Posts by user "ChristiaanJ" [Posts: 266 Total up-votes: 0 Page: 10 of 14]¶

CliveL ,
Wasn't me, honest, guv. 'T was that other dude...

Any chance of a pic or a drawing, M2dude?
It seems almost impossible to me that it was 'something' between inner and outer wing, since it would have had to 'jump' over the bathtub covers.
IMO everything went through rib 12, not under or over it.

CJ

Oops, I've done it again, forgetting that other people are also reading this thread, who wouldn't have a clue what we are talking about...

OK all.
On the 'blunties' and most other aircraft (subsonic or supersonic) there is a fuselage, and there is a wing.
The wing is connected to the fuselage by only a few very big bolts, linking a few very big forgings.

Concorde is different, right? Right.

Fuselage and inner wing are the same structure, and there were no "big bolts" that allowed you to separate fuselage and inner wing once the aircraft was built.

The only separate "bits" were the outer wings, the parts just outside the engine nacelles.

So 'rib 12' was the rib where the inner wing ended, and where the outer wing (built by Dassault, rather than Aerospatiale, actually) was attached.

Rib 12 actually was two halves, the one at the outboard side of the inner wing, and the one on the inboard side of the outer wing.
Both machined numerically from single 'blanks'...

And no, these two halves were NOT just bolted together with a few massive bolts. They were bolted together with hundreds of bolts in all. I did say Concorde was different, no?

Words now fail me, and I'll have to find or scribble some drawings ASAP.

In brief, so far.. each half of rib 12 had MANY machined "bath tub shaped" slots allowing to insert a bolt between the two halves, and bolt the outer wings to the inner wings.

And simplistically, the 'bath tub covers' were just small sheet panels held in place with fasteners fitted inside the 'bath tub' slots.

I should know.... I still have the scars of helping, one day, to refit a batch of them on Delta Golf at Brooklands

CJ

CliveL ,
Thanks for the picture, saves me a thousand scribbles.

And it also shows my mistaek... rib 12 was only inboard.
The outer wing did not have a "rib 12", it was the upper and lower edges of the skin that had their own "bath tubs".

CJ

Coffin Dodger , M2dude and Brit312 ,
M2dude will have to confirm that the 'lateral stiffeners' he is thinking of are indeed the very roughly 2' long and 5" strips at the location of each spar just outboard of the engine, that are very clearly visible on Coffin Dodger's photo of 'AA.
If so, they are indeed shown in the structural repair manual and listed as 'doublers'. There are ten of those, from spar 62 to spar 71.

Reading "between the lines", the modification dates from about 1978, and was applied by successive service bulletins to both the BA and AF aircraft.

CJ

Mike, I took the liberty to grossly 'tweak' your photo.....



and as you see, they show up quite clearly on Fox Bravo as well.

Judging by the page dates in the SRM, BA started it all, and Air France followed, with all the aircraft being modified by 1981. But that's just my guess.

CJ

Nope.....
You're looking at a generic picture of the junction between the upper and lower skins of the innner and outer wings at the level of rib 12, which is the rib just outboard of the engines.
The 'sample' you're looking at in that diagram has been "cut away" between two spars. The strengtheners are on the spars themselves, so they don't show up here.

CJ

No, you're right.
In my case, it's easier... I've become bitten by the Concorde bug again over the last ten years or so, and pulled dozens of similar diagrams from the documentation to refresh my memory.

I recently tried to do a rough list, but I lost count after sixty or so.....

The gates took care of the actual logic, but all the terms and laws and similar computing was done with op-amps.
Op-amps also were used for other functions such as demodulators (converting AC signals to DC) or comparators and level detectors.
I still mean to write some posts on "how to compute without a digital computer", but it'll have to wait until after the holidays.

I heartily disagree, Roger.

In the 'olden' days we'd draw block diagrams like the one for the SFC, and once we agreed about all the functions we wanted, we just drew the schematics for each of the functions.

No sequencing, no real-time clock, no A/D or D/A conversion, no worries about cycle time or memory allocation. No programming-language issues, no naming of variables, no compiler faults, no software to debug.
You should try it sometime......

The major issue was, of course, that you ended up with a lot more hardware for the same functionalities, hence more weight, and more power consumption.

And the other issue, already alluded to in earlier posts, is that analogue computing is inherently not highly accurate.
In many cases of system control, a percent or two of precision is perfectly acceptable. But if a far higher precision is needed, like for instance in the intertial navigation system, or the core computing for the air intakes, only digital computing can do the job.


Seasons greetings to everyone on this thread from me too.

Christian

Have a look here :
Flight envelope
Those are the official certified limits.
I doubt somehow anybody went beyond those "for the press".....
But during certification, yes, each of those limits was exceeded, slowly and carefully, to be able to draw those official operational limits on the document.
For instance, the certified Mmo is 2.04. During certification, G-BBDG (202) went to Mach 2.21....

Even while staying within the limits, she could could exceed Mach 1 just below 30,000 ft.

Also, during the acceptance flights after major overhauls, most of those envelope limits would be exceeded by a given margin, to prove the aircraft still met all the certification requirements. Whether any of that was done 'closer to the deck', I wouldn't know.

The 'issues' would vary. Performance would be one issue... Delta Golf (and 01, who went to Mach 2.23) basically "ran out of steam" at that speed.
Another issue would be that 'going beyond the borders' shortened the fatigue life of the airframe, and it was difficult to assess exactly by how much. It was one of the reasons why Delta Golf and Sierra Bravo (the certification aircraft) in the end never went into service.

CJ

Somewhere on these 50+ pages there is a mention of a narrow "to-be-avoided" speed band (buffet) which sounds as if referred to the same phenomenon, but I haven't been able to find it again.
Maybe the original poster remembers and can point us back?

CJ

For convenience, I repeat Bellerophon's diagram of the flight envelope here.



Mike's earlier question had me scratching my head too, hence my question.
What are the fundamental reasons for each of the limitations, and what were the consequences of going outside them?

Going clockwise from the left, we have :

VLA (lowest admissible speed)
One would expect a curve for constant alpha max against IAS and altitude, not the staircase in the diagram.
Was this for simplicity of use of the diagram?

Max altitude (60,000ft)
This is the 'simplest' one: it was the highest 'safe' altitude from which an emergency descent could be made, in the case of a window blowing out, without having the blood of the pax boil....
Test flights (without pax, and with the crew pressure-breathing oxygen) did go as high as 69,000ft.

Mmo (max operating Mach number)
Mach 2.04 is usually quoted as having been chosen to assure an adequate life of the airframe.
But what effect does a higher Mach number as such have?
Or are Mmo and Tmo (127\xb0C) directly related?

Vmo (max operating speed) = 530kts until 43,000ft
I suppose this is related to structural limits (qmax)?

Vmo reducing to 380/400kts at about 33,000ft
What is the limiting factor here (other than qmax)?

Vmo constant at 380/400kts down to 5,000ft
What is the limiting factor here? The answer will no doubt also explain why this is slightly weight-dependent.

Vmo reducing to 300kts between 5,000ft and 0 ft
Why the sudden change below 5,000ft?

CJ

CAAAD ,
LOL.....
If so, same question.
Can you explain the boundaries of the Olympus Relight Envelope?

Cheers,
CJ

PS : If you have a graph for that, it would be most gratefully received here, I'm sure!

To refresh memories, here's the only, not very helpful, entry in the Flying Manual that I've found.



My guess is that the upper digital counter indicates the proportion of the fuel flow that goes to the reheat but it's only a guess.

Sorry, I have no figure for the max fuel consumption.
The '35 tonnes/hr' limit on the indicator is obviously beyond the upper limit, like the speedo on a car.....
But yes, fuel consumption at takeoff with reheat was horrendous, and would have emptied all the tanks in an hour or less.

CJ

Any chance of you telling the tale?

We're looking forward to a few more people like you telling their story.

Peronally, I still remember vaguely there's a tale of the customers of a country pub somewhere in England actually chartering a Concorde for a "round-the-bay" flight, but I've never been able to find the full story.

CJ

There's often so much so deeply buried in our memories, that we don't even know about it anymore until something, like an image, brings it all back in a flash.
To most people, a Concorde cockpit is just a bewildering array of 'clocks' and other bits.
People like Bellerophon and Exwok read it all in seconds.
Even an ancient like me, seeing a cockpit photo, instantly recognises a museum photo, because of the toppled emergency horizon, or because of the odd bits and pieces we used on the autopilot controller on G-AXDN (01).

Yes, two women. One in France, one in Britain.
Unless you also include Jacqueline Auriol, probably the world's first female test pilot, who flew Concorde 001 in the earliest days.

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.

Christian

Roger, you're so right.
She was the first French woman test pilot, and maybe also the first woman with a formal FAA(?) test pilot license.
She did fly a few 'hairy' aircraft.
But indeed nothing like Hanna Reitsch flying the V1 "Reichenberg", or the Me-163, or a very early Focke-Wulf helicopter before the war!

CJ

Roger ,
I've never seen that mentioned.... would be really interesting to know if it actually happened.

Of course everybody knows about Phil Collins "being in two places at once" thanks to Concorde, but with the right timing an overflight of Wembley sounds quite possible.

CJ

That was obviously a personal memory... so it did happen!

CJ

PS I was just reading all the other comments from that BBC link.... Sad.

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....

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 Mus\xe9e 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 Andr\xe9 Turcat's book "Essais et Batailles".
And because he was flying the plane.... he himself never saw the eclipse as such.

CJ

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 , 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).