Concorde question
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Hey Dude
Saw your posts about the Concorde reheat spray bar and flame holder assembly in another thread, might it be worth reposting it in this thread to keep it all in the same place?
On a related note, what changed in the engine parameters if the Contingency mode was entered on take-off? And what would trigger that mode?
Oh yes, and once engaged, is there a time limit on how long it can be maintained? I'm assuming in an engine out case that at heavy weight the reheats have to remain engaged on the remaining engines until the speed has built up to get off the back of the drag curve.
Saw your posts about the Concorde reheat spray bar and flame holder assembly in another thread, might it be worth reposting it in this thread to keep it all in the same place?
On a related note, what changed in the engine parameters if the Contingency mode was entered on take-off? And what would trigger that mode?
Oh yes, and once engaged, is there a time limit on how long it can be maintained? I'm assuming in an engine out case that at heavy weight the reheats have to remain engaged on the remaining engines until the speed has built up to get off the back of the drag curve.
Last edited by Feathers McGraw; 24th Oct 2010 at 17:44.
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Concorde Reheat
Consider it done Feathers. 
As promised, here are a few diagrams of the Concorde reheat (afterburner, for our American friends) system. The ORIGINAL design was done by SNECMA, but due to them getting into all sorts of trouble with the fuel injection system and flame stabilisation, Rolls Royce baled them out, and it became a Rolls Royce/SNECMA design. (The core engine was a 100% Rolls design, with no French input whatsoever. However some engine sub-assembles were manufactured by SNECMA).
The basic way the afterburner worked was by spraying the fuel FORWARDS intially at high pressure, against the jet stram about one inch, until it hit the anvil. . As the fuel strikes the anvil it is blown back by the jet stram and atomises, passing over the of the spray ring and the over the flame holder. The ignition operated by passing 15KV across a dual cylindrical tube, the resulting arc was 'swirlied' into the fuel stream by blowing engine 5th stage HP compressor air into the tube (there were 7 stages in all).
The key to successful ignition was a healthy spark, a good supply of air to the ignitor and accurate scheduling of fuel flow. (This was scheduled against dry engine flow as a funtion of total temperature). The other important factor (as with any afterburner) was correct and rapid operation of the exhaust nozzle. Fortunately, Concorde used it's primary nozzle for control of engine N1 anyway, so adapting this to operate as an afterburning nozzle also was a relative walk in the park, and it operated superbly.
During the light up phase of 3.5 seconds, the fuel ratio is a fixed 0.45 (ie. reheat fuel is 45% of dry fuel). After the light up phase the full scheduling commenced. As far as the FLIGHT RATING figures go (not take-off) the ratios were 0.6 at a TAT of 54 deg's C, falling linearly to 0.3 at 107 deg's C and above. (Remember that Concorde used afterburning really sparingly, just for take-off and then transonic acceleration; cut off at Mach 1.7 altogether.
Dude
As promised, here are a few diagrams of the Concorde reheat (afterburner, for our American friends) system. The ORIGINAL design was done by SNECMA, but due to them getting into all sorts of trouble with the fuel injection system and flame stabilisation, Rolls Royce baled them out, and it became a Rolls Royce/SNECMA design. (The core engine was a 100% Rolls design, with no French input whatsoever. However some engine sub-assembles were manufactured by SNECMA).
The basic way the afterburner worked was by spraying the fuel FORWARDS intially at high pressure, against the jet stram about one inch, until it hit the anvil. . As the fuel strikes the anvil it is blown back by the jet stram and atomises, passing over the of the spray ring and the over the flame holder. The ignition operated by passing 15KV across a dual cylindrical tube, the resulting arc was 'swirlied' into the fuel stream by blowing engine 5th stage HP compressor air into the tube (there were 7 stages in all).
The key to successful ignition was a healthy spark, a good supply of air to the ignitor and accurate scheduling of fuel flow. (This was scheduled against dry engine flow as a funtion of total temperature). The other important factor (as with any afterburner) was correct and rapid operation of the exhaust nozzle. Fortunately, Concorde used it's primary nozzle for control of engine N1 anyway, so adapting this to operate as an afterburning nozzle also was a relative walk in the park, and it operated superbly.
During the light up phase of 3.5 seconds, the fuel ratio is a fixed 0.45 (ie. reheat fuel is 45% of dry fuel). After the light up phase the full scheduling commenced. As far as the FLIGHT RATING figures go (not take-off) the ratios were 0.6 at a TAT of 54 deg's C, falling linearly to 0.3 at 107 deg's C and above. (Remember that Concorde used afterburning really sparingly, just for take-off and then transonic acceleration; cut off at Mach 1.7 altogether.
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Feathers McGraw
Contingency mode could be either manually or automatically selected during take-off. It would automatically be selected if an engine dropped below 58% N2, PROVIDED that the take-off monitor button was set, and reheat was selected. (A small yellow CTY light on the centre dash panel would flash in this case also). OR it could be manually selected by moving the 4 reheat selector switches through a clever little gate, from RHT to CTY. In this case, the yellow CTY light would illuminate steadily.
Actually at entry into service, contingency had a real problem, in that when selected the reheat flame would burn very fiercely, become unstable and extinguish altogether. (So instead of getting more power, you ended up with less; with just the increase in dry thrust, and no reheat at all
). It seems that the reheat flame holder was too small to support the bigger contingency flame, which effectively would just fall over. What we had to do in the early days of service was to isolate the wire that provided the contingency discreet to the reheat amplifier, ensuring that the reheat would hopefully still operate normally when contingency was invoked, so at least you got a small increase in power from the dry engine. The solution was the welding of 7 small 'fingers' to the outer part of the reheat flame holder, this made the flame holder 'appear' bigger than it really was to the flame. It worked perfectly, and we could therefore re-connect our wire again. 
(Just making the flame holder physically bigger would have had a detrimental impact on the operation of the dry engine).
Dude
On a related note, what changed in the engine parameters if the Contingency mode was entered on take-off? And what would trigger that mode? Oh yes, and once engaged, is there a time limit on how long it can be maintained? I'm assuming in an engine out case that at heavy weight the reheats have to remain engaged on the remaining engines until the speed has built up to get off the back of the drag curve.
Actually at entry into service, contingency had a real problem, in that when selected the reheat flame would burn very fiercely, become unstable and extinguish altogether. (So instead of getting more power, you ended up with less; with just the increase in dry thrust, and no reheat at all
). It seems that the reheat flame holder was too small to support the bigger contingency flame, which effectively would just fall over. What we had to do in the early days of service was to isolate the wire that provided the contingency discreet to the reheat amplifier, ensuring that the reheat would hopefully still operate normally when contingency was invoked, so at least you got a small increase in power from the dry engine. The solution was the welding of 7 small 'fingers' to the outer part of the reheat flame holder, this made the flame holder 'appear' bigger than it really was to the flame. It worked perfectly, and we could therefore re-connect our wire again. (Just making the flame holder physically bigger would have had a detrimental impact on the operation of the dry engine).Dude
Last edited by M2dude; 24th Oct 2010 at 22:23.
Effect on range of single reheat failure to light on T/O
I understand that you could continue the takeoff if one reheat failed to light, but two questions. if you will:
TC
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But... yes and no....
Whether you could actually continue the take-off, if one reheat didn't light, depended on several factors, such as t/o weight, runway length, ambient temperature, and suchlike. This was all calculated before take-off, and there was a little tab on the forward panel (I'll have to find a photo), which you would flip to either "3" or "4" as an instant reminder.
If the little tab said "4" and you got only three reheats coming on, you didn't have to think or go through a checklist... you rejected the takeoff.
M2dude probably can quote the speed.... but it was still well below V1, so such a RTO was not nearly as spectacular as a really nasty one around V1.
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100kts
E/O calls "Power set" if you have a minimum of 4 engines and 3 reheats (for a "goer" - your flippy thing set to "3"!) else "Engine Fail" and therefore an RTO. 4-engines and 4-reheats (4 greens) needed at 100kts for a "power set" call for a "stopper" - flippy thing at "4". It was simply how far off TOW was from PLTOW and a concept introduced following a commercially unacceptable number of RTOs which weren't necessary from a perf-A POV...
(A single reheat failure, although rare, could be accepted after 100kts at any weight)
(Just noticed Brit312 covered this earlier - sorry!)
E/O calls "Power set" if you have a minimum of 4 engines and 3 reheats (for a "goer" - your flippy thing set to "3"!) else "Engine Fail" and therefore an RTO. 4-engines and 4-reheats (4 greens) needed at 100kts for a "power set" call for a "stopper" - flippy thing at "4". It was simply how far off TOW was from PLTOW and a concept introduced following a commercially unacceptable number of RTOs which weren't necessary from a perf-A POV...
(A single reheat failure, although rare, could be accepted after 100kts at any weight)
(Just noticed Brit312 covered this earlier - sorry!)
Last edited by NW1; 25th Oct 2010 at 02:29.
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Thanks Dude, very interesting!
As for the 7 fingered reheat flame-holder, do you know of or have any photos? I'm quite fascinated by this, I'd like to see what it looks like. I have never heard of this modification anywhere else so once again this thread manages to surprise by turning up things that one couldn't find out any other way.
As for the 7 fingered reheat flame-holder, do you know of or have any photos? I'm quite fascinated by this, I'd like to see what it looks like. I have never heard of this modification anywhere else so once again this thread manages to surprise by turning up things that one couldn't find out any other way.
Last edited by Feathers McGraw; 25th Oct 2010 at 19:43. Reason: Spelling correction
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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
) 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
Last edited by M2dude; 25th Oct 2010 at 21:22.
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Thanks Dude.
Not quite what I was expecting but very interesting all the same. I see that each finger appears to have an inlet at the base to allow gas flow to alleviate some of the turbulence behind it.
Now to find a picture of a Concorde reheat flame rosette to see how the flame matches up to the finger pattern.
Good game!
Better still, I found a picture of the reheat assembly with the fingers fitted:
Google Image Result for http://heritageconcorde.com/wp-content/uploads/2010/03/reheat-picture.jpg
Not quite what I was expecting but very interesting all the same. I see that each finger appears to have an inlet at the base to allow gas flow to alleviate some of the turbulence behind it.
Now to find a picture of a Concorde reheat flame rosette to see how the flame matches up to the finger pattern.
Good game!
Better still, I found a picture of the reheat assembly with the fingers fitted:
Google Image Result for http://heritageconcorde.com/wp-content/uploads/2010/03/reheat-picture.jpg
Last edited by Feathers McGraw; 25th Oct 2010 at 22:16. Reason: Add image link
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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).
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The entire collection of "Ailes Anciennes Toulouse" has been moved to a different location only very recently... one can merely hope that at least some of the bits and pieces of "0001" have survived...
Maybe VOLUME can tell us more?
Maybe VOLUME can tell us more?
Found one more picture...
Sad to see this masterpiece of engineering rotting away.
I always thought that the sloped area at the aft end of the floor was the rear airstair (just present on the pre-production aircraft), but I just read on heritageconcorde.com/ that this is for "system routing". Does somebody know more ? Seems to be a lot of space for systems that would end just in the middle of the cabin.
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... but I just read on heritageconcorde.com/ that this is for "system routing". Does somebody know more ? Seems to be a lot of space for systems that would end just in the middle of the cabin.
The picture on 'heritageconcorde' is a good find!
If you look at the perspective drawing bottom right, you're basically looking at the volume of fuel tank n° 6 (which is located under-floor just to the rear of the main landing gear bay) with the floor on top and the sloped area leading into the main landing gear bay in front ; the rear wall of the landing gear bay is in the plane of fuselage frame n° 60 (see the side view at the top of the picture).
The "system routing" would therefore simply refer to the various 'underfloor' services routed to the landing gear.
There was a lot of stuff passing right under your feet in Concorde!
One problem with your photo..... there is no door anywhere looking rearward from frame n° 60, neither on the prototypes, nor on any of the other aircraft.
However.... the forward wall of the landing gear bay is in the plane of fuselage frame n° 54. And the blueprints show the same type of 'sloped area' at that location, this time making an 'indentation' in tank n° 8, which is just forward of the landing gear bay.
And yes, on the prototypes, counting about 6 windows to the front, there is one of the two emergency exits (which were replaced by the mid-cabin passenger and service doors on all the later Concordes).
So the section on your photo was cut roughly at frame n° 54, and the photo looks forward into the cabin.
I hope this helps?
Unfortunately I do not have a flatbed scanner, and all the drawings I have are larger than A4. But I'll see what I can do... a picture always says more than a thousand words.
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I have a question related to returning a Concorde to the air.
Obviously it's a theoretical one...
IF funding were secured to get 1 Concorde from each fleet into the air again, which one out of each fleet would be the easiest to return to service, given what has gone on since retirement?
Also, a subpoint, does anyone have any finger-in-the-air figures as to how much cost it would take and whether there's any fundamental issues that would need to be sorted aside from the airworthiness certificate etc.
(no, i'm not a secret billionaire, i'm just curious as to what it would cost etc)
Obviously it's a theoretical one...
IF funding were secured to get 1 Concorde from each fleet into the air again, which one out of each fleet would be the easiest to return to service, given what has gone on since retirement?
Also, a subpoint, does anyone have any finger-in-the-air figures as to how much cost it would take and whether there's any fundamental issues that would need to be sorted aside from the airworthiness certificate etc.
(no, i'm not a secret billionaire, i'm just curious as to what it would cost etc)
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Did you need all 4 reheats to go from 0.95 - 1.7 ?
If you got to 1.3 and then one or more failed could you continue (albeit with slower acceleration ?)
I presume if you were unable to get the things lit at 0.95 you just turned round and went home again ? The procedure would take around 90 mins so would you need to burn off fuel or already be at acceptable landing weight by that time ?
Also, once when aboard at about 50K-55K feet the aircraft rolled I would estimate 3 degrees to the left and then came back level again almost immediately. I knew this was a glitch but no one else noticed. An announcement was made of a minor problem about 2 mins later and that was that ?
What might have cause such an event (I would guess an airflow issue with intake or engine ?)
If you got to 1.3 and then one or more failed could you continue (albeit with slower acceleration ?)
I presume if you were unable to get the things lit at 0.95 you just turned round and went home again ? The procedure would take around 90 mins so would you need to burn off fuel or already be at acceptable landing weight by that time ?
Also, once when aboard at about 50K-55K feet the aircraft rolled I would estimate 3 degrees to the left and then came back level again almost immediately. I knew this was a glitch but no one else noticed. An announcement was made of a minor problem about 2 mins later and that was that ?
What might have cause such an event (I would guess an airflow issue with intake or engine ?)
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Mike, there are already a couple of sites on the internet dealing with this particular pipe-dream, such as SaveConcordeGroup in the UK.
So, please, could you address your questions there?
Or start a separate thread in the JetBlast forum... I'll be only too happy to answer you there, and yes, I have answers to your questions.
Just don't pollute this particular thread with this nonsense... please?
CJ
So, please, could you address your questions there?
Or start a separate thread in the JetBlast forum... I'll be only too happy to answer you there, and yes, I have answers to your questions.
Just don't pollute this particular thread with this nonsense... please?
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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.
IF funding were secured to get 1 Concorde from each fleet into the air again, which one out of each fleet would be the easiest to return to service, given what has gone on since retirement? Also, a subpoint, does anyone have any finger-in-the-air figures as to how much cost it would take and whether there's any fundamental issues that would need to be sorted aside from the airworthiness certificate etc.
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
.
norodnik
...Did you need all 4 reheats to go from 0.95 - 1.7 ?...
No.
Two reheats were the minimum for transonic acceleration, however due regard would have to paid to the additional fuel usage with one or two reheats failed.
...If you got to 1.3 and then one or more failed could you continue (albeit with slower acceleration ?)...
Yes, as above, whilst remembering the 15 minute time limit on the use of reheat.
...I presume if you were unable to get the things lit at 0.95 you just turned round and went home again ?...
Yes, once you were convinced that at least three were not going to light up.
...The procedure would take around 90 mins so would you need to burn off fuel or already be at acceptable landing weight by that time ?...
Not something I ever had to do, fortunately, but even so, 90 minutes would seem somewhat excessive to me, given that the aircraft would still have been over the Bristol channel. On a transatlantic sector, fuel jettisoning would have been necessary to get down to 130,000 kgs (for a fuel saving landing) or 111,130 kgs (MLW) if the nature of the failure precluded a fuel saving landing.
...once when aboard at about 50K-55K feet the aircraft rolled I would estimate 3 degrees to the left and then came back level again almost immediately...what might have cause such an event (I would guess an airflow issue with intake or engine ?)...
Any number of things could have caused this, but probably the most likely one is the one you suspected, a (transient) intake problem.
Best Regards
Bellerophon
...Did you need all 4 reheats to go from 0.95 - 1.7 ?...
No.
Two reheats were the minimum for transonic acceleration, however due regard would have to paid to the additional fuel usage with one or two reheats failed.
...If you got to 1.3 and then one or more failed could you continue (albeit with slower acceleration ?)...
Yes, as above, whilst remembering the 15 minute time limit on the use of reheat.
...I presume if you were unable to get the things lit at 0.95 you just turned round and went home again ?...
Yes, once you were convinced that at least three were not going to light up.
...The procedure would take around 90 mins so would you need to burn off fuel or already be at acceptable landing weight by that time ?...
Not something I ever had to do, fortunately, but even so, 90 minutes would seem somewhat excessive to me, given that the aircraft would still have been over the Bristol channel. On a transatlantic sector, fuel jettisoning would have been necessary to get down to 130,000 kgs (for a fuel saving landing) or 111,130 kgs (MLW) if the nature of the failure precluded a fuel saving landing.
...once when aboard at about 50K-55K feet the aircraft rolled I would estimate 3 degrees to the left and then came back level again almost immediately...what might have cause such an event (I would guess an airflow issue with intake or engine ?)...
Any number of things could have caused this, but probably the most likely one is the one you suspected, a (transient) intake problem.
Best Regards
Bellerophon
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Thanks guys, and sorry for worrying you with such a potential thread divert Christiaan, that wasn't my intention and M2Dude answered my question with exactly what I needed to know (although I think it's closer to $100m than $100 
)
)
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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
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
Last edited by M2dude; 28th Oct 2010 at 05:04.
Thread Starter
Forgive me if this has been covered before but did the Concorde have bleed air wing or fin Anti-Icing ?
What about the engines
Or was this deemed unecessary ?
What about the engines
Or was this deemed unecessary ?
