September 15, 2010, 16:04:00 GMT
permalink Post: 5936365
bio161
Hi, I think that they are refereing to the French development aircraft 102 F-WTSA, I remember the event really well, the aircraft was even delayed on the ground in Paris while one of the 'passengers' (An American press reporter) went shopping in the terminal building. In spite of the delay Concorde still won the 'race' with ease.
Dude
- In June 1974 Air France pitted Concorde against the B747 in a direct race. The
Dude
Subjects
Boeing 747
F-WTSA
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
September 16, 2010, 14:14:00 GMT
permalink Post: 5938207
Keeping her warm
I used to work for BA at BHX (Engineering). BHX was one of the BA diversion airfields for when LHR got fogged out.
A few of us were therefore trained on non BHX based aircraft types in case of diversions. On my shift, I was trained on the B747 and my colleage on Concorde.
Of course we didn't see these aircraft very often, but when we did we had to get out the old course notes to refresh
.
However, whenever Concorde turned up, my overriding memory was of my colleage who was obsessed with 'keeping her warm" - at all costs. I remember an occasion where the GPU, that had been running for a few hours (connected to a Concorde), ran out of diesel and therefore the power dropped off-line. I thought my colleage was going to have a heart attack - he did not come down from orbit until power was restored and everything appeared 'normal' again.
I think that this was something drummed into him whilst on his Concorde training course
A few of us were therefore trained on non BHX based aircraft types in case of diversions. On my shift, I was trained on the B747 and my colleage on Concorde.
Of course we didn't see these aircraft very often, but when we did we had to get out the old course notes to refresh
.
However, whenever Concorde turned up, my overriding memory was of my colleage who was obsessed with 'keeping her warm" - at all costs. I remember an occasion where the GPU, that had been running for a few hours (connected to a Concorde), ran out of diesel and therefore the power dropped off-line. I thought my colleage was going to have a heart attack - he did not come down from orbit until power was restored and everything appeared 'normal' again.
I think that this was something drummed into him whilst on his Concorde training course
Subjects
Boeing 747
British Airways
GPU (Ground Power Unit)
LHR
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
September 21, 2010, 18:06:00 GMT
permalink Post: 5948141
For Mike_Bracknell
The rudder failures weren't really down to a fault with the original design, here's the story as I remember it:
The ctrl surfaces are made of a honeycomb-core bonded to the skins, essentially. They originally had a blunt trailing-edge, as was then de-rigeur with supersonic design. At some stage it was decided that a sharp trailing edge was actually beneficial so they had an extension fitted, which had the unfortunate effect of allowing a certain amount of water ingress to the core. Heating and expansion of this lead to disbonding and ultimately failure of the surfaces. (I suspect my engineering colleagues will have a much better and more accurate explanation).
Now - here's the important bit, and another example of this aeroplane's excellent failsafe engineering; Concorde had two rudders, one above the other (same as the 747). Each is driven by one dual-bodied PFCU. You ABSOLUTELY don't want a PFCU endangered by ctrl surface damage so each surface is divided in two, either side of the PFCU control horn.
Visualise the PFCU attached to the centre of two surfaces with an end rib on each, but skinned to look like one surface. Therefore, in the case of the surface suffering damage, it can only spread to a point short of the all-important PFCU. Look at the rudder-failure pictures and you'll see what I mean.
So - far from the 'rudder' breaking up, the reality is that half of one of the rudders had failed.
It was somewhat inevitable that Concorde's control sfcs would suffer, given the horrific loads they endured, and this was dealt with at the design stage. The elevons had the same sort of design.
It does of course look bad when you land with bits missing and this, plus the Regulators and company safety depts ensured that eventually some HUGELY expensive replacements were built.
The ctrl surfaces are made of a honeycomb-core bonded to the skins, essentially. They originally had a blunt trailing-edge, as was then de-rigeur with supersonic design. At some stage it was decided that a sharp trailing edge was actually beneficial so they had an extension fitted, which had the unfortunate effect of allowing a certain amount of water ingress to the core. Heating and expansion of this lead to disbonding and ultimately failure of the surfaces. (I suspect my engineering colleagues will have a much better and more accurate explanation).
Now - here's the important bit, and another example of this aeroplane's excellent failsafe engineering; Concorde had two rudders, one above the other (same as the 747). Each is driven by one dual-bodied PFCU. You ABSOLUTELY don't want a PFCU endangered by ctrl surface damage so each surface is divided in two, either side of the PFCU control horn.
Visualise the PFCU attached to the centre of two surfaces with an end rib on each, but skinned to look like one surface. Therefore, in the case of the surface suffering damage, it can only spread to a point short of the all-important PFCU. Look at the rudder-failure pictures and you'll see what I mean.
So - far from the 'rudder' breaking up, the reality is that half of one of the rudders had failed.
It was somewhat inevitable that Concorde's control sfcs would suffer, given the horrific loads they endured, and this was dealt with at the design stage. The elevons had the same sort of design.
It does of course look bad when you land with bits missing and this, plus the Regulators and company safety depts ensured that eventually some HUGELY expensive replacements were built.
Subjects
Boeing 747
Elevons
Expansion
PFCU (Powered Flying Control Units)
Rudder
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
September 22, 2010, 23:54:00 GMT
permalink Post: 5950686
You had to stop and look.
Having spent the last 11 years based JFK, it never got old to see this magnificient bird arrive and I think to a man, or woman, every one always took a moment to look.
I have loved aeroplanes since I was very young - I genuinely understood Bernouli's principle when I was about nine - and I always looked at aeroplanes, indeed I still do. But most of the time, when the engine note was obviously a 747 or 727 (noisey!) or some such, I would perhaps concentrate on what I was supposed to be doing. But in the early evening, the absolutely inimitable sound of 593s would draw the eyes of nearly everyone in our area. We saw her every day and yet we all looked. Always. Extraordinary.
Not being in the flying profession, I only have two Concorde stories of my own. Back before the M25 was completed and it stopped at Poyle, I would take the opportunity to use what became the Poyle northbound on ramp as a 'plane spotters' place. One evening I stopped in the gathering dusk and got out to watch a few planes. 737s and 757s abounded as the light faded, leaving a broad, light blue band across the horizon, tinged with peach and little colour anywhere else.
Then I heard her on her way and the old heart beat a bit quicker. Suddenly she was up and passing and my mind's eye took the photograph I always wanted and now will never get.
Concorde, silhouetted against the horizon, the cabin lights just visible, but the four, electric blue reheat exhausts - including shock diamonds - the only other colour in the monochrome image. Unforgettable.
The second was day time. I was parking my car in the north car park - when it was basically all the way down one side of 27R. On my way, I think, to Stockholm Arlander, I was ignoring the succession of 'light iron' going by very close. Again, I heard her light up and just stood and waited. Fabulous sight of Concorde, just rotating as she passed me and climbing away to the west trailing thunder ..... and every car in the north car park sounding their tribute when the reheat set off their alarms.
You just had to look - every time.
Roger.
Subjects
Afterburner/Re-heat
Boeing 747
Glide
JFK
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
September 23, 2010, 02:50:00 GMT
permalink Post: 5950840
I agree that the 747-400 had tail tanks but the 747 upgrade was approx 20 years after Concorde first flew!
Regards
Nick
Regards
Nick
Subjects
Boeing 747
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
November 03, 2010, 04:28:00 GMT
permalink Post: 6035000
Fuel: Conc vs 737
For those who wanted to know what the difference in fuel burn between a 737 and Concorde LHR-MAN........I don't know! (Never had the pleasure of flying the 737).
My best guess - at least 200% more. Probably higher.
A comparison:
Typical Concorde taxying fuel burn: 6500kgs/hr
Typical 777-200 cruising fuel burn: 6500kgs/hr
Of course, as we've already discussed earlier, the magic thing about Concorde was that once you'd got to Mach2 its efficiency was outrageously good - better miles per gallon than a 747. An option not available, however, between LHR and MAN.
Edited to add: a slow taxy out at LHR would almost definitely consume more fuel than the 737 would burn for the sector.
My best guess - at least 200% more. Probably higher.
A comparison:
Typical Concorde taxying fuel burn: 6500kgs/hr
Typical 777-200 cruising fuel burn: 6500kgs/hr
Of course, as we've already discussed earlier, the magic thing about Concorde was that once you'd got to Mach2 its efficiency was outrageously good - better miles per gallon than a 747. An option not available, however, between LHR and MAN.
Edited to add: a slow taxy out at LHR would almost definitely consume more fuel than the 737 would burn for the sector.
Subjects
Boeing 747
Fuel Burn
LHR
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
November 11, 2010, 01:19:00 GMT
permalink Post: 6053012
As a Yank, the Concorde was Europe's, including the UK, of course, Apollo project. And nothing short of it, either. Concorde required industrial cooperation and collaboration on a huge scale, ground-breaking technology that is still paying back in the 21st century and required political daring unheard of today. Huge applause!
Think of the Sixties projects--Apollo, Concorde, 747, SR-71, motorways, the Beatles, miniskirts--none possible today, the politics alone would kill 'em.
GF
Think of the Sixties projects--Apollo, Concorde, 747, SR-71, motorways, the Beatles, miniskirts--none possible today, the politics alone would kill 'em.
GF
Subjects
Boeing 747
SR-71
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
November 11, 2010, 11:39:00 GMT
permalink Post: 6053722
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
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
Think of the Sixties projects--Apollo, Concorde, 747, SR-71, motorways, the Beatles, miniskirts--none possible today, the politics alone would kill 'em
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
Sorry again folks more misunderstanding when I said terrible waste I meant the cancellation and grounding not the work done
Dude
Subjects
Afterburner/Re-heat
Boeing 747
Lift Drag Ratio
SR-71
Tu-144
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
November 18, 2010, 03:17:00 GMT
permalink Post: 6068572
Roger
My appreciation for your complement. Anyone, yank or otherwise, who does not appreciate the long term and continuing world wide cooperation that is required for any project like Concorde or Apollo is simply being xenophobic. Today, Boeing has a large engineering bureau in Moscow, BMW has a design office in California.
Many of the engineers that worked on Apollo, 747 and, even, the C-5, were Canadian ex-pats fired from the Avro Arrow program shutdown. BTW, my nomination for least appreciated, least known but most ambitious aircraft design.
GF
My appreciation for your complement. Anyone, yank or otherwise, who does not appreciate the long term and continuing world wide cooperation that is required for any project like Concorde or Apollo is simply being xenophobic. Today, Boeing has a large engineering bureau in Moscow, BMW has a design office in California.
Many of the engineers that worked on Apollo, 747 and, even, the C-5, were Canadian ex-pats fired from the Avro Arrow program shutdown. BTW, my nomination for least appreciated, least known but most ambitious aircraft design.
GF
Subjects
Boeing
Boeing 747
Engine Shutdown
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
November 18, 2010, 17:39:00 GMT
permalink Post: 6070011
Galaxy Flyer
Many of the engineers that worked on Apollo, 747 and, even, the C-5, were Canadian ex-pats fired from the Avro Arrow program shutdown. BTW, my nomination for least appreciated, least known but most ambitious aircraft design.
GF
GF
Roger.
Subjects
Boeing 747
Engine Shutdown
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
November 21, 2010, 18:21:00 GMT
permalink Post: 6075931
QUOTE]I'm wonder if all 4 Olympus 593 all died in flight and unable to restart. Is it
possible to be able to land at the nearest airport[/QUOTE]
As CristiaanJ says , it depends on how far the nearest airfield was away, but given that there was one close enough then yes in theory it was possible.
On Concorde there were two checklist to cater for a four engine failure that assumes the engine have flamed out but not seized thus the system can be fed by windmilling engines. The two drills are
4 ENGINE FAILURE ABOVE MACH 1.2
4 ENGINE FAILURE BELOW MACH 1.2
When above M1.2 the windmilling speed of the engines should keep the engine generators on line and you should have good hyd pressure also.
Therefore the main point of the drill at this speed is to try and relight the engines, by selecting relight on all 4 engines at the same time. You normally got the chance to go through 2 and some times 3 relight sequences before the speed dropped to Mach 1.2
At mach 1.2 with no engines then the windmilling speed is reaching a point where it is not sufficent to hold the generators on line so the drill concentrates on switching as much of the systems onto essential electrics which will be supplied by the hydraulically driven emergency generator.
To help support the yellow and green hyd system below M1.2 the ram air turbine is lowered. Engine relights will continue to be attempted but as you are on essential electrics now they can only be attempted individually.
If no relights and below 10,000ft then the c/list tells you to prepare the aircraft for landing by lowering nose/visor and gear by emergency systems with speed reduced now to 270 kts. To conserve hyd pressure being mainly derived now from the RAT for the flying controls the emerg gen is switched off during the approach and approch speed is 250 kts with min landing speed
of 200kts
During this all this descent the aircraft had to be flown and navigated, radio calls made along with PA and cabin briefing and all the normall descent checklist complied with so you can imagine it was quite a busy time
This drill used to be practised on the sim ,but the crew would normally find the engines started to relight before 10,000ft so as to give the crew confidence that the drill worked.
However after many years of operation there was some talk about doing away eith the drill as no one could envisage it ever happening. then the BA 747 lost all 4 engines in the volcanic ash cloud and all such talk stopped
possible to be able to land at the nearest airport[/QUOTE]
As CristiaanJ says , it depends on how far the nearest airfield was away, but given that there was one close enough then yes in theory it was possible.
On Concorde there were two checklist to cater for a four engine failure that assumes the engine have flamed out but not seized thus the system can be fed by windmilling engines. The two drills are
4 ENGINE FAILURE ABOVE MACH 1.2
4 ENGINE FAILURE BELOW MACH 1.2
When above M1.2 the windmilling speed of the engines should keep the engine generators on line and you should have good hyd pressure also.
Therefore the main point of the drill at this speed is to try and relight the engines, by selecting relight on all 4 engines at the same time. You normally got the chance to go through 2 and some times 3 relight sequences before the speed dropped to Mach 1.2
At mach 1.2 with no engines then the windmilling speed is reaching a point where it is not sufficent to hold the generators on line so the drill concentrates on switching as much of the systems onto essential electrics which will be supplied by the hydraulically driven emergency generator.
To help support the yellow and green hyd system below M1.2 the ram air turbine is lowered. Engine relights will continue to be attempted but as you are on essential electrics now they can only be attempted individually.
If no relights and below 10,000ft then the c/list tells you to prepare the aircraft for landing by lowering nose/visor and gear by emergency systems with speed reduced now to 270 kts. To conserve hyd pressure being mainly derived now from the RAT for the flying controls the emerg gen is switched off during the approach and approch speed is 250 kts with min landing speed
of 200kts
During this all this descent the aircraft had to be flown and navigated, radio calls made along with PA and cabin briefing and all the normall descent checklist complied with so you can imagine it was quite a busy time
This drill used to be practised on the sim ,but the crew would normally find the engines started to relight before 10,000ft so as to give the crew confidence that the drill worked.
However after many years of operation there was some talk about doing away eith the drill as no one could envisage it ever happening. then the BA 747 lost all 4 engines in the volcanic ash cloud and all such talk stopped
Subjects
Boeing 747
British Airways
Checklists
Engine Failure
Olympus 593
RAT (Ram Air Turbine)
Relight
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 21, 2010, 18:39:00 GMT
permalink Post: 6135993
Ref the landing manoeuvre: CliveL is quite correct - there was a distinct nosedown pitch generated by descent into gnd effect.
The machine was very light in pitch on approach (spring feel only and not much positive stability, especially with the A/T active owing to its destabilising effect) so minimal pitch input was the order of the day. Then you descended into gnd effect and a steadily increasing pull was reqd to hold the desired attitude (any nose down change at this stage was a prelude to disaster!).
The overall effect was not unnatural, since it was similar to a flare and hold off in a conventional aircraft (although more Stearman than 747).
AFTER touchdown, selection of reverse caused a distinct pitch up, and if this was allowed to get hold it was a real problem to get the nose back down. As explained pages earlier this deprived you of braking ability.....for this reason both pilots pushed the control column firmly forward after nosewheel touchdown, and I'm guessing that's what ChristiaanJ meant .
The machine was very light in pitch on approach (spring feel only and not much positive stability, especially with the A/T active owing to its destabilising effect) so minimal pitch input was the order of the day. Then you descended into gnd effect and a steadily increasing pull was reqd to hold the desired attitude (any nose down change at this stage was a prelude to disaster!).
The overall effect was not unnatural, since it was similar to a flare and hold off in a conventional aircraft (although more Stearman than 747).
AFTER touchdown, selection of reverse caused a distinct pitch up, and if this was allowed to get hold it was a real problem to get the nose back down. As explained pages earlier this deprived you of braking ability.....for this reason both pilots pushed the control column firmly forward after nosewheel touchdown, and I'm guessing that's what ChristiaanJ meant .
Subjects
Air France 4590
Boeing 747
Braking
Landing Gear
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 22, 2010, 12:01:00 GMT
permalink Post: 6137291
Turb mode
'Dude -
I didn't ever use this mode, and never saw anybody else use it.
Significant turbulence was almost unheard of in supercruise - light to mod was the worst I ever had. Subsonic one would be subject to the same air as the blunties, but in an aircraft which had a high wing loading and good controls. Once you got down into the low-level turbulence on a windy day (say 2000' and below) you were in vortex lift and this seemed even better.
I flew this machine through some vicious conditions and it was - by a country mile - the best aeroplane I've ever flown in bad air, better even than the 747. I could bore you with war stories, but will illustrate the point with the time we asked Tower to advise the aircraft following us that it was pretty wild below 2000', only to hear that everyone else had cleared off owing to the wind conditions.......
The only people that really got a rough ride were the flt crew, who were at the front of a long extension ahead of the really stiff part of the hull, which tended to whip around long before it got bumpy in the cabin.
It wasn't like flying a transport aircraft at all in rough conditions, and this was a real help in keeping a prestige operation in the air when bad wx appeared. (Of course it wouldn't have helped in the present BAA-induced debacle).
I didn't ever use this mode, and never saw anybody else use it.
Significant turbulence was almost unheard of in supercruise - light to mod was the worst I ever had. Subsonic one would be subject to the same air as the blunties, but in an aircraft which had a high wing loading and good controls. Once you got down into the low-level turbulence on a windy day (say 2000' and below) you were in vortex lift and this seemed even better.
I flew this machine through some vicious conditions and it was - by a country mile - the best aeroplane I've ever flown in bad air, better even than the 747. I could bore you with war stories, but will illustrate the point with the time we asked Tower to advise the aircraft following us that it was pretty wild below 2000', only to hear that everyone else had cleared off owing to the wind conditions.......
The only people that really got a rough ride were the flt crew, who were at the front of a long extension ahead of the really stiff part of the hull, which tended to whip around long before it got bumpy in the cabin.
It wasn't like flying a transport aircraft at all in rough conditions, and this was a real help in keeping a prestige operation in the air when bad wx appeared. (Of course it wouldn't have helped in the present BAA-induced debacle).
Subjects
Boeing 747
Super-cruise
Vortex
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 27, 2010, 14:04:00 GMT
permalink Post: 6145144
A pot pourri of responses after my Christmas reading!
This actually is interesting in that the n umbers show one of the fundamental features that made the Ol 593 such a good choice. If you look closely at the TO and cruise values you will find that at TO the overall compressor pressure ratio is 13.5 the compressor exit temperature 460 degC and the turbine inlet temperaure is 1152 degC. In cruise the pressure ratio is 10.5, the compressor exit is 565 degC and the TET 1100 degC.
Somebody, I can't find the exact post, was asking whether the elevated cruise total temperatures affected engine life, and here we see why this is so. As Christian said in another posting, when you compress air it gets hotter - from 21 degC to 460 degC at take off and from 127 degC to 565 degC in cruise. A fundamental limit on engine operation is the turbine entry temperature. Not only does it affect the maximum TO thrust you can get but also the continued exposure to cruise TETs has a very big effect on engine fatigue life, and engine manufacturers have shown extremes of ingenuity when developing new materials and ways of cooling the blades to increase allowable TET.
The problem with supersonic operations is that you start from an elevated intake delivery temperature so that when the flow exits the compressor it is already very hot 565 instead of 460 to be exact. But the maximum temperature one can stand for fatigue reasons is limited, therefore the amount of fuel you can pour in must be limited also, and the thrust you can develop per pound of airflow is roughly proportional to the fuel input/temperature rise. To get any sensible cruise thrust then one must squeeze the cruise TET as high as you dare for fatigue reasons but also you need to keep the compression ratio down so that the temperature going into the combustion chambers is as low as you can get away with. This tend to drive engines designed for extended supersonic operations to having a low pressure ratio. This is against the trend in subsonic operations where compression ratios have been steadily increasing along with bypass ratios.
The net result then is that the engine must be designed with a low OPR and must operate with cruise TET much closer to its TO TET value than would be necessary, or indeed desirable, on a subsonic design.
Actually, here, as on some other apparent carry-overs, one should look at the equipment supplier rather than the aircraft manufacturer to trace continuity. Here we have Messier supplying Concorde's gear and Dowty (OK they are now part of Messier) supplying the A330. And having worked on both, I seem to remember that the means of doing the shortening are quite different.
Yes, they both came out of the Bristol drawing office. One minor anecdote: the 'ramshorn' stick was a novelty to the Concorde flight test crews but they got to like it, or at least put up with it. All went well until it came to the time when Dave Davies, the ARB Chief Test Pilot, came to put his rubber stamp on the aircraft.
Concorde's seats, just like those on your car, could be moved back and fore to get your legs on the pedals and up and down so you could see over the bonnet (sorry, instrument panel). The control column of course stayed in one place, so the relationship of the 'horns' to ones thighs varied with ones height. Andre Turcat was about 6ft 2in, Trubbie and the others of average height. The smallest regular pilot was Jean Franchi at, I suppose, about 5ft 7 or 5ft 8. No problems. But Dave Davies was short like me and he found that he could not get full back stick and full aileron because the ramshorn fouled his thighs.
Consternation! Completely unacceptable! I don't know what arguments they used to convince him it was all OK really, but it got through certification. I would certainly be interested to learn from the pilots in this group as to whether it was ever a problem.
I can't resist this one!. Has anyone ever noticed/wondered about the tiny bit of the outer elevon that has been chopped off? That was my first real input into the design as a young erk looking at variability of touchdown conditions and coming to the conclusion that if the pilot got into trouble and was trying to pick up a trailing wing with too much AoA as well then he was likely to hit the ground with the downgoing elevon. I persuaded my boss that this was so and we made a small adjustment.
In self defence I am going to plead that this was well before the days of the Type 28 nozzle, so the issue of buckets contacting the ground first never came up!
To the point where an American Airline maintainance engineer, watching a prototype taking off and with full benefit of being located strategically for maximum sideline noise, remarked on what he described as 'visible acoustic radiation'
On another occasion, it was reputed that Stanley Hooker, watching a TO in the company of HRH the Duke of Edinburgh, remarked that "You know Sir that that noise represents less energy than it takes to boil an egg". to which he got the reply "Then I must congratulate you Sir Stanley, on producing so much noise for the expenditure of so little energy".
There was an effect and in consequence the aircraft performance brochures were formally calculated for north/south flight. Pity really, it would sometimes have been nice to be able to fly guarantee performance demonstrations in the most favourable direction
That's enough for today!
CliveL
Originally Posted by
M2Dude
I hope this one is interesting; it's a Rolls Royce diagram illustrating what the wildly varying differences were in terms of the engine between take off and supersonic cruise. The primary nozzle can be seen at the rear of the engine, together with the reheat assembly and the secondary nozzle (reverser buckets).
This actually is interesting in that the n umbers show one of the fundamental features that made the Ol 593 such a good choice. If you look closely at the TO and cruise values you will find that at TO the overall compressor pressure ratio is 13.5 the compressor exit temperature 460 degC and the turbine inlet temperaure is 1152 degC. In cruise the pressure ratio is 10.5, the compressor exit is 565 degC and the TET 1100 degC.
Somebody, I can't find the exact post, was asking whether the elevated cruise total temperatures affected engine life, and here we see why this is so. As Christian said in another posting, when you compress air it gets hotter - from 21 degC to 460 degC at take off and from 127 degC to 565 degC in cruise. A fundamental limit on engine operation is the turbine entry temperature. Not only does it affect the maximum TO thrust you can get but also the continued exposure to cruise TETs has a very big effect on engine fatigue life, and engine manufacturers have shown extremes of ingenuity when developing new materials and ways of cooling the blades to increase allowable TET.
The problem with supersonic operations is that you start from an elevated intake delivery temperature so that when the flow exits the compressor it is already very hot 565 instead of 460 to be exact. But the maximum temperature one can stand for fatigue reasons is limited, therefore the amount of fuel you can pour in must be limited also, and the thrust you can develop per pound of airflow is roughly proportional to the fuel input/temperature rise. To get any sensible cruise thrust then one must squeeze the cruise TET as high as you dare for fatigue reasons but also you need to keep the compression ratio down so that the temperature going into the combustion chambers is as low as you can get away with. This tend to drive engines designed for extended supersonic operations to having a low pressure ratio. This is against the trend in subsonic operations where compression ratios have been steadily increasing along with bypass ratios.
The net result then is that the engine must be designed with a low OPR and must operate with cruise TET much closer to its TO TET value than would be necessary, or indeed desirable, on a subsonic design.
I
s this another item that Airbus used for the A330/340? I can't remember the exact arrangement for Concorde, but the 330 uses a clever lever arrangement at the top of the leg.
I was not even aware of this A33/340 similarity, sounds yet another case of Airbus using Concorde technology. (Immitation still is the greatest form of flattery I guess). As far as I am aware Concorde had none of the lubrication issues that you describe. M2Dude
I was not even aware of this A33/340 similarity, sounds yet another case of Airbus using Concorde technology. (Immitation still is the greatest form of flattery I guess). As far as I am aware Concorde had none of the lubrication issues that you describe. M2Dude
Actually, here, as on some other apparent carry-overs, one should look at the equipment supplier rather than the aircraft manufacturer to trace continuity. Here we have Messier supplying Concorde's gear and Dowty (OK they are now part of Messier) supplying the A330. And having worked on both, I seem to remember that the means of doing the shortening are quite different.
Originally Posted by
Brit312
The Britannia and now you are talking about the love of my life and yes I do remember the story of the nose and visor selector, but we have forgotten the most obvious. Where do you think they got the idea for the control column from
Yes, they both came out of the Bristol drawing office. One minor anecdote: the 'ramshorn' stick was a novelty to the Concorde flight test crews but they got to like it, or at least put up with it. All went well until it came to the time when Dave Davies, the ARB Chief Test Pilot, came to put his rubber stamp on the aircraft.
Concorde's seats, just like those on your car, could be moved back and fore to get your legs on the pedals and up and down so you could see over the bonnet (sorry, instrument panel). The control column of course stayed in one place, so the relationship of the 'horns' to ones thighs varied with ones height. Andre Turcat was about 6ft 2in, Trubbie and the others of average height. The smallest regular pilot was Jean Franchi at, I suppose, about 5ft 7 or 5ft 8. No problems. But Dave Davies was short like me and he found that he could not get full back stick and full aileron because the ramshorn fouled his thighs.
Consternation! Completely unacceptable! I don't know what arguments they used to convince him it was all OK really, but it got through certification. I would certainly be interested to learn from the pilots in this group as to whether it was ever a problem.
Originally Posted by
exWok
........which was one reason it was so important to touch down with the wings level - even a very small angle of bank could result in bucket contact as they translated to the reverse position. It was a surprise coming to Concorde to find it was even more restrictive than the 747 in this respect
I can't resist this one!. Has anyone ever noticed/wondered about the tiny bit of the outer elevon that has been chopped off? That was my first real input into the design as a young erk looking at variability of touchdown conditions and coming to the conclusion that if the pilot got into trouble and was trying to pick up a trailing wing with too much AoA as well then he was likely to hit the ground with the downgoing elevon. I persuaded my boss that this was so and we made a small adjustment.
In self defence I am going to plead that this was well before the days of the Type 28 nozzle, so the issue of buckets contacting the ground first never came up!
As far as your point about the prototype engines; they were way down on thrust anyway, (even without the 'help' of the silencers), produced more black smoke than a 1930's coal fired power station.
To the point where an American Airline maintainance engineer, watching a prototype taking off and with full benefit of being located strategically for maximum sideline noise, remarked on what he described as 'visible acoustic radiation'
On another occasion, it was reputed that Stanley Hooker, watching a TO in the company of HRH the Duke of Edinburgh, remarked that "You know Sir that that noise represents less energy than it takes to boil an egg". to which he got the reply "Then I must congratulate you Sir Stanley, on producing so much noise for the expenditure of so little energy".
Originally Posted by
CJ
One example : in theory the aircraft did weigh 1.2 % less, so the lift was 1.2 % less and the drag was 1.2 % less, so the fuel consumption was less too, so did Concorde have another 50-odd miles range thrown in 'free' by flying higher and faster than it's low-down subsonic brethren?
There was an effect and in consequence the aircraft performance brochures were formally calculated for north/south flight. Pity really, it would sometimes have been nice to be able to fly guarantee performance demonstrations in the most favourable direction
That's enough for today!
CliveL
Subjects
Afterburner/Re-heat
Airbus
AoA
Boeing 747
D. P. Davies
Elevons
Fatigue
Intakes
Nozzles
Olympus 593
Rolls Royce
Sir Stanley Hooker
Thrust Reversers
Visor
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 27, 2010, 21:19:00 GMT
permalink Post: 6145620
In general I'm with Christian on this, and for the record I think a few 'counterfactuals' should be recorded. I am not trying to reopen a sterile debate - as CJ has said irrevocable decisions have been made and the subject is done and dusted. However, let us remember that:
G-BOAF was, and is the property of BA; BAe and now AI are merely caretakers.
...
So far as AI's decision to hand back the C of A is concerned, they would have already recognised from the post-Gonesse activity that most people with sufficient expertise on the Concorde design were retired (or worse!) They have enough people to keep a subsonic aircraft going, but Concorde would, I think, require additional experience. AI management would certainly have consulted AI Engineering about this, and I have to say that the then Head of Engineering was someone I know well. He, like me, worked on Concorde in the early days and he is definitely not antiConcorde. I for one would respect his decision.
So far as the decision to stop services goes, we all knew they would be cut off sometime.the only question was when.
G-BOAF was, and is the property of BA; BAe and now AI are merely caretakers.
...
So far as AI's decision to hand back the C of A is concerned, they would have already recognised from the post-Gonesse activity that most people with sufficient expertise on the Concorde design were retired (or worse!) They have enough people to keep a subsonic aircraft going, but Concorde would, I think, require additional experience. AI management would certainly have consulted AI Engineering about this, and I have to say that the then Head of Engineering was someone I know well. He, like me, worked on Concorde in the early days and he is definitely not antiConcorde. I for one would respect his decision.
So far as the decision to stop services goes, we all knew they would be cut off sometime.the only question was when.
I've said something similar (while at the same time being full of admiration and effusive praise for M2Dude). It's worth bearing in mind that at the time (2003 or thereabouts), AI were fighting a battle to keep the A380 project viable (like Boeing with the 747, they'd effectively "bet the company" on the project's success) - and sadly, in terms of business realpolitik Concorde was costing them money, being just a small-run legacy airframe capable of operating profitably for a single customer. Things weren't going to get any better, and as such AI's decision was as understandable as it was regrettable.
I have far less sympathy for BA, who acted with what seemed to me indecent haste to permanently mothball the airframes (the press at the time speculating that Branson would try to get his hands on at least one of them), and while the UK Concorde community have a right to feel aggrieved at the way things panned out - the fact that what was left of BAe effectively bowed out of the Airbus consortium, the better to focus on military hardware with the Americans, meant that we'd thrown away any chance of having a say in what happened to Concorde in the end.
EDITED TO ADD : In reference to Bellerophon's post below - this was *not* intended to take the technical discussion off-course. I was simply trying to thank Clive for summing up how I felt about the whole situation far better than I ever could. Sincere apologies if this was misconstrued as such.
Last edited by DozyWannabe; 29th December 2010 at 01:21 .
Subjects
Airbus
Boeing
Boeing 747
British Airways
G-BOAF
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 29, 2010, 11:21:00 GMT
permalink Post: 6148025
That's a very 'Concorde' picture, Bellerophon.
Gentle descent in the crz, N1 max, N2 max, similar fuel burn per engine as a 747 (but over double the speed), Airspeed and Mach numbers just shy of the barber's poles, must have been well above FL500 given the Mach number yet the cabin alt is a smidge over 5000'.
Elapsed time 1hr 31, Longitude over 41W. Took me over three hours to get to 40W yesterday.......
PS and it has to be OAD, because for some reason the nose/visor control panel is black. I've no idea why I can remember stuff like that, but not the name of someone I met last week......
Gentle descent in the crz, N1 max, N2 max, similar fuel burn per engine as a 747 (but over double the speed), Airspeed and Mach numbers just shy of the barber's poles, must have been well above FL500 given the Mach number yet the cabin alt is a smidge over 5000'.
Elapsed time 1hr 31, Longitude over 41W. Took me over three hours to get to 40W yesterday.......
PS and it has to be OAD, because for some reason the nose/visor control panel is black. I've no idea why I can remember stuff like that, but not the name of someone I met last week......
Subjects
Boeing 747
Fuel Burn
N1 (revolutions)
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 29, 2010, 13:53:00 GMT
permalink Post: 6148266
Originally Posted by
EKWOK
similar fuel burn per engine as a 747 (but over double the speed
Subjects
Boeing 747
Fuel Burn
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
December 29, 2010, 15:34:00 GMT
permalink Post: 6148446
Fair point topbunk - I mis-phrased that, we certainly didn't achieve double the miles per gallon of a 747. I should also have made it clearer that I was comparing it with contemporaries, i.e. -100 and -200. (I recall about 2.5 - 3tonnes per hour per engine on a typical Atlantic sector)
So I agree it wasn't double the miles per gallon - although in terms of mpg the Conc was markedly better in the cruise than the 747 classic. Of course, you paid for it in the process of actually getting to M2 as well as dragging around the pattern at 300kts.
So I agree it wasn't double the miles per gallon - although in terms of mpg the Conc was markedly better in the cruise than the 747 classic. Of course, you paid for it in the process of actually getting to M2 as well as dragging around the pattern at 300kts.
Subjects
Boeing 747
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
January 25, 2011, 20:30:00 GMT
permalink Post: 6202791
Shaggy Sheep Driver
She's always looked good, but probably didn't look any better in 1969 than she does now.
Cars are 'styled' and are therefore subject to fashion whims. So a car of 1969 looks awfully old fashioned by 2011 standards.
Concorde wasn't styled. She is the shape she is because that's the shape she needs to be to enable her to do what no other aeroplane could do - carry 100 shirt-sleeve comfort passengers at Mach 2 and 60,000' for up to 4.5 hours.
Concorde was form following function. Her beutiful lines did not come from a stylists drawing board, but from those of the aerodynamicist and other engineers involved in her design. So she hasn't dated!
Cars are 'styled' and are therefore subject to fashion whims. So a car of 1969 looks awfully old fashioned by 2011 standards.
Concorde wasn't styled. She is the shape she is because that's the shape she needs to be to enable her to do what no other aeroplane could do - carry 100 shirt-sleeve comfort passengers at Mach 2 and 60,000' for up to 4.5 hours.
Concorde was form following function. Her beutiful lines did not come from a stylists drawing board, but from those of the aerodynamicist and other engineers involved in her design. So she hasn't dated!
We read posts in this thread from people, all over the world, who saw Concorde once, maybe a couple of times in their lives and will never forget the occasion. Not surprising in many ways. Those of you who worked with her don't find that surprising, because you never tired of looking.
I have been an aeroplane geek since I was eight, have lived under the 'funnel' for 28L for fifty-five of my years and I pretty much know what's overhead by the sound. Much as I like and admire the stately 747, I can pretty much take or leave them, if distracted or busy. I saw Concorde almost every day, sometimes twice, in all the years she was flying and I always stopped and stared upwards. Always.
Roger.
Subjects
Boeing 747
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.
January 30, 2011, 13:15:00 GMT
permalink Post: 6212514
Landroger - the 'tube' houses various nav antennae - can't remember offhand which - it's less obvious than it appears in this pic which is at just the right angle to accentuate it.
It was always impressive how similar the ADCs' outputs were compared to the 747 of the same era, and M2Dude has mentioned how the RVSM trials showed their accuracy.
Of course there was always the infamous OAF 'glitch' which threw up false ADS warnings accelerating through M1 which happened regularly during my time on the fleet and was subject to a tech log supplement. It never seemed to affect the machine in any other way. I dunno if she did this from new or it was a result of her nosejob.
It was always impressive how similar the ADCs' outputs were compared to the 747 of the same era, and M2Dude has mentioned how the RVSM trials showed their accuracy.
Of course there was always the infamous OAF 'glitch' which threw up false ADS warnings accelerating through M1 which happened regularly during my time on the fleet and was subject to a tech log supplement. It never seemed to affect the machine in any other way. I dunno if she did this from new or it was a result of her nosejob.
Subjects
ADC (Air Data Computer)
Boeing 747
Links are to this post in the relevant subject page so that this post can be seen in context.
Reply to this quoting this original post. You need to be logged in. Not available on closed threads.