Concorde question
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You'll have everybody here green with envy....
Even if it was on a "blunty" it was still spectacular.
And I think Kai Tak is already in the Brooklands sim database.... so you can now come and fly it yourself....
Out of interest Bellerphon was there a supersonic acceleration point for JFK departures or as you were soon over the ocean, was it a case of it happened when it happened?
Thanks Christiaan for your Concorde book thread. I am hoping that Santa brings me the Haynes manual!
CJ
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I wish Christiaan. No it was always "blunties" for me into Kai Tak. Still exciting though!
Well I never knew that about Concorde and Cardiff airport. Would love to know more as Cardiff is my local field. In fact my first flight was from there in 1967 in a Cambrian Viscount to Genoa. Another great British plane.
Regards
Nick
Well I never knew that about Concorde and Cardiff airport. Would love to know more as Cardiff is my local field. In fact my first flight was from there in 1967 in a Cambrian Viscount to Genoa. Another great British plane.
Regards
Nick
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but there once was a low-weight take-off from Cardiff straight out to sea, without any restrictions, that IIRC still holds the record for the shortest time to Mach 1 and Mach 2 from brake release....
Throttles opened for take -0ff
At 500 ft switch off reheats
At 1000ft select Climb Rating with the switches on the overhead panel
At M0.95 select reheats in pairs
At M1.7 switch off reheats
At 50,000ft select Cruise Rating on the switches on the overhead panel
Sit back and have lunch before decel
The aircraft would be heavy and the ground temps high so the climb accel would be slower than out of Cardiff,but it was still impressive.
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Gentlemen,
I am new to this thread, and indeed to Pprune. PBL pointed me at this fascinating Concorde thread and I think I may be able to throw in a few points from the point of view of one of the original design team.
It may take a while because there are so many interesting aspects, so I propose to start with early postings and work through. My apologies if this results in some duplication!
I suspect I may have worked with some of the major contributors.
I am new to this thread, and indeed to Pprune. PBL pointed me at this fascinating Concorde thread and I think I may be able to throw in a few points from the point of view of one of the original design team.
It may take a while because there are so many interesting aspects, so I propose to start with early postings and work through. My apologies if this results in some duplication!
I suspect I may have worked with some of the major contributors.
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Autotrim
It wasn't quite as simple as that. The fuel transfer system really fixed long term problems like getting the elevator trim broadly at optimum throughout (and really at optimum in cruise of course). The Mach trim/autotrim really worked on a shorter timescale to maintain stability at constant CG.
Sure the autopilot made it superfluous to some extent, but to certificate the aircraft it had to be conventionally stable when flow manually, and applying a nose down command to get a speed increase is a basic airworthiness requirement for all aircraft.
Sure the autopilot made it superfluous to some extent, but to certificate the aircraft it had to be conventionally stable when flow manually, and applying a nose down command to get a speed increase is a basic airworthiness requirement for all aircraft.
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Sure, Concorde was the first aircraft to fly with FBW flight controls, but electric signalling on a major aircraft system was introduced on the Proteus engines that powered the Bristol Britannia. These were of course built by the same company, Bristol Aero Engines, that built the Olympus.
There are some (I am not among them) who would say that the Concorde project was a good way to learn how NOT to run a major international collaboration
There are some (I am not among them) who would say that the Concorde project was a good way to learn how NOT to run a major international collaboration
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Concorde was unique in having take off performance scheduled for a 'point'CG. Before that all aircraft had FM performance based on the most adverse CG in the certificated range - normally the forward limit. I well remember lying on the grass on the airfield at Madrid waiting for Concorde to get back from a 'hot and low performance' test flight and chatting to the CAA surveyor responsible for that aspect of the certification and speculating on whether we could cash in on the ability to control the CG accurately.
After about half an hour we came to the conclusion that provided we put certain checks in place, and still retaining the 'classic' performance in the Flight Manual, we could insert a special TO technique using a single point CG which would give, from memory, about 1.5 tonnes more TO weight - something not to be sneezed at when your payload fraction is as low as Concorde. Needless to say this 'special' soon became the norm. I doubt if we could get agreement on such a topic in that timescale today!
I noted in another post that memory was blurring after seven years from active flying. I am writing about events thirty or even forty years ago, but I still have my notes.
After about half an hour we came to the conclusion that provided we put certain checks in place, and still retaining the 'classic' performance in the Flight Manual, we could insert a special TO technique using a single point CG which would give, from memory, about 1.5 tonnes more TO weight - something not to be sneezed at when your payload fraction is as low as Concorde. Needless to say this 'special' soon became the norm. I doubt if we could get agreement on such a topic in that timescale today!
I noted in another post that memory was blurring after seven years from active flying. I am writing about events thirty or even forty years ago, but I still have my notes.
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Clive,
Re the autotrim, tell us some more?
I wasn't directly involved with the control laws themselves, more with trying to assure those control laws were respected to well below 1%.
I thought it was the first civil aircraft, and that the Vulcan had already been there and done that...
I know what you're saying.....
Still, I think you'll agree that lessons were learnt, rather than totally ignored.
I would say Airbus can trace its history back to the lessons learned from Concorde.
CJ
Re the autotrim, tell us some more?
I wasn't directly involved with the control laws themselves, more with trying to assure those control laws were respected to well below 1%.
There are some (I am not among them) who would say that the Concorde project was a good way to learn how NOT to run a major international collaboration
Still, I think you'll agree that lessons were learnt, rather than totally ignored.
I would say Airbus can trace its history back to the lessons learned from Concorde.
CJ
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I haven't worked out how to reply to postings and quote the relevant remarks yet - cut and paste doesn't seem to work, sorry.
Anyway, after that 1980 engine fire incident we did find a couple of small holes in the centrewall and as a result we fitted some ceramic coated steel plates in the vulnerable areas.
But as stated, the fire precautions built in did a good job. In this connection though it is worth saying that the cooling air passing over the engine comes from the ramp bleed in the intake and that it is controlled by 'secondary air doors' in the corners left between the circular engine and the square nacelle. These are there to stop air flowing back from the engine bay into the intake during takeoff and are opened once the pressure diferential between intake and engine bay is favourable. Part of the fire drill was to close these doors so the engine fire was deprived of oxygen, which helps a lot
CliveL
Anyway, after that 1980 engine fire incident we did find a couple of small holes in the centrewall and as a result we fitted some ceramic coated steel plates in the vulnerable areas.
But as stated, the fire precautions built in did a good job. In this connection though it is worth saying that the cooling air passing over the engine comes from the ramp bleed in the intake and that it is controlled by 'secondary air doors' in the corners left between the circular engine and the square nacelle. These are there to stop air flowing back from the engine bay into the intake during takeoff and are opened once the pressure diferential between intake and engine bay is favourable. Part of the fire drill was to close these doors so the engine fire was deprived of oxygen, which helps a lot
CliveL
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Way back in August Tim 00 was asking about preset limits on the fuel transfer system.
One of the major challenges was to match the fuel transfer rate and initiation point to the aircraft performance. Once started the fuel pumps change the rate of CG shift in a more or less constant manner, but the aircraft acceleration through the transonic range is very dependent on weight and OAT, so the actual CG at any one mach number will vary from flight to flight. But it must be possible to make an emergency deceleration form any point in the acceleration backdown to subsonic conditions where the aerodynamic centre will be further forward and hence there is a risk that the aircraft might get into unstable conditions.
A lot of work went into this problem and the allowable CG boundaries reflect thsi to some extent.
CliveL
One of the major challenges was to match the fuel transfer rate and initiation point to the aircraft performance. Once started the fuel pumps change the rate of CG shift in a more or less constant manner, but the aircraft acceleration through the transonic range is very dependent on weight and OAT, so the actual CG at any one mach number will vary from flight to flight. But it must be possible to make an emergency deceleration form any point in the acceleration backdown to subsonic conditions where the aerodynamic centre will be further forward and hence there is a risk that the aircraft might get into unstable conditions.
A lot of work went into this problem and the allowable CG boundaries reflect thsi to some extent.
CliveL
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Throttles opened for take -0ff
At 500 ft switch off reheats
At 1000ft select Climb Rating with the switches on the overhead panel
At M0.95 select reheats in pairs
At M1.7 switch off reheats
At 50,000ft select Cruise Rating on the switches on the overhead panel
At 500 ft switch off reheats
At 1000ft select Climb Rating with the switches on the overhead panel
At M0.95 select reheats in pairs
At M1.7 switch off reheats
At 50,000ft select Cruise Rating on the switches on the overhead panel
When this thread is finished I think we should have the info necessary to retire to the back shed and knock one up. Keep it up Gents.
Good question, Brian. Reminds of the A-10 joke when I flew it--remove the throttles and install switches marked, OFF, IDLE and FLY. Idle was more than sufficient to taxi, line up and select FLY because it was so underpowered, full throttle was pretty much the only power used except in cold wx.
GF
GF
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Concorde and SR-71
I didn't read all 45 pages only the first 30 and the last page so my question about how much thrust was acquired from the front of the engine because of the pressure differential may have been answered. Also the question may not pertain to the Concorde like it was to the SR-71, but a large quantity of the SR-71 thrust was acquired at the front of the varible nose cone because of the huge pressure differential of the engine. This issue was relayed to me by a Lockheed test pilot who tested both the A-12 and SR-71.This test pilot also said the limiting speed factor of the SR-71 was the wing leading edge temperature of 734 degrees which was 3.2 mach although the plane could go faster. Above FL600 there is no wind so the flight times were always the same either way for the SR-71 and I assume that was true for the Concorde although the SR-71 normally flew at FL800+ except when they came down for a quick drink from a tanker.I really appreciate the ex Concorde drivers and engineers sharing their experiences and time. It should be interesting reading by our great-grandchildren in 100 years.
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"I haven't worked out how to reply to postings and quote the relevant remarks yet - cut and paste doesn't seem to work, sorry."
Can someone with greater skill than I have please post some instructions for Clive and myself on how to include quotes from others posts in replies?
I, like all here I suspect, look forward to CliveL's posts on this wonderful aircraft.
Great to have another of the inside team contributing to this fantastic thread. It is probably turning into a valuable historic document, if I may indulge in a little hyperbole.
John
Can someone with greater skill than I have please post some instructions for Clive and myself on how to include quotes from others posts in replies?
I, like all here I suspect, look forward to CliveL's posts on this wonderful aircraft.
Great to have another of the inside team contributing to this fantastic thread. It is probably turning into a valuable historic document, if I may indulge in a little hyperbole.
John
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Can someone with greater skill than I have please post some instructions for Clive and myself on how to include quotes from others posts in replies?
Keith
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the limiting speed factor of the SR-71 was the wing leading edge temperature of 734 degrees
Thread on the Concorde inlets here http://www.pprune.org/tech-log/42690...ke-thrust.html
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To everyone who has contributed to this thread, a BIG thanks. It has been an absolute pleasure to read ( unlike other threads on pprune 
). The time and effort spent to share stories and knowledge is truly appreciated and no doubt an appropriate reflection on the brilliance that was Concorde. To everyone that was part of the Concorde dream you have my deepest admiration. Have yourselves a safe and fabulous holiday wherever you are. Looking forward to reading many more great posts in the coming year.
Thanks for keeping the memory of our GREAT ICON truly alive. She was a beauty !
cheers !
). The time and effort spent to share stories and knowledge is truly appreciated and no doubt an appropriate reflection on the brilliance that was Concorde. To everyone that was part of the Concorde dream you have my deepest admiration. Have yourselves a safe and fabulous holiday wherever you are. Looking forward to reading many more great posts in the coming year. Thanks for keeping the memory of our GREAT ICON truly alive. She was a beauty !
cheers !