Concorde question

[ChristiaanJ]

Originally Posted by DavvaP

Another thing I've found today whilst searching for all things Concorde, were several mentions about the eclipse chasing that Concorde did during its lifetime. One really stood out and that was the chase during 1973. Here's a link to a photograph taken:
Concorde During Eclipse | Surfer Jerry

There were two 'sessions' of eclipse chasing by Concorde.
The first one was the 1973 chase over Africa by Concorde 001, which lasted 74 minutes in all.
The other one was the one in 1999, when three Concordes did a brief chase, but without any special equipment on board.

BTW, the picture from "Surfer Jerry" is a very nice and impressive PhotoShop creation... but it's not real. There was no other aircraft accompanying 001 during that flight....

The intriguing part of the 1973 story though is the special "window" put into 001 to view the eclipse through. ChristiaanJ, you've posted previously on another forum about this (dated back to 2004 ) - are there any photographs of the windows installed for this event?
Chasing The Sun: A Supersonic Celestial Observation | Scienceray
It sounds a completely magical experience!!

Your 'ScienceRay' link describes the 1973 flight in good detail.
IIRC there were three windows installed in the roof.
I've seen photos of the installation, but I'm not sure if any of them are on the internet.
If you're really interested I can ask the Musée de l'Air.
The windows were removed after the flight and the openings blanked off, but if you know where to look you can still see them.

For those who read French, there's a great description of the flight in André Turcat's book "Essais et Batailles".
And because he was flying the plane.... he himself never saw the eclipse as such.

CJ

[ChristiaanJ]

In earlier posts we were talking about the complex shape of the wing.

Looking through my 'archive', I've finally found this photo again... been looking for it for ages.



Kinky .... !!


Found on the net a few years ago. It's either 002 (G-BSST) or 01 (G-AXDN) at Fairford.

All Concordes have this 'kink', but the interesting thing is, that it's only visible from one very precise spot in line with with the wing leading edge. A few metres to the left or right, or forward or back, and the 'kink' disappears.
Many people are not even aware it exists.

Happy 2011 to all !

CJ

[CliveL]

I think it is 002 - 101 had a take-off performance camera 'target' painted on the fuselage between wing and cockpit and it looks to me as if the intake doesn't have the cut-back leading edge. In addition, the front of the intake was 'black' on 002 but white on 101 as in roll-out photo below.





And of course a happy 2011 to all!

CliveL

[DozyWannabe]

The clincher being that 002 carries the legend "SUD AVIATION FRANCE", whereas G-AXDN carries "AEROSPATIALE FRANCE".

Happy New Year, all!

[CliveL]

The clincher being that 002 carries the legend "SUD AVIATION FRANCE", whereas G-AXDN carries "AEROSPATIALE FRANCE".

OK Hercule

CliveL

[DozyWannabe]

For a second, 'astings, I thought I 'ad been premature...

Later photographs of 002 show her bearing the Aerospatiale name, like her sister ship - she'd presumably been repainted at some point. However, the photo of 101 Christiaan posted is captioned on concordesst.com as being taken at her rollout, which I am presuming means that she never carried Sud Aviation titles, the companies presumably having merged before 1971.

[CliveL]

Yes, you are right - on her first flight G-BSST had Sud Aviation logo; in 1971 and now at Yeovilton she carries Aerospatiale. Sud became AS in 1970.

My own humble black and white photos of 101 roll out show her with the Aerospatiale logo.

I guess from that data one could approximately date the LE photo that Christiaan posted.

[ChristiaanJ]

CliveL, DozyWannabee,
It's always fun doing a bit of 'aero-archaeology'.... isn't it?

You're both right.
At the roll-out, 01 was already marked "AEROSPATIALE", and the tracking camera 'target' was already painted on the right-hand side (but not on the left!).
So the earlier photo in question is definitely 002.

I recently re-scanned my ancient 'Filton' photos... only black-and-white, but maybe worth adding them to the 'records'.


G-AXDN being moved out of the hangar.
Interestingly, no tracking camera target on the left-hand side.... it must have been added very soon after, because I have a photo from a few weeks later, where it's in place on both sides.




Roll-out or not, G-AXDN still wasn't quite finished... three of the four engine nozzles/thrust reversers are still missing and replaced provisionally by 'space frames'.




This one again confirms the "AEROSPATIALE" marking. Also, somebody hadn't gotten round to painting the tail cone yet....



CJ


Oh, and a PS....

Another 'kinky' photo, this one of 001 when still outside the Le Bourget museum.



(Photo from the ConcordeSST.com site).

[CliveL]

Interestingly, the 'concordesst' site has a photograph of G-AXDN under construction and I would think about 2 weeks from rollout where "British Aircraft Corporation" has been painted on but there is a big gap where "Sud Aviation/ Aerospatiale" should be. This would be in November/early December 1971 I think. Just maybe this was the time when the new French company were making up their mind how they would like to be known. I know they didn't like the simple use of company initials - Societe Nationale Industrie Aerospatiale if I remember correctly and one must admit that Aerospatiale sounds a whole lot nicer than SNIAS! Maybe Christiaan could comment?

CliveL

[ChristiaanJ]

CliveL,
I should have kept a diary... never did.

According to the ConcordeSST site, the roll-out was on 20 September 1971, but (according to various internet items) Aerospatiale was already formed in 1970.

Looking at the general mess, the photo you mention (see below) was several weeks, if not a few months, before the roll-out.
Look closely.. I would say even the leading edges are not in place yet.



CJ

[AlphaZuluRomeo]

CliveL, ChristiaanJ,

About the picture above, AEROSPATIALE FRANCE is already painted on the aircraft (although obscured by a sort of cover).

Cheers (and happy new year) to all contributors & readers.
AZR.

[CliveL]

ChristiaanJ

Although it looks messy and there are parts missing (LE, nozzles and probably tail cone) none of them would take long to fit, which is why I estimated a couple of weeks before rollout, but I wouldn't quarrel with a longer time.

I knew the company merger was in 1970, but AS took a while to decide that they wanted to be known as Aerospatiale, so I thought that maybe, just maybe, this fell into that time slot. Obviously it didn't.

AZR

Your eyesight is better than mine! I had to fiddle with PSP to see it, but yes, the Aerospatiale logo is there. I was fooled by seeing the red fuselage stripe underneath into thinking that cover was more transparent than it actually was.

CliveL

[DozyWannabe]

Was there a reason - other than it was the second example built - that the French pre-production model had the longer tail assembly fitted, whereas 101 did not?

[ChristiaanJ]

Originally Posted by DozyWannabe

Was there a reason - other than it was the second example built - that the French pre-production model had the longer tail assembly fitted, whereas 101 did not?

Maybe somebody else here has the more complete story?

01 first flew in December 1971, 02 in January 1973, more than a year later.
So I suppose a lot of the planned improvements "came to fruition" just about then.

Apart from the new visor, 01 still looked a lot like another prototype, while 02 was externally almost indistinguishable from the production aircraft (long tail, new nozzles/thrust reversers, tail wheel, etc.).

However, from my own limited experience, as far as the cockpit layout, and systems like the AFCS, were concerned, 01 was already far closer to the production version than to the prototypes, which were still very much mid/late '60s designs.

The two prototypes were very much experimental and proof-of-concept aircraft, and it's interesting to see in how many aspects they differ from the final production aircraft.

CJ

[M2dude]

First of all a hearty 'Happy New Year' to all our readers. As I've been 'away' for a week or so, I hope you will all indulge me as I answer a few posted points. (I totally agree with what Bellerophon said about restricting our posts to the 'techy' and nostalgic stuff, so will not respond to anything else here) .

CliveL

Seriously, they couldn't possibly know that the new nozzle fell short of it's design promise. There was no means of measuring thrust in flight installed on the aircraft and even if there had been the possible precision would not have allowed one to make such judgement. The only certain thing in aircraft design is weight, and that could be established unequivocably - it was lighter than the original. Any aerodynamicist looking at the two designs could tell you that the drag of the TRA (Tuyere Reverse Aval) was going to be less than that of the prototype nozzle, but establishing an exact value was another matter.

I accept and understand of course Clive that this was a difficult issue to predict with any certainty, it was just a shame that's all, that the Type 28 never fully lived up to its promise and potential. However, the one aspect of the SNECMA design that was very poor indeed was Secondary Nozzle system integrity. Throughout the operational life of Concorde, there were almost more operational disruptions due to short-fallings here (bucket runaways) than any other issue. It was only near the very end of Concorde's operational life that modifications were finally forthcoming from SNECMA to address this.

Poornamechoice

My grandad (departed earth long before I was old enough to ask him questions about it unfortunately) worked for a company (don't believe they were a specific aerospace firm just a precision engineering firm, he also worked on flaps/droops on Tridents and said he had many a sleepless night when G-ARPI initially crashed). They won the contract to make the keys for Concorde, my grandad makes the keys according to the designs, and for extra measure thinking they will be a souvenir no doubt one day decides he will make a set for himself (and who knows, I could've ended up with them). So the story goes the dies then get destroyed. Launch day of Concorde comes, BA lose the set of original keys made and only asked ever for one set - the launch looks in jeopardy and a somewhat panicked launch party are wondering what they are going to do. Luckily my grandad steps up and says you have been saved, as he had a spare set all along and gives them to BA who launch as planned but loses out his souvenir in the long run.

I am so sorry to dispel this particularly charming story, but there were absolutely no keys as such for Concorde, Sorry (But I am so glad that you are enjoying this wonderful thread).

ChristiaanJ

It is clear from this fabulous thread that the passing of Concorde has left an aching void in the lives of the contributors here. Maybe, and maybe not.
Speaking for myself, no, it's not a void, it's a highlight, that I now like passing on, in the hope other generations will find inspiration in the 'Concorde Story' for their own endeavours.

Oooooh speaking for myself (and I suspect a whole lot more of the BA Concorde familly) there is a void alright. Having lived with the 'lady' day in, day out for almost 30 years (up to November 2003) there was an absolutely yawning chasm left for me personally. (The world of the blunties is just not the same.. just a whole lot slower ).
What is gratifying though, is the enormous amount of interest that there still is for Concorde; both in this thread and in the world at large. I guess she lives on after all.

These pictures of 101 etc are absolutely marvellous; I really like the 'sexy' wing shape photo's. One little unique point about 102; she flew with a different intake control system to any other Concorde, being an 'improved' Ultra Electronics analog system. (Although the intake itself was aerodynamically the same as the later aircraft). Never really understood why our French friends chose this particular path with this aircraft. (Perhaps CliveL can shed some light on this??).
Very best regards to all.

Dude

[CliveL]

Originally Posted by M2Dude

, it was just a shame that's all, that the Type 28 never fully lived up to its promise and potential.

One little unique point about 102; she flew with a different intake control system to any other Concorde, being an 'improved' Ultra Electronics analog system. (Although the intake itself was aerodynamically the same as the later aircraft). Never really understood why our French friends chose this particular path with this aircraft. (Perhaps CliveL can shed some light on this??)

I don't think I agree with you Dude. We 'did' the performance calculations at Filton, and I honestly don't remember any performance shortfall. If you are just talking system reliability then OK, I wouldn't know.

One of the things I like about this thread is the way in which it reminds me of things I had forgotten about the design phase - or in this case informs me of things I maybe never knew! I just do not remember any improved Ultra AICU design. So far as the French 'choice' on the matter, they probably weren't given one. Like the rear fuselage alterations referred to in another posting , it was all a matter of timing. 102 came after 101 so 102 got the lengthened rear fuselage (which was done to improve the 'area rule' distribution and gave about 2.5% drag reduction). We (BAC) were going to do the AICU development so it made sense for 101 to get the early hybrid units. [If you were cynical you might equally say that there was no way we were going to let AS have them first!].

CliveL

[ChristiaanJ]

CliveL, You wrote:
"We (BAC) were going to do the AICU development so it made sense for 101 to get the early hybrid units. [If you were cynical you might equally say that there was no way we were going to let AS have them first!]."
Is that a typo and did you mean "it made sense for 102 to get the early hybrid units."?

I think M2dude had more fun with the air intakes at the time than I had with the AFCS, although getting MAX CLIMB and MAX CRUISE to work was, to say the least, "interesting".

Christian

[CliveL]

ChristiaanJ, you wrote:Is that a typo and did you mean "it made sense for 102 to get the early hybrid units."?

No. it wsn't a typo, but you may have been misled by my use of 'hybrid' by which I meant the final AICU version which most people describe as digital.It had digital law generation but analogue servo control loops. We were responsible for development of the AICU 'laws' and with Fairford being less than an hours drive from Filton it was far more convenient to do the flight testing out of Faiford so that results could be evaluated rapidly and the next day's flight test sequence planned.

CliveL

[M2dude]

The thar intakes

Clive & Christian
Gentlemen, I think you will find that 102 did indeed have a totally 'unique' analog intake control system. Not only were the RDCUs (not AICUs in this case chaps) totally different, there were major architectural changes over the prototype system too. Also, although the basic intake structure was the same as 101 and all subsequent aircraft, there was still the prototype approach to local pressure sensing adapted, ie. Intake face total pressure P∞ sensed directly via the infamous 'magic holes' rather than using digitally synthesised values based on mainline aircraft manometric probe, total (pitot)pressure. As 101's intakes only went 'live' in mid-march 1973, I assumed that maybe they (AS) wanted an operative intake system from the outset on 102 when it first flew in January of that year. What puzzled me was why they went for this seemingly enhanced (and expensive) analog system on 102 and not the original system. (As 102 used a production type intake, I guess that they would have to have at least made some changes to the control system ; there was no exotic double hinged 'Dump Door', but the far simpler and elegant 'Spill Door' with integral Aux' Inlet Vane that was known and loved by us all). Rumour had it that AS still wanted to pursue the 'magic holes' solution and were dead against the decision to go digital. (This particular decision was taken in October 1970, which makes the 102 AICS route seem all the more strange).

And ChristiaanJ; what you guys achieved with the MAX CLIMB/MAX CRUISE was nothing short of remarkable. Just about the most exotic (and complex) autopilot mode that I've ever seen, that solved so MANY problems. (Still the only A/P mode I've ever seen where the Autothrottle is engaged in a speed mode at the same time as the AUTOPILOT ).
Best regards

Dude

[atakacs]

Performance would be one issue... Delta Golf (and 01, who went to Mach 2.23) basically "ran out of steam" at that speed.

Just wondering was that the maximum speed "in" the design ? I understand that "the higher & the colder = the faster" was the key to the performance and that the Mach +/- 2.0 cruise was implied by limiting altitude to FL 600 in order to mitigate cabin depressurization consequences. I guess there where also thermal issues but was, say, Mach 2.2 @ FL700 "warmer" than Mach 2.0 @ FL600 ?

Also wondering what was the max altitude ? Was high altitude stall (for the lack of a better word) ever experimented during tests or training ?