of engineering rotting away.
I always thought that the sloped area at the aft end of the floor was the rear airstair (just present on the pre-production aircraft), but I just read on heritageconcorde.com/ that this is for "system routing". Does somebody know more ? Seems to be a lot of space for systems that would end just in the middle of the cabin.

I would say that the SR-71, and the Tu-144, are in a way honorary members of the Concorde family, so I don't mind if they fly into the discussion every now and then.

The full list of names (up to 2002) for both BA and AF can be found in "The Concorde Story" by Chris Orlebar. For BA, a quick count shows about 170 names. That book also mentions, that the maximum number of crews qualified at any one time was 28, in 1980, and that the average was about 20 crews.

Photos can lie.... or rather, they are rarely close-up enough to show clearly where corrosion has set in.

As an example, F-BVFC at Toulouse, which was the last one to remain at least taxyable, now has some patches of corrosion starting to show, when you know where to look. Not to mention the nasty smell of damp and mould in the cockpit which bodes no good for what's going on underneath the floor.

And even F-BTSD, kept "live" to some extent at Le Bourget, leaks some hydraulic fluid (like all Concordes did on the ground), so it's easy to imagine the dried-out hydraulic and fuel seals on the other museum aircraft.




And yes, that's kitty litter...
The composite material of the floor and the hydraulic fluid don't agree too well.

I'll leave M2dude to answer that one.

CJ

ChristiaanJ
With respect my friend that is utter codswallop. You can doubt things all you want, they've already said that they would remove it all; that by definition means all the cabin side-walls, galleys and roof panels, as well as the underfloor areas. When G-BBDG (202) was cocooned at Filton they did just that, and the only intact part of the interior left was the flight deck!!

Quote:

At present, the 'permanent home' is planned to be at Cribb's Causeway, where land is already available. Since this is only just on the other side of Filton airfield, so far there is no question of breaking up the airframe, or road transport.

Unfortunately, this lot have a habit of talking with forked tongue as far as Concorde goes; you can not in any way be sure about this, and we should really stop believing everything that this lot in Toulouse tell us . (Recent history here has taught us this all too well, and nothing would please scarebus more than there to be no reminders of Concorde at all on the airfield at Filton). More to the point, there is absolutely no certainty that the Cribb's Causeway site will ever be built anyway, you just can NOT say that the airframe will not ne broken up for road transportation, because if she does go to another museum in the absence of the Cribb's Causeway site being built, that will DEFINATELY happen. But at least we now have another 'written off' British Concorde; I guess this fact obviously pleases some people

Quote:

I doubt this.... The "pressures" from these bodies and people consist only of noises on internet forums and in the press. As long as BA (as the owner), Airbus (as the current 'guardian' and legacy manufacturer) and the CAA (as the regulatory body) say "NO", Airbus knows perfectly well it'll never happen, pressures or no pressures. My own take is simply, that they're fed up with a Concorde on their site, that their early 'enthusiasts' who campaigned for 'A Concorde at Filton' have now left, and that it's now Airbus exerting pressure on the Concorde Trust and other bodies to provide that 'permanent home' they've been talking about for years.

Total crap I'm afraid Christian. You can doubt it all you want; you're entitled to your opinions as we all are here. But the fact remains that there is a certain producer of airframes in Europe that has come out with nothing but lies and deceit with regard to Concorde, since early 2003, and it continues to do so to this day. (Guesses anyone?) You conveniently seem to forget that it was scarebus themselves who unilaterally closed the Concorde Filton exhibit...'for maintenace' .. YET ANOTHER TOTAL PACK OF LIES!!
And as far as responding to pressures; They could not give a flying about Concorde pressures, they JUST DO NOT WANT TO KNOW!! And yes they are fed up with Concorde.. poor dears. Perhaps OAF should never have gone to Filton in the first place; The continuing thought of Filton bending over backwards to please it's French masters makes one want to throw up. The basic fact remains that any British Concorde anywhere NEAR an Airbus plant is nothing more than an embarassment to them, and is fundimantally always in jeapordy.

Quote:

In 2003, the issue with G-BOAF was that she was almost 'out of hours', with only a few hours left until the next big overhaul (an 'Inter', IIRC). At the time, this was the reason why G-BOAF did not partake to the full extent in the flying during the last months, so as to have a few hours 'spare' for the last few flights, and of course the final flight.

Big deal, she needed a C Check. Unlike in France, a Concorde major (D check) here did not take over a year to complete, and an inter could be in and out of the shed in a couple of months. Oh, and the check was completed correctly and thoroughly.

Quote:

And that's another reason why Airbus wouldn't be bothered by those "pressures" mentioned earlier... they know perfectly well nobody is going to come up with the \xa3100M +++ to re-create the necessary infrastructure.

I tend to agree with the RTF point, the \xa3\xa3\xa3\xa3\xa3's involved are generally prohibitive and it will probably never happen, but you and I have been in aviation long enough to realise that nothing is impossible. (At least not this side of the Channel). All aircraft left outside in the elements are obviously going to suffer, and it is irony of ironies that the FRENCH aircraft are generally stored indoors in the dry and warm, where the British were ALL intitially stored outside, exposed to the elements. (Only OAC in Manchester and OAE in BGI are now finally cared for under cover, the poor old 'wing clipped' OAA in Edinburgh does not really count). This ridiculous fact is is a source of both wonder and ANGER in the minds of most Concorde people in the UK. (Makes me sick personally!!).

Dude

quote:I remember at Fairford in mid 1974, a CAA test pilot (I honestly forget the gentleman's name) was taking the British pre-production A/C 101 (G-AXDN) for a special test flight.unquote

It was almost certainly Gordon Corps, possibly the finest 'engineering' test pilot I have ever worked with. After Concorde certification Gordon went to work at Toulouse wher he did most of the development flying that led to the A320 FBW system. BZ was the public 'face' of the design, but knowing the two men I have a very shrewd idea as to who did the original thinking! Perhaps Andy could confirm?

Tragically Gordon died young whilst trekking to an A300 crash site somewhere in the Himalayas

ClivL

quote:Rolls Royce did some analysis on the flight, and were amazed at how well the propulsion systems coped with some of the temperature sheers that we encountered, sometimes 4 to 5 deg's/second. They said that the prototype AFCS had been defeated by rises of only 0.25 deg's/second ).unquote

Just for the record, the intake control system was designed to cope with a temperature shear of 21 deg C in one mile (about 3 seconds)

quote:Not meaning to go off onto a (yet another) tangent; Negative temperature shears, very common at lower lattidudes, always plagued the development aircraft; you would suddenly accelerate, and in the case of a severe shear, would accelerate and accelerate!! (Your Mach number, quite naturaly, suddenly increased with the falling temperature of course, but because of the powerplant suddenly hitting an area of hyper-efficiencey, the A/C would physically accelerate rapidly, way beyond Mmo). Many modifications were tried to mitigate the effects of severe shears, in the end a clever change to the intake control unit software fixed it. (Thanks to this change the production series A/C would not be capable of level flight Mach numbers of any more than Mach 2.13, remembering that Mmo was set at 2.04).unquote

Not temperature shears, and not AICU modifications (which I see has been discussed in a later posting). But back to the 'shears':

Most of Concorde's flight testing was, naturally, done out of Toulouse and Fairford, i.e. into moderate latitude atmospheres where the tropopause is normally around 36,000 ft so that the supersonic flight testing was done in atmosphers where the temperature doesn't vary with altitude. The autopilot working in Mach hold would see an increase in Mach and apply up elevator to reduce IAS and recover the macg setting. But at the lower latitudes around the equator the atmosphere is different in its large scale characteristics. In particular the tropopause is much, much higher and can get as high as 55,000 ft. Nobody had been up there to see what it was like! Now when the A/P applied up elevator to reduce IAS it went into a region of colder air. But the speed of sound is proportional to air temperature, so as the aircraft ascended the IAS dropped alright but since the ballistic (true) velocity of the aircraft takes a while to change and since the speed of sound had dropped the Mach number was increased, so the A/P seeing this applied more up elevator and the aircraft went up and the speed of sound dropped and ........

Like solving crossword clues, the answer is obvious once you have spent some time finding it!

This phenomenon rather than temperature shears (encountered mainly over the tops of Cb clouds) was the reason for the autopilot modifications which included that clever use of autothrottle (I can use that adjective since it was my French colleagues that devised it)

And before anyone asks; yes, the same problem would relate to subsonic aircraft operating in Mach hold driven by the elevators and flying below the tropopause, but:
a) Subsonic aircraft are old ladies by comparison with Concorde in that they fly at only half the speed. At Concorde velocities even modest changes in pitch attitude can generate some pretty impressive rates of climb or dive!
b) Subsonic aircraft are normally constrained by ATC to fly at fixed flight levels - the use of elevator to control Mach number is not really an option - you have to use an autothrottle.

There was that other problem, also described in later postings, where the aircraft regularly 'rang the bell' when passing through the Vmo/Mmo corner in the lower latitudes, but this was simply due to the additional performance one got in these ISA minus conditions in comparison to the temperatures encountered around the same corner in higher temperatures.

Anyway, the flight test campaign got me my first sight of sunrise over the Arabian desert and my first trip to Asia, so it goes into my Concorde memory bank.

I've pulled this quotation out at random from what I have found a rather disappointing sequence of postings. I could write reams about this (and like everyone in this thread I would write as a Concordophile), but I won't - or at least I will try not to. In general I'm with Christian on this, and for the record I think a few 'counterfactuals' should be recorded. I am not trying to reopen a sterile debate - as CJ has said irrevocable decisions have been made and the subject is done and dusted. However, let us remember that:

G-BOAF was, and is the property of BA; BAe and now AI are merely caretakers.
AI's statement cross-posted from the Heritage website strikes me as a very reasonable statement; we found that your roof is leaking, if you don't get it fixed it is going to get worse rather rapidly; if you (BA) agree and will pay us to do it we will take it indoors and fix it. I don't see any sinister intent here, and given the weather we have had in the UK over the past weeks it must be regarded as a happy, if fortuitous decision!
Those who know Filton will also know that there is nowhere that Alpha Fox could be stored under cover except in the hangar where she was first assembled. They will also know that this hangar is buried in the centre of the factory and nobody, in a post 9/11 world, is going to give more or less unrestricted public access to somewhere containing a lot of valuable real estate! So when BA took the decision to locate AF at Filton it must have been in the knowledge that she would live in British weather until some form of shelter could be organised.
That it has taken so long to (fail to) organise such shelter is regrettable, but the blame can hardly be uniquely allocated to AI. BA own the aircraft, BAe/AI had a 40% share in building the airframe, RR a 60% share in building the powerplant. IMHO they should all have chipped in to construct some sort of shelter - it was never on the cards that local enthusiasts could have raised enough in a short time.
Although 'Dude' says that all the UK airframes were left out in the weather, this is not exactly true is it? 002 at Yeovilton (certainly) and 101 at Duxford (I think) are under cover and receive lots of TLC. It is at least arguable that these early airframes have more historical significance than Alpha Fox.

So far as AI's decision to hand back the C of A is concerned, they would have already recognised from the post-Gonesse activity that most people with sufficient expertise on the Concorde design were retired (or worse!) They have enough people to keep a subsonic aircraft going, but Concorde would, I think, require additional experience. AI management would certainly have consulted AI Engineering about this, and I have to say that the then Head of Engineering was someone I know well. He, like me, worked on Concorde in the early days and he is definitely not antiConcorde. I for one would respect his decision.

So far as the decision to stop services goes, we all knew they would be cut off sometime.the only question was when. When we were designing the aircraft the general feeling was that she would stay in service for about 30 years, but we also feared that it would only need one fatal accident to bring the whole lot crashing down. [Incidentally, it was that latter philosophy that made us (we hoped) ultracareful with airworthiness issues] In the event it was 28 years and one accident.
Even before Gonesse AF were losing money on their Concorde services. One might have thought that they would stop right away, but I suspect that a combination of Gallc pride and politics ensured that they would carry on.
But eventually there came a point where, on an airline losing money and in a recession, an unsentimantal and yes, generally unsympathetic, management would have to say enough is enough.
What else would you have them do? Continue to fly loss making services so that their rival BA could go on with their profitable? operations? One would have to say 'Get real!'
Once AF had decided to stop, what do you expect of AI? They are a company with a duty to make profit for their shareholders. OK, they had a duty, also to support in service aircraft, but that duty does not extend to doing that at a loss. With AF out of it therefore AI had no alternative but to ask BA to shoulder the full bill. I have no doubt that when BA declined to do this AI breathed a huge sigh of relief, but at the end of the day the decision to stop all Concorde services was above all an AIRLINE decision.

Sorry to go rabbiting on, but it is a subject that arouses strong emotions!

CliveL

Not photshopped I assure you. That's 201 in the dress she wore for the celebrations of Concorde's first flight in Toulouse. 'orrible isn't it? I don't think she ever flew like that. As Shaggy said it would completely screw up the skin temperatures.

Shaggy - your serious question - the pressure at 60,000 ft is 1.04 psi and at 6000 ft it is 11.78 psi so 10.74 psi differential.

Clive

Don't want to be 'picky', but my photograph was of AS's 201 at Toulouse on the occasion of the party to celebrate the 20th anniversary of 001's first flight. If I understand correctly, the 'Pepsi' aircraft was 213 and belonged to AF. I don't think 201 flew with that Tricolour paint scheme. Can anyone throw more light on this?

CliveL

Clive, you're right.
F-WTSB (201) was painted in that horrific scheme by students at Toulouse.
Since that was in 1989, and 'SB made his last flight in 1985, and was not maintained airworthy, he never flew with that colour scheme....
The 'Pepsi' aircraft was indeed F-BTSD (213), and leased from AF for the occasion.

CJ

If the Flight article from the 80s that says only 10 hrs of flying was done is correct, it can only have been for limited in flight handling and not anything approaching the limits of the understood flight envelope......and I sure you would not have been contemplating take offs and landings.

A few of the Toulouse ex pats might be the people who would know, Dudley Collard etc...