Posts by user "M2dude" [Posts: 257 Total up-votes: 1 Page: 7 of 13]¶

Here you go Feathers, it's in French but you can see what the modification did. (Before the modification was embodied there was an RTOW limit placed on the aircraft; perhaps Brit312 can remember the figures? OH, and as to the contingency time limit (which I forgot to answer your quesy, soorry ) it was 2 1/2 minutes. (The only time that I can recall the limit being accidently exceeded we told Rolls Royce who after a few minutes of head scratching came back with a 'no problem man, don't worry about it ).
Regards
Dude

Very good photo Feathers. The reheat really was just about the most fragile part of the powerplant, and gave us numerous headaches throughout the service life of the aircraft. The most unreliable part of all was the ignition side of things; the ignition transformer itself being the main culprit here. Also the swirl ignitor itself was rather fragile, as the smallest blockage in the air supply would render the ignitor useless. The failure of the reheat system resulted in the majority of rejected take-offs in the service life of the aircraft. (Failures during transonic acceleration would sometimes respond to a second selection of reheat, but this was often due to spontaneous llight up, due to the much higher total temperatures at Mach 0.95, rather than a recovery of the ignition system itself).

Dude

Mike-Bracknell
It is not nonsense, and you are quite at liberty to post here. Wow, that's still quite a question though Mike. There are two TECHNICAL issues that overshadow all others, namely airframe corrosion and hydraulic system deterioration. Unfortunately none of the BA aircraft were stored inside from the outset, so we have a real issue here as far as corrosion goes, plus all the hydraulic systems were drained, resulting in seal drying out and probable moisture ingress into the 3 systems. But given sufficient funds (and assuming you find an organisation to take over design responsibility from Airbus; ironic when you consider that without Concorde there would almost certainly have been no such organisation ) there is still no technical reason why the problems (and there are dozens of other problems to consider) could not be overcome, the money side of things is another matter
Looking first at the French fleet, the main candidate for restoration to flight status would be F-BTSD at Le Bourget. Not only has this aircraft been lovingly cared for and stored INSIDE, but the aircraft has had several systems (including the Green hydraulic system) powered and reservoirs not drained.
The British story is less clear; G-BOAA in East Fortune was effectively killed when the wings were cut off for transportation, so that one is out of the question. G-BOAB, the last and only Concorde at LHR has been left to rot outside, in fact holes were even drill in the fuselage to drain water, so this one is a no no too. G-BOAC at Manchester, now the oldest surviving production aircraft was initially stored outside, but now resides in a purpose built exhibition 'hangar'. Now she COULD be a potential candidate for consideration; when I last saw her just over a year ago she was absolutely pristine; a testament to the team that have been caring for her there. G-BOAD, stored next to the USS Intrepid in New York, we can probably forget, due to having been exposed to 7 years worth of salt water corrosion from the Hudson River. (Also, while she was temporarily stored in New Jersey a couple of years ago, some IDIOT in a truck bent the whole nose section when he hit her. The radome was smashed (replaced with a rather clever fibreglass fabrication) and the nose straightened with a blow-torch and hammer (I am not joking!!). G-BOAE at Grantley Adams airport in Barbados has been stored under cover for much of the time; provided she has not suffered too much from the wam damp atmosphere of Barbados, well she could be a potential candiitate too. G-BOAF in Filton, well PROVIDED she is still OK after her 'removal from public view' experience could also be a potential candidate also. And finally, G-BOAG in Seattle; well she had been left outside, right next to a highway (and close to a truck stop too). She did not look too good the last time I saw her; the undercarriage barrels werer all brown and discoloured and the paintwork was completely dull and matte. (She had a new paint job not too long before retirement too). So out of the 'BA Seven', I PERSONALLY would go for G-BOAF, G-BOAC or G-BOAG.
As I have said often here before, it is EXTREMELY unlikely that what you, Mike, suggest will ever happen, but in spite of what others might say, IT IS NOT IMPOSSIBLE. My own gut feeling is a resounding 'no', but I could be wrong, . (And NO ONE would be happier than I if I am wrong; I was with the BA aircraft through construction, flight testing and the entire service life with BA).
As for the cost? It really is a case of 'how long is a piece of string', but for 2 aircraft we could be looking in excess of $100 or more, who knows?
But as the Everly Brothers used to sing 'All I have to do is dream.'
Keep posting Mike.

Dude .

hahaha Mike, sorry about that, yes I DID meen $100 MILLION.
norodnik
I can not personally recall a triple reheat fail ever happening, as Bellerophon explained in his answer to your post, but I can recall one occasion several years ago where the 15 minute time limit was inadvertantly exceeded for a couple of minutes. This was reported to both Rolls Royce and SNECMA, but no checks etc were instigated. The reheat ignition system, as I posted previously, was far too fragile; we did some investigations with Rolls Royce about 15 years ago into using 'hot streak' injection as a backup ignition source, but this was ruled out on cost grounds.

Dude

jodelistie
First of all Rod, welcome to our Concorde thread, and thank you very much for your kind words.
Now as far as the rumour goes, I'm afraid that it is nonsense, however the truth is an even more complex story of collusion, betrayal and intrigue. You may read that 'Concorde was retired by BA and Air France purely due to economic reasons', however that is not quite the case (and as far as THIS side of the English Puddle goes, is total poppycock!!). Now BA lost a huge amount of her regular traffic as a result of the 9/11 tragedy and also as a result of the 2003 Iraq war, but things were improving nicely. In her 27 years of operation, Concorde had survived countless dips in her traffic, only to return stronger as market conditions improved.
It is early 2003, and French Concorde traffic to the USA has almost vanished, down to single digit loads. This is due mainly to total French opposition the impending US/UK invasion of Iraq, and US businessmen using BA Concorde almost exclusively. (French business seems to be boycotting the US altogether, so their contribution to passenger loads virtually ceased). Due to the apalling loads, AF are losing absolutely MILLIONS of Euros, at a time when the carrier is trying to privatise itself ... but there is more:
In the same February, AF very nearly lost ANOTHER Concorde, yet again largely down to total incompetence and lack of adherence to established procedures. Aircraft F-BTSD was flying between CDG and JFK when there was a failure of the reheat delivery pipe that runs from the engine 1st stage fuel pump to the reheat shut-off valve. This failure, although not particularly serious, led to a chain of events that very nearly resulted in the loss of the aircraft, and all those onboard. (Air France engines were overhauled seperately to BA, who never experienced this particular failure). What was required in the case of this failure was a precautionary engine shut-down, closing off the fuel supply to the engine totally, and a descent/deceleration to subsonic speed, carefully monitoring fuel consumption all the time. Unfortunately the crew 'forgot' to shut down the fuel LP valve, and this resulted in the fuel continuing to gush out of the failed pipe at an alarming rate. (Oh, and also they forgot to monitor the fuel consumption). Only after the crew FINALLY noticed that they were still losing fuel did they remember to close the engine LP valve, but it was almost too late. The aircraft just managed to land in Halifax, with barely enough fuel left in the tanks to taxi!! So, herer we are, AF are horrified that they have come very close to yet another disaster, knowing full well that yet again human error was a major factor.
But there is more....
One week later another AF aircraft loses part of a rudder panel due to de-lamination of the honeycomb surface, not particularly serious in itself, but it put even more jitters up the trousers of AF. (Rudder failures had happened to BA aircraft many years previous to this, but BA had purchased brand new and improved rudders from Airbus UK in Filton, but Air France chose not too).
So it seems that the chairmen of both Air France and Airbus (who regards Concorde as a waste of its valuable resources) have a 'secret' meeting to plan what was effectively the murder of Concorde. There is no way that AF want BA to carry on flying Concorde while they have to cease operations, so the plan is for Airbus to make a huge hike in their product support costs; these costs would have to be borne by BA exclusively, which they both knew would not be possible. If these support costs were not met, there would be no manufacturers support, and without this there would be no type certificate, and without this, no more Concorde.
Their (AF & Airbus) hope was that BA would not challenge this move legally, and sadly for the world of aviation they did not. At a meeting, BA AND AIR FRANCE!!!! were told by Airbus about the hike in product support costs, and BA would also have to cease operations. BA were not even allowed to continue until March 2004 (the Barbados season was nearly fully booked already), and so would have to cease operations in October 2003.
But the British were far from blameless in all this; a now retired very senior British airline person had always obsessively HATED Concorde, so the French conspiracy was a very early Christmas present for him; he finally got what he had always wanted. The 'end of Concorde' anouncement by both airlines was made in April 2003; AF had got what their executives wanted and finished flying in May, reluctantly leaving BA to fly until late October. If you want a full (and extremely well informed) explanation of what happened in that whole debacle, the article by Don Pevsner is worth reading. It can be found at this website:
THE BETRAYAL OF CONCORDE
There is absolutely no doubt in my mind that without the truly disgusting events in France in early 2003, Concorde would still be proudly flying for BA. (And with modifications and enhancements would fly safely for many more years).
quote** "in the hands of true professionals, Concorde was the safest aircraft that ever flew. and in the hands of BA crews at least, she was always just that..*

Oh and yes you were correct, the Olympus (the world's first ever 2 spool engine) was originally a 'Bristol-Siddeley' design, before BS were absorbed into Rolls-Royce. Stanley Hookers book is in my view totally superb, a true classic.

Dude

Brit312
mm I guess they were not to blame for flying for over one hour with a red throttle light on (the engine is under no electronic control), resulting in the severe engine overspeed (N1 overspeed protection amplifier already disabled) and the subsequent scrapping (on the orders of Rolls Royce) of the entire rotating assembly of the engine. Or for omitting TWO intake trunnion blocks during a ramp actuator replacement, and then the E/O continually and cyclically operating the intake lane selector switch, following a spill door runaway, until he manages a double engine surge and near destruction of the 'forgotton parts' intake and engine also. I suppose they are not to blame for the experimental tripping of the LPOG circuit breaker by the E/O, during an engine power mismatch, resulting in serious damage to the engine and intake due to the resulting massive over-fueling surge. I suppose again, that they were not to blame for ignoring for over 6 months a simple electrical load defect, eventually resulting in a not too minor fire in the electronics racks that had to be extinguished by the crew with extinguishers. And yet again, I suppose they are not to blame for putting skydrol into Concorde hydraulics systems, almost resulting in the loss of the aircraft, as well as a 9 month grounding while all of the hydraulic components were replaced. And it was not Air France that hammered Fox Delta twice into the runway at Dacca, resulting in so much airframe distortion that the aircraft performance was seriously compromised (and eventually broken up). And of course they were not responsible for the technical and operational failures, including the (forgotton AGAIN ) missing spacer and overweight take-off etc.) on 25th July 2000. Silly me.
And although I might have said 'precautionary engine shut-down', we are talking about a quite an eventful episode here indeed, you can NOT excuse the further mistakes made on that day, 'just because they are poor old Air France. With the greatest of respect Brit, there are 3 crew members on that flight deck, do you not think that the loss of over over 5 tonnes of fuel over a period of time might just be noticed????? The subsonic 3 engined leg was carried out for quite a time before it computed to them that they were still losing fuel. There is no excuse for flying with your eyes closed, I'm sorry.
For goodness sake, this is probably the biggest single episode that was behind the demise of Concorde, poor Air France my eye!!!

Dude

ChristiaanJ
I could not agree more my friend. There has been a total wealth of queries and information from people from all over, not necessarily involved with aviation, let alone Concorde. Keep asking away everybody
I'm sure that ChristiaanJ, Brit312, Bellerophon, EXWOK and myself and others (ooh, lets not forget Landlady) will be only too glad to churn away at our poor worn out old brains and try and come up with some semi-intelligible (at least) answers.

Dude

Bellerophon
There were no specific airframe inspections associated with a fuel saving landing (the possibility of which EXWOK eluded to) ; the 2899XX00 log code would however trip a flag that required the landing vertical and longitudinal accelerations to be analysed on the QAR readout. (The vertical G was also locked into the memory of the AIDS management panel, and was there until the next landing). And would I or anyone within Concorde engineering blame you guys for 'bending it'?....
(Only joking everybody, the most important thing after any minor incident was for us all to sit down and have a thorough post landing chat, so that everyone was clear as to what happened, and the cause of the 'bump in the night' could be nailed and remedied ASAP).
Leg it indeed.. (chuckle).

Dude

NW1
I do remember well that the AF incident was as a result of severe vibration, that was what I was (not very elequently) eluding to in my previous post. The engine shut down was due to these vibrations, not because of any fuel loss. According to Rolls Royce the fuel pipe fracture ended up being as a result of an engine build failure, on the part of the AF sub-contractors. However my 'eyes closed' comment still holds here I'm afraid, it's basic situational awareness folks. And I'm not jumping to any conclusions here , I helped investigate the first of the serious errors (the experimental c/b tripping/overfuel surge incident) when I was still at British Aerospace in early 1977 and learned long ago to get my facts straight as far as possible in these things.
As a grotty old engineer I tend to lack the subtlety and diplomatic skills of you guys, but this coming at the end of such a long catalogue of gross errors, this possibly last straw in the life of Concorde was in my view also the very last straw in terms of these serious procedural failures too.
There are so many events in Concorde's history that we would like to 'roll back the clock' on, but this extremely pivotal one has to be just about at the top of a very big pile (save of course for the Gonesse tragedy).

Dude

NW1
I agree that my wording regarding precautionary engine shut-down was not quite correct my friend ; with WW3 going on out there under the wing I think we can both agree that that check list ddi not in any shape or form cover the events ensuing.
And as for the AM/CF dynamic duo; I could not agree more; these two wankers/toss-pots/cretins etc (being a gentleman forbids me from printing here my real thoughts on these veritable slime buckets) I would not place them in charge of a broken down manure truck. . One had the avowed aim of destroying Concorde and the other, in a position to do some good did his master's bidding and was party in no small way to this madness. Pity 'skippy' did not have some balls too!!
Best Regards

Dude

I have to admit that some of the subsonic fuel burn figures for Concorde were truly eye watering, and without massive engine and airframe modifications there was precious little in service that could be done to improve things. Paradoxically improvements to the supersonic efficiency of the powerplant were easier to implement, and several modifications were implemented, tried or proposed to improve fuel burn:
Way back in the late 1970's we did a major modification to the intakes that increased capture area by 2.5% and gave us typically a 1.6% improvement in trans-Atlantic fuel burn, and although this was our biggest performance improvement modification, there were more:
The famous elevon and rudder trailing edge extension modifications (that due to poor design, produced in later life the water ingress induced honeycomb failures) together with the re-profiled fin leading edge modification, I never saw the performance gains quantified (anyone have any ideas?).
Can anyone here remember the riblet trial? In the mid 1990's Airbus supplied 'stick on' plastic riblets, applied to various areas on the under-side of the wing on G-BOAG. These riblets had very fine undulations moulded into the surface; the idea being that as the air flowed through and around the riblet patches, boundary layer turbulence, and hence induced drag would be reduced. Now, the performance gains (if any) were never quantified, mainly because the riblet patches either peeled off or the surface deteriorated with the continuous thermal cycle. (I was over in JFK when the aircraft first arrived after having the riblets fitted, and as the crew were trying to proudly show me these amazing aerodynamic devices, they were sadly embarassed, as several had dissapeared in the course of a single flight).
There was one modification, proposed by Rolls Royce in the late 1990's that did have quite a lot of potential; this was to increase the engine N1 by around 1.5%. This would have had the effect of increasing engine mass flow and therefore reducing the drag inducing spill of supersonic air over the lower lip of the intake. Depending on the temperature, the performance gains were in the order of a 1.5% improvement in fuel burn at ISA Plus upper atmosphere temperatures ('normal' LHR-JFK) to none at all at significant ISA Minus temperatures (LHR -BGI). The modifacation had been trialed on G-BBDG before her retirement in the early eighties, and was proven in terms of performance enhancement and engine stability. In order to keep TET at the pre-modification level, there was a small increase in N2 commanded also. (The higher N1 required an increase in primary nozzle area, reducing TET). The main reason for the modification not being implemented was one of cost; The Ultra Electronics Engine Control Units were analog units, and the modification was a simple replacement of two resistors per unit. However because ultimate mass flow limitation was also controll by the digital AICU (built by British Aerospace Guided Weapons Division) the cost of getting a software update for this exremely 'mature' unit was found to be prohibitive.
A certain 'brainy' SEO and myself were working on a modification to improve fuel burn on ISA minus sectors. The idea was to force the autopilot, in Max Cruise at low temperatures only , to fly the aircraft close to Mmo, rather than at Max Cruise speed of Mach 2 - 2.02; this would have given us gains of up to 1%, depending on the temperature. The basic electronics involved for the modification were relatively straightforward, but it was never pursued due to the complexity of dealing with temperature shears and the cost of certification.

Dude

NW1 and ChristiaanJ
Ahh yes, the super hi-tech 'HUD'. It was right up there with the 'eye level datum' indicator and not to forget, the reheat capabiliy indicator in terms of sophistication. (Extremely reliable though ).
As far as 3 engined ferries went; well NW1, not sure if you'd call me seasoned or just just clapped out and wrinkly, but it did happen a very few times in days of yore, mostly from SNN back to LHR. There were at least two; OAF in 1980 when she had the infamous LP1 blade fail (and Monty Burton's immortal words during the 'event' "what *** ing drill?). The second one that I can remember was OAA in 1991 when there was another far less serious compressor blade failure. In each case for the ferry flight, the broken engine was 'swaged' to prevent it windmilling and the aircraft would be flown back to the LHR garage by a management crew. There was however another required ferry measure as well as the engine swaging, this measure was to prevent the good engines going into contingency, due to the very slightly flamed out dead 'donk'. This procedure required the Engine Speed Unit to be removed from the electronics rack and a special jumper plug fitted in it's place (without the jumper fitted the start switch would never latch in. In this case also the E/O would also need to manually disengage the start switch at 25% N2). I have to admit that I never in my life ever saw this jumper plug, and in the cases that I can remember the aircraft departed SNN with the three engines at contingency. I remember that the case of OAA back in '91 most certainly was; I was flown out to SNN equiped with a pile of circuit diagrams and test boxes to investigate what we all thought was just a surge related engine shutdown. only to find a slightly more hairy state of afairs, with a very broken engine indeed. As a matter of interest, this particular failure was the only one ever in the history of Concorde in BA attributed to the engine having run for a protracted time in rotating stall. (This had happened on the previous day). A lot was learned by both BA and Rolls Royce after this event, and this failure never occured again.

Dude

Oh darn it Feathers, if you insist (LOL).
First of all, what is rotating stall? All gas turbine engines are prone to this to some degree or another, the Olympus was particularly prone (so we discovered to our cost). What happens is that extremely LOW figures of N2, small cells of stalled air rotate around the anulus of the early stages of the HP compressor (at approximately half the rotational rpm), resulting in parts of the airflow becoming choked and highly distorted. This often results in the combustion process being disturbed to the extent that combustion instead of occuring in the combustion chamber, occurs in the turbine itself. This of course results in massive overheating of the turbine blades and stators (and is what is suspected occured in the #2 engine on G-BOAA in 1991.
To prevent running in rotating stall, the Olympus automatic fuel start schedule would accelerate the engine quickly to around 67% N2 before dropping back to the normal idle figure of around 65% N2. (The stall clearance N2 figure was ambient temperature dependant, the higher the temperature the higher the N2 that was required and hence scheduled by the automatics).
What had happened on G-BOAA was an engine starting/accelerating problem, where the N2 ran at a sub-idle of around 40% N2 for several minutes. This was enough for the malignant effects of rotating stall to take hold, and the resulting turbine blade failure over the Atlantic the following day. In all fairness to everyone involved, none of us, including Rolls Royce realised just how potentially serious this phenonomen was, and salutary lessons were learned by one and all. (The following year Air France had a similar failure; their first and last also).
I flew out to Shannon on a BAC 1-11, that was sent to fly the Concorde passengers back to London. As I and my colleague were coming down the ventral door steps of the 1-11, a chirpy Aer Lingus engineer asks 'have you guys come to fix the broken engine?, there are bits of it lying in the jet pipe'. Now up to now, from the information we'd been given in London, we thought that we were going to be looking at either an intake or engine induced surge, a few systems checks and boroscope inspections and we'd all be on our way, so we naturally thought the Aer Lingus guy was joking. He was most certainly was not; as you looked into the jetpipe (through the secondary nozzle buckets) you could see a large quantity of metal debris, accompanied by a strong smell of burnt oil. I remember this day well, it was the day that the first Gulf war ended; how ironic.
The aircraft departed on three engines, flown by a management crew late the following day, my colleague and I returned to London by Aer Lingus one day later. (No passengers whatsoever are permitted on ferry flights, even expendable ones like me).

Dude

Cron
Sounds like the helicopter engineer's guess was right, they'd be the static wick mountings.
Feathers McGraw
Yes there was, that was the problem alright Feathers. I'd only heard an engine stuck in rotating stall during startup once; even on the flight deck it sounded like a tom cat with his gonads trapped in a vice, and we shut the thing down straight away. (The engine, not the tom cat ).
It was mainly a case of increased vigilance during engine start; it was always noticable to see rotating stall clearance on startup as the N2 went past normal idle and then rolled back. As far as modifications go, I'd designed a modification to detect and alert the crew if rotating stall had not been cleared on startup, but it was felt to be too costly and complex, when increased vigilance by all could prevent the nasty event happening in the first place. (I suppose only one BA occurence in 27 years is not so bad, and if the automatics did their job you had no problem anyway). But now at least EVERYBODY was aware of the malignant consequences of not clearing rotating stall on startup; it was no longer just a phrase that we all learned in training, but scary reality.

Dude

Landroger
Good to see you here again Roger, I'll try my best to give you my take on rotating stall. (I worked very closely with Rolls Royce in the Concorde days, and everything I know about the process is thanks to them). Turbine engine combustion is a precise and delicate affair, particularly during start, and too much or too little fuel can cause severe problems. With rotating stall, the rotating cells of stalled air. if they manage to take 'hold' can cyclically choke the flow into the latter compressor stages (it's the cyclic nature of the cells that is the real problem, hence the 'rotating' stall term). The cells as they 'hit' the compressor blades (the cells are rotating at half shaft speed in the opposite direction of shaft rotation) can cause blade vibration and can also cause minor surges within the engine. The combustion fire literally can burn in the turbine section, but any distortion to the combustion process will result in local overheating, due to poor air/fuel mixing etc. In some engine types, damage can be also be caused to the HP compressor blades (due to vibration) but with the Olympus the main danger was to the turbine blades and stators. It's difficult to relate to any common analogy for this lot I'm afraid Roger.
Rotating stall was avoided in the Olympus by starting the engine with the primary nozzle driven wide open, and controlling two parameters; those being the opening rate of the fuel valve and the rate of rise of exhaust gas temperature. (During the start sequence, once ignition had occured the EGT rise was held to 6 degrees per second, right up until rotating stall clearance at 65% temperature corrected N2 ). So the engine accelerates without let or hinderance right through the danger zone, but was prevented from dipping below 65% temperature corrected N2, where the danger zone starts again. (Absolute minimal idle for the Olympus 593 was set at 61% N2).
I sincerely hope this blurb helps Roger, if not then feel free to ask again or PM me.
Regards

Dude

Biggles78
oooo that's a hard one to answer. The financial crisis that we are (I hope) clambering out of would almost certainly have impacted in a big way the load factors on the aeroplane. This almost certainly would have resulted in at least a severe curtailment in the operating schedule, but quite possibly now she would be absolutely THRIVING in the recovering world airline business. To answer your question fully, I think that there would at least NOW have been the willing and ability within the airline to keep her going in a big way, but there would be major expense over the last and next few years. The FAA SFAR88 directive would have already resulted in a major review of all fuel tank wiring and components. (However this appplies to any aircraft, ageing ones in particular). EGPWS would have been mandated by now, which means provision for at least one (probably two) GPS antennas. This upside of this would have meant the relative ease of incorporating a more accurate navigation system, the Litton LN93 system (Laser INS with GPS update) was already being looked at before retirement. A major structural modification to the fuselage crown area would certainly have been mandated under the FAA/EASA ageing aircraft programme, although the mods were pretty much drawn up before retirement (and would have been a permanent fix for the one chink in her supersonic armour). It is also probable that predictive windshear would have been activated. (The Bendix RDR4a had this capability but it was disabled in Concorde). I think that for PWS and RWS to operate correctly you'd need some sort of pilot display in any case.
Another seperate issue would be having sufficient 'O' licensed Engineering Officers in the airline; due to basic demographics there would be precious few left in the airline now. (My personal guess is that pilots would have to be trained as to qualify as P3's).
So although it would be far from easy to keep her going, if she was earning sufficient current and potential revenues, then I'd say yep!! (But this is just my humble opinion of course).

Dude

Nick Thomas
Hi again Nick, I totally agree that anyone suggesting tha Concorde was a 'terrible waste' is either totally mis-informed or naive; either way they are totally wrong anyway. The Airbus spinoffs as well as the know how gained on both sides of the English Puddle were immense. What she brought to BA as a brand of course is a totally different matter; for BA she was just the best thing since sliced bread.
As far as another SST, well you never know. I maintain that in aviation you can never say 'never', but far more likely than an SST as such is a hypersonic sub-orbital machine such as the Reaction Engines Lapcat. In any case such a venture will require immense financial investment as well as HUGE political balls to have any sort of chance of becoming anything more than a paper aeroplane. More conventional SST designs are around both in Europe and Japan, perhaps a trans-continental venture is the answer here?

ChristiaanJ
I'm with you on the business jet angle, it's such a quick and convenient way of getting from city centre to city centre. And as for the SSBJ, it did sound promising didn't it, that would have been the ultimate business travel tool. (Shall you and I design a 'mini-conc') ?
Regards to all

Dude

Landroger
SSBJ is Supersonic Business Jet Rog', there have been a few designs but the most famous (and had the most potential) was the Sukhoi-Gulfsteam S21. This aircraft would carry about a dozen passenges at Mach 2.2, with a range of 4,500 miles. Gulfstram pulled out of the partnership; there werer serious doubts about the viability of the Russian engine as well as serious aerodynamic issues too.
I would not personally utter 'Concorde and Tornado' in the same breath Rog; you need to carry this 6 tonnes over more than several HUNDRED miles. There is absolutely no comparison between the performance of Concorde and the Tornado I'm afraid, you'd need to base any military adaption on a far better design than that.
Although design of the powerplant for any future SST is pivotal to the whole design, you still need an aerodynamic model with a significantly higher lift/drag ratio than Concorde to make the project viable. And as good as the SR-71 was (I'm one of her biggest fans) she was still using afterburning/reheat at Mach 3 cruise.
galaxy flyer
Great to see you back here GF. I DO hope that you are wrong about mini-skirts
You are so right about the massive industrial collaboration required; it seems that there was so much more of a 'daring spirit' in the 1960's, makes you wonder where all the balls have gone today. (Oh I know, there are so much more deserving causes than aviation for us to spend BILLIONS of $'s and \xa3's on today).
Nick Thomas
No need to apologise for any thread drift Nick; this is such a diverse thread now; your points are perfectly valid here. And thanks for your kind comments again Nick; CJ the rest of the guys and myself are more than happy to bore the socks off of you and all the other posters and readers.
hoofie
So glad that you enjoyed your Concorde experience. The Jeddah flights were a fairly brief 'experiment',it would be great if one of my pilot/flight engineer friends here did a trip, we'll soon know. The double 'shove in the back' would indeed as you say have been the inboard/outboard reheat selection. Glad you are enjoying the thread, it is certainly bringing back memories for me about this seemingly eternal aereplane.
jodeliste
No problem Rod, I think most of us here agree about that one. A terrible waste and a giant leap BACKWARD in aviation.

Dude

Landroger
Come on Rog, let's not be silly now. I was not 'upset', and you can use the 'T' word any time you feel that you need to lad. It's just that you used a very poor example to use when, I don't know what your point was anyway, comparing Concorde with any other aeroplane.
The J58 powerplant design for the SR-71 is superb, and considering the early 1960's era that it was developed, was nothing short of astounding.
For Mach 3 cruise air is bypassed around the engine core and fed staright into the afterburner duct, where it supplied the afterburner directly. Still a remarkable design though, even now.
Oh she didn't; she just leaked. (not on the same scale as the SR-71 though).. If you were nuts enough to walk under a fully fueled Concorde without an umbrella you often got quite wet and smelly. The leaks were 'drips' and not running streams, and maximum permissable leak rates were mandated and controlled, but if she became particularly 'drippy' it was straight back to the hangar for tank re-sealing for our Concorde. The fuel tanks were sealed using liquid viton rubber, the idea being that the viton when it solidified would filll in all the nooks and crannies of the tanks. Controlling leaks was one of the most time and labour consuming aspects of Concorde maintenance, to get in and seal some of the smaller tanks was challenging to say the least, and some pretty small chappies were required for some of the tank areas.
I still remember that when we were building Concorde, this idiot of a production manager at Filton (the same one that was responsible for the debacle of G-BOAD sitting on her tail) insisted that the fuel tanks were filled with fuel as soon as the tanks were completed, whether the sealant was dry or not. I still wonder how much of the in-service leak maladies could be directly attributed to him.

Dude

Mr Vortex
First of all, 'welcome aboard'; I'll do my best to answer your queries.
The area of the primary nozzle Aj, was varied for 2 'primary' purposes :
a) To act as a military type 'reheat' or 'afterburning' nozzle; opening up to control the rise in jet pipe pressure P7, as reheat is in operated.
b) To match the INLET TOTAL TEMPERATURE RELATED (T1) speed of the LP compressor N1 to the HP compressor N2 against a series of schedules, ensuring easch spool is as close as safely possible to its respective surge boundary, (with a constant TET, see below) and therefore at peak efficiency.
Now, in doing this a complex set of variables were in place. As the nozzle is opened there is a REDUCED pressure and temperature drop across the LP turbine. This has the effect of enabling a HIGHER N1,as less work is being done by the turbine. Also the change (in this case a decrease) in the temperature drop across the turbine will obviously affect the turbine entry temperature, TET. A closing down of the nozzle would obviously have the opposite effect, with a DECREASE in N1 and an INCREASE in TET.
In practice at a given T1 there was always an ideal N1 versus N2 on the control schedule (known as the E Schedule), the TET staying more or less constant from TAKE-OFF to SUPERSONIC CRUISE!!
As far as noise abatement went; when reheat was cancelled and power reduced after take-off, an E Schedule known as E Flyover was automatically invoked. This had the effect of driving the primary nozzle nearly wide open, reducing both the velocity of the jet efflux and in essence the noise below the aircraft.
The real beauty of this primary nozzle system was that it really did not care if the engine was operating dry or with afterburning ('it' did not even know). P7 was controlled against a varying compressor outlet pressure, the variable being controlled by a needle valve operated by the electronic engine controller. (If this is unclear I can post a diagram here that shows this control in action).

As soon as I receive back the majority of my technical notes that I have out on long-term loan (I've requested their return) I will post a schematic here. But for now; The tanks were vented to atmosphere via tandem vent galleries, the two vents openings being on the left hand side of the tail-cone. At an absolute static pressure of 2.2 PSIA (around 44,000') twin electrically operated vent valves, also in the tail-cone, would automatically close; the tanks now being pressurised via a small NACA duct on the right side of the fin. A tank pressure of around 1.5 PSIG was maintained by the action of a small pneumatic valve at the rear of the aircraft. There was massive protection built in to guard against over-pressure (eg. if a tank over-filled in cruise).

I hope this answers some of your queries
Best Regards

Dude