Concorde question
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I understand it fell victim to the dreaded Canterbury Nor'west wind. From memory, a servicing platform got blown about and punctured a fuel tank. It was reported in the local papers at the time but there was very little fuss made about the incident at the time.
There were several Concorde visits to Christchurch, all very popular to the locals (including myself). However, Concorde suffered at least two incidents that could be attributed to the Nor'west wind at Christchurch. The other one that gained more publicity was when it lost part of its rudder flying across the Tasman sea. There was some evidence that when parked overnight at Christchurch airport, the wind came up and started slamming the unlocked rudder about...
There were several Concorde visits to Christchurch, all very popular to the locals (including myself). However, Concorde suffered at least two incidents that could be attributed to the Nor'west wind at Christchurch. The other one that gained more publicity was when it lost part of its rudder flying across the Tasman sea. There was some evidence that when parked overnight at Christchurch airport, the wind came up and started slamming the unlocked rudder about...
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..... not convinced that theory's true.....
The PFCUs will offer a lot of damping, even while unpressurised. I've never seen a control surface 'slam' side to side on a hydraulically powered aircraft for tis reason.
The cause of the rudder failure was internal corrosion brought about by a mod which added a fillet to the trailing edge.
I suggest the surface winds were a red herring.
The PFCUs will offer a lot of damping, even while unpressurised. I've never seen a control surface 'slam' side to side on a hydraulically powered aircraft for tis reason.
The cause of the rudder failure was internal corrosion brought about by a mod which added a fillet to the trailing edge.
I suggest the surface winds were a red herring.
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EXWOK ...well it was some time ago and my memory may not be what it was...
Anyway, pprune was not around then so the only rumour network speculating about such events was the local newspaper and the comments about the wind have stuck in my memory.
I wouldn't dismiss the Canterbury surface winds too lightly - they can and have caused a lot of damage especially to property and trees. Sitting in a 737 in a Nor'wester at Harewood at departure time can be a shaky experience.
However, I take your point about back driving a PFCU. Thinking about it, I would doubt that ground wind forces would come anywhere near the forces experienced in supersonic flight
Anyway, pprune was not around then so the only rumour network speculating about such events was the local newspaper and the comments about the wind have stuck in my memory.
I wouldn't dismiss the Canterbury surface winds too lightly - they can and have caused a lot of damage especially to property and trees. Sitting in a 737 in a Nor'wester at Harewood at departure time can be a shaky experience.
However, I take your point about back driving a PFCU. Thinking about it, I would doubt that ground wind forces would come anywhere near the forces experienced in supersonic flight
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Superb aircraft, superb thread 
I would like to know how susceptible both the clever intakes and the Olympus engines were to damage from bird ingestion, and if it ever happened in flight. I assume the answer might lie in the positioning of the ramps at takeoff and bird inhabited altitudes?
Also, a theme throughout the thread has been that the two projects of the era that people wanted to work on were Apollo and Concorde. My question is; were there any companies (and particularly individuals) who were lucky enough to work in some part (large or small) on both of these marvels of engineering?
I would also be very interested to hear:
i) From the pilots - what the "worst" (both subjectively and objectively if you like) situation or failure was that you trained for in the sim or on a real aircraft.
ii) From the engineers - the "Concorde factor" aside, how was she to work on and how did her systems compare in terms of ease of maintenance to regular passenger aircraft of the day? What were the jobs/events most and least looked forward to?
iii) Any more about the de-tune facility in some of the pictures posted earlier - was its sole function to hold the bird in place and quieten the engine noise, or did it serve any other purpose (e.g. did it contain any measuring instruments).
Disclaimer: Not a pilot/engineer.
I would like to know how susceptible both the clever intakes and the Olympus engines were to damage from bird ingestion, and if it ever happened in flight. I assume the answer might lie in the positioning of the ramps at takeoff and bird inhabited altitudes?
Also, a theme throughout the thread has been that the two projects of the era that people wanted to work on were Apollo and Concorde. My question is; were there any companies (and particularly individuals) who were lucky enough to work in some part (large or small) on both of these marvels of engineering?
I would also be very interested to hear:
i) From the pilots - what the "worst" (both subjectively and objectively if you like) situation or failure was that you trained for in the sim or on a real aircraft.
ii) From the engineers - the "Concorde factor" aside, how was she to work on and how did her systems compare in terms of ease of maintenance to regular passenger aircraft of the day? What were the jobs/events most and least looked forward to?
iii) Any more about the de-tune facility in some of the pictures posted earlier - was its sole function to hold the bird in place and quieten the engine noise, or did it serve any other purpose (e.g. did it contain any measuring instruments).
Disclaimer: Not a pilot/engineer.
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Jet noise
Were the primary nozzle spade silencers mentioned in this Flight article used on production aircraft?
Also, again in this article, was it a production feature to open the primary nozzle to reduce noise?
Thank you.
1972 | 2644 | Flight Archive
Also, again in this article, was it a production feature to open the primary nozzle to reduce noise?
Thank you.
1972 | 2644 | Flight Archive
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I'd like to add a few words to the discussion a few posts earlier about the reasons of the commercial failure of Concorde.
Concorde killed by Americans.
This is an article published in a very famous french magazine in 1972. This article describes the various measures taken by the american to stamp down the european aeronautic industry and more particularly the Concorde.
According to this article, it started with a campaign to warn the US Congress about the supposed stratospheric pollution that SST would create. The danger was off course exaggerated but nevertheless the congress refused to vote credits for the american SST. That is the main reason why Boeing stopped the development of their own SST. Harold Johnson, from the university of Iowa, even affirmed that the SST would destroy the ozone in the stratosphere and, as a result, decimate the humanity with uncurable skin cancers and retina burnt.
Also, US firms proposed to South American companies to buy back all their Caravelles at catalog price if they promise to buy only boeing aircrafts for the next 10 years with credit over 8 years and only 2% interest.
And, finally, the Export Import Bank (Eximbank) whose many arilines's cash depends on, announces that they will not give any loans to buy european aircrafts. On top of that, some political pressure were also used to discourage some countries that could be interested in buying european aircrafts.
Under those circumstances, Concorde, despite its incredible technological advance, had almost no chance to become a commercial succes.
It is intersting to note that Concorde came to life thanks to political decisions but also never really took off partly because of political reasons.
Concorde killed by Americans.
This is an article published in a very famous french magazine in 1972. This article describes the various measures taken by the american to stamp down the european aeronautic industry and more particularly the Concorde.
According to this article, it started with a campaign to warn the US Congress about the supposed stratospheric pollution that SST would create. The danger was off course exaggerated but nevertheless the congress refused to vote credits for the american SST. That is the main reason why Boeing stopped the development of their own SST. Harold Johnson, from the university of Iowa, even affirmed that the SST would destroy the ozone in the stratosphere and, as a result, decimate the humanity with uncurable skin cancers and retina burnt.
Also, US firms proposed to South American companies to buy back all their Caravelles at catalog price if they promise to buy only boeing aircrafts for the next 10 years with credit over 8 years and only 2% interest.
And, finally, the Export Import Bank (Eximbank) whose many arilines's cash depends on, announces that they will not give any loans to buy european aircrafts. On top of that, some political pressure were also used to discourage some countries that could be interested in buying european aircrafts.
Under those circumstances, Concorde, despite its incredible technological advance, had almost no chance to become a commercial succes.
It is intersting to note that Concorde came to life thanks to political decisions but also never really took off partly because of political reasons.
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@ msbbarrat I agree with your viewpoint but i'd like to clarify a few points. analog circuits use a continuously variable signal where as digital circuits use an interrupted signal . both analog and digital circuits can be INTEGRATED Circuits or DISCREET Circuits . Both do the same job . Both use transistors capacitors etc . The difference ofcourse is as you stated in a discrete circuit you can swap out individual components like transistors or capacitors . In an IC Integrated circuit however the manufacturing process in microscopic and its all on one chip . so its physically impossible to figure out what transistor has blown , some will fail during the life of the circuit but there is an acceptable amount of multiplexing going on to keep things chugging along smoothly . Unless ofcourse some critical part fails in which case you have to replace the entire board / chip etc. IC offer much more redundancy , weight savings , efficient power use and ease of repair-ability when compared to discreet electronics. Now the switch to digital circuits took place because it is much more difficult to engineer analog circuits and analog signals are prone to interference/ noise , much more precise signal control is required .
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msbbarratt
That of course is essentially what was done on the intake control system. The basic analogue "inner loop" was retained to do the actuation but it operated to non-linear laws and limits defined by a digital system.
I often wonder though; given that all flight dynamics on all aircraft types can (presumably) be expressed by systems of differential equations, are we missing a trick? Implement the equations in analogue but have a digital wrapper around it to provide the modern supervisory functions? If it could be done it would save weight, power, cost; an analogue circuit could be made really, really small these days.
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The problem with software systems is that [...] you cannot prove them to be correct
hence the triplication, heavy emphasis on configuration control and high cost.
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There's also no need for triplication for a start, at least not from the point of view establishing correct system output.
All that an analogue control system is doing is implementing a series of differential equations.
The problem with software systems is that they're way too complex
Analogue control circuits are also largely immune to component selection ... a capacitor is still a capacitor. Obsolescence is a significantly reduced problem.
We won't be seeing A380s, etc. flying once the spares run out.
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NHerby:
No doubt the nuts were already influencing the radial political agenda in the U.S. by then.
The beginning of the slow decline of the U.S. Having said that Europe, for the most part, is seriously screwed up as well.
Alas, the moderators will likely delete both your message and mine.
No doubt the nuts were already influencing the radial political agenda in the U.S. by then.
The beginning of the slow decline of the U.S. Having said that Europe, for the most part, is seriously screwed up as well.
Alas, the moderators will likely delete both your message and mine.
Airbus/Boeing FBW systems use hardened versions of obsolete commodity hardware - the suppliers won't stop making them as long as there's a demand.
IC Part obsolescence is actually a big problem in aviation - our market is too small to justify keeping these components in production when they are decades obsolete in consumer products.
The best option is 'life time buys' - where the vendor stockpiles what they hope is a life time supply of the critical components (IC chips, ASICS, basically any logic devices). Of course, life time buys are not foolproof - not only is it dependent on accurate forecasts of need, but other things go wrong - crates go missing, warehouses burn down, bean counters dispose of what they think is excess inventory, etc.
The second option is to periodically certify hardware packages where they update components and re-certify. This is difficult and expensive - it takes extensive testing and analysis - even subtle changes in things like throughput timing can turn a digital system on it's ear. But it is done (in the last 10 years or so we've had FADEC parts obsolescence updates on both the PW4000/94" and CF6-80C2 FADEC controls - which date back to the mid 1980s).
The third option is just do a clean sheet of paper new device - really expensive and difficult, and often means having to update the associated s/w as well (this is what Pratt did with the PW2000 FADEC, coming out with completely new control - hardware and s/w - around 1995 to replace the original that dated back to about 1980).
But in the end the airplanes keep flying
IC Part obsolescence is actually a big problem in aviation - our market is too small to justify keeping these components in production when they are decades obsolete in consumer products.
The best option is 'life time buys' - where the vendor stockpiles what they hope is a life time supply of the critical components (IC chips, ASICS, basically any logic devices). Of course, life time buys are not foolproof - not only is it dependent on accurate forecasts of need, but other things go wrong - crates go missing, warehouses burn down, bean counters dispose of what they think is excess inventory, etc.
The second option is to periodically certify hardware packages where they update components and re-certify. This is difficult and expensive - it takes extensive testing and analysis - even subtle changes in things like throughput timing can turn a digital system on it's ear. But it is done (in the last 10 years or so we've had FADEC parts obsolescence updates on both the PW4000/94" and CF6-80C2 FADEC controls - which date back to the mid 1980s).
The third option is just do a clean sheet of paper new device - really expensive and difficult, and often means having to update the associated s/w as well (this is what Pratt did with the PW2000 FADEC, coming out with completely new control - hardware and s/w - around 1995 to replace the original that dated back to about 1980).
But in the end the airplanes keep flying
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Alas, the moderators will likely delete both your message and mine.
I don't want to slide in a political argument here, that is not my point at all. I just want to highlight that lobbying against SST, even with totally foolish pleas, had a very negative impact on the commercial outcome of both Concorde and the Boeing SST. Put on top of that what has to be called an economic war between USA and Europe and the fate of Concorde was sealed, no matter how beautifull, technologically advanced and fantastic was the plane. And I think this is the main resaon why no other airliners but BAC and AF bought Concorde.
R.e the Concorde damage in NZ... it was actually caused by a set of HS-748 air-stairs blown across the tarmac by the Canty Norwester.
Many red faces at Mt Cook - and apologies to BA.
The jet was on a charter flight full of American millionaires.
It was left leaking fuel from a puncture underwing.
They towed it around to the Air NZ maintenance hangar and fixed it within 24 hours from memory.
Requests from the local meeja to cover expert Air NZers patching the world's fastest pax jet were bluntly declined by BA's man in London.
The millionaires departed on a charter 767 for Sydney.
And late the next glorious summer evening - a slightly younger Tartare heard the unearthly roar of 4 Olympuses - and watched the Speedbird depart to the North, leaving four trails of soot over the garden city.
Many red faces at Mt Cook - and apologies to BA.
The jet was on a charter flight full of American millionaires.
It was left leaking fuel from a puncture underwing.
They towed it around to the Air NZ maintenance hangar and fixed it within 24 hours from memory.
Requests from the local meeja to cover expert Air NZers patching the world's fastest pax jet were bluntly declined by BA's man in London.
The millionaires departed on a charter 767 for Sydney.
And late the next glorious summer evening - a slightly younger Tartare heard the unearthly roar of 4 Olympuses - and watched the Speedbird depart to the North, leaving four trails of soot over the garden city.
Moderator
Alas, the moderators will likely delete both your message and mine.
This mod errs on the side of leaving things alone .. unless they be quite out of order.
a slightly younger Tartare heard the unearthly roar of 4 Olympuses
June 72 we first saw the bird in Oz.
I was a UniSyd final year engineering undergrad at the time. The lot of us nicked off from lectures that day to watch the departure .. forget how it was organised but we stood about where the 16 GP antenna is located now in front of the international terminal construction work.
The bird's takeoff was to the south (our left to right) .. lots of mach diamonds and the visceral excitation was not at all comfortable ... but, what a hoot.
The aerodynamics lecturer - one of whose lectures we absented ourselves from - opined at the start of the next lecture that we should study independently for the finals in his subject and walked out ... nice chap but a rabid greenie and more than a tad anti-Concorde.
C'est la vie ... vague memory suggests I think I scored an HD for the subject and we all passed anyway .. the power of fearful heads in the textbooks in the absence of lectures in a subject.
This mod errs on the side of leaving things alone .. unless they be quite out of order.
a slightly younger Tartare heard the unearthly roar of 4 Olympuses
June 72 we first saw the bird in Oz.
I was a UniSyd final year engineering undergrad at the time. The lot of us nicked off from lectures that day to watch the departure .. forget how it was organised but we stood about where the 16 GP antenna is located now in front of the international terminal construction work.
The bird's takeoff was to the south (our left to right) .. lots of mach diamonds and the visceral excitation was not at all comfortable ... but, what a hoot.
The aerodynamics lecturer - one of whose lectures we absented ourselves from - opined at the start of the next lecture that we should study independently for the finals in his subject and walked out ... nice chap but a rabid greenie and more than a tad anti-Concorde.
C'est la vie ... vague memory suggests I think I scored an HD for the subject and we all passed anyway .. the power of fearful heads in the textbooks in the absence of lectures in a subject.
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To add to this, there's also the ability to create a hardware abstraction layer (similar to virtualisation) which allows you to swap out the underlying components whilst maintaining a uniform look and feel to the systems they support. I would expect (if it's not already being done) this to be one of the drivers for newer aircraft, as they can then forklift the proven systems from one aircraft type to the next, and provide redundancy/resilience and obsolescence-proofing.
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But there's no CPU on the planet with a formal proof of its design.
And, yes, there has been at least one case of a completely proved microprocessor design. The reason we haven't seen more is presumably because complete proof has turned out not to be necessary to achieve sufficient assurance of design correctness.
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This wonderful thread about the birth and operation of Concorde is a fascinating read.
Unfortunately the last few pages have been filled with off topic drift and discussions regarding the commercial aspects of the aircraft's operation.
I'm sure those that have spent so much time answering technical questions would appreciate it if the thread could continue as originally conceived. It would be a shame if those contributors lost interest in the thread due to the thoughtless prattle of some posters.
Unfortunately the last few pages have been filled with off topic drift and discussions regarding the commercial aspects of the aircraft's operation.
I'm sure those that have spent so much time answering technical questions would appreciate it if the thread could continue as originally conceived. It would be a shame if those contributors lost interest in the thread due to the thoughtless prattle of some posters.
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Getting somewhat closer to the topic - does anyone know what the Tu-144 used for computing? The NASA report on the Tu-144LL says that they had a digital controls for the engines, but since those were new engines the control system was probably a good deal more modern than the original. I can't see any mention of how the intakes were controlled, or what the original engines used.
And really on-topic, was there any work done towards updating this for Concorde-B? Or did they never get that far? Or was the plan to just keep using exactly the same stuff, since it was already working so well?
And really on-topic, was there any work done towards updating this for Concorde-B? Or did they never get that far? Or was the plan to just keep using exactly the same stuff, since it was already working so well?