Concorde question

[Jane-DoH]

Bellerophon

You call 3-2-1 Now, start your stopwatch, pre-set to countdown from 58 seconds, and slam the throttles fully forward till they hit the stops. Four RR Olympus engines start to spool up to full power and four reheats kick in, together producing 156,000 lbs of thrust, but at a total fuel flow of 27,000 US gallons per hour. A touch of left rudder initially to keep straight, as the #4 engine limiter is limiting the engine to 88% until 60 kts when it will release it to full power. The F/O calls Airspeed building, 100 kts, V1, and then, at 195 kts, Rotate. You smoothly rotate the aircraft, lift-off occurs at around 10° and 215 kts. You hear a call of V2 but you keep rotating to 13.5° and then hold that attitude, letting the aircraft accelerate.

The F/O calls Positive Climb and you call for the Gear Up. On passing 20 feet radio height, and having checked the aircraft attitude, airspeed and rate of climb are all satisfactory, the F/O calls Turn and you slowly and smoothly roll on 25° left bank to commence the turn out over Jamaica bay. Some knowledgeable passengers will have requested window seats on the left side of the aircraft at check-in, and are now being rewarded with a very close look at the waters of Jamaica Bay going by very fast! As you accelerate through 240 kts, the F/O calls 240 and you pitch up to 19° to maintain 250 kts and keep the left turn going to pass East of CRI.

I remember that -- the initial rotation was pretty normal other than being a bit faster, then from there it was brought up to a very steep climb (it feels worse than it is, but I was guessing it was around 22 or so degrees -- it has to do with eyeballing the angle of the horizon to the plane's current path -- 22.5 degrees is 1/4 the way up, 30 is 1/3, 45 is 1/2, 60 is 2/3's and so forth). Clearly I'm not a human ADI :}

[Jane-DoH]

How many shockwaves does the concorde's inlet produce? I've been told it was like 3 or so, but looking at some diagrams it looks like there are 7... two stronger ones, three weaker ones, a bendy stronger one, a gap and then the terminal shock.

[ask26]

Regarding the engine start-up, was Two-Engine Taxi out ever considered/used in an effort to save some of the vast amound of fuel consumed before take-off.

Related I guess to the above, was there a minimum time limit after engine start before which full thrust could be applied?

[Green Guard]

1. Yes ( of course if you have more then 2 )
2. Yes ( every engine, even the one in car or a motorbike etc. )

[M2dude]

Jane-DoH

How many shockwaves does the concorde's inlet produce? I've been told it was like 3 or so, but looking at some diagrams it looks like there are 7... two stronger ones, three weaker ones, a bendy stronger one, a gap and then the terminal shock.

OK here we go:

1) The first shock was generated from the top lip of the intake

2) A second shock is generated from the fwd ramp hinge

3) A third isentropic fan shock is generated from the progressively
curved section of the fwd ramp

4) A 4th shock was generated fron the bottom lip
5) A terminal shock system is generated by the coalescence of
still supersonic and now subsonic air at the upper section of the ramp
area.

http://i1237.photobucket.com/albums/ff476/riconc11/Concorde/Shox.jpg

Hopefully these two diagrams will help. The first hand illustration above gives the 'theoretical' shock pattern and the second below gives an illustration of practical flows within the inlet. Both assume critical operation at Mach 2.

http://i1237.photobucket.com/albums/ff476/riconc11/Concorde/ShockComplex.jpg
I hope all this blurb helps


Best regards
Dude :O

[Shaggy Sheep Driver]

During the take off roll there was a power check called (by the FE, I think). I've heard this on recordings and videos variously as "power checked" and "Power set". Assuming they are one and the same check, which is correct?

[CliveL]

Dude, those are very nice illustrations, but I would make a small correction to the lower picture - the bleed flow is shown as entering the void at the front of the slot between the front and rear ramps whereas in reality it goes (sorry went :-( ) in at the rear behind the terminal shock. The increase in pressure behind that shock was the 'drive' for bleed flow.

Regards

CliveL

[Brit312]

During the take off roll there was a power check called (by the FE, I think). I've heard this on recordings and videos variously as "power checked" and "Power set". Assuming they are one and the same check, which is correct?

I think you are referring to the 100kt call, when the F/E was expected to give a call as to the state of the powerplant [both engine and reheat] achieving desired power for take off. He was assisted in this decision by the illumination of 4 green lights [ one per engine] which came on if the engine power was OK. Should one green light fail then he would confirm the correct engine operation by observing that engine's N2 and Area position

If all OK at 100kts the F/E would call ---- "Power Set"
If not all Ok then he would call ----------" Engine Failure" which would
result in a rejected Take off

In the early days there was no concession and every take off had to have 4 green lights illuminated so the call then was " 4 Greens" , but when the concession came along that term would not fit so the change in call

The concession were
1] one green light out [seeabove]
2] and basically if weight, and airport conditions allowed it a take off could be continued even with one reheat failed at 100kts

Up to 60 kts the F/E could reselectt a failed reheat so hoping it would be
OK by 100kts
At 100kts the conditions in the above concessions applied
Above 100kts the take off would continue even if a reheat failed however
if another fails when below V1 the take off would be rejected

So finally to answer your question the correct call [well in 1998] was

" Power Set "

[M2dude]

:OCliveL
Dude, those are very nice illustrations, but I would make a small correction to the lower picture - the bleed flow is shown as entering the void at the front of the slot between the front and rear ramps whereas in reality it goes (sorry went :-( ) in at the rear behind the terminal shock. The increase in pressure behind that shock was the 'drive' for bleed flow.

Clive, thank you so much for your correction; I will ammend this diagram in my files immediately. :ok:
(As always you are of course 100% on the bal. And what do aerodynamisits know about aerodynamics anyway :) :D :)).

Best regards
Dude :O

[CliveL]

And what do aerodynamisits know about aerodynamics anyway

Well if you ask two aerodynamicists about a problem you will probably get at least three opinions, so there is at least one in three chance of being right whatever you say:ok:

CliveL

[Shaggy Sheep Driver]

Thanks Brit 312. "Power set" it is, then. I was aware of the '3 reheat' possibility which is decided before T/O depending on T/O parameters ('is this a 3 re-heat day or a 4 re-heat day?').

On the P1 side of the cockpit is a small hinged piece of metal which can be moved to show '3' or '4'. This is set before flight depending on whether 3 or 4 re-heats are the acceptable minimum for take off that day, so if there is a re-heat failure on T/O, a glance at that indicator will show if it's OK to continue with '3 lit' or not.

[M2dude]

Ahhhh... the famous Reheat Capability Indicator. (Yes that was its official title). I seem to remember that before we did the modification to fit the 'RCI' in the late 1970s, the guys used to set an INS CDU thumbwheel as a memo to whether the take-off was a 'go-er' or a 'stopper'.
It seems a million years ago when we fitted this high presicion lump of alluminium. (Hang on a minute, it WAS :p).

Best regards
Dude :O

[skyhawkmatthew]

I've read the entirety of this thread with great interest, having never got to see Concorde in flight, but only visited OAG in Seattle. What a beautiful machine!

My question is: disregarding the certified FL600 / M2.04 / 127ºC restrictions, how high and/or fast do you Concorde builders and designers think she could have gone? :)

[Quax .95]

Hello skyhawkmatthew!

M2dude gave a good answer on your question in post #1085, so I think I may quote this here again.

As far as the MAX SPEED bit goes, Concorde was as we know flown to a maximum of Mach 2.23 on A/C 101, but with the production intake and 'final' AICU N1 limiter law, the maximum achievable Mach number in level flight is about Mach 2.13. (Also theoretically, somewhere between Mach 2.2 and 2.3, the front few intake shocks would be 'pushed' back beyond the lower lip, the resulting flow distortion causing multiple severe and surges).

The maximum altitude EVER achieved in testing was I believe by aircraft 102 which achieved 68,000'.

[Jane-DoH]

M2Dude

3) A third isentropic fan shock is generated from the progressively
curved section of the fwd ramp

What's an isentropic fan-shock?

5) A terminal shock system is generated by the coalescence of
still supersonic and now subsonic air at the upper section of the ramp
area.

So the lower lip forms a normal shock and the airflow goes subsonic immediately behind it, the supersonic flow above somehow collide and form a shock between the ramps? I understand how the subsonic and supersonic flow coming together would reduce the average velocity -- I'm still surprised the gap between the forward and rear ramps wouldn't act like a divergent surface and cause the supersonic flow to accelerate rather than come down to subsonic speed.

[CliveL]

What's an isentropic fan-shock?

The first bit of the moveable front ramp was carefully shaped to give a sequence of weak shocks that reduced the Mach Number so gradually that shock losses were minimised. This was close to an isentropic process, hence the name. The geometry was arranged so that as the progressive shocks were generated and the Mach angles and shock angles changed the weak shocks tended to 'focus' on a point just ahead of the lower lip. This then became effectively a single 'shock' at that point. Hence isentropic fan shock.

So the lower lip forms a normal shock and the airflow goes subsonic immediately behind it, the supersonic flow above somehow collide and form a shock between the ramps? I understand how the subsonic and supersonic flow coming together would reduce the average velocity -- I'm still surprised the gap between the forward and rear ramps wouldn't act like a divergent surface and cause the supersonic flow to accelerate rather than come down to subsonic speed.

The shock from the lower lip would, on its own, give subsonic flow across the intake, but the change in flow direction where the flow off the solid ramp started to traverse the gap (where Dude's drawing shows the flow going into the void) produced an expansion 'fan' that accelerated the flow in its vicinity and this gave supersonic flow in the upper half of the duct but there was a shear across the height of the duct there. The total effective duct area however was convergent back to about the leading edge of the rear ramp, so the Mach Number reduced continually up to that point. Then the 'terminal shock' brought the flow down to below Mach 1 and from there on the divergent subsonic duct did the usual deceleration job. The whole point of the intake geometry was that the purely aerodynamic boundary between main duct and ramp void was infinitely flexible in shape, which made the design very tolerant of flow disturbances.

[Jane-DoH]

CliveL

The first bit of the moveable front ramp was carefully shaped to give a sequence of weak shocks that reduced the Mach Number so gradually that shock losses were minimised.

Must have been a highly efficient inlet for a Mach 2 plane: Two traditional oblique waves; a fan-shock (also oblique); a shockwave off the lip that is normal and oblique depending on how far you are away from the lip, and a normal terminal shock.

This was close to an isentropic process, hence the name.

So, isentropic would, in this context, mean that no shock-losses occurred at all?

The whole point of the intake geometry was that the purely aerodynamic boundary between main duct and ramp void was infinitely flexible in shape, which made the design very tolerant of flow disturbances.

Makes sense for an airliner that you would design an inlet this way

[Mr.Vortex]

Thanks for your reply CliveL and thanks M2Dude and CliveL again for the great
reply with detail about the intake.:D

[CliveL]

Must have been a highly efficient inlet for a Mach 2 plane: Two traditional oblique waves; a fan-shock (also oblique); a shockwave off the lip that is normal and oblique depending on how far you are away from the lip, and a normal terminal shock.

Yes is was very efficient - 94.7% pressure recovery at M 2.0 cruise

So, isentropic would, in this context, mean that no shock-losses occurred at all?

In theory yes, but in practice there was a small loss.

[M2dude]

And a thank you from me CliveL for your superb explanations regarding intake shock structure. It can not be over-emphasised just what an amazing achievement the Concorde engine/intake combo was. I can think of no other design in the world, before or since, civil or military, where a supersonic engine/intake marriage gave such incredidable levels of performance, stability and predictability. I just regard myself as being extremely fortunate to have been able to 'play with' this amazing kit for so many years and see what design excellance really is. (And at least pertly understand it too).

[911slf]

I believe that engine #4 was limited to somewhat less than max power until 60kt because of a vibration issue. Did this mean that reheat for that engine could not be selected until 60kt was achieved?

[Shaggy Sheep Driver]

All 4 reheats were selected 'on' before take off. They wouldn't actually light until the engine was up to a certain power, so the answer is 'no'. The power-limiting ensures no. 4's re-heat doesn't light below 60kts.

Watch a video of Concorde taking off which gives the view from behind. You'll notice no.4 light up marginally after the other 3 (but there's not much in it as it didn't take the aeroplane long to get to 60kts!).

[Quax .95]

Not quite right: the reheats ignite if
throttle lever >10% open; at takeoff the throttle levers have to be slammed to fully open within a secondselected RHT or CTY
N1 >81%

The N1 of number 4 engine is limited to a maximum value of 88% up to 60kts, thus within the operational requirements of the reheat.
(At temperatures colder than -35°C the engine control schedule limits the N1 of all engines to 88% or less.)
Up to 60 kts the F/E could reselect a failed reheat so hoping it would be OK by 100kts

Regards

[Shaggy Sheep Driver]

Thaks Quax. So all 4 reheats should light about the same time, then, regardless of power limiting on #4? It does seem that #4 lags a fraction in vids I've seen.

[Quax .95]

This might be because the #4 engine accelerates less fast than the others due to the limiter, reaching 81% N1 a little bit later. But this thread is too brilliant for presumptions (don't want to repeat the mistake of my first post...;) ). Let's see what the Concorde-geniuses add.

[Landroger]

I can think of no other design in the world, before or since, civil or military, where a supersonic engine/intake marriage gave such incredidable levels of performance, stability and predictability.

I think Dude's above statement more or less characterises the Concorde design and therefore this entire thread - which I have read, avidly, since post #1. However, since Dude made the statement most specifically about the synergy of the whole intake, engine and nozzles, it is worth reiterating that Concorde's only real peer in her occupation of the very highest and fastest regimes of wing borne flight - the SR71 - initially at least, had a lethal gene. Asymmetric 'Unstart' caused by intake instability.

Without proper scheduling, disturbances inside the inlet could result
in the shock wave being expelled forward--a phenomenon known as an
"inlet unstart." That causes an instantaneous loss of engine thrust,
explosive banging noises and violent yawing of the aircraft--like
being in a train wreck. Unstarts were not uncommon at that time in
the SR-71's development,


This quote is from a much longer article quoted in this thread, about a test flight by Bill Weaver, a Lockheed development pilot, in which Weaver was, quite literally torn out of the aeroplane at Mach 3.2, as was his back seater who, sadly, did not survive the incident.

Basically, a relatively small failure within the intake/spike structure of the SR71 engine, was enough to simply tear the airframe apart within seconds of onset. The scale of forces within these structures therefore, must be almost beyond imagination and yet the Concorde design was such that she did not suffer such destructive failures.

My admiration for everyone who worked on her is endless.

[SundayForever]

there were already several conduits through tank 11, such as hydraulics for the tail wheel, various electrics, and the 'backbone' fuel manifolds, that ended at the fuel jettison port in the tailcone.
A couple of fairly substantial air ducts would only have displaced a few hundred kgs of fuel at the most, out of the more than 10,000 kgs in tank 11.

[Jane-DoH]

M2Dude

I can think of no other design in the world, before or since, civil or military, where a supersonic engine/intake marriage gave such incredidable levels of performance, stability and predictability.

Well, the XB-70 had an inlet with an efficiency in the 90% range but it wasn't as stable/predictable (it suffered unstarts).


911slf

I believe that engine #4 was limited to somewhat less than max power until 60kt because of a vibration issue.

What kind of vibration issue occurred?

[M2dude]

Jane-DoH
One of the real beauties of the Concorde intake was that it was completely self-startiing, and so unstarts as such were never heard of.
Regarding the vibrations thing, here is my post #80:The reason that #4 engine was limited to 88% N1 on take-off was an interesting one, down to something known as 'foldover effect'. This was discovered during pre-entry into service trials in 1975, when quite moderate levels of first stage LP compressor vibrations were experienced at take-off, but on #4 engine only. Investigations revealed that the vibrations were as the result of vorticies swirling into #4 intake, in an anti-clockwise direction, coming off the R/H wing leading edge. As the engine rotated clockwise (viewed from the front) these vorticies struck the blades edgewise, in the opposite DOR, thus setting up these vibrations. The vorticies were as a result of this 'foldover effect', where the drooping leading edge of the wing slightly shielded the streamtube flowing into the engine intake. #1 engine experienced identical vorticies, but this time, due to coming off of the L/H wing were in a clockwise direction, the same as the engine, so were of little consequence. It was found that by about 60 KTS the vorticies had diminished to the extent that the N1 limit could be automatically removed. Just reducing N1 on it's own was not really enough however; some of this distorted airflow also entered the air intake through the aux' inlet door (A free floating inward opening door that was set into the spill door at the floor of the intake. It was only aerodynamically operated). The only way of reducing this part of the problem was to mechanically limit the opening angle of the aux' inlet door, which left the intake slightly choked at take off power. (The aux' inlet door was purely aerodynamically operated, and diff' pressure completely it by Mach 0.93).

I seem to remember that Rolls Royce proposed a solution of their own, whre the right hand pair of engines would rotate ant-clockwise (viewed from the front) rather than the clockwise norm for just about any 'Roller' that I can think of. Although this would have completely solved the vibration problem, and was great business for the folks at RR in Patchway (just about doubling the required number of engines) it was a pretty lousy idea if you were an airline and required a much latger holding of spare engines.

[CliveL]

Investigations revealed that the vibrations were as the result of vorticies swirling into #4 intake, in an anti-clockwise direction, coming off the R/H wing leading edge.

Only one comment Dude; as I said to you in a PM the vortices came off the intake sidewall leading edge rather than the wing. If you think about it, the highly swept, sharp leading edge of the sidewall looks just like a delta wing on its side, so that flow coming on to the sidewall leading edge from the outside generates a vortex just like that above the main wing, but now going inside the intake. At low speeds the engine is sucking in air from everywhere it can, so there is a substantial flow entering from the side of the intake. As you increase speed the potential air supply coming from the streamtube directly ahead of the intake increases enormously so the 'sidewash' onto the intake sidewall diminishes and the vortex is suppressed. On the other side of the aircraft of course the sidewall vortex was handed the other way.

[M2dude]

OMG Clive yes, sorry about that. I remeber it well now, I just did a search and posted up my original.

[canuck slf]

I seem to recall from my two take offs in 1978 or 9 that all four reheats were selected in pairs for take off and lit while holding on the brakes, with a preamble/warning over the PA that this was what was going to occur. Is this another indication of my failing "little grey cells" or did the procedure change?
Same PA announcement and lighting in pairs also occurred when going supersonic.

[M2dude]

For take-off reheat was selected (armed) on all 4 engines together, and certainly not in pairs. (As was stated previously, once 81% N1 was reached the reheat light-up sequence was automatically initiated). You would not wind up on the brakes either, the carbon brakes were extremely sensitive to overtorquing. For transonic acceleration however you are quite right about the 'burners in pairs' bit.

[howiehowie93]

I saw some questions earlier about performance but that's pretty well documented. I was wondering more about for how much longer ( if there had been no retirement )??


Was there a Fatigue Index as other aircraft of the same era – I only know of the Tornado in this respect: a long calculation was made per flight taken of flight duration, G readings, TO weight, Landing weight etc leaving a small number of 0.0000x per flight. Then added to the current FI to give a forecast of life left. If anyone remembers the Tornado 25FI Update Program debacle in the 90's ???


So how was the Concorde's airframe life calculated ?? Flying hours or perhaps pressurisation cycles ? Did a higher altitude effect anything since there would be a higher differential pressure??


On the Engine side, I remember an Olympus Service Bulletin describing the calculation of Fatigue Cycles for the Oly 200:- There was a calculation with several parameters but instruction to disregard below a certain figure, 85% to Max RPM & back was a regarded as a cycle and the LP Turbine Disc was the component with the lowest number of cycles before the need for overhaul.Was this still the case with the 593 ??

[CliveL]

So how was the Concorde's airframe life calculated ?? Flying hours or perhaps pressurisation cycles ? Did a higher altitude effect anything since there would be a higher differential pressure??

I can't answer for the engines, but the airframe life was going to be limited by thermal fatigue cycles. There was an on-going programme of testing at RAE Farnborough where, from memory, 21000 cycles had been accumulated by the time it was shut down. The airworthiness authorities were demanding a safety factor of 3 because nobody had flown under that sort of limit before, so the theoretical life would have been 7000 flights.

Not so bad as it sounds in calendar years, as the annual utilisation of any one aircraft was very low, and there would also have been scope for life extension by applying certain modifications to the fuselage.

[Jane-DoH]

M2dude

One of the real beauties of the Concorde intake was that it was completely self-startiing, and so unstarts as such were never heard of.

What does self-starting mean exactly? Does it mean self-stablizing?

I seem to remember that Rolls Royce proposed a solution of their own, whre the right hand pair of engines would rotate ant-clockwise (viewed from the front) rather than the clockwise norm for just about any 'Roller' that I can think of. Although this would have completely solved the vibration problem, and was great business for the folks at RR in Patchway (just about doubling the required number of engines) it was a pretty lousy idea if you were an airline and required a much latger holding of spare engines.

Ironically, that idea worked on piston-driven aircraft. The P-38 actually used a left-hand and right-hand prop; in order to make the prop spin in the desired direction, one of the V-1710's were installed backward.

[M2dude]

Hi again Jane-Doh. Self starting meaning (at least to my non-aerodynamicist avionics infected brain) that the shock system will establish itself perfectly without specific movement of the variable surfaces. Similarly it will not experience the phenomonem (unstart) where the whole shock system will be violently expellled to the extent that it can not tbe safely re-established without changing both the engine power setting and the variable surface position. (This whole thing being the 'train wreck' phenomen :yuk:).
That was interesting stuff about the P38, I must admit I'd not heard that one. (Makes sense I suppose though, provided that the engine can be easily be re-positioned in such a way).

[howiehowie93]

I had to look it up on Wikipedia::ugh:

Counter-rotation was achieved with the use of "handed" engines, which meant that the crankshaft of each engine turned in the opposite direction of its counterpart. The V-12 engines only required that the spark plug firing order be changed in order for the direction of the crank shaft to be reversed, according to the General Motors Allison V1710 Service School Handbook.Lockheed P-38 Lightning - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/P38_Lightning)

sorry for the thread drift. :=

regards
Howie

[forget]

Modern day contra-rotating props. (Shacks don't count.)

http://www.pprune.org/military-aircrew/440739-a400m-flight-testing-progress.html#post6231665

[M2dude]

CliveL
The airworthiness authorities were demanding a safety factor of 3 because nobody had flown under that sort of limit before, so the theoretical life would have been 7000 flights.
The RELIFE programme had already taken the aircraft to 8,500 cycles, and the escence of RELIFE 2 had already been agreed when the maggots pulled the plug in late 2003. My own personal guess is that we'd now be looking at RELIFE 3 within a few years if we were still operating. It always really was a case of 'how long's a piece of string' as far as how long the aeroplane could be kept flying.

[Shaggy Sheep Driver]

If I may be permitted to tread drift a bit re engine rotation effects: prop-driven aircraft suffer a range of unpleasant effects that jets don't. Not least is the prop slipstream effect; the propwash spirals around the aeroplane and pushes on the fin inducing a turn. This is at its worst at take off, with no slipstream and high power; even our Chipmunk needs a bootful of left rudder to keep straight when full power is applied at the start of the take-off roll. A really powerful aeroplane like a Spitfire cannot use full power until there is sufficient airspeed to make the rudder effective enough to keep straight; one reason why later Spits had contra-rotating props.

Then, for a taildragger like the Chippy, there's the 'assymetric blade effect' or 'p' factor, where with the tail down the down-going prop blade produces more thrust than the up-going one. And the engine torque effect particularly noticable on soft runways with powerful aeroplane where one mainwheel tyre is pushed into the ground with more force than the other, and finally the gyroscopic swing induced in a taildragger as the tail comes up and the prop disc is tilted to the vertical.

All of these effects are cumulative, and it's one reason why tail-wheel prop pilots learn to use their feet! All are obviated by contra-rotating props or, for twins, 'handed' engines which rotate in opoosite directions to each other.

When I had a share in a Yak52 I used to use the 'engine torque effect' to steer the aeroplane on Barton's muddy winter surface; using the conventional method (braking the appropriate mainwheel; the nosewheel was free-castoring) didn't work as the (quite thin) wheel would just lock and slide along, not inducing a change of direction at all. But whack on a fistful of Vendeneyef and 360hp would dig the right main into the ground and she'd turn right. Pull the power off suddenly and the left main would dig in, turning her left. Worked a treat!

[CliveL]

M2dude,

Thanks for that info Dude - you were still working on the beast long after I left it!

Tomorrow is the launch for the 7th edition of Chris Orelbar's book and I hope to meet a few old friends there. Maybe something interesting will emerge:ok:

[Mr.Vortex]

Hi all,

I have read through some book and it said that in cold ambient condition [ISA -15C or less], the intake can suffer a supercritical condition and I did look up a picture of intake in supercritical condition and it show that the shock wave seems to get "sucked" in and the shockwave isn't concentrate at lip area. I don't understand that if the aircraft is travelling at M2.0 then the air passing through the engine should have the same mach no and hence the shockwave should be identical to the normal condition but it isn't. Can some explain this for me please.:8

Best regards

[Brian Abraham]

Basically, a relatively small failure within the intake/spike structure of the SR71 engine, was enough to simply tear the airframe apart within seconds of onset.Not quite the case, although the potential for a very rough ride was always there. Bill Weavers accident was the only one that involved an unstart, and was due in no small part to the test nature of the flight - CG out the back door. In Bills own words,

Jim Zwayer, Lockheed flight-test specialist, and I were evaluating systems on an SR-71 Blackbird test from Edwards. We also were investigating procedures designed to reduce trim drag and improve high-Mach cruise performance. The latter involved flying with the center-of-gravity (CG) located further aft than normal, reducing the Blackbird's longitudinal stability.

On the planned test profile, we entered a programmed 35-deg. bank turn to the right. An immediate unstart occurred on the right engine, forcing the aircraft to roll further right and start to pitch up. I jammed the control stick as far left and forward as it would go.

No response. I instantly knew we were in for a wild ride.

The cumulative effects of system malfunctions, reduced longitudinal stability, increased angle-of-attack in the turn, supersonic speed, high altitude and other factors imposed forces on the airframe that exceeded flight control authority and the Stability Augmentation System's ability to restore control.

The next day, our flight profile was duplicated on the SR-71 flight simulator at Beale AFB, Calif. The outcome was identical. Steps were immediately taken to prevent a recurrence of our accident. Testing at a CG aft of normal limits was discontinued, and trim-drag issues were subsequently resolved via aerodynamic means. The inlet control system was continuously improved and, with subsequent development of the Digital Automatic Flight and Inlet Control System, inlet unstarts became rare.

[steve-de-s]

Concorde G-BOAF heading for the London Eye?

http://heritageconcorde.com/?page_id=7739

[Nardi Riviera]

As a Concorde enthusiast since day one, I'd like to express my sincere gratitude for all the inside info you guys have shared with us outsiders in this thread.

Keep it up, please... :ok:

[steve-de-s]

Was Concorde 202 a production standard Concorde that could have been used as an airliner, or was it nothing more than a development Concorde that could only have been used for flight testing?

[M2dude]

She was a a test airframe only, although in circa 1985/86 we did look at modifications that would bring her up to production aircraft standard. The modifications required to the powerplant alone (mainly engine and intake control logic and management) were truly massive, as well as other things like engine instrumentation and other systems' control management. The total cripler however was the cost of a TOTAL RESKIN of the forward fuselage section (Component 30, made at Brooklands). The production series aircraft had a thicker skin here, and we were told that the CAA insisted on this being done as part of any conversion to airliner standard. Costs of around £30 were being banded about for bringing the entire airframe up to production aircraft standard. Also of course she had an MEPU when flying rather than a HYRAT for emergency power and of course a large flight test observers position.
I worked on 202 personally quite a bit during the mid to late 70's, but she never remotely 'felt' like a real production aircraft. Even aircraft 204 (G-BOAC) in her pre-route proving days was a radically different beast. (The OAC post route-proving modifications although at system level were quite extensive, these were miniscule in comparison to the differences between 202 and what we like to call 'the REAL Concorde'. Don't get me wrong, 202 did some absolutely stirring work in terms of route-proving and certification trials, and the restoration done at Brooklands is most impressive indeed, but she is and always was, nothing other than a test aircraft. She was no more a production airframe in reality than the pre-production aircraft 102, and I'm afraid that anyone thinking that she is anying other than this is truly deluding themselves my friend.
I'm sorry if this reality is dissapointing steve-de-s, but if you want to see a Concorde that is truly representative of what the aircraft was really all about I suggest that you pop up to either Manchester or East Fortune. (The only airliner museums in the UK now open to public viewing). The Manchester exhibit in particular is truly superb and beautifully kept by some great people, and shows you exactly what Concorde, THE AIRLINER was actually like, rather than just seeing a test specimin. (A superb specimin 202 indeed she was, but this is ALL she ever was, a test specimin).

Best regards
Dude :O

[gordonroxburgh]

agreed Dude...

202 was built as 2nd Production, with a defined role as a test aircraft. Several studies were carried out over the years to see if she could be reused. Initially with the manufacturers, where if Concorde has been a success she could have been refurbished and sold to another airline at a "good" price. Of course here flying outside the certified flight envelope led to a lot of further concerns that really was curtains for any modification.

BA had robbed a lot of parts from her in the 80s, especially to bring G-BOAG back into service, so it was a no brainier in the end to put her in a hangar and rob whatever was required to kept the fleet of 7 in the air.

One little point, in the very late 70s here MEPU was decommissioned and she was fitted with the HYRAT...although the guts of the de-contaminated MEPU is still up in her tail cone.

If you want to see an Concorde as it was in Airline Service go visit MAN or EF, fantastic displays showing an Airline Concorde in the 90s or 00s

If you want to visit a Concorde and want to see the 4 stories in one (Concorde story, the unique story of a development aircraft, the airliner passenger experience and they story of how Concorde pilots were trained).... then visit Brooklands.

We've never been able to prove from a documented drawing perspective at Brooklands that the roof of the forward fuselage was any thiner than that of 204.

[M2dude]

Well in that case you are obviously right I suppose and BA, BAe (as it was) and the CAA were all wrong as far as component 30 goes. And everything that I was told at Fairford was wrong too. I guess it goes to show I suppose that all these bodies can be wrong.
There were several semi-structural and 'heavy' system components that were robbed by BA (I removed some stuff myself in the mid 80's and early 90's), but the fact remains that there were massive system differences that could never be reconciled by simple 'mods'. The fact also remains that she was a 5100 variant aircraft and not a 5101/5102 variant (or a 100 series aircraft either) and was significantly D-I-F-F-E-R-E-N-T to the 'real' aircraft, the airliners. I was THERE and I SAW the differences myself enough times for goodness sake, and the fact remains she was NEVER an airliner and never had any real prospect of being one. (But as I said before, she was a wonderful TEST specimin and did some stirling work). Brooklands really has a lot to offer the visitor as an exhibit I suppose but if you want to see Concorde THE AIRLINER then you really need to go elsewhere. Manchester in the only place where you can now see an intact production series Concorde in the UK and as I said before is NOW lovingly cared for by some brilliant people.

Regards
Dude :O

[ChristiaanJ]

....The fact also remains that she was a 5100 variant aircraft and not a 5101/5102 variant (or a 100 series aircraft either) and was significantly D-I-F-F-E-R-E-N-T to the 'real' aircraft, the airliners.M2dude, any chance of clarifying the "variants" (if only with a little table)?
I always thought "100" was the "bare" production aircraft definition, "101" and "102" were the AF and BA specs (equipment, cockpit, cabin), "103" being PanAm, etc. and I've never seen a mention of a "5100/5101/5102" definition.
Would be nice to get this sorted in my ancient brain...... thanks in advance!

CJ

[CliveL]

Dude, can I join Christiaan in requesting more information on that '5000' series numbering; I have never come across it before.

Also, I have asked the CAA surveyor who was most likely to have made that reskinning decision for more data. Perhaps he can remember the problem with the forward fuselage skins. Certainly when we were standing together inside 102 last week and talking about fuselage modifications for relifing the aircraft the problem of Component 30 was not mentioned!

I'll keep you in touch.

CliveL

PS: You were going to get a lot for your £30:ok:

[Mike-Bracknell]

Costs of around £30 were being banded about for bringing the entire airframe up to production aircraft standard.

I think even in 1985, at the age of 14, I could have possibly scraped £30 together if you'd told me i'd get a trip in her :}

[Biggles78]

I think even in 1985, at the age of 14, I could have possibly scraped £30 together if you'd told me i'd get a trip in her
Oh you guys are so cruel. :D

[CliveL]

Dude

The production series aircraft had a thicker skin here, and we were told that the CAA insisted on this being done as part of any conversion to airliner standard.

I have now asked two senior CAA surveyors about this, and neither remember anything but the crown modifications that went with RELIFE. Sounds like somebody didn't want to do the conversion :hmm:

CliveL

[asc12]

I hate to go back several pages, but I still have a basic question about the lift generation when the AoA was more moderate.

When not generating vortex lift, was the airflow attached over both the upper and lower wing surface?

The mental picture I have is that during supersonic flight and also during subsonic but high-IAS phases, the wing was generating lift in a way Newton and Bernoulli would have immediately recognized. As the IAS decreased and AoA increased, the vortex started at the leading edge, and gradually grew in both size and contribution to overall lift until the vortex (or vortices) accounted for all the lifting force.

[CliveL]

When not generating vortex lift, was the airflow attached over both the upper and lower wing surface?

As the IAS decreased and AoA increased, the vortex started at the leading edge, and gradually grew in both size and contribution to overall lift until the vortex (or vortices) accounted for all the lifting force.

The simple answer is yes, it was attached flow.

The vortices never provided all the lifting force. Up to about 6 or 7 deg AoA there was no vortex lift, just the usual wing tip vortices. Above that AoA the non-linear (vortex) lift grew steadily until at stall (about 23 deg AoA) the vortex lift was around 45% of the total.

[twochai]

CliveL:

Was the vortex lift characteristic of the ogee wing aerodynamics fully understood before the aero configuration of Concorde was finalised?

How much did the BAC 221 (the Fairey Delta II analog of Concorde) contribute to the understanding of vortex lift of this wing?

TwoChai

[CliveL]

twochai

Was the vortex lift characteristic of the ogee wing aerodynamics fully understood before the aero configuration of Concorde was finalised?

I would say that it was. Remember that the design went through several phases before it was finalised and we did an awful lot of testing and tweaking of the detailed geometry to eliminate a gradual pitch-up and to increase the vortex lift at any given AoA, so by the time we defined the production aircraft wing we knew pretty well all there was to know about vortex development from the AoA at which it started right through to the AoA at which the vortices burst.

How much did the BAC 221 (the Fairey Delta II analog of Concorde) contribute to the understanding of vortex lift of this wing?

The BAC221 didn't contribute much to the details of this understanding as it was rather too late to help in prototype definition and the production development was all about the details of planform, camber and twist. But then the 221 wasn't intended to study vortex development; it was built to examine the handling characteristics of slender ogee wings at supersonic speeds.

CliveL

[twochai]

Interesting, as always.

Thanks.

[ChristiaanJ]

CliveL, correct me where I'm wrong.

* Most deltas develop some vortex lift, and there were several deltas flying long before Concorde, so the phenomenon was not unknown.
Shaping the wing, and in particular the leading edge, optimised the effect on Concorde.

* The ogee (slender delta) wing was original proposed by NASA (possibly still NACA at the time) as best suited for a supersonic transport. The information was in the public domain by the time the "BAC223" and "Super Caravelle" were first revealed (they later "merged" into the Concorde design).
The Tu-144 design used the same information, which is a major reason for its resemblance to Concorde, rather than espionage...
How much the full advantages of the 'vortex lift' were understood at the time, is still an open question, IIRC.
I'll have to look for the original NASA TN (Tech Note)... it may be on the web somewhere.

* I would think the Handley Page HP115 slender-delta low-speed test aircraft must have contributed some details about vortex lift.
http://upload.wikimedia.org/wikipedia/en/thumb/9/92/HP.115.gif/300px-HP.115.gif
Sorry, I can't find my own photos of the beast.
It's now in the Fleet Air Arm Museum at Yeovilton (UK), together with Concorde 002 and the BAC-221.
It still has the "smoke tube" on the left wing leading edge, that was used to visualise the vortex over the wing (not yet fitted when the photo above was taken).

CJ

[asc12]

The simple answer is yes, it was attached flow.

Dare I ask for the more complicated version?

Sidebar: in a supersonic wind tunnel test, do you get a sonic boom?

[CliveL]

Christiaan

Most deltas develop some vortex lift, and there were several deltas flying long before Concorde, so the phenomenon was not unknown.
Shaping the wing, and in particular the leading edge, optimised the effect on Concorde.

Quite true, and I hope I didn't give the impression that it was otherwise. On this side of the Atlantic France had the Mirage series, UK the Javelin, the two Avro aircraft and of course the FD2. However these all had relatively rounded leading edges which reduced the effect somewhat.

* The ogee (slender delta) wing was original proposed by NASA (possibly still NACA at the time) as best suited for a supersonic transport. The information was in the public domain by the time the "BAC223" and "Super Caravelle" were first revealed (they later "merged" into the Concorde design).
The Tu-144 design used the same information, which is a major reason for its resemblance to Concorde, rather than espionage...
How much the full advantages of the 'vortex lift' were understood at the time, is still an open question, IIRC.
I'll have to look for the original NASA TN (Tech Note)... it may be on the web somewhere.

I must admit that I was not aware that NACA had proposed an ogee wing for supersonic transports, although all the US SST designs featured 'double deltas' . Ken Owen's book says that US firms had been working on SST research and design studies since the late 1950s, and since the UK equivalent, the Supersonic Transport Advisory Committee (STAC) ran from 1956 to 1959 and definitely included sharp-edged slender wings amongst their studies, I would say UK work was at least in parallel.

But to be frank, the basic idea sprang from German research done during WW2. They were well ahead in knowledge of the aerodynamics of delta wings as part of their research into aircraft suitable for the higher speeds that went with those new-fangled jet engines. Then, after the war's end, the German scientists migrated to either the UK and US (if they were lucky) or got carried off to Russia. They brought with them all the knowledge they had gained (and of course there were specific trained teams whose job it was to search the German research establishment records for any useful data. On the UK side certainly the idea of exploiting vortex lift for use on an SST was generated by German researchers working at the RAE (Kuchemann and Weber in particular). My guess (I don't know for sure) is that similar things happened in the US, although "their Germans" seemed to be more interested in rocketry.

* I would think the Handley Page HP115 slender-delta low-speed test aircraft must have contributed some details about vortex lift.

Not as much as you might think, because like the 221 it was too late to have much influence and it also was built to study slender delta handling, in particular a possible problem known as 'Gray's oscillations' rather than vortex lift as such.

Clive

[CliveL]

Dare I ask for the more complicated version?Not sure I know how to answer this! I will need to think on it.

I had thought I might have some pretty pictures but I haven't got anything for low AoA. I find it difficult to respond to such a general quetion though. Could you be a little more specific as to the bits that interest you?

Sidebar: in a supersonic wind tunnel test, do you get a sonic boom?Good question!

I THINK the answer is no. You will get the bow shock of course and this will be reflected off the tunnel walls so you must have a big tunnel or a small model to avoid these reflected waves interfering with the flow over the tail of the model, but the pressure rise on the tunnel floor is 'static' and the tunnel walls are massive steel construction. I may be wrong here, but I associate sonic booms with a rapid rise in pressure and a 'movement' of that pressure rise past the observer. In a tunnel you don't get this 'dynamic' effect (unless of course you can arrange to walk past the working section at 660 mph :ok:


CliveL

Edited after some thinking

[M2dude]

CliveL (And ChristiaanJ)
Dude, can I join Christiaan in requesting more information on that '5000' series numbering; I have never come across it before.


Sure can Clive. These are the BA 5102 numbers, Air France 5101 numbers were corespondingly identical chronologically.: G-BOAC - 5102-01. G-BOAA - 5102-02. G-BOAB - 5102-03. G-BOAD - 5102-04. G-BOAE - 5102-05. Although G-BOAG (G-BFKW) and G-BOAF (G-BFKX) were originally Variant 192 (British Unsold) aircraft, these correspondingly became 5102-06 and 5102-07. I wonder if anyone here remembers G-BOAF doing her pre-delivery flying at Filton registered as G-N91AF? I remember when I was at Filton doing one of my Concorde type courses in 1980, and there was good old Foxy Lady with her 'Branniff' registration. She was re-re-registered :rolleyes: to G-BOAF prior to delivery to BA.

Also, I have asked the CAA surveyor who was most likely to have made that reskinning decision for more data. Perhaps he can remember the problem with the forward fuselage skins. Certainly when we were standing together inside 102 last week and talking about fuselage modifications for relifing the aircraft the problem of Component 30 was not mentioned!


The Component 30 skin thickness issue was not relevant for RELIFE 2; you and I know that the major 'skin' issue here was the centre fuselage crown area. The issue of Component 30 was a 201/202 issue only. (Assuming that the French had the need/desire/capability of adding another airframe to their fleet.
And sorry everyone about the £30 cost of converting 202 into an airliner, I meant (dumb ass that I am) £30 MILLION. :\

Best regards
Dude :O

[Shaggy Sheep Driver]

The vortices never provided all the lifting force. Up to about 6 or 7 deg AoA there was no vortex lift, just the usual wing tip vortices. Above that AoA the non-linear (vortex) lift grew steadily until at stall (about 23 deg AoA) the vortex lift was around 45% of the total.

I though delat wings didn't stall provided there was sufficient power to overcome the drag (thought at ludicrously high AoA that power requirement would be ginormouse!)?

[ITman]

In the book The Concorder Story (5th edition) on pages 138 / 139 it talks about the crown modification with pictures of what was done. In précis it states that the crown modification was to strengthen the top of the fuselage at rotate, it states that this was a candle sticked task which required the a/c to be jacked up so the skin has zero stress. The crown modification also included an additional strap over the fuselage just to the rear of the Center door. Appologies for the précis of the text but I hope that this is of use. Oh yes the pictures of the modification are on page 140.

[CliveL]

Dude,

Agreed on crown issue, but I am getting completely negative responses from CAA guys regarding any 201/202 differences such as you describe - nobody remembers it!

(Check your PMs)

SSD

By "Stall" in this case I meant the maximum ift we could use. There was in fact a small 'hiccup' in the lift curve against AoA, but the lift went up again afterwards. However, there was a definite nose-up 'break' in the pitching moment which we took to be the limiting AoA and regarded as a 'stall'

CliveL

[ITman]

May I ask you guys another question relating to the book I mentioned earlier, in the same book it shows a Concorde with a Airbus sidestick control. I wondered if anymore information is known on this modification I suspect t must have been quite an systems integration exercise.

[asc12]

Could you be a little more specific as to the bits that interest you?

No, I probably couldn't.

Let me ask it this way: Could a student in Aeronautical Engineering calculate the lift and drag for (non-vortex) Concorde using the same equations he would use to calculate lift and drag for say, a 777?

In other, other words... I understand that there's a very different phenomenon developing a chunk of lift at high AoA. But the wing still has a very unique shape and camber, so I wonder if-- when the AoA is *not* as high-- phenomena responsible for our 777 staying up fully apply to Concorde.

If I'm just missing the boat completely here, just give me the stern eye and ask me to reread some physics.

[ChristiaanJ]

May I ask you guys another question relating to the book I mentioned earlier, in the same book it shows a Concorde with a Airbus sidestick control. I wondered if anymore information is known on this modification I suspect t must have been quite an systems integration exercise.
ITman, nice question.
I haven't seen any of the detailed (block) diagrams, so I'm not sure at all how the sidestick was "hooked into" the AFCS.

Don't forget Concorde already used "electrical flying control signalling" (aka "Fly-By-Wire")., so system integration would have been easier than on some other aircraft.

For those unfamiliar with the story... F-WTSB, very late in its career, was used for some flight trials with a sidestick controller fitted to the left-hand position (the right-hand seat controls still being the normal ones,and with the right-hand seat occupied by a 'safety' pilot).
The flight test data were later "fed" into the A-320 programme.

How much of the "rate" control and other A-320 control logic was already implemented in the test system is unknown, AFAIK....
Would be interesting to know some more about it, I agree!

CJ

[gordonroxburgh]

The side stick fitted to 201 (in 1977 according to Flight International), was very much proof of concept for what would be the future A320 programme sponsored by the French government, very very limited hours were flown using it apparently (like 10!). The next step I believe in the development was to fit it onto a FBW modified A300 in the early 80s, but for the initial tests to see if a pilot could fly with a "computer joystick" it had to be done on Concorde as this was the only a/c with a suitable FBW system.

It would be good to know how it was done, but I guess it could have been wired into the emergency flight control system, which relied on electrical strain gauge inputs to move the control surfaces if there was a control column jam.

[CliveL]

asc12

Let me ask it this way: Could a student in Aeronautical Engineering calculate the lift and drag for (non-vortex) Concorde using the same equations he would use to calculate lift and drag for say, a 777?


Well yes, there is no magic difference. You could calculate the lift and drag using the same methods as you would for any other delta winged aircraft, or indeed for aircraft with a 'classic' planform. You might have a bit of trouble handling the effects of camber, especially leading edge camber, if you were starting from a clean sheet of paper, but skin friction, form drag and lift curve slope (attached flow) are all calculable by standard methods. You might be pushed to get a decent estimate of lift dependent drag - I spent many hours in my youth looking for wind tunnel results on low aspect ratio delta wings to get some idea of what might be expected, but once you have tunnel tests on 'your' aircraft course there is no problem.

In other, other words... I understand that there's a very different phenomenon developing a chunk of lift at high AoA. But the wing still has a very unique shape and camber, so I wonder if-- when the AoA is *not* as high-- phenomena responsible for our 777 staying up fully apply to Concorde.


Again the answer is yes - in subsonic cruise (0.93M in this case) exactly the same sort of aerodynamics applies - different in detail, but the same in principle.


CliveL

[CliveL]

SSD

I should perhaps add a bit to my first response, which was:

By "Stall" in this case I meant the maximum ift we could use. There was in fact a small 'hiccup' in the lift curve against AoA, but the lift went up again afterwards. However, there was a definite nose-up 'break' in the pitching moment which we took to be the limiting AoA and regarded as a 'stall'
Although delta wings do not stall in the classic sense there is nevertheless a limit to what lift they can provide. As the AoA increases the vortices also increase in intensity, but there comes a point where the vortex flow becomes unstable and the vortex 'bursts', i.e. the circular motion degenerates into chaos and the diameter of the 'vortex' increases greatly.


The point in the vortex track at which this happens moves up towards the wing TE as AoA increases and when it reaches the TE the wing pressure distributions change and you get a break in the pitching moment curve. This happens earlier on one wing if you have sideslip, so you then tend to get a wing drop. This does not meet the airworthiness requirements so effectively vortex bursting over the wing equates to stalling.


[On another thread it has been pointed out that on the FA18 vortex bursting (off the LE extension) has caused handling problems due to interference with the fins]

[CliveL]

Gordon Roxborough
It would be good to know how it was done, but I guess it could have been wired into the emergency flight control system, which relied on electrical strain gauge inputs to move the control surfaces if there was a control column jam



ChristiaanJ

How much of the "rate" control and other A-320 control logic was already implemented in the test system is unknown, AFAIK....
Would be interesting to know some more about it, I agree.


I can't add too much as I was only on the fringes of this.


I think it might have been done by fitting a D/A converter to substitute the digital signals from the sidestick for the normal Concorde stick resolver output. The 'laws' could then be treated as a special case of pitch damper etc. inputs so that the standard Concorde electrical signalling system could be used downstream. I don't know this for sure, it is just a thought - maybe Christiaan could comment on its feasibility.


I think they were looking at at least the rate control but probably not all the envelope protections. Certainly at that time we were having discussions with them about the merits of their FBW laws against the laws we (BAe) were trying out on our BAC1-11 flying test bed. No prizes for guessing who won that argument. :ouch:


And before anyone asks; no I don't remember (if I ever knew) how we were implementing FBW into the 1-11!


CliveL

[gordonroxburgh]

I think it might have been done by fitting a D/A converter to substitute the digital signals from the sidestick for the normal Concorde stick resolver output. The 'laws' could then be treated as a special case of pitch damper etc. inputs so that the standard Concorde electrical signalling system could be used downstream. I don't know this for sure, it is just a thought - maybe Christiaan could comment on its feasibility.

My only reasoning for guessing on the Emg flight system was that its would be easy to turn on and off and recover to the normal flying controls.

For a very short test programme, well ahead of any A320 programme which did not come about till 1984, I suspect this was no more than a belt and braces to see if you could fly an aircraft from a side mounted stick.

[Landroger]

For a very short test programme, well ahead of any A320 programme which did not come about till 1984, I suspect this was no more than a belt and braces to see if you could fly an aircraft from a side mounted stick.

That cannot of been the sole objective, surely Gordon? Concorde was far too complex and expensive an aeroplane to simply want to prove that with her? Wasn't the F16 flying then? That had side stick - and a 'lay down in the bath' seating position didn't it? :eek:

As for the aerodynamics, what a fascinating discussion! I'll readily admit it is mostly on the fringes and way above my understanding, but I can hang on to enough of it to make the subject utterly intriguing. My maths are not and never were anywhere near good enough to make this a career choice, but the image conjured of vorteces and laminar flows and shock waves is quite beautiful.

Thanks again everyone.

Roger.

[CliveL]

Gordon,

[quote] My only reasoning for guessing on the Emg flight system was that its would be easy to turn on and off and recover to the normal flying controls. [quote]

I see what you mean, but surely it would be just as easy to insert a kill switch in other systems?

I'm with Landroger on this in that I feel they would want to do a lot more than just find out if aircraft can be flown with a sidestick. I would expect them to want to know about how much stick movement was optimum and this they could not do with the EMG solution (if I have read your remarks correctly that would have been a stick fixed/force signalled system?)

I am also pretty certain that they investigated control laws; with a simple 'can you fly with a sidestick?' system they would surely be effectively in a electronic version of mechanical signalling?, and although you could fly the bird in mechanical it would be making life difficult for yourself, which is the last thing you want to do when investigating something really new.

[DozyWannabe]

I think Gordon probably meant "airliner" rather than "aircraft".

The implementation of FBW on the F-16 was intended to solve a very different problem than that of the A320 series. The F-16 was one of the most maneouverable fighters of it's day, but the way General Dynamics achieved that was by having an aerodynamically unstable airframe that *required* constant computer correction to keep her airborne and going in a straight line. The A320 was designed to be as aerodynamically stable as any other airliner, but the FBW was simply designed to assist the pilot by easing the workload when it came to actually controlling the thing, as well as provide safety features as backstops when things got hairy.

The only Western analogue FBW aircraft of the time of comparable size to an airliner (IIRC) were the Avro Vulcan and Concorde. France had no Vulcans, so the airworthy test Concorde they had to hand was the obvious choice.

[M2dude]

I personally doubt very much if the Emergency Pilot would be the 'way in' for the sidestick input. EFC ROLL commands were inputed from the SFC computer to the Autostab computers as 'stab demands' and therefore drove the MIDDLE and OUTER elevons only for roll. To make matters worse, if your test flight was really 'exciting' and you found yourself at any time at Vmo + 20 KTS, roll control would be through the middle elevons ONLY. I'm with CliveL in that the most likely scenario would be for the demand would feed via a D/A converter somehow. (It would be great to find out though).
I would have thought that the whole venture was a proof of concept by SFENA for future implementation in the Airbus family. This excersise would have been both costly and highly complex at system level, any other reason would really have been quite daft.

Best Regards
Dude :O

[gordonroxburgh]

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...

[spfoster]

Hi,

I am trying to find out some details of the Farewell Tour for a project I am undertaking.

The flights I refer to were are the following:

Heathrow - Birmingham - Heathrow (20 October 2003)
Heathrow - Belfast - Heathrow (21 October 2003)
Heathrow - Manchester - Heathrow (22 October 2003)
Heathrow - Cardiff - Heathrow (23 October 2003)
Heathrow - Edinburgh - Heathrow (24 October 2003)

All of these flights were scheduled to leave Heathrow at 10:00 hours and arrive at their respective locations at 11:45, and the return was to leave at 16:05 and arrive at Heathrow at 17:45 (apart from the last Edinburgh flight which left Edinburgh earlier in order to get to Heathrow around 16:00)

Does anybody have any details of the routings that these flights took? I have some information about the Edinburgh flight but I cannot find anything out about the others, if anyone can supply me with anything it would be very much appreciated.

Also, were these flights purely subsonic or was there a short supersonic section in there somewhere, after all it doesn't take 1:45 to get to Cardiff, Birmingham or Manchester etc if you go direct.

Many thanks in advance for anything you can offer.

Regards,

Steve.

[gordonroxburgh]

Steve,

I don't have exact details, but I understand the Manchester, Birmingham, Cardiff and Belfast flights were supersonic "round the bay". The round the bay was essentially a trip out to 8w on the normal supersonic flight path, turning 70 miles around the tip of lands end, then decelerating back in down the English channel over Guernsey, where they then routed to the relevant airports.

Edinburgh was supersonic out over the north sea.

[M2dude]

gordonroxburgh
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
It matters not I'm afraid Gordon. I would not have thought that anyone would design ANY flying control system, experimental or otherwise, that does not have full potential authority in all axis. := As we do not know what the PROPOSED flight regime was, on the part of SFENA and Aerospatiale,we also can not assume that any particular manoeuvr would not have been considered. (But as I said before, it would be great to find out the whole story).
The limited authority for roll autostabilisation (and hence Emergency Flight Control) was of course a very deliberate piece of design. (You could test the Emergency Pilot on the ground at ADC Test 2 (Which simulated several seperate overspeeds, including Vmo +20) and when you put in a roll demand (against some resistance), only the MIDDLE elevons deflected. It really looked wierd on the ICOVOL as well as outside the aircraft.
(To any chaps or chapesses who are not aware, above Vmo+20 KCAS, a system known as OUTER ELEVON NEUTRALISATION was invoked, where any input demand to the outer elevons was met by an automatic equal and OPPOSITE input, that of course completely neutralised the demand, giving a zero OUTER elevon deflection).

Best regards
Dude :O

[spfoster]

gordonroxburgh,

Many thanks for that, I had a feeling that's how it would have been.

I assume the return would be routed from say Birmingham or Manchester towards UPGAS to enable it to pick up the normal routing to do the trip out to 8 West and then back into Heathrow.

Not sure how the Belfast one would have routed though, back down to the Bristol Channel via the Irish Sea, or cut across Ireland and pick the track back up when she was back over the Atlantic?

Thanks,

Steve.

[johnjosh43]

"The only Western analogue FBW aircraft of the time of comparable size to an airliner (IIRC) were the Avro Vulcan and Concorde. France had no Vulcans, so the airworthy test Concorde they had to hand was the obvious choice."

The Vulcan wasn't pure fly-by-wire. It's control surfaces were remotely signalled but had a physical connection rather than electrical. Sort of fly-by-stiff wire :-)

One of the spin-offs of having Concorde at Manchester is that it is used by many different organisations for events. One a while back had a discussion about Technology benefits due to Concorde, part of that was about Concordes "1sts". First FBW was challenged as the feeling was that there must have been another by then. Nobody could think of another so it stood the debate. Is anyone aware of any others ?

[MFgeo]

If you limit consideration to aircraft that entered serial production, you may be correct. If aircraft that were prototyped and flew are included then the Avro Arrow was probably the first, as it was designed, flew a partial test program, and got cancelled all prior to 1960!

[ChristiaanJ]

The Vulcan wasn't pure fly-by-wire. It's control surfaces were remotely signalled but had a physical connection rather than electrical. Sort of fly-by-stiff wire :-)Not the first time that's mentioned.
Do you (or does anybody ele) have a schematic of the Vulcan system?
It should be on my CD of the Vulcan manual, but unfortunately my CD drive is on strike.....

MFgeo, I think we're talking Europe here... the Avro Arrow was Canadian,so I would think it unlikely the flight test results would have been available to Airbus.

CJ

[gordonroxburgh]

It matters not I'm afraid Gordon. I would not have thought that anyone would design ANY flying control system, experimental or otherwise, that does not have full potential authority in all axis. As we do not know what the PROPOSED flight regime was, on the part of SFENA and Aerospatiale,we also can not assume that any particular manoeuvr would not have been considered. (But as I said before, it would be great to find out the whole story).


Knowing more now about the safety system, I am agreement with you, getting straight in at resolver level looks the best bet on how it may have been done.

[CliveL]

As we do not know what the PROPOSED flight regime was, on the part of SFENA and Aerospatiale,we also can not assume that any particular manoeuvr would not have been considered. (But as I said before, it would be great to find out the whole story).

I have some feelers out to see if I can get Dudley C's contact details. As Gordon says, he would/should be a good source - keep fingers crossed

CliveL

[johnjosh43]

ChristianJ

Is this what you wanted ?

http://www.flickr.com/photos/josh43/5659650094/

[ChristiaanJ]

Thanks, johnjosh43.

Not a hundred percent legible (lack of resolution), but I'll try to decipher it.

I agree, no trace of any electrical signalling ("FBW").

CJ

[Mark Meeker]

I have been reading these all night, and find all this information really helpful in learning more about this wonderful aircraft.. I do have a question, what was the fuel burn in Mach 2 cruise?? I did not find anything specific about that, and I was just curious..

Thanks
Mark M

[Shaggy Sheep Driver]

About 18 tons an hour I think. More like 80 tons an hour at take-off! The higher and faster she went, the more efficient she became!

[Mark Meeker]

Thats gotta be 18 tons (2000 lb) or roughly 9000 lbs per hour, at cruise?? The 80 ton to top of climb would be 40000 lbs an hour??? Wow..

Thanks
Mark

[dixi188]

I don't know the fuel flow figures but from the type certificate data the max fuel load was 210,000 lbs and the max take off weight was 410,000 lbs. More than half its weight at take off was fuel.

The figure of 18 tons per hour or about 40,000 lbs per hour in the cruise would be about right as the max duration of flight was about 4 hours.

[CliveL]

For a mid-cruise weight of say 300,000 lb and a lift/drag ratio of 7.5 the thrust required would have been 40,000 lbf and the powerplant sfc was around 1 lb/hr/lbf, so 40,000 lb/hr is just about right.

CliveL

[DavvaP]

Out of interest with any successor to concorde, what lift/drag ratio is now technically possible, and likewise from more advanced powerplants that could be available now what lb/hr/lbf numbers could be achieved?

One other question if I may - how much of a compromise was concorde's wing with respect to the balance of supersonic vs sub-sonic efficiency? What I'm trying to ask is if the wing could be a variable geometry with no weight cost (impossible I know) how much more efficient could the supersonic wing have become - or was the compromise very much on the sub-sonic performance and not much to gain in terms of supersonic efficiency?

Once more - thanks for all the great answers to the really intriguing questions!! I'm fascinated by Concorde - and regret I never had the means to fly on her whilst she was still where she belongs!

[CliveL]

Out of interest with any successor to concorde, what lift/drag ratio is now technically possible, and likewise from more advanced powerplants that could be available now what lb/hr/lbf numbers could be achieved?

One other question if I may - how much of a compromise was concorde's wing with respect to the balance of supersonic vs sub-sonic efficiency? What I'm trying to ask is if the wing could be a variable geometry with no weight cost (impossible I know) how much more efficient could the supersonic wing have become - or was the compromise very much on the sub-sonic performance and not much to gain in terms of supersonic efficiency?

I'll try!

The last time I had anything to do with it people were talking about L/Ds around 10.5 in cruise (up from 7.5).

There are technical issues why one cannot use high bypass engines for supersonic cruise, so the thermodynamic cycle would be much the same as the Olympus. That being so the only real gain would come from higher TETs today so the benefits would be limited - two or three percent sfc perhaps?

[Yes I know the USAF are flying supersonic cruise aircraft, but look at how much bypass their engines actually have and the supersonic cruise Mach Numbers]

Obviously the MOST IMPORTANT condition was supersonic cruise, so this dominated the compromise. OTOH, the reserve fuel was largely driven by subsonic performance, so one couldn't give too much away. It might surprise people, but the 0.93M specific range is much the same as the 2.0M value.

As for variable geometry wings (1970s style), the best I can offer is that Boeing started with a variable geometry design (with which they won the design competition), but as the design process progressed the amount of wing that varied got less and less until the Boeing aircraft looked very much like the Lockheed design that lost the original competition.

What do you think?;)

CiveL

[Bellerophon]

Concorde Take-Off. MTOW, LHR, Calm, ISA day, Fuel SG 0.80

Fuel Flow at Take Off, Reheat ON:

20,700 kg/hr/eng......Total: 82,800 kg/hr


45,635 lb/hr/eng.......Total: 182,540 lb/hr


5,704 gph/eng..........Total: 22,818 gph


6,850 USgph/eng......Total: 27,400 USgph


25,931 lit/hr/eng.......Total: 103,724 litres/hr


Start of Roll to Reheats OFF: 83 seconds


Fuel Used: 1,909 Kg / 4,209 lbs / 526 g. (So you can see why the Reheats were turned OFF fairly quickly!)


Concorde Cruise/Climb. 140,000 kgs, ISA, Still Air, Optimum altitude for her weight, speed and number of operating engines:

Fuel Flow in Cruise/Climb, Reheat OFF:


4e...FL520...M2.00...1,147 kts...5,783 kg/eng/hr...23,132 kg/hr


4e...FL290...M0.95......562 kts...3,576 kg/eng/hr...14,304 kg/hr


3e...FL270...M0.95......567 kts...5,560 kg/eng/hr...16,680 kg/hr


Concorde fuel usage.

20kg of fuel to travel each supersonic mile, at M2.00


25kg of fuel to travel each subsonic mile, at M0.95 (four engines)


30kg of fuel to travel each subsonic mile, at M0.95 (three engines)


60% higher at M2.00 than at M0.95 (four engines)


40% higher at M2.00 than at M0.95 (three engines)


Concorde Range reduction.


When we factor in the decel, descent, approach and landing (all of which had obviously been originally flight planned at subsonic speed anyway) and the actual decrease in range, following a speed reduction, was roughly:

M2.00 to M0.95 (four engines) a range reduction of 20%


M2.00 to M0.95 (three engines) a range reduction of 30%


It was this last figure, the circa 30% loss of range following an engine shutdown and subsequent deceleration to subsonic cruise, that perhaps most occupied the minds of her operating crews.

Coupled with the change from a generally benign environment of low winds and low temperatures at FL550+, to the more hostile environment of high temperatures and much stronger (head)winds to be expected around FL290, this meant that on routes such as LHR-BGI, the greater challenge was often keeping the 3-engined diversion airfield (usually ANU) in range, rather than the destination airfield (BGI).

Fortunately the fuel planning and monitoring on this route was eased greatly with the publication of some pilot-friendly "How-Goes-It" types of graphs and charts by one particularly bright Flight Engineer.

LHR-BGI, always a challenge, always enjoyable!


Best Regards

Bellerophon

[CliveL]

4e...FL520...M2.00...1,147 kts...5,783 kg/eng/hr...23,132 kg/h

I stand corrected, but am surprised it was so high :O

[Bellerophon]

CliveL

You got me a little worried there, so I've just checked the figures I quoted in case I'd slipped up! They were extracted from the Cruise Control Manual (rather than from observation on an actual flight) for a lecture some years ago.

I'm relieved to say they appear to be correct. By way of contrast, to show the variation in fuel flow there could be, the following is perhaps typical of Concorde approaching her decel/descent point into BGI.


Concorde Cruise/Climb. 110,000 kgs, FL600, ISA -15°C:

Fuel Flow in Cruise/Climb, Reheat OFF:


4e...FL600...M2.00...1,107 kts...4,308 kg/eng/hr...17,232 kg/hr


Best Regards

Bellerophon

[CliveL]

Bellerephon

Digging a little I see that your numbers correspond to an sfc of 1.23 where I was remembering a value around 1.0.
I forgot the installation losses :O

Best Regards

Clive

[Self Loading Freight]

So, uh, what's happening here?

Feòrag NicBhrìde - So, what's this then? (http://feorag.livejournal.com/444744.html)

Some very odd activity around Concorde recently at LHR, or so the poster claims. No idea if the pic is genuine or how recent it is if so, but it can't be that old.

[Self Loading Freight]

Here's the link to the same image (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=heathrow+airport&aq=&sll=50.431691,-4.145614&sspn=0.091415,0.222988&ie=UTF8&hq=heathrow+airport&hnear=London+Heathrow+Airport+(LHR),+234+Bath+Rd,+Harlington ,+Hayes+UB3+5AP,+United+Kingdom&ll=51.475379,-0.423408&spn=0.00271,0.006968&t=h&z=18) in Google Maps


So it is kosher.

[steve-de-s]

It’s a very out of date picture, even the structure hiding her has now been demolished, and there is a more up to date picture of her present location in the latest news section of Heritage Concorde

[ZimmerFly]

June 27th, 2010 according to Google Earth :8

[steve-de-s]

Well Google is wrong!

She has been moved to the new location!!

[ChristiaanJ]

Google was right....

G-BOAB has been moved around LHR repeatedly, and she was indeed parked for some time inside the old "detuner" (engine run-up silencer), which is what that recent "what's this then" post and picture are all about.

It's a pity, really.... All the other British Concordes have found a "home" one way or another (except G-BOAF, maybe,, but let's not go into that for the moment), and G-BOAB is slowly becoming the "forgotten" Concorde.

CJ

[rh200]

G-BOAB is slowly becoming the "forgotten" Concorde.You could send her over here, I'm sure there plenty of people in Aus who would love to give lots of love and attention!

[Quax .95]

You would not wind up on the brakes either, the carbon brakes were extremely sensitive to overtorquing.
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?

[Self Loading Freight]

Club Concorde (http://www.clubconcorde.co.uk/) seems very bullish about its plan to moor G-BOAB in the Thames outside the London Eye. I asked around the office here (just down the river in Southwark); nearly everyone thought it was a fabulous idea.

[tristar 500]

Quax .95
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?

What makes you think they would not have any brakes?? When performing any engine runs always set the brakes & chock the wheels.

Just think back to the A340 that was written off in France when the brakes were released & the aircraft jumped the chocks.

tristar 500

[forget]

When performing any engine runs always .... chock the wheels.:=

I've got good reason for knowing that's wrong. Some time ago in the A340 discussion I said that chocks shouldn't touch the wheels but be set ahead of them by about a foot. Welllll ...... The wrath of the Eng and Tech city fathers came down on my head - until some kind soul posted the passage from the 747-400 AMM. Bingo. :ok:

[ChristiaanJ]

Quax .95
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?
What makes you think they would not have any brakes?? When performing any engine runs always set the brakes & chock the wheels.
Just think back to the A340 that was written off in France when the brakes were released & the aircraft jumped the chocks.
tristar 500tristar,
The question is less odd than it seems....
With full take-off power plus reheat, Concorde could not be held on brakes alone (hence the various procedures at take-off).

Maybe somebody has the full story.... in the light of chocks being less than perfect....

CJ

[ZimmerFly]

I cannot imagine any requirement for more than one engine (with or without reheat) to be run at full power when parked in the detuners. Thus there would be very little chance of exceeding the brake torque limits.

[steve-de-s]

I was at Heathrow on last Sunday, 15th May; G-BOAB is still in the location detailed by Heritage Concorde. Also I can confirm that the detuner where you can see G-BOAB parked in the other picture, has now been completely demolished.

[tristar 500]

ZimmerFly said
I cannot imagine any requirement for more than one engine (with or without reheat) to be run at full power when parked in the detuners. Thus there would be very little chance of exceeding the brake torque limits.

Brake torque us only one of the things you have to think about when running at high power.

Consider running an engine on one side with all the others at idle or even shut down, what do you do when the aircraft starts to slide sideways?

The engine run drills call for "balanced" power. What this means is that you have to balance the power which means running the opposite engine at high power also.

Been there, done that!!

tristar 500

[ZimmerFly]

I know we seem to be straying a little off topic, but having two engines at high power against brakes set to park and all wheels chocked is going to produce a lot less torque than say a sudden stop from 30 knots at RTOW.

[I am too lazy to attempt the sums !]

[forget]

.... brakes set to park and all wheels chocked :hmm:

4 years ago Spanner Turner came to my rescue on ground runs with -

Quote below is from the Maintenance Manual. (a 747 manual, but you get the picture).

C. Prepare for Engine Operation.

(1) Check that airplane is parked in clean area with wheels on areas
that are free of oil, grease, or other slippery substances.


(2) Make sure the wheel chocks are installed at the main landing gear
wheels and ground locks are installed.


(a) Do these steps if you will operate the engines for a high power
engine run.


1) Make sure that the forward wheel chock is six to twelve
inches in front of the tires.

NOTE: This will cause the thrust of the engine to be held
by the frictional force between the airplane tires and the
ground, and not the wheel chock. The wheel
chocks do not have the same frictional force as the
tires. If the tires touch the wheel chock, some of
the frictional force between the tires and the
ground is lost, and the airplane can skid. The
wheel chocks are only used to prevent the airplane
from rolling if the airplane brakes were
accidentally released before or after the engine run.

[atakacs]

maybe not the proper place but I wanted to share this (http://www.konnek-t.com/Info/Images/concorde/index.html) very nice and supposedly recent photo gallery on the topic...

[Landroger]

maybe no the proper place but I wanted to share this very nice and supposedly recent photo gallery on the topic...

Oh wow! :ok:

Roger

[ChristiaanJ]

Photoshop, most of it, I would say.
Still, well done.

CJ

[rodlittle]

it does say cgi if you lookhttp://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/wink2.gif
rod

[Landroger]

Photoshop, most of it, I would say.
Still, well done.

CJ


it does say cgi if you look
rod


I know, I know. :rolleyes: I saw that, but the images are just the ones you would like to have taken ............ if you wouldn't have been arrested if you'd tried to. :uhoh:

Roger.

[ChristiaanJ]

Landroger,
What triggered my remark was merely that I don't think there's any record of a BA and AF Concorde flying in formation near to the LearJet....
But yes, we would all want to have taken photos like that.

And all of us still hope that there is a video somewhere, somehow, of one of Jean Franchi's barrel rolls.....

CJ

[max_torque]

Firsty, i would like to say a big "hello" and "thanks" to everyone who has contributed to this fantastic record of Concorde development and Service!!

I grew up in South Oxfordshire, and on weekday mornings, at what i remember to be a bit after 11am, we would hear the "roar", and run outside into the garden to look up as she passed overhead. The most wonderful racket ! A perfect white arrow, spearing off to exotic destinations, we used to try to guess who might be aboard ;-)

Certainly one of the things that made me interested in engineering, and something to be proud of ;-)


So, here's 2 questions that i hope someone might be able to answer:


1) roughly, how many people worked on the complete development program?

and

2) How many total passenger miles did the fleet clock up over it's service life??


As someone who is now an automotive controls engineer, i have serious respect for the people who built and tested Concorde. We now take for granted being able to log and analyse data over 100's of channels at kHz rates with just a laptop and a small input conditioning box. Having been round 101 at Duxford, and seen the size and capabilites of the engineering flight recorders fitted (and the 1000's of wires linked to them) i tip my hat to anyone trying to get that all to work ;-) :ok:

[M2dude]

I've been away 'cruising' for a few weeks (lecturing about Concorde) and thought it was time I popped back into this wonderful forum.
There were a few questions regarding ground running Concorde, so here are some 'facts' as far as I recall (Wrinkled old brain permitting).

Concorde was ALWAYS ground run in the detuners at the BA Engineering base at Heathrow, with the parking brake ON. (Save idle runs on the ramp after, say, replacing a PNC actuator etc. on departure. The required high power nozzle trim run could be deferred until the aircrafts return to LHR). Sadly I can confirm that the Concorde 'Hush House' was being demolished when I was last over the engineering patch a few weeks ago, and is probably all gone now.

The detuner chocks were like nothing else you could imagine. They were HUGE steel affairs that needed wheels to be wound down in order to move into position (took a couple of guys at least to move). Once in position forward and aft of the undercarriage, the wheels would be retracted and these 'chocks' would be tension chained together. Believe me, nothing was going to move these suckers!! :=

Engines WERE NOT run in symmetrical pairs, but the adjacent engine always was run at idle power. The reason for this was so that there was airflow over the T1 probe of the adjacent engine, a winding in this being used by the alternate engine control lane if needs meant it might be required if the main lane failed during the engine run. The way that the aircraft was tethered meant that symmetrical high power running was not any sort of issue.:ok:

We were very mean too. In the summer the hangar doors of TBK opposite would invariably be open during the day, the challenge was to see how long it took for us to make them close the doors to shut out the din. (Like I said, Concorde engineers were mean :}).

Good to be back
Best regards to all
Dude :O

[Jane-DoH]

What was the minimum maneuvering speed for Concorde
- At a typical takeoff weight?
- At MTOGW?

Also what was the typical climb speed
- At lift-off?
- Once 240 kts is achieved?
- At minimum maneuvering speed at typical takeoff weight?
- At MTOGW?

[NW1]

What was the minimum maneuvering speed for Concorde
It was expressed in the flight manual as "Lowest Authorised" speed, Vla, and didn't depend on weight. 0-15,000' Vla=V2 or Vref as appropriate, 15,000'-41,000' Vla=250kias, 41,000'-60,000' Vla=300kias

Also what was the typical climb speed I'm guessing you mean rate of climb rather than IAS?
- At lift-off? From memory Vr was around 200kts, V2 around 220kts and if restricted to 250kts (way below min drag) you'd get pretty poor rates of climb - about 1000fpm if you were lucky and IIRC - you'd quickly want to lower the nose, just barely climb and get her up to 400kts when she'd really fly...
- Once 240 kts is achieved? see above - but once you got her up to min drag (about 400kts at MTOW) things went better - about 4000fpm without reheat
- At minimum maneuvering speed at typical takeoff weight? At V2 she staggered up due the the drag of the slender delta wing at low IAS - but climb performance on three engines (in contingency reheat) at V2/MTOW was better than a conventional subsonic jet on three / MTOW / V2 due to conservative certification requirements of the TSS
- At MTOGW? Does the above answer your Q? Happy to add more if you need...

Edited to add, most transatlantic takeoffs were at MTOW - around 185 tonnes - and due to the slender delta aerodynamics, weight didn't affect performance as much as a conventional wing anyway because induced drag was the bigger player at slow speeds - and I've just completely exhausted my very limited grasp of aerodynamic engineering!!

[911slf]

That 250 kt limit had a truly startling effect on climb rate. Compared with an unrestricted climb, how much would that limit cost in fuel?

[CliveL]

Well it took a long time, but Dudley eventually came up trumps!

http://i1080.photobucket.com/albums/j326/clivel1/scan0110.jpg (http://www.pprune.org/%3Ca%20href=)">

If anyone wants more, the source is an AGARD CP 260 by Cazenove and Ivroas ( but I have not been able to access the only URL that comes up on Google!)

CliveL

[Bellerophon]

http://i303.photobucket.com/albums/nn142/Bellerophon_photos/minimanchebr4.jpg

[CliveL]

Thanks for that much better picture Bellerephon.

I have a bit more information now, although my French is very rusty so I may not have it all correct - CJ can probably correct me if necessary.

They did 8 flights over 10 hrs, preceded by about 30 simulator 'flights'. Most of the flight testing was looking at low speed behaviour, since that was where they expected to see most gains on Concorde, and where the most problems might be expected, but they did go up to 2.04M. The primary advantage was seen to be the possibility of using very aft CGs for takeoff to reduce trim drag - they flight tested as far back as 56% at around 0.4M (no consideration of limits from U/C location of course for this sort of testing). In addition they were predicting a weight saving of around half a tonne.

The simulator work sorted out the basic laws, where they tested a pure pitch rate feedback and a C* law with load factor and pitch rate terms. The pilots preferred the latter (which became in time the basis for the A320 laws).
The simulator was also used to establish the best ergonomics (movement and force harmonisation) of the sidestick.

The 'blue' electrical signalling system for elevons was replaced by the digital control and sidestick arrangement, keeping the 'green' signalling as a safety backup. Normal rudder control system was retained, as well as the mechanical backup.

In the general arrangement of the digital control system one can see clearly the genesis of the A320 design - two computers with the software written by separate teams etc.

Pilot reaction seems to have been very favourable, the aircraft being somewhat easier to fly than the basic Concorde (which was already pretty good ....).
In particular the paper suggests that the precision with which the aircraft could be positioned was much improved.
Stick force per 'g' was pretty much the same throughout the speed range at about 7daN/g, whereas on Concorde it varies from 20 to 40 daN/g - but on a sidestick rather than a control column of course.

One problem that did show up, although not peculiar to Concorde, was the sensitivity of these systems to structural response, particularly during ground roll.

Not contained in the report, but in a side letter from Dudley, is a remark that the guy most responsible for the development of the Concorde basic system and later in charge of the Airbus system thought that these Concorde experiments were the key to the success of the A320.

'Nuff said!

CliveL

[stilton]

Never get tired of this thread !


Very interesting about the sidestick, was the installation and testing purely for research / experimentation purposes or was it seriously contemplated for use in production Aircraft ?



If so, why was it decided against ?!

[CliveL]

Basically an R&D exercise I think, funded by the French government in the same way as NASA might fund as similar research project.

It was done at just about the time that Concorde development was being abandoned, but had anyone seriously contemplated a Concorde 2 then ths would certainly have figured in the design.

[M2dude]

As I recall, they referred to this research project as a CCV (Controlled Configured Vehicle) design study. It would be great if we could get this confirmed, but they talked about subsonic drag reductions of 10 to 15% by flying (not taking off!!) with a far more aft CG than the norm. The 'system' I seem to remember, as a result naturally commanded some down elevon, which increased lift. As the aircraft could then fly with less alpha, I guess this is where the drag reduction comes from. (Clive, I wonder if you could find out through one of your contacts if this was true?).
I'd still personally like to know how the sidestick was integrated into the flying control system, I've been thinking and can not now believe that sidestick inputs could be simply input to the flying control system 'at resolver level'. Remember that the concept of the FBW system on Concorde was that resolvers were utilised as simple 4 wire synchros, and the pitch and roll axis utilised a CX/CDX/CT chain, which produced the error signal to the ESA's in the Autostab computers. Using a sidestick completely breaks up the chain, and my guess is that a seperate digital unit contained the flight rules which were summed against PFCU CT position and sidestick input would have been necessary. It is possible then that an analog output from this 'box' could be fed to the Autostab Computer ESAs and hence drive the elevons. I'm probably completely wrong, but I'd surely still love to know the truth. As you say Clive, ideal stuff for Concorde 2.

Best regards
Dude :O

[CliveL]

Don't need no contacts Dude. The drag reduction came simply from flying at a lower AoA when trimmed at an aft CG. Less 'up' elevon, which is similar but not the same as 'down elevon' in an absolute sense, so less adverse elevon lift and work the wing to a lower AoA in consequence. Just an extension of the basic Concorde certification with a 'point' TO CG really.

They were certainly looking to study control laws that allowed flight at very aft CGs to increase aircraft performance, so yes, this was a CCV exercise, but they were also seeking experience with digital control and system architectures that could be transferred to other active control applications.

The 'sidestick' arrangement was virtually a complete A320 style arrangement using two computers and digital signalling throughout. For just 10 hrs they wouldn't need anything more complicated than a 'panic switch' to return control to the standard Concorde green system that was still there and available.

Clive

[M2dude]

Thanks for the info Clive, now all is explained. (And I take your point about the elevon deflection).

Best Regards
Dude :O

[Shaggy Sheep Driver]

Shirley the aft CG research for lower cruise drag could equally be done with conventional Concorde controls? Why is it associated only with sidestick control?

[CliveL]

They weren't looking for cruise drag reductions; just takeoff climb improvements which would have required genuine relaxed stability - CGs back at the aerodynamic centre etc.
This entailed introducing artificial stability terms that would have been difficult in a purely analogue system such as the basic Concorde controls, so they decided to go digital.
Sidestick or conventional control column doesn't come into that of course - see Boeing vs AI FBW systems; but no doubt the French government saw the opportunity to get two for the price of one .....

CliveL

[stilton]

Did the Sidestick controller have the same authority as the Conventional Control yoke or were there 'hard limits' a la Airbus 320 and on ?

[CliveL]

Same authority as basic controls - no envelope 'protections' or other hard limits so far as I know.

[Jane-DoH]

NW1

It was expressed in the flight manual as "Lowest Authorised" speed, Vla, and didn't depend on weight. 0-15,000' Vla=V2 or Vref as appropriate, 15,000'-41,000' Vla=250kias

I assume in the US then you were restricted to 250 kts below 10,000 feet just like all other aircraft?

41,000'-60,000' Vla=300kias

Why higher speed? That have to do with shockwaves and the resulting pressure distribution differences?

I'm guessing you mean rate of climb rather than IAS?

No, I meant the airspeed you'd be flying at while climbing (post takeoff)

if restricted to 250kts (way below min drag) you'd get pretty poor rates of climb - about 1000fpm if you were lucky

Wow, that's pretty bad. You'd figure with a T/W ratio of around 0.40 you'd do far better than most other aircraft.

and IIRC - you'd quickly want to lower the nose, just barely climb and get her up to 400kts when she'd really fly...

Were you allowed to get over 250 below 10,000 feet in the US, or UK? Regardless, what rate of climb would you get at that speed?

most transatlantic takeoffs were at MTOW - around 185 tonnes

408,000 pounds?

[CliveL]

Quote:
if restricted to 250kts (way below min drag) you'd get pretty poor rates of climb - about 1000fpm if you were lucky
Wow, that's pretty bad. You'd figure with a T/W ratio of around 0.40 you'd do far better than most other aircraft.

With respect, that sounds more like the sort of climb rate associated with noise abatement rather than full power. Brian Calvert quotes 250 kts/2000ft/1000fpm/12deg attitude/reduced thrust for this. At 8000ft/400 kts/dry climb thrust he quotes 3000fpm, which is more the sort of number I would have expected (it is all a long time ago ......)

[Jane-DoH]

CliveL

Brian Calvert quotes 250 kts/2000ft/1000fpm/12deg attitude/reduced thrust for this.

Then what does 250 kts, 19-degrees of climb, afterburners engaged produce?

[galaxy flyer]

Noise, high rates of fuel consumption, mostly.

GF

[NW1]

<<I'm guessing you mean rate of climb rather than IAS? >>
<<No, I meant the airspeed you'd be flying at while climbing (post takeoff)>>

OK, then the answer to your Q's:
Also what was the typical climb speed
- At lift-off? About 200kts
- Once 240 kts is achieved? 240kts
- At minimum maneuvering speed at typical takeoff weight? Vla after takeoff was V2 until 15,000'. I.E. about 220kts
- At MTOGW? V2 didn't vary much by weight

Out of JFK we flew at Vmo once further than 12nms from the coast. Vmo=400kts IAS at low level.

Out of LHR overland the IAS restriction was 300kts until past the speed limit point early in the SID - much less draggy than 250kts and hence better climb rates. But you'd quickly be released to get to 400kts (barder's pole) where it was designed to be flown.

<<Why higher speed? That have to do with shockwaves and the resulting pressure distribution differences?>>
The flight envelope was bigger and more complex than subsonic types: it was developed in flight test and probably had many considerations involved. I think someone posted it earlier in this thread in graphical form (from the flight manual) if you want to see it. In practice, you had to be aware of three basic parameters - IAS, Mach and CG position (the CG "corridor"). Once understood, it wasn't that difficult to keep up with it...and the IAS and Machmeters had barber's poles handily programmed to show the limiting values (including, cleverly, max temp on the nose Tmo=127 degrees celcius).

Regarding climb rates - best ROC was at 400kts (MTOW) or 380kts (MLW). As speed reduced below that, drag increased and ROC reduced. At MTOW and 400kts you'd get about 4000fpm max dry power. At 250kts it was all noise and very few feet per minute - after noise abate procedures you had to lower the nose, just barely climb, and get IAS up toward min drag as soon as possible. With an engine failed go for 300kts minimum - Vmo as soon as you can.

<<shockwaves and the resulting pressure distribution differences>>
You had to avoid the "transonic" region due to these effects: maximum subsonic cruise was 0.95M due to the auto-stabilised flying controls become over-active as shockwaves started to "dance" around the airframe (usually asymmetrically). This calmed down by about 1.3M in the acceleration (when the intake ramps started to do their thing). To accelerate to 2.0M you needed reheat until 1.7M so you didn't hang around between 0.95M and 1.7M. FL260 was best for subsonic cruise because at that level 400kts IAS = 0.95M...

[ask26]

At the time Concorde stopped flying was she making a profit?

My question however is this:
If we assume that the Concorde operation is not for profit, what should have been the cost of a ticket per person in 2003 to have broken even.

If she was still in service today, given airframe and engine servicing, fuel prices etc... what would have been the cost today of a ticket?

[Heliport]

Heads up for Concorde enthusiasts -

http://www.pprune.org/aviation-history-nostalgia/455846-wind-beneath-my-wings-john-hutchinson-concorde-pilot.html


Biography just published.

[M2dude]

Concorde Profitability
Ahhh that question again. Just concentrating then on matters on the UK side of the English Channel. Prior to the Paris crash, BA was making a very healthy profit indeed on it's Concorde operation. There were some blots on the horizon that had to be overcome (Relife 2, SFAR regulation implementation, EGPWS and GPS navigation enhancement etc.) but all these things were 'doable' and under both study and disussion.
After the Paris crash came the horrible events of 9-11; around 40 regular BA Concorde passengers were tragically lost in the twin towers alone. When the aircraft returned to service in November 2001 the loads (and profitablity) were understandably taking a major hit, but as all times in her service life Concorde had the ability to weather the storm and was already bouncing back well. Unfortunately in 2003, due to some totally disgusting goings on, on the French side of the Channel, the aeroplane never got the chance to fully recover and BA services ceased in October of that year. (It is to the eternal shame of certain individuals on THIS side of the Channel that this French Disconnection was never challenged legally).
Concorde was only ever run (that is at least in the UK) for profit, but the hike in oil prices would obviously pushed up ticket prices significantly, and the massive economic downturn of last year would have certainly meant a temporary reduction in services. But in spite of all this, I firmly believe that Concorde would have weathered this storm, and would have been now earning those bucks for BA yet again.

John Hutchinson - The Wind Beneath My Wings
A superbly interesting read, written about arguably the most eloquent of all Concorde pilot speakers. One of lifes true gentlemen and a superb pilot, it is a long overdue biography, well done Hutch.

Best Regards
Dude :O.

[Shaggy Sheep Driver]

Concorde's min drag speed... was it 350kts or 400? I've seen both reported. Whichever it is, I understand it equates to approx M0.95 at 29,000 feet hence the subsonic cruise being generally flown at that relatively low altitude.

SSD

[speedbirdconcorde]

Just viewing some 'old' in-flight footage...gosh...she was such a beauty...have to say I've never been on any other aircraft which, during taxi, had people stop what they were doing ( servicing aircraft ! ) and just watch her pass by .... anyhow, before I become a sentimental ol' bugger........I noticed that the time between Mach1 being displayed in the cabin, and, in this case Peter Benn announcing that we were indeed Mach1, 40 seconds had passed ! ( Thanks Peter for making that flight so memorable. Your obvious enthusiasm for Concorde made for a very memorable flight - thank you ) - I know Christiaan gave an explanation some time back...but 40 seconds seems a long time ! Any other reasons as to the 'very' early Mach 1 announcement in the cabin ??

Best wishes everyone,

d :ok:

[M2dude]

Speaking as a fellow sentimental ol' bugger, Peter Benn's commentary 'delay' (a truly nice guy by the way) is a simple case of between Mach 0.98 and Mach 1.02 the displays only showed Mach 1.0. So that's where we get our delay from.
Mach 2 was a bigger 'lie'. Anytime you were above Mach 1.98 the displays would only show Mach 2. (I've been to Mach 2.1 on test fliights but the pesky things still only showed us Mach 2).

Best regards
Dude :O

[joelgarabedian]

I've always been fascinated by Concorde, and I've been following this incredible thread for some time now.

For my birthday last month my wife bought me an experience on the Concorde Simulator at Brooklands, which has been mentioned on this thread a couple of times. I had an outstanding time, not only with the simulator itself, but meeting people who were involved with Concorde and keen to share their enthusiasm. I heartily recommend the experience to anyone with an interest in Concorde. And the money goes to improving the simulator, so it's for a good cause!

Joel.

[sAx_R54]

71 pages later my personal edification is complete!! All contributors, particularly the 3 venerable concateers (you know who you are!), many thanks for the most captivating of insights.

3..2..1..Now indeed! Bravo I salute you:D:D:D:D:D!!

sAx

PS Having watched the Concorde Story, some consideration of sorts would need to be taken of events in the immediate aftermath of the Gonesse crash. AF from their perspective took the responsible position to ground aircraft, where BA continued flights later that evening following a business as usual approach. This proved quite upsetting on the French side of the Channel, as reasons behind AF4590's crash where unknown at that stage. The Gonesse Mayor being very critical about what appeared to his eyes to be a quite callous BA attitude, placing commercial consideration before public safety.

To rule any two individuals, the age old philosophy is to divide them. By the time recriminations started to fly from the BA side concerning AF maintenance standards, then the joint collaboration had achieved this for themselves. This left little room for manoeuvre for the CAA, who had to be seen to be placing the public interest before any cash as usual continuity. Their stance would need to be unequivocal, showing the public that the 'gamekeeper' would not be making any attempt to be seen in collusion with the 'poacher' and hence removal of the air worthiness certificate. This is not a riposte of any previous post, but just my $0.02c of what may have played a contributory part in the final decision to retire Concorde. Regardless of any attempt to present a united front, the end result may well have been the same. but it would have gone someway to underline public confidence in the responsible attitudes of both AF and BA.

[steve-de-s]

BA made the right call regarding continuing to fly their Concordes following the crash, and it was a massive mistake by the CAA to ground the British fleet. The whole crash has been one massive cover-up by the French who operated Concorde badly with regard to their maintenance procedures. The crash lies firmly at the door of Air France.
Of course we could go into the list of near crashes by Air France, such as the time when they topped up the hydraulic fluid on Concorde SD with the wrong fluid. The French had problems with their Concordes that the British never suffered, and I am surprised that there were not further crashes with their fleet.
Well done BA for a wonderful nearly 28 years of safe supersonic passenger services!

[johnjosh43]

or at least undercarriage doors. We had a bunch of guys up here at Manchester from AF at Filton last week. They needed a "Concorde fix". While underneath on of them said "Oh Yes your doors are different colours like ours."
I'd never noticed that the metal on the inside of the main undercarriage doors that are open when she's on the ground are different colours. One is a drab green and the other is khaki.
Is there any reason for this or is it just a new one has been fitted at some time and happens to be different ?

[M2dude]

Glad the Filton AF guys enjoyed their Concorde fix. (There is no other Concorde in the UK, bar none, that able to achieve this fix better than G-BOAC can :ok:). As far as the gear door colours go, well the 'normal' colour is the light brown one that you describe, the green primer colour door is a replacement one. (As to when we did that replacement I really can't remember I'm afraid - Extreme Brain Fatigue :\).
I'll have a closer look at that door when I'm next up in Manchester in 10 days.

Best Regards
Dude :O

[gordonroxburgh]

The secondary doors across the whole fleet had lots of issues over time. Like the elevons, rudders and belly panels they were made of a honeycomb lattice structure that eventually dis-bonded causing a lot of overhaul stress in the workshops.

I think it would be fair to say that it would be a freak of nature if any of the aircraft actually had the same doors fitted that they left the factory with!

[whenrealityhurts]

The Concord was scrubbed because when ran as an airline, using typical overweight, RTO type mentality, it's was an accident waiting to happen.

Reminds of the Shuttle...Rutan gets a plane in space...for one billionth the price...so the Shuttle goes away because the people can't keep costs down.

Maybe all this should be put into the private sector where people 'try'.

[galaxy flyer]

Watch out--SSG V 1.0 thru 9.0, the fickle finger is now over here telling us how stupid everyone in aviation is, himself excluded, of course. Apparently, single-pilot Citation drivers (Slow-tation) are thoroughly knowledgeable in Concorde operations.

GF

[whenrealityhurts]

Galaxy, I ponder why you haven't been banned, all I can guess is that you wake up with JT every morning.

[M2dude]

gordonroxborough

The secondary doors across the whole fleet had lots of issues over time. Like the elevons, rudders and belly panels they were made of a honeycomb lattice structure that eventually dis-bonded causing a lot of overhaul stress in the workshops.
I think it would be fair to say that it would be a freak of nature if any of the aircraft actually had the same doors fitted that they left the factory with!

Speaking as someone who was actually THERE during the entirity of Concorde commercial operations (rather than just an amature outside observer), I can assure you that replacement doors were almost always painted when fitted to the aircraft, and NOT left in the green primer colour. Alpha Charlie was a bit of an exeption in that the door was never painted and THAT is the point being made here. No one is even suggesting a freak of nature for goodness sake, and no matter what you may have read etc, this was regular Concorde engineering practice.

whenrealityhurts

The Concord was scrubbed because when ran as an airline, using typical overweight, RTO type mentality, it's was an accident waiting to happen.
Reminds of the Shuttle...Rutan gets a plane in space...for one billionth the price...so the Shuttle goes away because the people can't keep costs down.
Maybe all this should be put into the private sector where people 'try'.

Wow, what total and absolute drivel. For a start it's CONCORDE and not that rather wonderful town in Middlesex County thank you very much. There was NEVER any 'operated using typical overweight RTO mentality' this side of the English' Channel EVER and anyway this had absolutely NOTHING to do with the assasination of the amazing aeroplane.. As far as being 'an accident waiting to happen', well you are obviously at best very poorly informed and at worst you are used to speaking out of an orifice diagonally opposite to your mouth sir.:yuk:
Galaxy Flyer has made a large number of very valuable contributions to this thread and as an ex C5A pilot and highly experienced aviator deserves infinately more respect than you. As far as any bannings here, well look in the mirror fella, and I suggest that you restrict your postings to something that you maybe have some expertise. (Is there a section here on paper aeroplanes maybe?).

Regards (particularly to you GF) Dude :O

[steve-de-s]

Well said M2dude!
I appreciate your comments greatly, which I am fully aware of are based on nearly 37 years of experience, starting with the construction of the Concorde airframes for BAC at Filton, and following this as an engineer with BA keeping these beautiful birds flying.
You are one of the real heroes and stars of the Concorde world, one of the most respected Concorde engineers in the world, add to this fact that you also basically wrote the book for BA on the air in-take system!
It's a pleasure to read all your truly amazing posts based on such great knowledge gained from your mass of Concorde experience, unlike some posts on here which are based on reading books, and listening to the rubbish that’s out there written by those who lack any experience regarding this great aeroplane


Steve

[stilton]

I second that M2Dude and thank you for correcting this m*ron




Interesting how this 'accident waiting to happen' enjoyed a thirty year plus accident free record with BA.

[gordonroxburgh]

Speaking as someone who was actually THERE during the entirity of Concorde commercial operations (rather than just an amature outside observer), I can assure you that replacement doors were almost always painted when fitted to the aircraft, and NOT left in the green primer colour. Alpha Charlie was a bit of an exeption in that the door was never painted and THAT is the point being made here. No one is even suggesting a freak of nature for goodness sake, and no matter what you may have read etc, this was regular Concorde engineering practice.

You missed my point completely really, yes some have green primer , some had beige primer on The INNER side, that was the discussion, not the outer side.
The freak of nature was again a point totally missed on you, which is surprising Ricky. So to explain it in simple words, it's highly unlikely that the aircraft in the fleet are today fitted with the said doors they rolled out of the factory with...that was the point, not a about bad engineering practices about painting or anything silly like that.

[M2dude]

Yawn... For goodness sake let's not nit-pick here :ugh:. If you'd been THERE Gordon you would know what I meant. I WAS refering to the inner side of the secondary door as it happens, any aircraft engineer would know that. (It is just slightly obvious that the outer skin would be painted you know).
The point here is that it is far better if you leave ANSWERS to technical and operational issues to pilots and enginers that were involved with Concorde development and operation and actually KNOW what happened in service. It can be infuriating to the extreme when people that had absolutely nothing to do with the Concorde operation, their entire repertoire of knowledge being based on reading all about in any publication that they could get their paws on or listening to any old nonsense being spurted about by goodness knows who, try and post replies to queries here as if they have set themselves up as a self-appointed 'Mr Concorde'. (Personally I'm happy and humble enough to admit that's certainly not me. Concorde was always a non stop learning process for me and I have never stopped learning to this very day).
Joining the cut up bits of 202 back together is not in the same universe I'm afraid, as living with the aeroplane day in and day out, year in, year out, as impressive as that feat may be to you.
Lesson ends.


Regards
Dude :O

[speedbirdconcorde]

360° Virtual Reality tour of the Cockpit of Concorde by Ken McBride (http://www.kenmcbride.com/concorde/index.html)

:ok:

Check out Kens other VR images on his site...

[hissinsid]

What a cracking image and again, what a cracking thread which I read and re-read to appreciate the machine and the people who operated and cared for it.

Having watched David, Les and Roger more times than my wife cares to remember and studied Mr Calvert's excellent book I find the image facinating in that to the rear of the Captain there are lots of trip switches (?) and below the Flight Engineers table on each side many items that I havent seen before.

If someone could explain what they are I would be extremely thankful!

Kind regards

Sidders

[M2dude]

hissinsid
I have to admit, this is one superb image (and a nice high resolution one also) of my old friend Alpha Alpha.

As far as the trip switches to the rear of the captain, not quite sure what you are refering to I'm afraid unless you mean the area on 213 circuit breaker panels? Also located here are the Audio Selector Panel, the emergency windshield de-ice switches (quite hairy really , 200 volts placed straight on the main windshield heating film with no temperature regulation or overheat protection). As well we also have the lighting controls for the panel and a fully deployed observer's coffee cup holder. :)
As far as the bits either side of the E/O's table, well there is a fair bit, but I'll do my best:
To the left we have the engine start panel, the air conditioning test panel (also encompassing the fuel vent suppression test and indication and gauge limit reset button) and door warning panel. Below these panels are the mode selector panels for the Inertial Navigation Systems and the artificial feel test and Ram Air Turbine control panels. At the very bottom we have the air intake test and diagnostic panels, as well as the anti ice indicator panel. The E/O's Audio Selector Panel and last of all we have the radiation meter and landing gear fault annunciator. (This item is not fitted to aircraft G-BOAG or any Air France aircraft).
To the right we have the Aircraft Integrated Data System panel and immediately below that the compass control panel. (Concorde was one of the very last aircraft to have a magnetic heading reference system, modern aircraft synthesise magnetic heading against true heading and geographic position). Below that we have the oxygen indication panel and to the top right of the section we have the engine and fire test panel. Immediately below this we have the automatic test panel for Automatic Flight Control System and below this the smoke detector test panel. Below this we have the cockpit voice recorder panel and last of all the current monitor panel for the intake secondary air doors.
WHEW!! I hope this helps but if not please ask away.

Regards
Dude :O

[hissinsid]

Dude

Many thanks for your comprehensive reply, you have indeed answered my curiosity and I couldn't for the life of me think of the words "circuit breakers" when I typed my message but you are right, thats what I meant in terms of the area behind the Captain and where the fourth cup holder is :ok:.

I dont think this question has been asked so far and I always wonder, did they all fly the same or did the crews know that each airframe had her own foibles? I do understand that AA was a bit heavier than AG but were there examples of knowing that AC was a bit slow to get her nose and visor down for example?

Many, many thanks for your contributions and expertise I do so enjoy reading this thread, even with a heavy heart knowing shes no longer pushing Mach 2.00.

Regards

Sidders

[speedbirdconcorde]

It certainly makes one wonder what a modern day Concorde cockpit would look like with side sticks and glass everywhere.... would love to be a part of that design team :-) Maybe even update those coffee cup holders and make a place for a latte machine with good ol' bone china cups for the crew when they have a moment to admire the outside view from the heavens.........!! :) lol

Really, if only Britain had the money, the dream could come true all over again....

Regards to all,

speedbird

[Reverserbucket]

M2dude,

Can you tell me what the 'hole' forward of the throttle quadrant between the INS units on the centre console was for please? Would something have been there in service?

Many Thanks

[M2dude]

hissinsid
I dont think this question has been asked so far and I always wonder, did they all fly the same or did the crews know that each airframe had her own foibles? I do understand that AA was a bit heavier than AG but were there examples of knowing that AC was a bit slow to get her nose and visor down for example?
Really one for one of my pilot friends to answer, but there was the one issue where OAC had a heavier right hand wing than the left!! (Due to a major repair done in the early 1980's). And as you correctly point out, the last few aircraft built were indeed lighter than their earlier cousins.
speedbirdconcorde
Love the bit about the latte machine.:D An updated flight deck would indeed look radically different than our 'classic' Concorde office. Perchance to dream:) Personally I think this country needs to find a vision again, not just the money.
Reverserbucket
The hole you mention was a supersonic book stowage. Not very high tech I'm afraid. :E

Regards to all
Dude :O

[steve-de-s]

Save Bristol’s Concorde and the Brabazon Hangar

The Brabazon Hangar dominates the south side of Filton Airfield. During the 1960s it became the home of the UK Concorde production line, but Concorde wasn’t the first aircraft to be built within this amazing structure.
The hangar was originally built during the 1940s to enable the construction of the massive Bristol Aircraft Company’s type 167, which is better known as the Brabazon and hence this is where the name of the hangar came from. This giant airliner aircraft had a 230ft wingspan, and was powered by eight pair-coupled Bristol Centaurus piston engines and was Britain’s attempt at a non-stop trans-Atlantic airliner.

The prototype flew in 1949 six years and £3 million after the conception, and sadly the aircraft was already obsolete. The British de Havilland Comet jet-powered airliner was already well on the way and on the other side of the Atlantic, Boeing were developing their 707, and both of these would fly faster and carry more passengers than the Brabazon The prototype flew for a short while and a second turboprop-powered prototype (Brabazon II) was being built when the project was abandoned. Both aircraft were subsequently broken up in 1953.
With the demise of the Brabazon project Bristol was then left with one of the largest aircraft production facilities in Europe and therefore the giant Brabazon hangars were put to other uses, these included being used for the production line for the much more successful Bristol Britannia airliner.

But the Brabazon hangar has become more famous today as the birthplace of all the British built Concordes, ten airframes were built there, one prototype known as 002, one pre-production known as 01, one development production known as Delta Golf, and of course the seven airliner production airframes detailed below…
G-BOAA
G-BOAB
G-BOAC
G-BOAD
G-BOAE
G-BOAF
G-BOAG
Concorde 216 G-BOAF was the last Concorde built anywhere in the world, and of course the very last one to fly in November 2003. During her final flight she flew back to her birthplace, to Filton to form a major part of a new planned Bristol aviation museum. The plan was to house the whole of the Bristol Aviation Collection, known as the BAC, in one building, a centre to celebrate Bristol’s incredible aviation history, and let’s not forget that Bristol led the world.
But like so many things in this fast changing world, ideas and directions soon change and as in this case not for the better.
Heritage Concorde has heard of one idea that it wishes to push forward with anyone who would be willing to work alongside the group. With next years closure of Filton airfield, one incredible heritage building stands at risk of being ripped down and lost forever, the Brabazon Hangar. So why not use this building as the centre of the history of Bristol aviation and space industry, and in memory of the man who started it all, Sir George White. It’s large enough to form one of the most incredible museums in the world; it would be able to house the whole BAC collection with Concorde 216 at the centre, where she was built.
This idea needs to be looked into and not dismissed so easily by the people leading the effort for the new museum. Heritage Concorde will start to develop this idea further.

Any ideas, any offer of help or advice???
Steve de Sausmarez

[ChristiaanJ]

Hi Steve,

"Any ideas, any offer of help or advice???"
I live too far away to join in the battle, as you know.

But I was thinking of Duxford... which has kept its runway, allowing airshows, fly-ins, etc. (Been there, done that.)
So maybe the runway should stay.... ?

Rather than enclose the Brab hangar in another batch of "little boxes on the hillside" ?

CJ

[EXWOK]

hissinsid;

did they all fly the same or did the crews know that each airframe had her own foibles?

The answer is that they were remarkably similar in handling, I guess this is a function of the flight control system. Certainly the 747-100s and 200s I flew before Conc had a definite change of 'feel' from hull to hull. (The 777s don't).

They all had certain other 'foibles', although none were of any note operationally. I believe that AF's habit of generating ADS master warnings at M1 has been prevously covered, as has AG's 'French' DC system. There were certainly some hulls you'd rather have than others on the LHR-BGI sector, although I think I flew them all there at some point or another.

As for Filton - it's always sad to see an airfield close, but especially so when there's so much history attached. It would be great to see the runway remain active, but the costs are pretty steep and the value of the land rather high. I wish all thise involved the very best of luck and hope you succeed in at least turning the hangar into something which recognises its own history and gives it a real purpose for the future.

[steve-de-s]

There will never be another Concorde, she came from an age that saw flying as something amazing, beautiful and exciting, and there was glamour and style. Today’s world sees flying as cheap and very unglamorous.
But what we have to remember is the as far as the BA operation was concerned, this fuel eating plane as you called it Kalium, paid for itself and made a massive profit for the company, and could have been doing the same today in 2011.
Building another Concorde isn’t about the money, or the dreams. It’s about having the vision and drive to achieve something that can help deliver something truly amazing, Concorde did so much for this country alone, what about all the small companies that were involved with the project, even making the simple items such as ash trays, the project provided work and the workers paid taxes.
We have lost the drive and alone with that the skill to deliver anything of any greatness in this country, we let the world in so many areas and for awhile in aviation, then handed it all over to other countries like France and walked away.
The latest joke is the way we are turning our backs on these amazing new aircraft carriers; they will be world leaders in design and provide so much work for so many.
What is important now is that we fight for the heritage of Concorde, and make sure that we protect the few airframes that we do still have, each one is a prototype, they are so different, what a really shame that the short sighted governments didn’t allow the teams to build production model number 17, this one would of made so much difference and possibly sold in mass numbers.
Concorde, born of a time when we had vision and drive to achieve so much, Concorde was grounded by people with a lack of vision and of course by the nasty Alan (I killed a plane) McDonald!

[speedbirdconcorde]

"Yes, with fuel prices on the rise it's the perfect time to build a fuel-guzzling aircraft."

Who said anything about building a 'fuel-guzzling aircraft' ?

Your words....certainly not mine...:=

I don't believe supersonic travel is dead...maybe just not too alive at the present moment...

As I said, if Britain had financial wealth, they could do something special again ( Just look at Reaction Engines )... But as Dude also added, Britain needs a little more than money....it needs a vision...

and it appears to me, reading some of the posts, that Britain currently has neither..

[steve-de-s]

Britain was in a far worse state financially when she went ahead with the start of the Concorde Project than it is now. But the skills have gone mainly due to bad decisions made by former governments, and you will never get that back again!

There will never be another supersonic passenger aircraft, the next type will have to be faster than supersonic.

[Volume]

Yes, with fuel prices on the rise it's the perfect time to build a fuel-guzzling aircraft.
Today’s world sees flying as cheap and very unglamorous.Well, today there are a lot of cars which are very cheap and fuel economic. And there are those fuel-guzzling SUVs, Sports cars and Luxury Limousines.
Which ones sell better and make more profit for their manufacturers ?
Which British cars are still built ? The Morris or the Mini? Or maybe the Jaguar, Rolls Royce, Range Rover or Aston Martin ?

Of course there is no market for 1000 new Concordes, but maybe for 100. There are still enough people around that pay any price if only they can be special. There are still enough people for whom time is BIG money, and arriving before you depart easily pays off for those. Working the morning in London and having lunch with business partners in New York and signing the contracts in the afternoon is still very attractive.

[Shaggy Sheep Driver]

I think the estimate is that the supersonic passenger requirement today could be satisfied by ten airframes. Hardly an attractive economic proposition for a manufacturer. If it were otherwise, Boeing and Airbus would be addressing that market with a state-of-the-art SST.

[M2dude]

I think we could all speculate until the cows come home just how many SSTs could be built. To put my own two penny worth in here, personally I tend to agree with Steve that to justify the huge capital investment required, a hypersonic aircraft with just about antipodal range would be required. Here in the UK, the Reaction Engines Lapcat A2 project seems to be the way to go. Fueled with liquid hydrogen, making London to Sydney in just around 3 hours carrying THREE HUNDRED passenger. All this using four Scimatar hybrid engines. Contrast this proposal with the clumsy Airbus ZEHST effort that has to use THREE different types of engine for the flight cycle, carries only 100 passengers and won't be around (acording to them) for FORTY YEARS!!. Both imagination and practicalilty seem to be totally absent here.
It seems that the technology required for an HST already exists in the UK (the Scimitar engine is a deritive of the engine originally designed for HOTOL, thanks to the genius of Alan Bond and Bob Parkinson) but we need partners for obvious economic reasons, (probably not European), the will, and most of all, as I mentioned before, the vision to do great things again. In my humble opinion Lapcat A2 should be the true successor to Concorde. If only......

Best regards
Dude :O

[M2dude]

This is obviously a really emotional topic, we can only hope that good sense prevails and the AAH is preserved, along of course with our beautiful G-BOAF. (When I worked at Filton many moons ago it was the largest single span building in Europe, not sure if that is the case now or not).
It would be really nice if the SOUTH of the UK had a non-derilict 'proper' Concorde on display to the public, and good old Alpha Fox would be the ideal example, displayed inside the building where she was born).
There was so much activity in that hangar over the years, wouldn't it also be great if examples of as many as possible of the aircraft that were built, part built or modified there could be displayed too. Let's all keep our fingers crossed.

Best regards
Dude :O

[EEngr]

Is there any development along the lines of a supersonic business jet?

I'd think that the market for air travel breaks down into the masses, willing to pile on board a huge cattle car type AC and sit there for a few hours longer just to save a few dollars (Pounds, Euros, etc.). And then there's a smaller market segment willing to pay whatever for first class accommodations. And possibly to shave a few hours off a transatlantic or transpacific flight.

You are going to want to schedule a few flights on each route per day. When the rich folks (or business people) want to fly, they want to fly NOW. So the passenger loads will be spread across a number of flights, reducing the per aircraft capacity requirements.

[hissinsid]

EXWOK

Thank you for your reply, to hear from someone who flew these truly magnificent machines humbles me somewhat (as did Dude's reply). You made reference to some hulls that you would prefer not to have on the BGI run, could I ask why?

Kind regards

Sidders

[oldchina]

All major aircraft manufacturers publish comprehensive market forecasts, looking at a period of at least 20 years. Not one thinks there's a big enough market for an SST.

These guys are not stupid and would not want to miss out on a juicy new market segment (as the US initially failed to see the domination of the widebody market by twins).

Many things have changed since Concorde was developed. Today probably less than 1% of business travellers can elect to pay more: travel budgets are tightly controlled and firms negotiate bulk fares with airlines.

So the customer base comes down to a few corporate chiefs and a few seriously rich individuals. Not a base for launching a (my guess) $30b development programme. That's a non-recurring cost of $150m per plane over say 200 units.

[EEngr]

That makes sense from the carriers' point of view. Adding SSTs to their fleet would cannibalize their first class. As long as they can keep these passengers happy, they help pay for hauling the cattle in the back.

[M2dude]

As far as the SSBJ goes, there really does not seem to be sufficient demand by the corporations out there, although there have been several stabs at the idea, the most famous being the Sukhoi/Grumman S21. The problem now is, as has been laboured ad nauseam, that neither scarebus or boingo want to go down the road of a long and expensive R & D process without KNOWING whether there are lots of sales at the end of that tunnel. Basically neither of the world's only large aircraft manufacturers have any interest in such a gamble. (And without any serious competition out there they have no reason to either). But we still have the attraction of the HST, typically the Lapcat A2. Anyone who has flown out of Terminal 3 at Heathrow on one of the late night JSA Far East services would know that both First and Business class cabins are invariably bursting at the seams, the intrepid travellers knowing that anything up to the next 24 hours has to be completely written off to the journey. Anyone doing the round trip then has two days completely taken out, not counting those many sweet sweet hours of jet lag. It does not take a genius to work out that a journey time of only THREE hours would be incredibly attractive to a large number of these folks, the trick of course is that the ticket price has to be realistic. The West Coast of the USA is another plumb route, but of course the problem becomes supersonic flight over the continental USA. Polar flying, or over northern Canada is a rather long way round, but possible solution, but of course this whittles down some of the time saving and means we burn more fuel in the process, albeit cheap and very environmentally friendly hydrogen. (And we have of course to assume that a cost effective way of producing and storing large quantities of our liquid hydrogen can be found). It seems that the need for speed is not really out there right now, and to all of us in the world of aviation that has to be a bit of a shame. When Concorde was abandoned mankind took a giant stumble backwards, and for the very first time in history had to settle for far slower journey times. We can only guess I suppose what the future of air travel holds; maybe people are just resigned to being stuffed into bigger and bigger tin cans that go no faster than those cans that came before, who knows. All some of us can do I guess is HOPE that someone out there has just a little imagination.

[DunePrune]

I partly read the book, "By the Rivers of Babylon". Threw it away when I reached the bit about the Concord with an APU (I am not a Concord pilot).

[ChristiaanJ]

I partly read the book, "By the Rivers of Babylon". Threw it away when I reached the bit about the Concord with an APU (I am not a Concord pilot).DunePrune, the book wasn't THAT bad.
And, as you may have seen earlier in this thread, the notion of a Concorde with an APU wasn't all that far-fetched, especially for an El-Al Concorde.

[DunePrune]

I seem to remember that there was no runway in the story, so the pilot just landed his APU equiped Concord in the desert. I am a desert pilot. The author was off his patch and poaching on mine.

[Shaggy Sheep Driver]

Dune Prune; as a pilot myself I long gave up on the film industry poaching on my patch! Life's too short.... the trangressions too numerous!

[DunePrune]

Quite right SSD. Those were my only two posts since joining this forum. I'll maintain a decorous silence from now on.

[M2dude]

Hey DunePrune don't go...... you voiced a perfectly valid point about that book, voiced from the point of view of a pilot too. :ok: I think I speak for the majority of posters when I say that you are most welcome here, please carry on posting. :)
As far as the book goes, well I suppose just like most books it's a rather subjective thing but PERSONALLY I think that book was total crap!! :\ Apart from the old 'Concorde APU' side of things (and I still chuckle at the thought of a sizable pneumatic pipe, carrying HOT passing air through a large fuel tank trying to get certification) there were also several other goofs that gave one the idea that the author was, ahem... not very 'plane minded'. Placing the bomb inside Tank 11 'before it was welded shut' shows total ignorance as far as the way that aircraft are built. The other one was the description of locating a wire by it's colour and the colour of a tracer within that wire. Concorde, just like most aircraft used plain white Poly-X or yellow Kapton Liquid-H cable with circuit identification printed on the cable at regular lengths.
All you did was to voice your very valid opinion here, so don't stop posting DunePrune and stay around.

[Shaggy Sheep Driver]

I'll echo M2's sentiment - stay around Dune and keep on posting. This is a friendly thread! And one that I have found extremely interesting.

[NWSRG]

Hi all,

I'm a humble PPLer, and have been (speed) reading the last 70 pages...a fabulous story, of engineering and operational excellence, which I will read again at length when time permits.

I have only seen Concorde in the flesh on a few occasions...generally while passing through LHR.

But in October 2003, I had the privilege to watch the final Concorde take-off from Belfast at close quarters. I was standing at the GA Apron at Aldergrove as she took off on runway 07, actually getting off the ground barely 150yds from where we stood. I was among a crowd of local aviation buffs, all of whom had managed to cajole, bluff, and persuade their way into the GA area to see her go. And it was awesome. The afterburner roar rippled through my body, the noise was deafening, the reheat flame was mesmerising, but above all she was a beautiful creation.

Art comes in many forms, and to my mind, Concorde was up there with the works of all the great masters.

[asc12]

I was in Seattle for a wedding this weekend, and got to see BOAG at the Museum of Flight.

It was gratifying, but I can't say she's in stellar condition. I'd give her a solid "B" grade. For one thing, it drives me nuts that all the literature and display placards all say "the Concorde." I far prefer Concorde to stand on her own. Her paint was dull and oxidized, and the exhibit sort of stands alone, without much in the way of history or surrounding material. It pained me a bit to see her outside in the Seattle weather, too. The interior is nice, being cordoned off by plexiglass that could stand a replacement sometime soon. I didn't see peeling paint.

That said, it was a spectacularly more enjoyable experience than the last time I saw Concorde F-BVFA at the Udvar Hazy museum in DC, thanks completely to this thread. I noticed things I'd never seen before, and took a much more profound appreciation of things like the curve and droop of the wing leading edge and the complexity of the engine intakes... and I loved seeing the difference in fuel consumption numbers between Concorde and the SR-71 also on display. My wife thinks I'm a genius because I knew why #4 engine was N1 limited below 60kt and what the little 3/4 tag to the left of the engine EGT gauges was for.

Thanks again to all the knowledgeable individuals on this thread.

[DozyWannabe]

My wife thinks I'm a genius because I knew why #4 engine was N1 limited below 60kt and what the little 3/4 tag to the left of the engine EGT gauges was for.

I daren't use the language my wife uses to describe me for knowing that! ;)

[Shaggy Sheep Driver]

I think M2dude had something to do with developing that 3/4 flag! ;)

[asc12]

My wife thinks I'm a very odd, slightly obsessed, guy who knows too much about airplanes he doesn't fly.

I bet I know more about Concorde than the Cirrus I'm actually able to fly. Don't look at me that way-- no forum I frequent has ever had a "Cirrus Question" topic nearly as engaging as this one.

[M2dude]

Nice one guys. I honestly is a pleasure to share my experiences (and feeble knowledge) of the aeroplane with so many wonderful people here, be they aviation professionals, former supersonic SLF or just inerested enthusiasts. Guys and gals, just keep posting away here and remember there is no such thing as a stupid question.
Unless of course it's from me. 'What pert of the aeroplane was manufactured by a division of General Motors in the USA?'.
Oh Shaggy, can't claim credit for the 3/4 flag, or reheat capability indicator', but I remember having a right chuckle when we fitted this highly comples piece of precision engineering (:sad::yuk::sad:) in the early eighties. I thought it was some kind of belated April Fools's joke.

[Philflies]

Sad news on the conculsion of the project in Manchester. Lets hope something can move forward in the future.

Onto this 3/4 tab on the EGT? Can someone tell me more? Or point me in the direction? I have one of Concorde's EGT gauges sat on my TV at home. Extra facts about it to bore visitors with would be brilliant!

[M2dude]

Hi Philflies
The 3/4 tab mounted by the #4 EGT indicator had in fact nothing to do with the EGT indication at all. It wasa reheat capability indicator and was set by the crew prior to take off. Set to 4 meant that all 4 reheats were required for take-off (and if one failed it then meant that the take-off should be rejected). Set to 3 it meant that a single reheat failure could be tolerated and the take-off could continue.
I hope this helps Philflies.
Oh and check out the website BRINGING CONCORDE G-BOAC BACK TO LIFE - Welcome (http://concordeprojectflagship.com/) The fat lady aint singing yet. Also check out the Concorde comes alive thread here too.

[M2dude]

It seems that the Concorde comes alive thread has been deleted. This is such a shame, I tried as hard as I could to keep things civil but others hijacked it again, just as the original thread was. Perhaps we may be allowed to post points about G-BOAC in Manchester here, I do hope so because it is such a fascinating story and is a story still being told.

[john_tullamarine]

The thread hasn't been deleted. I have moved it to an internal review place for comment from those higher up the totem pole. It may or may not return depending on the outcome.

Can I suggest that we let the other subject sit for a while ?

[ChristiaanJ]

Philflies,

M2dude is right, and IIRC there is already a description of this much earlier in the thread.

The background of the 3/4 tab is, that
... on most aircraft you can - at the start of the take-off - 'run up the engines against the brakes', check they all deliver full power, and release the brakes only then.
... on Concorde it was impossible to 'hold the aircraft on the brakes' while going to full t/o thrust including the reheat (not so much because of insufficient brakes as insufficient 'footprint' of the wheels, IMHO).
... so, full t/o thrust (including reheat) didn't occur until the aircraft had already started the take-off roll.

If, at that point, one of the four reheats didn't light (which did happen at times), you did not have an awful lot of time to decide on whether you could continue 'on three' or had to reject the take-off.
Rather than having to check your pre-flight take-off calculations in a sheaf of papers or rely on your memory of the briefing, that little Heath Robinson "3/4 tab" gadget told you instantly whether to RTO NOW, or whether you could continue the take-off.

Sorry to repeat an old story, but Philflies asked the question, and not everybody has read the entire thread.....

[gordonroxburgh]

The thread hasn't been deleted. I have moved it to an internal review place for comment from those higher up the totem pole. It may or may not return depending on the outcome.

Maybe it should be in one of the Misc forums?

[Brit312]

Christiaan,
Just to add a bit more to your explanation is that

The reheat decision speed on every take off was 100kts

If the little tag showed 4 then you needed 4 reheats at 100kts to continue
the take-off

If the little tag showed 3 then at 100 kts you could continue the take-off even if one reheat had failed

If above 100kts you could always continue with the take off, even if a reheat had failed [ always required 3 reheats working]

So if it was a "3 reheat day" and a reheat failed prior to 100kts then a further reheat failure between 100kts and V1 would require the take off to be rejected.

Hope that makes sense??

[ChristiaanJ]

Brit312,

Thanks for that 'add-on'.
And yes, makes perfect sense.

[Philflies]

M2Dude, ChristiaanJ & Brit312. Thankyou for your informed explanations much appreciated. It took a little while trawling through pics on Google images to locate this intruiging tab. It does not appear on most pics, was it a late modification?

Mrs Philflies despairs of the energy wasted looking for this obscure feature! oh well.

Anyway, with the risk of looking daft, is it not by the No 1 EGT? (M2..said No 4 which is maybe why it took me so long to find)

Regards

[Shaggy Sheep Driver]

It's on the captain's side - no. 1.

[BN2A]

Apologies if this (or something like this) has been posted before.. Lots of pages are taking lots of time to get through!!

How it's done.... (http://nycaviation.com/2009/01/concorde-cockpit-videos-takeoff-acceleration-and-landing/)

:ok:

[M2dude]

Humble aplogies to all, of course its mounted by the #1 EGT gauge (ANOTHER senior moment on my part). The RCICS, Reheat Capabilty Indication Control Sub-system (Oh OK then, I just made that up :*) was fiitted in the very early days of Concorde operation. It looked at first sight a belated April Folls joke, but as was said (much) earlier prior to this amazing piece of technology the #3 INS CDU waypoint thumbwheel was used as the reheat GO/NO-GO indicator.
And NB2A, no apologies needed from you sir. A great link to the video starring Dave Rowland and Roger Bricknell (sorry Les).

Best regards to all
Dude :O

[Landroger]

Many thanks for those three clips, that's a half hour out of my life I don't begrudge or regret one bit. :) I'm just so glad the crew were all British and were speaking in the completely clear and unhurried, relaxed yet alert tones of people who know what they are doing. I could understand virtually every word.

Dave Rowland's explanations were very clear and made such a lot of sense when they were happening as part of the sequence. Flying Concorde must have been so, so satisfying? Every flight must have been a small triumph and to think you guys got paid for it!

And yet again Dude, I simply marvel at the amazing systems that made the aeroplane do what it did - and not a digital circuit (except the later engine/intake control processors?) in the place. Truly amazing. Thanks again guys.

Roger.

[ChristiaanJ]

Many thanks for those three clips, that's a half hour out of my life I don't begrudge or regret one bit.
Roger, they're clips from a far longer video (available both as VHS- 2 tapes- or on DVD) from a firm called IITV.
I'm not even sure about the copyright issues of the UTube clips....
But I can assure you the full video is worth watching (and owning...).
Starts off with a full walk-around at LHR, and a lot more 'stuff'.

CJ

[johnjosh43]

Christaan

That video company is ITVV - Intelligent Television and Video. DVD copies are still around on Ebay. 300 minutes of pure delight.

[ChristiaanJ]

Christaan
That video company is ITVV - Intelligent Television and Video. DVD copies are still around on Ebay. 300 minutes of pure delight.Sorry for the typo.
I've got the two VHS tapes rather than the DVDs.

But "pure delight".... yes.
If you're a Concorde 'enthusiast', get your hands on a copy. You won't regret it.

CJ

[Concorde Rules]

A comment was made to me a very long time ago that BA/AF were looking at upgrading her avionic systems [before retirement].

Is this true? What extent of upgrades would occur if they had gone through with it?

[ChristiaanJ]

A comment was made to me a very long time ago that BA/AF were looking at upgrading her avionic systems [before retirement].
Is this true? What extent of upgrades would occur if they had gone through with it?Interesting... but unlikely.

The first question : why? The old analogue systems still worked well.

Second question : who? There were only 14 aircraft in service... who would paid the immense bill for redesign and recertification?

A third question : we know one of the major factors in the 'end of service' decisions were related to the rapidly increasing maintenance costs (as billed by Airbus). A complete upgrade of the avionics (digital, glass cockpit, etc.) would not necessarily have resulted in less maintenance costs.... it would still have been for only 14 aircraft.

In the end, the only real and 'visible' avionics upgrade was the installation of TCAS, and that was only because it was made mandatory.

CJ

[M2dude]

In actual fact BA looked very seriously in the mid 1980s at a limited glass cockpit, where the primary flight and engine instruments would be replaced by and EFIS/EICAS setup, ala Boeing 757. Studies were quite advanced, the main cited advantage was 'reduced cost of ownership.' It seems that the reason it never went any further was, now here's the irony, 'increased training costs. (You have to remember that the 757 was the only glass cockpit BA had at the time, with nothing much else on the horizon).
There would certainly needed to be other upgrades avionics wise, in the fullness of time, but the glass cockpit was not really top of the list. Glaring requirements were improved navigational accuracy, as well as EGPWS together with predictive and reactive windshear protection. (Although to really get the most out of this an EFIS type system is crucial). We (BA) were already looking at both EGPWS and the replacement of the DELCO Carousel 1VAC INS. The Litton 92 had been suggested early on, as it was the only laser INS available with a GPS card fitted, but it is possible that given time an IRS with separate MMR interface would have been used. (This of course now requires an FMC, with a potentially rather involved VNAV profile). As far as EGPWS (and GPS navigation), the main problem was going to be 'where to put the darned GPS antenna' up there on the fuselage crown, but this was being looked at right up to 2003. Providing there was an adequate way of displaying the warnings, predictive windshear protection would have been a breeze, as the Bendix RDR4B radar system (itself retrofitted in the mid 1990s) had the PWS capability merely disabled on Concorde). As Concorde was a highly profitable enterprise for BA during the vast majority of her service life, it is my view that natural avionics updates, such as those described, would have found their way onto Concorde given enough time. (EGPWS, GPS NAV as well as PWS protection would almost certainly have been on board by now).

Best regards
Dude :O

[johnjosh43]

When we are doing the cockpit section of our tours at Manchester on Alpha Charlie we always show guests where the expansion gap is. The other day one of the guides had someone who had been involved in Concorde and he seemed to remember that the expansion was visible somewhere else.
Is this true ?

[ChristiaanJ]

Thanks Dude for the info... something I didn't know either.
Wasn't there also an issue with RVSM (reduced vertical separation minima)?

CJ

[M2dude]

Actually NO CJ. The old steam powered:} analog electro-mechanical Air Data Computers met RVSM minima quite comfortably when trials were carried out, and that amazed the hell out of most of us. (But a Penny & Giles DADC was still being looked at in the early to mid 90s as a potential ADC replacement).
As far as the expansion joint question goes John, there were several expansion joints all over the aeroplane but I don't recall personally being able to see evidence of thermal expansion anywhere else than the aft flight engineers panel. Perhaps someone else here may know something?.

Best regards
Dude :O

[ChristiaanJ]

Thanks Dude,

It amazes the hell out of me, too.
Steam-powered clockwork describes it quite well.....

I was equally amazed that the ADCs on Sierra Delta still work (as described elsewhere).

CJ

[Mr.Vortex]

Hi all Concorde gurus,

Could somebody shed a light to me on how the de-air system work on Concorde and none of the subsonic commercial aircraft have it? Also, if possible,I would like to know that among 32+ fuel pumps,excluded EDP, in the Concorde which one is the most powerful.

Thanks for yours reply. :8

[Kiltrash]

We cannot let this thread be consined to the annuls of forgotten history

There must still be a million questions that you always wanted to ask about this wonderfull plane

So here is mine

On Wikipedia they tell us there were 20 Concordes built, 14 production and 6 pre production

Also Wiki tell us there were 67 olympus 593 engines built

Forgive me but this does not seem possible, not enough engines were built to satisfy 'new' engines for 'new' planes on the production line


Does this mean that the 6 pre production a/c donateded some engines to production aircraft so some BA and AF planes flew, even from new, with 'used' engines??

Many thanks

[ChristiaanJ]

We cannot let this thread be consigned to the annals of forgotten history
There must still be a million questions that you always wanted to ask about this wonderfull planeAll questions still welcome!

So here is mine
On Wikipedia they tell us there were 20 Concordes built, 14 production and 6 pre productionNot quite....

There were two prototypes, 001 and 002 (the ones with the odd porthole visors).
There were two preproduction aircraft: 01, the British one, with a full 'look-through' visor' and 02, the French one, the first one that looked like the production model, with both a 'full' visor, and the 'pointy' tail.
Then there were two 'near-production' aircraft, that were used for certification, route-proving, and suchlike, but that never entered airline service (201 and 202, now best known as 'F-WTSB' and "Delta-Golf").

And yes, then there were 14 production aircraft, that in the end all made it into service with BA and AF.

Also Wiki tell us there were 67 olympus 593 engines built
Forgive me but this does not seem possible, not enough engines were built to satisfy 'new' engines for 'new' planes on the production line.This is still a slight puzzle.....
The '67' figure probably refers only to the version of the 593 engnes for the production aircraft (4x14=56, plus spares), and not to the earlier versions used for development/testing, for the prototypes, the preprods and the cerification aircraft.

Does this mean that the 6 pre production a/c donateded some engines to production aircraft so some BA and AF planes flew, even from new, with 'used' engines??AFAIK, all the production aircraft flew with 'new' engines.

Funnily enough, there's a current discussion on a French Concorde forum on the same subject, trying to figure out not only exactly how many engines were built, but also the "where are they now?".

It would be a nice item to add to the "Concorde Story". We may have to appeal to the RR Historical Trust to open their archives, and tell us exactly how many Olympus 593's were built, and what they can tell us about their history.

CJ

[Shaggy Sheep Driver]

Were there not 21 airframes built? The ones ChristiaanJ lists above, plus the one used for heat and stress cycling in the 'rig'?

[ChristiaanJ]

Were there not 21 airframes built? The ones ChristiaanJ lists above, plus the one used for heat and stress cycling in the 'rig'?You're halfway right....
There were 22 airframes built, even if only 20 of them flew.
There was one in Toulouse, used for static (structural) tests, and vibration tests, and suchlike, and the one at Farnborough, used for heat and stress cycling.
Neither of them survived. It seems a few sections of '0001' still exist somewhere at Toulouse, and a few sections of '0002' are still on display at the Brooklands (UK) museum.
I have no idea whether either actually had space models of the engines in place, or simply representative ballast weights.

CJ

(I made up the '0001' and '0002' designations.... maybe somebody here can still remember what those 'static' airframes were referred to formally at the time?).

[Landroger]

I was recently able - for the first time in about twenty-five years - to visit the London Science Museum. Not only which, I was able to spend the whole day, on my own, with no children dragging me along. :D As always, the Aviation Gallery occupied a lot of my time there, but I was quite surprised that there is very little about 'our lady', when I should have thought she was sufficiently 'white heat of the technological revolution' to qualify for a whole display to herself?

Going on from remarks about tracing the number of 593s still around, there is one there. Right at the back corner of the Aviation Gallery, on a yellow trolley and next to an RB211. Very little explanation to it and none whatsoever of the astonishing intake/engine/thrust bucket combination.

The only other Concorde exhibit, that I could find, was a beautiful 'cut away' model, standing on a mirror. The model was so detailed and interesting, I took a photograph of it, as I did of the 593, but I find my "PPRuNe Posting Rule" do not allow me to post attachments. :ugh:

Is it not slightly surprising that there is not more about Concorde there? After all, I was able to revisit an 'old friend' of mine - the original EMIScanner MkI CT scanner from Atkinson Morley's Hospital - that I used to look after back in the day. :rolleyes:

Roger.

[ChristiaanJ]

Roger,
Slightly O/T, but one does wonder about the Science Museum.
I've been a few times, many years ago....

They had a fascinating exhibit about radar, including its early history (and after all a lot of radar technology was invented in the UK). Then, about the last time I went, I found the entire historical exhibit had simply disappeared.

So, I expect the measly Concorde exhibit you saw will soon disappear too.....

Re your photos, download them to a site such as "photobucket",then post the links. PM me if that doesn't work.

CJ

[mfaff]

Tough crowd....

The Science Museum's primary Concorde display is at the FAA Museum, with 002 and the ogive winged Fairy Delta...

At South Ken the collection is thematically displayed, with Concorde items in a number of galleries; there is a nose cone in the materials gallery, wind tunnel development models in the milestone galleries, next to the Apollo capsule, and the Shorts SC1, plus computer units in the computer gallery and so forth.

Not ideal however quite well done in view of the way that collection is done.

[ChristiaanJ]

Tough crowd.... As I said, haven't been to the museum for years.... So my judgment may be outdated.
At South Ken...the Shorts SC1....Which had no real relation with Concorde. Unless you're confusing the SC-1 with the HP-115 (which is also at Yeovilton).

CJ

[mfaff]

C,

No worries, plenty of very good museums between you and South Ken...

Agreed SC1 has no relevance.. nor does Apollo.. the idea was to illustrate that the Concorde display runs thro' several thematic areas in the museum, often next to seemingly unrelated artefacts.

[ChristiaanJ]

mfaff,
Point taken.

In a way, Apollo is relevant.... At the time, there were two "prestige" programs to be on : Concorde and Apollo. I've been lucky, I was part of one of those !

CJ

[Shaggy Sheep Driver]

Well if South Ken want to get rid of that 593, we'll give it a home in our building next to G-BOAC.

[ChristiaanJ]

Shaggy,
I doubt South Ken would want to get rid of their 593 (BTW, I'm still curious where that one came from, and what model it is).

I thought Alpha Charlie arrived with all its four engines....
Without wanting to go into the current squabbles, couldn't the museum drop one of the engines for display? They're pretty well invisible from the outside, so taking one out (and replacing it with a couple of plywood panels inside the nacelle, to avoid the horrible hollow-tooth effect we saw on Alpha-Delta in NY), would not do any damage to the display, but it would add another attraction to the museum.

CJ

[Shanewhite]

That brings a question to mind. Under service conditions, how long would it have taken to remove and replace an engine, and how often would it have been done? Also, would the same engines have stayed with each airframe, or would they have "circulated" around the fleet?

[Shaggy Sheep Driver]

CJ - AC does indeed have all 4 engines in place and complete. I wouldn't want to drop an engine as that would make her an incomplete aeroplane, and actually you can clearly see the compressors deep inside the intakes during tours, which is nice. She'd look odd with one intake blanked off.

Ideally I'd like a sectioned 593 on display, as there's not a lot to see on the outside of a turbojet engine except the ancilliaries - and you can see those by opening the engine bay doors.

[Shanewhite]

That brings a question to mind. Under service conditions, how long would it have taken to remove and replace an engine, and how often would it have been done? Also, would the same engines have stayed with each airframe, or would they have "circulated" around the fleet?

Bump......

[Shanewhite]

Olympus, anyone?

eBay - The UK's Online Marketplace (http://www.ebay.co.uk/itm/110783047958?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)

[rh200]

I could afford the key ring, or salt and pepper shakers:(

[ChristiaanJ]

I could afford the key ring, or salt and pepper shakersI couldn't even afford those.... but my family paid for one of the last "Bay of Biscay" trips, and yes, I did keep the salt and pepper shakers.

CJ

[BN2A]

Was going to bid, but I'm a fiver short....

:(

[dixi188]

Why are the log book and other records being sold separately?

When you buy an aircraft or component, the records form an integrated part or the item is effectively worthless.

I think the price is somewhat over inflated as there is no operational use for this. If the seller takes some zeros off the end there might be some interest.

Maybe someone looking for an engine for a land speed record attempt might be interested but no museum would stump up this much.

Just my thoughts.

[ChristiaanJ]

Bump......
That brings a question to mind. Under service conditions, how long would it have taken to remove and replace an engine, and how often would it have been done? I was curious as well, and hoping somebody with practical experience would post an answer.
Also, would the same engines have stayed with each airframe, or would they have "circulated" around the fleet?The engines were interchangeable among the airframes. Just as well, really, otherwise it would have meant keeping a stock of spare engines for each aircraft !

A more practical issue was that the engines were "handed", so that if a "left-handed" engine failed and you had only "right-handed" engines in stock, you had a problem.....
There is a nice interesting chapter in the Olympus 593 manual on how to convert a "left-handed" engine into a "right-handed" one (it mostly involved moving auxiliaries and other connections from one side to the other), but it was work, and took time. More time than a 'simple' engine change .....

CJ

[Shaggy Sheep Driver]

Olympus, anyone?

eBay - The UK's Online Marketplace

Someone's dreaming! It cannot be used as an engine according to the text (BA restriction) so it has value either as a museum exhibit or as scrap.

So either no monetary value (museum exhibit) or a few hundred pounds (scrap). Minus a few hundred pounds to transport it to the scrapyard!

[ChristiaanJ]

Does anybody still have notes about how much the Olympuses at Dovebid went for at the time?

Shaggy, I doubt anybody would buy it to "use" it. I would bet that surplus military engines of the same kind of thrust rating could be had much cheaper. Not to mention that parts, ancillaries, etc., would be far easier to procure....

CJ