I am certainly glad neither of them did. It resulted in a piece of engineering art.

I've been trolling these forums for many a year and this has been or hopefully will continue to be the most fascinating, absorbing and educational thread I have ever seen.

Thank you gentlemen for your insights. 👍

Hopefully you mean "trawling". We would not want the moderators to get the wrong idea!

Concorde AICU
 

I have flitted through the threads, and have a few comments that might be of interest.
There were no classified components in the AICU, however there was company confidential in that we did not want the competition to have our lead, also there was an American embargo on delivering equipment with the 5400 series TTL logic integrated circuits which were milspec and chosen for their environmental screening.
Some of the printed circuit boards were 8-layer.
The program was contained in 512 lines of 24 bit instructions.

Concorde AICU
 

Hi Christian,I was a development engineer at Filton working on the AICU at first but ending up in charge of avionics test.
So as far as your AICU is concerned - I have handled all the boards extensively.
I first worked on the "A" model - the first manufactured box, followed by "A bar" (logically, not "A").
These did not have the doghouse connector on the front, and in order to see what was going on in the program, we made a strobe unit hard wired to the digital boards, this was followed by the connector on the front and an AICU test box.
When first switched on the whole unit rattled at high speed as all the relays chattered.
I spent several days adding decoupling capacitors on all the boards.
The birds nest chassis wiring was chosen to prevent cross- talk.
This was at the start of 1972, but I can still remember a lot of it.
Someone mentioned a prom change at Casablanca, I carried out a prom change there just before the C of A flight.
I am a volunteer at the Bristol Aero Collection, and we have just received a drawing cupboard with the AICS drawings.
We are at the moment documenting archives. One of the volunteers is Ted Talbot who I used to work with, and has been mentioned in posts.
Feel free to ask questions, I may remember the answers!

consub,
Slightly amazed about your note re the 5400 series TTL being embargoed.
I pulled a random board from "my" AICU, and all of it is 5400 series, datecodes 71 and 72.
I hope you can tell us some more...
I've been sniffing round the boards, but I haven't found the CPU or the clock... and yes, I know the AICU dates from before the arrival of the microprocessor!

Concorde AICU
 

Hi Christian,I was a development engineer at Filton working on the AICU at first but ending up in charge of avionics test.
So as far as your AICU is concerned - I have handled all the boards extensively.
I first worked on the "A" model - the first manufactured box, followed by "A bar" (logically, not "A").
These did not have the doghouse connector on the front, and in order to see what was going on in the program, we made a strobe unit hard wired to the digital boards, this was followed by the connector on the front and an AICU test box.
When first switched on the whole unit rattled at high speed as all the relays chattered.
I spent several days adding decoupling capacitors on all the boards.
The birds nest chassis wiring was chosen to prevent cross- talk.
This was at the start of 1972, but I can still remember a lot of it.
Someone mentioned a prom change at Casablanca, I carried out a prom change there just before the C of A flight.
I am a volunteer at the Bristol Aero Collection, and we have just received a drawing cupboard with the AICS drawings.
We are at the moment documenting archives. One of the volunteers is Ted Talbot who I used to work with, and has been mentioned in posts.
Feel free to ask questions, I may remember the answers!

Quite true about 5400 ttl, you had to sign that it wouldnt be exported when you bought it, however no one ever checked. the us govt were very touchy about "state of the art" ics in those days, mind you 5400 was only 7400 that passed more stringent temp tests;)

@rodlittle

Not just more stringent temperature tests. 5400 was also tolerant of twice the variation in supply voltage as 7400 (+/- 10% rather than 5%) and came in ceramic packages with hermetic seals rather than post-molded plastic packages (which could, over time, allow fluids to reach, and corrode, the active components and/or bond wires).

Hi Christian,
We chose the components for their environmental tests, and all the AICS components were subjected to acceptance testing when received, which was a bit of a problem sometimes because the BAC goods inwards system was so slow that some of the expensive ADC/DACs that were not quite good enough were returned to Harris, but were out of warranty by the time they were returned. The embargo was not just the 5400 TTL I/Cs but all milspec. components.
Its stretching my memory, but AICU1 was the ADC board, 2-5 were the processor, 6-10 were the prom boards. There was a bought in board (AICU 17 I think) that was supplied by ?????, that processed the sensor unit data.
The AICS was filled with redundancy, as well as the obvious 2 AICUs per intake, and 4 sensor units, the program calculated the output data with dummy inputs - twice, and if these were correct, the proper inputs were used and the result was output to the doors. On the analogue bit there were two channels for each output and at the end one output was compared with the other and if different a fail was produced.
We haven't opened the plan chests with the AICS drawings yet.
As well as the 8 AICUs on G-BOAF, we have the prototype AICU that was used on the AICS systems rig.

Nice Vid of the old girl at Liverpool

Ted Talbot's book
 

Reading for a second time to see what I missed the first time.

On p86 he says 'It followed the idea of multi-vane auxiliary air inlets into history."

Anyone know the story on these inlets?

Thanks.

They were an attempt to avoid the mechanical complexities of the prototype double hinged 'barn door' combined dump door/auxiliary intake by having several 'blow-in' vanes set in the door which were locked when the door was operated as a dump door.
Had their own set of mechanical problems and the idea was abandoned in favour of a single blow-in door (production solution)

Article: Researchers now know why Concorde was doomed to fail
 

I think this article is pretty wacky but the source seemed legit (Duke University / University of Toulouse Professors writing in Journal of Applied Physics) so thought I'd put it out there for discussion. Caveat emptor!

Law of physics governs airplane evolution

Law of physics governs airplane evolution

Researchers believe they now know why the supersonic trans-Atlantic Concorde aircraft went the way of the dodo—it hit an evolutionary cul-de-sac. In a new study, Adrian Bejan, professor of mechanical engineering and materials science at Duke University, shows that a law of physics he penned more than two decades ago helps explain the evolution of passenger airplanes from the small, propeller-driven DC-3s of yore to today's behemoth Boeing 787s.

The analysis also provides insights into how aerospace companies can develop successful future designs. The Concorde, alas, was too far from the curve of these good designs, Bejan says. The paper appears online July 22, in the Journal of Applied Physics.[snip]

In the case of commercial aircraft, designs have evolved to allow more people and goods to flow across the face of the Earth. Constructal law has also dictated the main design features needed for aircraft to succeed; the engine mass has remained proportional to the body size, the wing size has been tied to the fuselage length, and the fuel load has grown in step with the total weight.

[snip] The chart shows how the ratio of mass to speed of animals follows the same general rules as airplanes. Note that the Concorde is way off of the historical trend.

http://cdn.phys.org/newman/gfx/news/...wofphysics.jpg

http://cdn.phys.org/newman/gfx/news/...wofphysics.jpg

It's a fascinating posit, and one for aviation nerds to discuss at length down the pub - I'll give it that!

The general trend follows, but he doesn't spend much time on external factors (such as the 747's degree of success being aided significantly by the tribulations of Lockheed's L1011 development and MD's reaction to the DC-10's flaws).

It's interesting that the article writer seized on the paragraph about Concorde to frame his article though - it's almost a footnote in the original journal piece!

This sounds similar to a parametric design process used at BAC Warton in '70s. Used data of size, weight, power, etc to predict features of future aircraft. No idea how far it went as I was flight test and this was in design dept, Explained by a colleague at the time.

Comparing subsonic jets with supersonic jets is comparing apples with oranges. They both grow on trees but there the similarities end.:ugh:

What this article shows is that the most efficient design will win out in the long run. Being the best in an evolutionary niche is no guarantee of long term survival. Being the fastest animal on earth doesn't help if there is no prey left to hunt. Having a slow metabolism that enables an animal to lie in wait for extended periods before ambushing unsuspecting prey works better. Or moving more slowly but capable of travelling large distances in order to find more food is also a successful strategy.

There will always be outliers in any system that appear to enjoy great success by specialisation, but in the long term the non specialist, adapt to anything creatures are the ones that survive.

Look at the types of cars people drive for an everyday demonstration of this fact. The majority of cars on the road are optimised to carry a reasonable load, at a reasonable speed and with reasonable fuel consumption. Evolutionary (economic) pressure has resulted in moderate increases in performance, comfort and safety, but we are not all driving around in cars that are hyper efficient and capable of 100mph+ performance while using a teaspoon of fuel per mile. We have gas guzzling monster 4x4 off road vehicles, exotic sports cars and small efficient city cars, but the majority of vehicles on the road fall into the distinctively average category.

If road surface conditions get much worse in the UK, then evolutionary pressure will drive up sales of 4x4 off road vehicles to cope with the atrocious driving conditions. Increased fuel costs will drive up sales of small efficient city cars where people don't need to drive long distances. Just what appears to be the current situation in the UK.

Efficiency trumps everything in nature and so it should in engineering. Get the most bang for your money and it is difficult to go wrong. Being in the top three of everything is far better than being first in one thing and bottom of the table in everything else. Specialisation is a poor long term survival strategy.

I'm not sure I buy that argument entirely. Yes, the non-specialist compromise design might capture a major chunk of the market. But that doesn't mean that the niche market doesn't exist: Monster cars are being sold for decades. So are RVs & bulletproof cars & gigantic mining earthmovers.

There's a tiny market for a gigantic transport plane or the behemoth seagoing barge that can transport mega machines. But doesn't mean that's a dead market or money can't be made there.

Perfect example of nonsense theory!
The geopolitical factors are completely ignored in order to make the analysis work.

FE Hoppy

The theory is perfectly sound, but the application to a given situation might be inappropriate. The universe in general seems to run on using the minimum effort to achieve the maximum effect. Entropy will ultimately rule, but in the meantime efficiency and conservation of energy is what keeps everything going. That being the case, the most efficient design for a given circumstance will ultimately win out until the circumstances change and a better design is called for.

The laws of physics dictate that there is a rapidly diminishing return as the size of supersonic aircraft increase. It becomes too hard or too enviornmentally damaging to displace the air for very large craft. This is less of a problem at subsonic speeds, where even quite large increases in aircraft size are not accompanied by disproportionately large increases in drag or wing loading. In fact overall efficiency can be improved in many cases.

Geopolitical factors are just one of many things that need to be taken into account with analysis of this kind and it is right for you to point out that not everything is necessarily measurable as a physical quantity.

Well, the theory as presented *could* be argued to encompass that, but as far as I could tell from the original journal article, that's not what it was about - it did not distinguish supersonic from subsonic in terms of the conclusions drawn. This is why I pointed out that the mention of Concorde was almost a footnote in the original article, but for some reason bumped up to headline status in the phys.org article linked above.

Concorde was only mentioned in the original journal piece as it was (naturally) an extreme outlier on the general trend.

Of course - however the original journal article was not intended to be a historical precis of relative success of airliners - it was a purely scientific theory which showed that various equations regarding airliner specifications could be used to plot a trend showing how commercially successful they were based on the historical aspects (and presumably extrapolated for future reference if desired).

I just have a problem with studies that try to analyze human activities with reductionist statistics and math. Most of human achievement comes not from the masses (which perhaps can be studied that way) but from the outliers, the screwballs, the few who, through enhanced human cussedness and stubbornness, decide NOT to stay with the obvious, efficient or safe thing.

Concorde was a political animal, heavily subsidized because someone want it to happen, regardless of efficiency.

But then, ALL advances in transportation have been - and often still are - political animals, subsidized because someone with money and power wants it to happen, regardless of efficiency.

Columbus and Magellan were subsidized, to head straight out to sea when everyone else was sticking close to the coastlines. Look up the land grants to U.S. trans-continental railroads. Or the Air Mail contracts that supported the fledgling American air transport industry (and if you think "that was then, and this is now," - consider the budget of the FAA and NTSB and TSA, and the military contracts to Boeing and its suppliers.)

Cars? Consider how much tax money goes to build and maintain highway systems.

And consider the man who stood up in the U.S. Capitol and declared, "I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth."

Concorde failed because it lost political support** - just like Apollo and the Space Shuttle. But most of the other aircraft on those charts would also be, or have been, far rarer in the skies (or never appeared) if they lost (or never had) their own political backing and subsidies, direct and indirect.

**If the French government had felt it was in France's interest for Concorde to continue, I'm sure money for, and political pressure on, Airbus would have been found to keep her flying.

And Concorde also faced substantial political opposition - its market viability would have been much higher if U.S. authorities had been as lenient with its "furrin" sonic booms as they had been with our own home-grown booms ("The Sound of Freedom!", it was called.)

Now - Concorde's technology was pushing 40, and no doubt that particular airframe would have faded away, just like the 727 and the other designs from the 1960's. To be replaced with something newer. But the future of supersonic transport in general was cut short not because of some statistical failing, but simply because it no longer shared the same political support as subsonic aviation.

Well if you leave out that bunch of points on the graph that presumably represent the post-Concorde slowpoke moneymakers, the remaining points would fit a line sloping upwards that passes quite close to the Concorde point.


Hindsight is wonderful, innit?

ross_M

787s are hardly 'behemoths'

totally agree with @pattern_is_full, but I wonder here why noone of those rich Arabs invests in one Concorde plane instead of endless goldening of huge hotel-like planes like A380 etc.? Sure it would be a sign of prestige?

Concorde size limits would still be enough for one man and his suite so that wouldn't be a problem, and coming anywhere in the world in 4-5 hours would come handy as time is something he couldn't buy with any money. If he does, say, 30 long flights in a year it's like he gets 6 totally free days.

It's not that simple. Political support didn't diminish for no good reason. When you talk about Concorde, or any supersonic vehicle, you cannot ignore what used to be called "the sound barrier".

In a sense, it really is a barrier; not so much physical, but financial. If the drag curve between Mach 0.8 and Mach 1.8 was just a similar extension of the drag curve between Mach 0.5 and Mach 0.8 (i.e. a simple V squared relationship), then the political support along with the economic viability of supersonic airliners would mean rich folks could still buy a fast ride across the Atlantic. And, if there were no sonic boom either, then these fast airliners would be flying everywhere and be even more viable.

But that huge spike in the real-world drag curve as you pass through transonic air-speeds and the steep power-required curve beyond that forms what amounts to a really big spike in the money required to operate at high Mach numbers both from an initial hardware point of view but, more importantly, in the money required to both fuel and maintain such exotic airplanes. Pile the sonic boom issues on top of those costs, and it's no suprise very few people have ever gone supersonic.

Political support for the Concorde didn't simply go out of fashion. It faded for very good reasons, mostly related to good old Mother Nature and the odd shape of the real-world drag curve.

Concorde simulator at Brooklands
 

Nice to see this thread still active!

I wonder is there is a Concorde expert who could help me with a question please. I have booked some time in the Concorde simulator at brooklands in September and was wondering how I should best use the time I have (30 mins). What do you think would be the most interesting and enjoyable use of my time? I have read most of this thread, and gather that the JFK departures were spectacular. Is that what you think I should try?

I have spent a bit of time in other simulators (purely for fun), so what I am hoping to try in the Concorde simulator is something unique to Concorde.

@mozella

I guess my point would be that the same problems of supersonic flight existed in 1963-1976 as did in 2003. It was a technological challenge, and it was expensive.

The physics of the sound barrier did not change over that time. Nor did the constituent gases in Concorde's exhaust plume*, nor did the volume of the sonic booms.

However, in 1976, going supersonic was considered worth the costs, and in 2003 it was not, and that was a political (or if you prefer, cultural) calculation.

*Actually, I think the engines were tweaked to be less "smoky", but that may have been before commercial ops began.

I think you should try an outside loop, I'm sure Kennedy One departure, CRI climb will pale in comparison.

Evolution: Survival of the fittest.

An often misunderstood expression.
Fittest does not mean the most athletic or physically strong, it means fit for it's environment.

When the environment changes the animal/plant/aircraft needs to evolve to best fit that changing environment.
Living organisms take many generations to change due to the randomness of genetic mutation. Aircraft design, in comparison, changes relatively quickly as new technology and ideas develop.

The environment changed in the seventies, fuel prices exploded. The 747, and continued lines of fuel efficient wide bodies thrived, Concorde only continued due to political will. If the price of fuel was still $20/barrel Concorde (and probably a couple of successors) would be going strong as it would still "fit" the political and economic environment. (The greens may have put a bit of pressure on though:eek:)

Simples eh?

I see that average figure for planes is 49 mpg per passenger and Concorde is at 17, although it's almost 3 times more I can't see it as drastical figure as I thought it would be? Especially since it's very similar to a business jet.

Wasn't Concorde extremely fuel-efficient at M2 and 60,000', but the horrendous fuel consumption getting up there more than offset that?

Smokey engines were a feature of the pre-production machines. The production Concordes with a change in combustion chamber design had a much cleaner exhaust.

Turin has it on why Concorde didn't sell - massive increases in oil prices and perhaps more importantly, the advent of the wide body airliner in 1969 that changed the airlines' focus from speed to per-seat operating cost reduction, where it remains today.

oh well, make bigger Concorde then :)

Airworthiness Directives - Return to Service
 

Dear all,

I am looking for a .pdf copy of the AD issued at the time of the return to service of the Concorde, describing the package of modifications.

CAA Emergency Airworthiness Directive 001-09-2001 of 5 Sept 2001
and
DGAC Consigne de Navigabilité N° 2001-390-144(B) of 3 Oct 2001

I have already found a summary of the contents here, but I would like to have the documents in their original format.

If anybody has any of those, I would appreciate if he/she could send me a copy (please contact me via PM for the email address).
Thanks in advance!

Concorde Captain recent interview
 

For those willing to search out a podcast:
166 ? Flying the Concorde | omega tau

This time we talk with former Concorde pilot John Hutchinson about flying this Mach 2 airliner. We discuss the cornerstones of the design and construction of the aircraft, its operation (mostly with British Airways), flying characteristics as well as the infamous accident in Paris in 2000 (on which John has some very specific opinions).

After the crash a former president of the French Women Pilots association requested from the French Minister Gayssot to allow flights again, and to have a first French woman qualified on the type. That was done between may 2001 and the end of the flights.

Doing that, French women pilots wanted to express their confidence in Concorde and their wonderful British/French teams.:D

Foud it, but...
 

Duh? Is there a button to start PLAY?:ugh:

Scroll about a third of the way down the page and you will see a bar with the "Play" triangle on the left.

It's over two hours long... Probably best downloading it!!

Then look around the site, similar on the SR-71 and U-2 as well as the space shuttle..