Posts by user "ChristiaanJ" [Posts: 266 Total up-votes: 0 Page: 5 of 14]¶

I've been wondering about that too.... just looking for an easy way to do a "copy and save" of an entire thread.
Any ideas?
It would need some editing afterwards, to bring the various sub-subjects together.

Quite true... it was a pleasant surprise during the major overhauls. People like M2dude can no doubt tell you far more about that.

It would probably have been a major factor in extending the service life, if other things hadn't put an end to that in 2003.

Even if the moisture did not literally "boil off", most of it evaporated, with structural temperatures up to 100\xb0C in many places, as against the -40\xb0C and less in some subsonic aircraft.

The forward or the back one?
Neither look very fascinating.
For the back one just imagine a short stretch of cabin without any seats or fittings or windows. On Delta-Golf at Brooklands and Alpha-Echo at Barbados, they're now used as a sort of small "entry hall" for the visitors.

CJ

atakacs ,

Opinions and remarks like yours really belong on forums like "SCG" or the comments columns of tabloids....

But I'll try to answer you.

The aircraft were "decommissioned".
That means that they were fully prepared as public museum exhibits, rather than being "mothballed", ready to be put back into service.
The purpose was not to make sure they would never fly again, it was to make sure they were safe for the public to visit.
That included draining all fuel, hydraulic liquid, etc.
That meant removing all pyrotechnics, like those in the RAT.
That implied venting and/or removing all high-pressure vessels, such as the emergency slides, fire bottles, oxygen systems, nitrogen tanks.
In the case of the BA aircraft, it also meant removing the electric ground power connections, to avoid incompetent amateurs trying to put ground power back on the aircraft, and start a fire.

Most of these things could have been rectified quite easily. But there was no intent to ever fly any of these aircraft again, so there was no effort made to "mothball" the aircraft, which would have been done quite differently, such as inerting some of the systems, dropping all of the engines, etc. and, far more importantly, keep a maintenance structure in place, not allow public access to any of the aircraft, etc.

Once Airbus relinquished the Type Certificate, that was the end.

Nice one...
You clearly have no idea what that would have been involved.
Just the spares alone... most of them are "lifed", and would regularly need to be either retested and requalified, or would have to be binned and replaced.

Quite what are you talking about here? No airframes were "recklessly butchered", unless you're talking about Fox-Delta, which was not really worth saving because of serious corrosion.

CJ

You are presumably talking about landing and take-off.
Head winds... I doubt there was much of a limit, they would have made for both a shorter landing and a shorter take-off.
Tail winds... more of an issue... at max take-off weight in particular they would increase your take-off roll.
Cross winds.... not funny... and there are very definite cross wind limits in the manual.. I can look them up, but the pilots here can probably tell you far more about them than I can.

Nice one.... With nearly half of the take-off weight being fuel and payload, the allowed runway length varied hugely , and it was carefully calculated for every flight.
Sorry, I have no figures.
But with only a few passengers and little fuel, Concorde did some pretty spectacular take-offs from some pretty short runways.
St Maarten in the Dutch Antilles comes to mind.

CJ

Sorry, no. I don't feel offended.... I suppose I've just seen too much of that particular "conspiracy theory"....

Think back a moment to the 2003 context.

Due to the economic and political situation at the time (to put it simply), Air France was already flying their Concordes nearly empty, and wanted out.
BA wasn't doing marvelously either.
Airbus (being a company, not a charity) explained that in that case BA would have to carry the full cost of the maintenance.... which WAS already going up as a consequence of maintaining a 35-year old antique flying.
So BA decided to end the service as well, even if in the end at least they went out with a bang, not a whimper.

In those last months, people like Rod Eddington and others DID have a very serious look at keeping one or two aircraft flying in a "heritage role", and there was even a look at a joint venture with the "Alliance" project.

So yes, all of the alternatives WERE explored, but, AT THE TIME, none of these were found to be viable.

So, British Airways, Air France and Airbus all drew their conclusions, which made sense AT THE TIME, and closed down the Concorde operation.
And, instead of scrapping the aircraft, every single one of them went to museums.

The two airframes that "had an angle grinder taken to them" were Alpha-Alpha and Delta-Golf.

For a start, neither would have flown ever again, anyway...

Alpha-Alpha was never modified to post-2000 standard and would have slowly rotted away at LHR. Taking her to East Fortune was a great initiative, IMHO.

Delta-Golf was an ancient certication airframe, and cannibalised for years and years for spares, and destined for scrapping.
Instead, she's now at Brooklands, and rebuilt as one of the most interesting Concorde exhibits.

As to the "angle grinder", you really have to know where to look to find the traces......
And yes, I've seen both of them.

CJ

john_tullamarine ,
My apologies... I shouldn't have 'bitten' in the first place.

landlady ,
Yes, please stay!

A side note to your tale... the funny thing is that the businessman was right, strictly speaking....
Us techies did a lot of development work to make sure Concorde could take off and, above all, land in a pea soup fog, down to zero-zero visibility.
But of course, the rest of the airport would already have come to a complete standstill in those conditions, including the emergency services, hence the rules and regulations for minimum visibility.

Success with your book!
What's the title going to be? "Tea At Two" ?

CJ

You're right, it was 201 (F-WTSB).
After certification the aircraft was retained for several flight test programmes, not all of them Concorde-related.
In this case it was an early trial of the sidestick for the A320.
Concorde was already a fly-by-wire aircraft, so it was "relatively" easy to hook a sidestick into the system.
Unfortunately, I remember only some of the details...
It was only fitted on the left.
The righthand side remained fully conventional, and the RH seat pilot acted as the safety pilot.

Yes, definitely.
The story doesn't tell, I'm afraid. At the time it would have 'confidential', of course.

Not really... as I said it was just an early test for the A320.
At the time the aircraft were already certified, so it would have meant a MAJOR modification of the flying controls, AND recertification.
Also there was no requirement for it... the Concorde flying controls were judged perfectly satisfactory by the pilots.

Yes, that remained connected to the conventional controls (I'm not even sure whether the LH control column was removed).
Of course the sidestick would have its own, totally different artificial feel, since the control laws were different.

CJ

That's right, they unbolted the outer wings and the fin and the tailcone. And I'm almost certain they also dropped the engines (because of the weight).

You may have to search a bit, but somewhere on the net there is a huge photoalbum of the journey, interesting from beginning to end.

Oh, and I hope for you that nobody German reads this... it was not a 'canal', but the Rhine!

CJ

I've only seen photos... but judging from some recent ones they seem to maintain 'FB rather well, same as its companion, the Tu-144.

CJ

Hi Nick,
Your questions were already partly answered by NW1.
The solution was indeed in those two narrow strakes on the nose that generated a vortex on either side, the higher the AoA, the stronger.
Those two vortices "folded upwards", well before the leading edge of the wing, and around to the top of the fuselage, where they "stuck down" the air flow right to the end.
Hence the vertical tail was not "blanketed" by disturbed/turbulent air from the fuselage, and remained effective even at quite high angles of attack.

It was certainly a clever solution... but not new.
As stilton said, it was already used on the MD80.
On Concorde they had already been tested in the windtunnel and found to be effective, so if you look at photos of prototype 001 on its very first flight you will see they're already in place.

Vortices are funny things... usually you don't see them, but they contain quite a lot of energy and persist for quite a long time before dissipating. That's why those two small planks on Concorde work so well.

CJ

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

LOL !

True though... they're little more than two small flat surfaces... clearly marked " NO STEP ", so they're not even any use for standing on to clean the windows.

They look pretty insignificant, compared to the 'canards' of the Tu-144 or the big foreplanes on some other deltas, or the long forward wing extensions on aircraft like the F-16 and F-18, none of which have the same function.

And to be perfectly honest, I myself didn't know about their real function until after 2003, when I started delving into a lot of other technical aspects of 'our Lady'.

CJ

Questions already answered earlier, but I just found this photo on another forum.



The sidestick was located where the LH weather radar display normally is.

CJ

I'll have to find you a picture, I suppose!
But I would say the basic answers are
- the hydraulic lines at either end of the seal would be clamped down at some point,
- a hydraulic cylinder normally consists of a cylinder and a piston , with the latter of course missing in the seal arrangement.
You're quite right of course, but that would only be in the unpressurized part of the airframe.

The end result was of course that most if not all of the accumulated humidity either evaporated or indeed in some places literally 'boiled off', unlike subsonic aircraft.

CJ

Chu Chu ,

You're quite right, actually, especially assuming no flow.



"how would the fluid in the "cylinder" "know" it's pressing against pressurized hydraulic fluid in the inner tube and not a solid steel piston? "

The fluid wouldn't "know".. It would be pressing against pressurized hydraulic fluid further down the line.... but at the end, it would finally be pressing against the piston of a hydraulic cylinder of some kind at the end, like the 'cap' in my first scribble.
If nothing was restrained "downstream", indeed everything would be "blown apart".
Of course, that hydraulic cylinder (my 'cap') would be affixed to the structure, so it wouldn't move.

The problem is more like my second scribble.... with a bend in the pipe, and only the final 'cap' fixed, the pipe would continuously flex under pressure.... not a good idea at all, especially when the pressure in the pipe varies, because the 'cap' is not a real 'cap' but something like a PFCU (power flight control unit), with continously varying demand.

So yes, the hydraulic lines are restrained in all the right places, for the hydraulic expansion seals to work correctly without setting up stresses in the lines themselves (except for the pressure acting outwards, of course).

Hope this makes sense to you?

CJ

I should let the pilots on this thread answer, really,
But I would say yes , just tedious, and needing the PF to pay far more attention minute-to-minute to all the various basic flight parameters, and fly them, rather than just monitor the autopilot doing the job.

Basically, no.
The autopilots were quite reliable, and what's more, they were essentially independent, so the probability of both failing during the same flight was pretty remote.
If one dropped out in flight for whatever reason, you'd engage no. 2 and continue.

The only situation where losing both autopilots within a minute or so of each other would be critical, would be during a Cat.III autoland, and just before that you'd run an autotest of both computers. The probablity of then losing both almost at the same time during those last few minutes was in the order of 10E-09 or less, and indeed never happened.

Can one of our pilot friends oblige?

CJ

PS I should add, that normally only one of the two autopilots was engaged, with the other powered but inactive, and IIRC, with AP1 active, AP2 would refuse to engage until you disengaged AP1.

Only in LAND mode could both APs be engaged at the same time, with normally no.1 flying and no.2 as a "hot" standby.
The system was referred to as "fail active", in that no.2 would already be synchronised to what no.1 was doing, and would take over totally automatically, without a hiccup (except an "oh merde" from the pilots, probably).

Quoting from memory.

Not sure all of them are pure trivia!
Even myself, who supposedly knows the aircraft fairly well, is hesitating on several!
Give us a couple of days at least, Dude!

CJ

Thanks, EXWOK.
I was involved with tweaking the autostabs in those very earliest days... and it's still satisfying to this day to hear from the "users" we got it right!

NDBs? You're kidding, no?

CJ

Quite right!
Nevertheless there were three separate sets of landing/taxi lights there.

Quoting from the manual:

Two main landing lamps, one mounted in each wing root leading
edge, have retractable/extensible mountings and when not in
use are retracted in the lamp housing.
Two land/taxi lamps, similar to the main landing lamps, are attached to the
nose landing gear bay doors. The land/taxi lamps extend to
an intermediate position for landing, upon which they
automatically extend to the full position for taxiing, thus
changing the beam angle to compensate for the attitude change.
Two taxi/turn-off lamps, one mounted on each side of the
forward fuselage, provide ground illumination to identify
runway turn-off points.


These are the 'main' lights in the wing leading edge (600W each).





These are the lights in the nosewheel doors ("only" 450W each).





All three of the sets of lights had a cover to blend them in smoothly with the structure, much like the cabin windows.

The heat was less of a problem, actually.
The lights themselves were high-power sealed-beam units, the main units were 6 00W each, and the ones in the nosewheel doors were 450W ... nothing like your car headlights.
As a matter of fact, on the ground you were not suppossed to turn them on any more than 5 minutes in any 10 minutes.... they got a lot hotter when switched on, than they did in supersonic flight.

Good point!
What happened was that the main landing lamps in the wing roots were angled such, that they pointed straight ahead at the right angle to "hit" the runway during the landing itself.
Once the aircraft touched down, the land/taxi lights in the nose gear door extended further and lit a wider expanse of the runway ahead (see the earlier quote from the manual).
And then the third set of lights in the nose helped you to find the turn-off to the taxiway.

One nice little detail.... on F-BTSD, the Concorde at the French Le Bourget museum, those lights still work, and on G-BBDG, the Concorde at the Brooklands museum that was saved from the scrapheap, they brought those lights back to life, too.

CJ

Interesting.
Judging by the picture from the maintenance manual below, once the nosewheel was down, the main landing lights just lit up the ground below the nose, but not ahead.
Did you just rely on the runway lighting plus the ambient light (town lights reflected by the clouds, etc.) or did you usually extend the nosewheel door lights once you were down?





CJ

I copied this off M2dude's post a couple of days ago, and tried to answer it all offline without cheating by looking up the answers elsewhere.

1) How many fuel tanks were there on Concorde?
LOL... 13.
I suppose that, for the same reason there was no row 13 in the cabin, somebody decided to name two of the tanks "5A" and "7A", rather than call the tail trim tank (named no.11) number 13.
Yes, I forgot the scavenge tank.
And since it was "BA Concordes only" I didn't want to add the hydrazine tank on the two preprod and the two certification aircraft.

2) How many seats were there?
Good question.
As Nick asked, which seats?
Nominally there were 100 pax seats in the cabin, although originally up to 127 were certified.
Five (three plus two jump seats) in the cockpit.
Cabin seats for the cabin crew.... I honestly don't know. Seven?
Wrong twice... six cabin crew seats, AND I forgot to count the loos!

3) At what approximate altitude and KNOTS EAS was Mach 2 achieved?
Roughly, FL500 and 530 kts.
But not being a pilot I had to check an instant on my flight envelope crib sheet, which I have at hand all the time.....
It seemed pointless to be TOO precise, because that assumed ISA and creeping exactly up the right edge of the envelope.

4) Only one BA Concorde had three different registrations, what was it?
Without looking it up, no idea. My guess is G-BOAF, with a white-tail reg, a "British" reg, and a pseudo-American reg.
IIRC, G-BOAG never had a pseudo-American reg, but I'm not sure without looking it up.
Brain not completely addled, then.

5) What was the maximum permitted altitude in passenger service?
FL600, as certified.

6) How many wheels on the aircraft?
Twelve, if you count the two Spitfire wheels at the back

7) How many flying control modes were there?
Four. Blue, green, mechanical and ... what did we call it? Control jam, CWS?
Ah, thanks, Emergency Flight Control. I always considered it as a separate mode, even if it was virtually never used.

8) How many positions of nose droop were there?
Four. 0\xb0, 5\xb0, 12.5\xb0 and 17.5\xb0 (the latter only on the prototypes, and purely mechanically, after removing a stop, on the other aircraft).

9) What was the first microprocessor application on the aircraft?
No idea... you (M2dude) mentioned a Plessey data acquisition system?
It was after "my time"...

10) How many main electrical sources were there?
Again, not sure... You're presumably are talking about primary sources.
There was an AC constant-drive generator on each engine.
Then there were two DC batteries.
And IIRC there was an AC generator running off the RAT hydraulic generator when pillar came to post.
Reading M2dude's answer, I suppose the emergency generator just ran off the hydraulics, not specifically off the RAT. Far more logical.

Nice one, M2dude!
And certainly not all trivia!

CJ