22nd Aug 2010, 19:56
permalink Post: 72
Fascinating thread!
I think (along with the other PAX that day) that I can claim to have been faster on Concorde than anyone else.
Despite many trips, I only flew on BOAB once (sad I know) and there was obviously a malfunction of some sort as the speed (on the Marilake display), instead of stopping in the normal range of 1260-1320 mph continued steadily climbing to 1990 mph.
This was the second "fault" as we had previously begun the flight from JFK with a low speed RTO due to one of the computers disagreeing with the other 2 on takeoff. Despite the slow speed we still had to wait 10 mins for the brakes to cool.
I have it all on Video! (The RTO and the Speed anomaly)
I think (along with the other PAX that day) that I can claim to have been faster on Concorde than anyone else.
Despite many trips, I only flew on BOAB once (sad I know) and there was obviously a malfunction of some sort as the speed (on the Marilake display), instead of stopping in the normal range of 1260-1320 mph continued steadily climbing to 1990 mph.
This was the second "fault" as we had previously begun the flight from JFK with a low speed RTO due to one of the computers disagreeing with the other 2 on takeoff. Despite the slow speed we still had to wait 10 mins for the brakes to cool.
I have it all on Video! (The RTO and the Speed anomaly)
27th Aug 2010, 20:41
permalink Post: 142
notfred
,
Not exactly the same subject, but still brake-related.
Some of the earlier-mentioned items like "3-2-1-NOW", the little 3/4 tab for the afterburners, the "T/O monitor lights" and such, were all due to the fact that it was not possible to run up Concorde to full take-off thrust, light the reheats, check everything, and only then release the brakes.... she would start to slide forward well before full thrust was reached.
Only 185 tons TOW, only ten little wheels... in brief, not enough "grip" to keep almost 70 tons thrust stationary !
CJ
Not exactly the same subject, but still brake-related.
Some of the earlier-mentioned items like "3-2-1-NOW", the little 3/4 tab for the afterburners, the "T/O monitor lights" and such, were all due to the fact that it was not possible to run up Concorde to full take-off thrust, light the reheats, check everything, and only then release the brakes.... she would start to slide forward well before full thrust was reached.
Only 185 tons TOW, only ten little wheels... in brief, not enough "grip" to keep almost 70 tons thrust stationary !
CJ
27th Aug 2010, 21:32
permalink Post: 144
ChristiaanJ
The way I remember it was
"3-2-1 now" was to ensure that all 3 crew members started their stop watch at the same time i e on the call of NOW as that was the point the throttles were moved rapidy to the forward stops. In fact the noise abatement timing assumed the engines were allowed to accelerate at their own rate, rather than at a rate controlled by the crew
"Green lights" served two purposes
1] To allow the pilots to have a quick reference as to the state of the engines during the Take off
2] Prior to the nose gear mod ona rough runway [when it could be difficult to red the engine instruements] it did give the F/E an indication that the engines had reached the basic power required
3/4 tab. as different T/Os required diferent minimum reheats either 3 or 4
The small 3/4 tab was there just to visually remind crew as a back up to the briefing whether they were on a 3 or 4 reheat day
I have not I believe been on an aircraft where you run up to full power before releasing the brakes, but there again the memory could be fading, and I am sure the sudden release of brakes at full power would not do them any
good
Mind you I could be wrong
The way I remember it was
"3-2-1 now" was to ensure that all 3 crew members started their stop watch at the same time i e on the call of NOW as that was the point the throttles were moved rapidy to the forward stops. In fact the noise abatement timing assumed the engines were allowed to accelerate at their own rate, rather than at a rate controlled by the crew
"Green lights" served two purposes
1] To allow the pilots to have a quick reference as to the state of the engines during the Take off
2] Prior to the nose gear mod ona rough runway [when it could be difficult to red the engine instruements] it did give the F/E an indication that the engines had reached the basic power required
3/4 tab. as different T/Os required diferent minimum reheats either 3 or 4
The small 3/4 tab was there just to visually remind crew as a back up to the briefing whether they were on a 3 or 4 reheat day
I have not I believe been on an aircraft where you run up to full power before releasing the brakes, but there again the memory could be fading, and I am sure the sudden release of brakes at full power would not do them any
good
Mind you I could be wrong
27th Aug 2010, 22:25
permalink Post: 146
Brit312
Your memory is not fading; the ONLY disadvantage with carbon brakes is their susceptabilty to over-torque damage. For this reason 'max power on brakes wasalways verboten. I seem to remember that the development A/C with steel brakes could be 'wound up' on the brakes. But the improved braking performance, not to mention a 1,200lb weight saving of carbon made this a small price to pay.
The 3/4 tab; that takes me back, it was officially called the 'Reheat Capability Indicator', definately not the most sophisticated part of the Concorde flight deck. (I seem to remember that before the 'RCI
' was fitted, an INS CDU Waypoint thumbwheel was used as a 3 or 4 reminder).
Oh and ChristiaanJ; I always loved that clip.
Dude
Your memory is not fading; the ONLY disadvantage with carbon brakes is their susceptabilty to over-torque damage. For this reason 'max power on brakes wasalways verboten. I seem to remember that the development A/C with steel brakes could be 'wound up' on the brakes. But the improved braking performance, not to mention a 1,200lb weight saving of carbon made this a small price to pay.
The 3/4 tab; that takes me back, it was officially called the 'Reheat Capability Indicator', definately not the most sophisticated part of the Concorde flight deck. (I seem to remember that before the 'RCI
' was fitted, an INS CDU Waypoint thumbwheel was used as a 3 or 4 reminder).
Oh and ChristiaanJ; I always loved that clip.
Dude
27th Aug 2010, 22:39
permalink Post: 147
Brit312
,
Of course you're right on all those items.
I only mentioned them as they were linked in some way to the fact of not being able to run up to full thrust "on the brakes".
CJ
Of course you're right on all those items.
I only mentioned them as they were linked in some way to the fact of not being able to run up to full thrust "on the brakes".
CJ
28th Aug 2010, 03:37
permalink Post: 149
SLF in the jump seat
I rode Concorde two or three times and what a ride it was!
On one occasion I had booked to travel BA 'J' class from Washington to Delhi on a regular business trip. Out of DCA to JFK they booked me on the 'Concorde shuttle' (a Dash 8 of US Airways, believe it or not) to connect with a 744 to LHR and another connection on to Delhi. At DCA check in the agent mumbled something about a catering problem out of JFK, but I took no particular notice. On arrival at Kennedy an agent with a name placard diverted me to the Concorde gate, a nice surprise indeed, even for a BA Gold Card holder.
On boarding Concorde, I gave my business card to the purser, asking that she pass it forward. A few minutes later as the door was closing she came back to pass along an invitation from the skipper to join them in the cockpit. During the short delay for start clearance, the captain briefed me on the Canarsie 31L departure I was about to watch from the jump seat behind. "3-2-1 GO" as the aircraft lept forward, V1/Vr/V2, 100', roll left 30 degrees to track towards Canarsie, 1' 30" (or something similar, some details are long forgotten now) power back for 500'/minute ROC to 3,000', then accelerate to 250K as the heading continued around for the outbound course and the ocean crossing. A true aerial ballet.
For the balance of the climb I plied the guys with questions and received courteous and detailed answers to every one, along with a 'freebie' - some hilarious repartee between the BALPA captain and the management F/O type, with occasional interjections by the Engineer. I stayed through the supersonic acceleration until I thought I'd worn out my welcome at cruise climb, returning to my seat in the mid cabin area for lunch. They invited me back for the descent and approach, which was very well appreciated.
On descent over the U.K. and passing through 10K' abeam Southampton, as I remember it we got a yellow 'Radiation' caution light (normally to warn of higher than normal levels of radiation in the tropoause from sun spot activity, I believe), which caused me to ask WTHWT? The slightly bored F/O said, as he cancelled the light, "Oh, its 'just' a nuclear power plant down there, we get this all the time"! (And for all these years I had swallowed the PR line from the nuclear industry that they were squeaky clean, unlike those of us in the aircraft manufacturing business??)
The approach and landing at LHR was fascinating to watch, without the frenetic activity of the departure. No flaps and no configuration change after gear down, virtually no flare, perhaps even a little nose down pitch as I observed (was that true??) the handling pilot just let it float into ground effect for a gentle touch down, snappily into reverse and heavy, but not maximum braking. It looked easy, of course.
The F/E was a key part of the entire operation and I find it hard to believe that a Concorde "B" would have eliminated his position, no matter how automated the systems might have become. The whole flight was very, very professionally handled with that air of apparent casualness that comes only from a very disciplined team operating at the peak of performance. A true joy to watch.
I guess I was just a minor part of the vaunted 'halo' effect that BA marketing always claimed for Concorde - its ability to pull additional traffic to its worldwide services in a very competitive business climate. But it sure worked for me! And all because of a catering misadventure, or was that just an excuse??
However, the thing that has always truly amazed me about Concorde is that this machine was created by two companies, two countries, with two languages, two systems of measure and two very different cultures in a period before the invention of Computer Aided Design and on-line communications! What a marvellous thing that mankind created. My hat off to you all.
Thank you, John, that was some flight!
TC
On one occasion I had booked to travel BA 'J' class from Washington to Delhi on a regular business trip. Out of DCA to JFK they booked me on the 'Concorde shuttle' (a Dash 8 of US Airways, believe it or not) to connect with a 744 to LHR and another connection on to Delhi. At DCA check in the agent mumbled something about a catering problem out of JFK, but I took no particular notice. On arrival at Kennedy an agent with a name placard diverted me to the Concorde gate, a nice surprise indeed, even for a BA Gold Card holder.
On boarding Concorde, I gave my business card to the purser, asking that she pass it forward. A few minutes later as the door was closing she came back to pass along an invitation from the skipper to join them in the cockpit. During the short delay for start clearance, the captain briefed me on the Canarsie 31L departure I was about to watch from the jump seat behind. "3-2-1 GO" as the aircraft lept forward, V1/Vr/V2, 100', roll left 30 degrees to track towards Canarsie, 1' 30" (or something similar, some details are long forgotten now) power back for 500'/minute ROC to 3,000', then accelerate to 250K as the heading continued around for the outbound course and the ocean crossing. A true aerial ballet.
For the balance of the climb I plied the guys with questions and received courteous and detailed answers to every one, along with a 'freebie' - some hilarious repartee between the BALPA captain and the management F/O type, with occasional interjections by the Engineer. I stayed through the supersonic acceleration until I thought I'd worn out my welcome at cruise climb, returning to my seat in the mid cabin area for lunch. They invited me back for the descent and approach, which was very well appreciated.
On descent over the U.K. and passing through 10K' abeam Southampton, as I remember it we got a yellow 'Radiation' caution light (normally to warn of higher than normal levels of radiation in the tropoause from sun spot activity, I believe), which caused me to ask WTHWT? The slightly bored F/O said, as he cancelled the light, "Oh, its 'just' a nuclear power plant down there, we get this all the time"! (And for all these years I had swallowed the PR line from the nuclear industry that they were squeaky clean, unlike those of us in the aircraft manufacturing business??)
The approach and landing at LHR was fascinating to watch, without the frenetic activity of the departure. No flaps and no configuration change after gear down, virtually no flare, perhaps even a little nose down pitch as I observed (was that true??) the handling pilot just let it float into ground effect for a gentle touch down, snappily into reverse and heavy, but not maximum braking. It looked easy, of course.
The F/E was a key part of the entire operation and I find it hard to believe that a Concorde "B" would have eliminated his position, no matter how automated the systems might have become. The whole flight was very, very professionally handled with that air of apparent casualness that comes only from a very disciplined team operating at the peak of performance. A true joy to watch.
I guess I was just a minor part of the vaunted 'halo' effect that BA marketing always claimed for Concorde - its ability to pull additional traffic to its worldwide services in a very competitive business climate. But it sure worked for me! And all because of a catering misadventure, or was that just an excuse??
However, the thing that has always truly amazed me about Concorde is that this machine was created by two companies, two countries, with two languages, two systems of measure and two very different cultures in a period before the invention of Computer Aided Design and on-line communications! What a marvellous thing that mankind created. My hat off to you all.
Thank you, John, that was some flight!
TC
Last edited by twochai; 28th Aug 2010 at 04:05 .
3rd Sep 2010, 20:48
permalink Post: 204
Nick Thomas
... I think am right to assume there were no spoilers...
Correct.
...so on landing did the act of bring the nose down spoil the lift...
Yes, as with most conventional aircraft, reducing the aircraft pitch attitude (once the main wheels were on the runway) would reduce the angle-of-attack and therefore reduce the amount of lift being generated by the wing. Modern aircraft wings are very efficient and will still be generating a considerable amount of lift during the landing roll, even as the aircraft slows down.
Put simply, spoilers and/or lift dump systems are required to destroy this lift, in order to get as much of the aircraft weight as possible on the main landing gear, which, in turn, allows greater pressure to be applied to the wheel brakes before the wheels start to lock-up and the anti-skid units activate to release the applied brake pressure.
Concorde\x92s wing however developed very little lift at zero pitch attitude, so, once you had landed the nose wheel, there was no need for spoilers.
...is that the reason why the non flying pilot pushed the yolk forward once she was down?...
No.
The reason was that using reverse thrust on the ground on Concorde caused a nose-up pitch tendency, strong enough to lift the nose. The procedure was the handling pilot would call Stick Forward as soon as she had landed the nose wheel and the NHP would apply forward pressure on the control column to make sure the nose didn\x92t rise.
If the handling pilot applied reverse thrust before the nose wheel was on the ground, things could get very awkward very quickly.
Firstly, the nose would probably rise, quite possibly beyond the power of the control column to lower it. Secondly, the wing would still be generating (some) lift and so only reduced wheel braking would be available before the anti-skids kicked in, and the amount of runway left would be diminishing faster than normal.
The solution was to reduce to Reverse Idle power until the nose wheel was back on the runway, however, in the heat of the moment it was very easy to go through Reverse Idle and on into Forward Idle. Not only would this again hinder the deceleration of the aircraft, but it would also run the risk of scraping the reverser buckets on the runway (as the buckets moved from the reverse thrust position to the forward thrust position) so tight were the clearances between the buckets and the runway on landing.
Best Regards
Bellerophon
... I think am right to assume there were no spoilers...
Correct.
...so on landing did the act of bring the nose down spoil the lift...
Yes, as with most conventional aircraft, reducing the aircraft pitch attitude (once the main wheels were on the runway) would reduce the angle-of-attack and therefore reduce the amount of lift being generated by the wing. Modern aircraft wings are very efficient and will still be generating a considerable amount of lift during the landing roll, even as the aircraft slows down.
Put simply, spoilers and/or lift dump systems are required to destroy this lift, in order to get as much of the aircraft weight as possible on the main landing gear, which, in turn, allows greater pressure to be applied to the wheel brakes before the wheels start to lock-up and the anti-skid units activate to release the applied brake pressure.
Concorde\x92s wing however developed very little lift at zero pitch attitude, so, once you had landed the nose wheel, there was no need for spoilers.
...is that the reason why the non flying pilot pushed the yolk forward once she was down?...
No.
The reason was that using reverse thrust on the ground on Concorde caused a nose-up pitch tendency, strong enough to lift the nose. The procedure was the handling pilot would call Stick Forward as soon as she had landed the nose wheel and the NHP would apply forward pressure on the control column to make sure the nose didn\x92t rise.
If the handling pilot applied reverse thrust before the nose wheel was on the ground, things could get very awkward very quickly.
Firstly, the nose would probably rise, quite possibly beyond the power of the control column to lower it. Secondly, the wing would still be generating (some) lift and so only reduced wheel braking would be available before the anti-skids kicked in, and the amount of runway left would be diminishing faster than normal.
The solution was to reduce to Reverse Idle power until the nose wheel was back on the runway, however, in the heat of the moment it was very easy to go through Reverse Idle and on into Forward Idle. Not only would this again hinder the deceleration of the aircraft, but it would also run the risk of scraping the reverser buckets on the runway (as the buckets moved from the reverse thrust position to the forward thrust position) so tight were the clearances between the buckets and the runway on landing.
Best Regards
Bellerophon
7th Sep 2010, 10:02
permalink Post: 254
for atakacs:
Quote:
| Makes me wonder... In the event of a complete loss of thrust at Mach 2 (say fuel contamination) would the deceleration be significant ? If so I guess the fuel redistribution / pumping to maintain acceptable CG would become interesting... |
The drag incurred flying supersonic was once described to me as like flying through wood, not air. The only times I ever closed all 4 throttles at M2 was dealing with surges (see earlier posts on the subject). While not quite like flying into teak, the decel was very impressive - it more than once resulted in a member of cabin crew appearing in the flt deck in a semi-seated position, grimly trying to stop a fully loaded galley cart.......
As for four-engine flameouts - perish the thought. The checklists, like many, depended on flight phase;
Above M1.2 it was expected that windmilling would provide adequate eletric and hydraulic power so the c/list aimed to start a fuel txfr forward, use the spare hydraulic system to drive half the PFCUs, ensure a fuel supply to the engs and ensure cooling to equipment.
Below M1.2 the RAT would be deployed, it was less likely that the standard means of fuel txfr would work so valves were overridden and the hydraulic fuel pumps brought into use, and the Mach fell further the PFCUs were put on half-body use only, using the stby hydraulic system.
You weren't far from the ground, in time, at this stage so it was a good time to get an engine relit!
Given the Olympus' auto-relight capability a four engine loss was going to be caused by something fairly drastic.
8th Sep 2010, 11:04
permalink Post: 271
Ohhh.. and bits of Concorde on other aircraft etc:
The emergency generator (and generator control unit) were license built replicas of the units fitted to the F4K and F4M.
The air intake void (Pv) pressure sensor, built by Garrett Aireseach, was used in another 'case' as an inlet pressure sensor on the F14.
Carbon wheel brakes, pioneered on Concorde are now used by just about every modern commercial AND military aircraft. (Although originally trialled on a VC10 in a single brake installation).
(Already bleated on about Airbus pinching our audio warning tones etc).
The Triplex 10-20 glass, developed for and used on the visor panels were used in the automotive industry for many years to come.
I'm sure that there is stacks more.....
Dude
The emergency generator (and generator control unit) were license built replicas of the units fitted to the F4K and F4M.
The air intake void (Pv) pressure sensor, built by Garrett Aireseach, was used in another 'case' as an inlet pressure sensor on the F14.
Carbon wheel brakes, pioneered on Concorde are now used by just about every modern commercial AND military aircraft. (Although originally trialled on a VC10 in a single brake installation).
(Already bleated on about Airbus pinching our audio warning tones etc).
The Triplex 10-20 glass, developed for and used on the visor panels were used in the automotive industry for many years to come.
I'm sure that there is stacks more.....
Dude
9th Sep 2010, 12:44
permalink Post: 295
"Wheel Meet Again" - More on the rotating stuff
More on wheels and brakes
Concorde was without doubt the first ever aircraft to have a fully automatic, active braking system, with NO mechanical linkages to the brakes whatsoever: Firstly there was the 'normal' anti-skid, but the Concorde system was far from normal. Instead of the universally used anti-skid concept that monitors main wheel deceleration, we of course did it differently. Main wheel rotational velocity was compared with (un-braked of course) nose wheel rotational velocity. With zero skid the RELATIVE velocities would of course be the same, any difference would relate to the % skid value. That was the the real advantage of 'our' system; the percentage of main wheel skid could be calculated by the SNECMA (Hispano) SPAD Box, maximum runway 'stopping power' being achieved at around 20% skid. (I always thought that it was strange, the maximum runway adhesion being achieved while the wheel was skidding, but that's what it said on the tin). When the aircraft initially touched down, and the braking/anti-skid system was enabled, a fixed nose wheel speed Vo was used until the nose wheel touched down. (Can't quite remember what equivilant ground speed this related to though).
As well as anti-skid there was also torque modulation also, due to the use of carbon fibre brakes and the enormous amount of rotational torque involved. (A maximum figure of 8.5 MILLION ft./lbs. of torque springs to mind!!!). When a brake demand was input into the BRAKE ADAPTOR BOX (this also manufactured by SNECMA /Hispano) it was compared with a reference torque. As this brake demand input was applied to the 'box', the torque feedback from a torque link connected at one end to the brake would feedback the actual applied torque, where it was compared to reference torque, and the demand was modulated to suit.
The beauty of it all was that the anti-skid, basic brake demand as well as brake torque limits could all be superimposed on one another, giving a wonderfully flexible system that the pilots could have and did had an enormous amount of faith in.
Dude
Concorde was without doubt the first ever aircraft to have a fully automatic, active braking system, with NO mechanical linkages to the brakes whatsoever: Firstly there was the 'normal' anti-skid, but the Concorde system was far from normal. Instead of the universally used anti-skid concept that monitors main wheel deceleration, we of course did it differently. Main wheel rotational velocity was compared with (un-braked of course) nose wheel rotational velocity. With zero skid the RELATIVE velocities would of course be the same, any difference would relate to the % skid value. That was the the real advantage of 'our' system; the percentage of main wheel skid could be calculated by the SNECMA (Hispano) SPAD Box, maximum runway 'stopping power' being achieved at around 20% skid. (I always thought that it was strange, the maximum runway adhesion being achieved while the wheel was skidding, but that's what it said on the tin). When the aircraft initially touched down, and the braking/anti-skid system was enabled, a fixed nose wheel speed Vo was used until the nose wheel touched down. (Can't quite remember what equivilant ground speed this related to though).
As well as anti-skid there was also torque modulation also, due to the use of carbon fibre brakes and the enormous amount of rotational torque involved. (A maximum figure of 8.5 MILLION ft./lbs. of torque springs to mind!!!). When a brake demand was input into the BRAKE ADAPTOR BOX (this also manufactured by SNECMA /Hispano) it was compared with a reference torque. As this brake demand input was applied to the 'box', the torque feedback from a torque link connected at one end to the brake would feedback the actual applied torque, where it was compared to reference torque, and the demand was modulated to suit.
The beauty of it all was that the anti-skid, basic brake demand as well as brake torque limits could all be superimposed on one another, giving a wonderfully flexible system that the pilots could have and did had an enormous amount of faith in.
Dude
9th Sep 2010, 13:07
permalink Post: 296
And more.....
Just to round up the braking issuue....
A fully laden Concorde had a V1 significantly higher than a fully laden 747. (A figure of about 50 MPH springs to mind; perhaps one of the 'flyers' will confirm this). Although the Jumbo is twice the take-off weight, the amount of kinetic energy present in Concorde was significantly higher, due to energy = Mass x the SQUARE of the velocity. Added to this, Concorde had only eight braked wheels compared to the Jumbo's SIXTEEN. This really is further testament to the Concorde braking system, that had to have an enormous amount of stopping power, particularly in the case of a near V1 RTO. And all of this achieved with just eight compact, extremely reliable and relatively light brake units.
Dude
A fully laden Concorde had a V1 significantly higher than a fully laden 747. (A figure of about 50 MPH springs to mind; perhaps one of the 'flyers' will confirm this). Although the Jumbo is twice the take-off weight, the amount of kinetic energy present in Concorde was significantly higher, due to energy = Mass x the SQUARE of the velocity. Added to this, Concorde had only eight braked wheels compared to the Jumbo's SIXTEEN. This really is further testament to the Concorde braking system, that had to have an enormous amount of stopping power, particularly in the case of a near V1 RTO. And all of this achieved with just eight compact, extremely reliable and relatively light brake units.
Dude
9th Sep 2010, 16:06
permalink Post: 299
M2Dude.....
In response to your query: V1 was typically about 160kts on a transatlantic sector, with a Vr of about 190 and a V2 approx 220.
It wasn't in the flight manual but I seem to recall that the standing signal prior to nosewheel spinup was 100m/s. Presumably this also prevented brake application until the nose was down, being much higher than touchdown speed.
Anyone who travelled in the beast will know that we didn't use the brakes gently - they worked far better if you stood on them firmly and also seemed to wear less; certainly there seemed to be a lot more dust on the wheels if you used them gently.
Taxying out one had to be careful, it was easy to get a brake temp light on (was it 200degs? 220?) which meant waiting ages for it to cool. The watchword was minimum number of brake applications and make them firm, not feathery. And be careful on the lightweight departures as you needed them more.
Quote:
| a fixed nose wheel speed Vo was used until the nose wheel touched down. (Can't quite remember what equivilant ground speed this related to though). |
Anyone who travelled in the beast will know that we didn't use the brakes gently - they worked far better if you stood on them firmly and also seemed to wear less; certainly there seemed to be a lot more dust on the wheels if you used them gently.
Taxying out one had to be careful, it was easy to get a brake temp light on (was it 200degs? 220?) which meant waiting ages for it to cool. The watchword was minimum number of brake applications and make them firm, not feathery. And be careful on the lightweight departures as you needed them more.
9th Sep 2010, 16:44
permalink Post: 300
EXWOK
Mate I know the Concorde V Speeds, my query relates to the comparison with the 744.
Yeah that figure sounds familier, and you are correct on the presumption also. (That's why you got the eight 'R' lights illuminated on the anti-skid panel with the gear down on approach). With the fixed Vo signal and no output from the main wheel tacho's, the system sensed full skid and gave a FULL anti-skid release. The brakes were electronically held off by this, nomatter what, prior to landing.
Regards as ever EXWOK
Dude
Mate I know the Concorde V Speeds, my query relates to the comparison with the 744.
Quote:
| It wasn't in the flight manual but I seem to recall that the standing signal prior to nosewheel spinup was 100m/s. Presumably this also prevented brake application until the nose was down, being much higher than touchdown speed. |
Regards as ever EXWOK
Dude
Last edited by M2dude; 9th Sep 2010 at 22:47 .
9th Sep 2010, 17:52
permalink Post: 301
M2D
A B747-400 at max take off weight (398tonnes) ex LHR would typically have a V1 ~ 155 kts, a Vr of about 170 and a V2 of 182 kts, so not dissimilar V1 speeds, but very different Vr and V2.
[I should add that this figures are for using reduced thrust and about 1.6 EPR on the RB211-524G engines where max thrust is about 1.72 EPR. Full thrust may result in an increased V1, I would guess].
This would suggest similar braking capabilities bearing in mind the differing TOWs involved. As to the relative brake unit weights I couldn't comment, nor therefore on the relative design pros and cons.
Numbers offered purely in response to your request.
A B747-400 at max take off weight (398tonnes) ex LHR would typically have a V1 ~ 155 kts, a Vr of about 170 and a V2 of 182 kts, so not dissimilar V1 speeds, but very different Vr and V2.
[I should add that this figures are for using reduced thrust and about 1.6 EPR on the RB211-524G engines where max thrust is about 1.72 EPR. Full thrust may result in an increased V1, I would guess].
This would suggest similar braking capabilities bearing in mind the differing TOWs involved. As to the relative brake unit weights I couldn't comment, nor therefore on the relative design pros and cons.
Numbers offered purely in response to your request.
9th Sep 2010, 22:25
permalink Post: 303
TopBunk
Thanks very much for the info; totally blows my argument out of the water as far as a near V1 reject. (The Vr figure does not really matter so much; we aint going to be much braking there
).
I was repeating what we were told at the training school at Filton in the early '80s. OK, no 744s alive then but certainly 'Classics' around aplenty. (I'm sure the Classic's V1 figures are not going to be a mile away from the '400's). Perhaps more relevent is going to be the brake energy required for landing (average Concorde landing speed was around 160 KTS, how does that compare to the 744?).
Thank you again for the info TopBunk, and sorry for coming out with such bilge previously
Dude
Thanks very much for the info; totally blows my argument out of the water as far as a near V1 reject. (The Vr figure does not really matter so much; we aint going to be much braking there
).
I was repeating what we were told at the training school at Filton in the early '80s. OK, no 744s alive then but certainly 'Classics' around aplenty. (I'm sure the Classic's V1 figures are not going to be a mile away from the '400's). Perhaps more relevent is going to be the brake energy required for landing (average Concorde landing speed was around 160 KTS, how does that compare to the 744?).
Thank you again for the info TopBunk, and sorry for coming out with such bilge previously
Dude
11th Sep 2010, 22:24
permalink Post: 320
Quote:
|
Originally Posted by
stilton
Christiaan,
Since you were discussing the scenario of a nosewheel not lowering and that the CG was over the main wheels may I suggest a rather (amusing at least) possibility ?!! |
Let's admit that being faced with that nasty situation in reality would not have been amusing....
But kicking the idea around a moment, why not? It's what I did seeing the question at first.
Quote:
|
With a nose gear jammed up but all other gear lowered normally could the Flight Engineer pump fuel rearward adjusting the CG aft sufficiently to allow the Concorde to settle back on her 'Tailwheel'.
I realise there would be some damage, especially in light of what has been said about the occasional tailwheel contacts but I imagine it would be less than lowering the unprotected forward fuselage onto the runway. |
Quote:
| Of course some pax might have to move to the back of the cabin too ! |
Quote:
| If the CG was adjusted this far aft would there be controllability issues ? |
Quote:
| There could finally be a use for the 'full down position of the visor' landing in this attitude ! |
One thing that promptly occurred to me for this 'no nose wheel' scenario is braking, since both engine reverse and main gear wheel braking act below the CG, so they'd both act to pull the nose down.
At some point, stick fully back, hence elevons fully up, will no longer be enough to fully counteract that, so you'll have to cancel reverse and braking, and probably commit to an overrun.
Your scenario of doing it as a 'three-pointer' on the tail might wel be the better one !
And while we're at it, what about ditching a Concorde?
It's hinted at in the Safety Cards.
It's been tried lots of times, with models in water tanks.
It wasn't really feasible.......
CJ
12th Sep 2010, 11:10
permalink Post: 327
Hello Stilton,
Now you really have upset my Sunday as after many years being retired I have had to go up to my attic to get the Concorde books out so as to answer your question
Anyway as M2dude has said there were drills for everything on Concorde and if I remeber correctly the figure came to 194 seperate drills with 13 of them having a memory content. Never mind remembering the memory content it was hard enough sometimes to remember which drill had a memory content
Anyway I have found the drill for
"Landing with Nose gear not locked down "
To give just the essence of the drill you are asked to
Jettison as much fuel as possible
Set the C of G for landing to 53%--- sitting over main gear
After gear lowered select Standby lever to down position----- This ensures the gear jacks remain pressurized down on touch down
After lowering nose/visor on normal system seltct visor stby system to visor down---- this removes hyds from nose and visor system down jacks, so allowing nose/visor to raise if nose leg collapses
Brake lever to standby --- If nose leg collapse there is no ref anti skid signal and normal brakes would not work. Standby has no anti skid system and will work
Then on landing nose up attitude should be maintained and normal engine reverse selected as soon as possible remembering that engine reverse tries to pitch the aircraft nose up
Wheel brakes use gently and cease at 120kts
At 110 kts reduce attitude to touch nose wheel down gently
At 85 kts select engine reverse to idle power
At rest " Passenger Evacuation"
----------------------------------------------
So you can see this drill uses the nose up effect of engine revese to hold the nose gear off the ground for as long as possible.
I fear this explanation will gemerate more questios than it has answered, but
off for a cup of coffee now as grey cell are hurting
Now you really have upset my Sunday as after many years being retired I have had to go up to my attic to get the Concorde books out so as to answer your question
Anyway as M2dude has said there were drills for everything on Concorde and if I remeber correctly the figure came to 194 seperate drills with 13 of them having a memory content. Never mind remembering the memory content it was hard enough sometimes to remember which drill had a memory content
Anyway I have found the drill for
"Landing with Nose gear not locked down "
To give just the essence of the drill you are asked to
Jettison as much fuel as possible
Set the C of G for landing to 53%--- sitting over main gear
After gear lowered select Standby lever to down position----- This ensures the gear jacks remain pressurized down on touch down
After lowering nose/visor on normal system seltct visor stby system to visor down---- this removes hyds from nose and visor system down jacks, so allowing nose/visor to raise if nose leg collapses
Brake lever to standby --- If nose leg collapse there is no ref anti skid signal and normal brakes would not work. Standby has no anti skid system and will work
Then on landing nose up attitude should be maintained and normal engine reverse selected as soon as possible remembering that engine reverse tries to pitch the aircraft nose up
Wheel brakes use gently and cease at 120kts
At 110 kts reduce attitude to touch nose wheel down gently
At 85 kts select engine reverse to idle power
At rest " Passenger Evacuation"
----------------------------------------------
So you can see this drill uses the nose up effect of engine revese to hold the nose gear off the ground for as long as possible.
I fear this explanation will gemerate more questios than it has answered, but
off for a cup of coffee now as grey cell are hurting
Last edited by Brit312; 12th Sep 2010 at 11:34 .
30th Sep 2010, 13:58
permalink Post: 499
Concorde Trivia Quiz.. The Answers
As promised here are the answers to our trivia quiz.
Actually there were 14 (but if you are not necessarily a Concorde person, 13 is acceptable). There were '13 fuel tanks, numbered 1 - 11' as we used to tell all the visitors to the aircraft, (The wingtip tanks 5A & 7A making up the extra 2) PLUS a single small
scavenge tank
at the rear of the aircraft that was used to remove fuel from the vent lines and return this fuel via a transfer pump back to tank 3. (A fuel level sensor would trigger the pump with only 1 US Gallon of fuel in the tank). If the trim gallery became over-pressurised (ie tank 3 already full to the brim) an overflow relief valve (ORV) underneath the rear of the aircraft would open and dump the contents of the tank overboard. There was a flight deck indication if the scavenge pump was running in flight to give the crew an indication that a tank somewhere was probably over-filling and to take the appropriate action. There was one added goody about the ORV; If you were on the ground with the refuel door open and due to a refuelling overfill anywhere, fuel entered the scavenge tank, at 7 gallons the ORV would open and rapidly dump the fuel on the floor. For this reason a vent pipe and fuel drum was often placed underneath the ORV during high load refuels. If this was not fitted and you just happened to walk underneath the aircraft at the wrong moment during fuelling........
As a total aside to all this (or me going off on a tangent yet again) the fuel tanks themselves were gently air pressurised above 44,000' to around 2.2 PSIA. This was to prevent the beginnings of any boiling of the fuel in the tanks, due to the low ambient pressure/high fuel temperatures, causing pump cavitation. (Boiling itself could not occur much below 65,000'). A small NACA duct at the right side of the fin was used to supply the ram air for tank pressurisation, the two vent valves in the tail cone, one per trim gallery, closing off automatically at around 44,000', the pressure being controlled by a pneumatic valve, with full automatic over-pressure protection. OK sorry guys and gals, back to the answers:
This is the stinker.... there were 114 (although at entry into service there were 115!!). 100 passenger seats + 6 cabin crew seats + 5 flight deck seats (including the fold up seat in the aisle at the rear) PLUS 3 LOO SEATS (Originally 4 loos, the fourth loo being removed in the early 1980's).
50,189' and 530 KEAS, but we'll settle for anything around FL500 being correct.
Aircraft 216, G-BOAF, the last Concorde ever built. When 216 first flew in 1979 she was a variant 192 'British Unsold Aircraft' and was registered as G-BFKX. In late 1979, BA purchased the aircraft and it was subsequently converted to a Type 102 British Airways variant, and after modifications were complete, test flights were carried out from Filton under the registration of G-N94AF. This registration was to enable the aircraft to participate in the Braniff interchange between IAD and DFW, but when the Braniff Concorde adventure unfortunately ended in 1980, she was again re-registered to G-BOAF, this is how she was delivered to BA later that year.
Easy one this I hope; 60.000'. (As we've said before this limitation was imposed because of the dual window failure / emergency descent time consideration, not as a performance issue. On test flights 63,000' was routinely attained, and altitudes of up to 68,000' were achieved during development flying. (On her maiden flight, G-BOAB achieved 65,000' and Mach 2.04; the first British constructed Concorde to achieve Mach 2 on her maiden flight, and the ONLY one of the original five BA aircraft to achieve this).
Hopefully an easy one... there were TWELVE: 2 nose wheels, 8 main wheels and 2 tail wheels. (No, even I'm not nasty enough to include the wheels on the bar trolleys
). Oh, and there were 9 wheel brakes, one for each main wheel and as was mentioned in a previous post, a single steel disc brake for the nose wheels (the nose having a live axle), for automatic use during gear retraction only.
Three modes; Blue electronic signalling, green electronic signalling and mechanical signalling. I suppose we COULD be pedantic here and include the Emergency Flight Control mode where even with a jammed control column/control wheel, strain gauges (and Safety Flight Control Computers of course) would still enable you to control the elevons.
OK, three basically. Up (Duh!), 5 degrees for taxi/take off and low speed flight and 12.5 degrees for landing. As ChristiaanJ quite rightly pointed out in an earlier post, the prototype (and pre-production) aircraft landing position was 17.5 degrees of droop. (In my view the nose of the aircraft looked a little like an armadillo in this extreme configuration).
In 1977 the new digital Plessey PVS 1580 Aircraft Integrated Data System was progressively fitted to the BA fleet, this being the first microprocessor application on Concorde, this application being followed in several other systems during the life of the aircraft. The 'final' applications being TCAS and the superb retrofitted Bendix RDR-4A weather radar system.
No we are not including torch batteries and emergency lights etc.
There were a total of seven main power sources: 4 x 60KVA AC generators, one per engine, a single 40KVA hydraulically powered emergency generator and 2 lead acid (or ni-cad in the case of G-BOAG) main aircraft batteries. (Not a terribly Re-Volting question I hope).
I hope this quiz was fun and not too perplexing to any of you guys.
Dude
Quote:
| 1) How many fuel tanks were there on Concorde? |
As a total aside to all this (or me going off on a tangent yet again) the fuel tanks themselves were gently air pressurised above 44,000' to around 2.2 PSIA. This was to prevent the beginnings of any boiling of the fuel in the tanks, due to the low ambient pressure/high fuel temperatures, causing pump cavitation. (Boiling itself could not occur much below 65,000'). A small NACA duct at the right side of the fin was used to supply the ram air for tank pressurisation, the two vent valves in the tail cone, one per trim gallery, closing off automatically at around 44,000', the pressure being controlled by a pneumatic valve, with full automatic over-pressure protection. OK sorry guys and gals, back to the answers:
Quote:
| 2) How many seats were there? |
Quote:
| 3) At what approximate altitude and KNOTS EAS was Mach 2 achieved? |
Quote:
| 4) Only one BA Concorde had three different registrations, what was it? |
Quote:
| 5) What was the maximum permitted altitude in passenger service? |
Quote:
| 6) How many wheels on the aircraft |
). Oh, and there were 9 wheel brakes, one for each main wheel and as was mentioned in a previous post, a single steel disc brake for the nose wheels (the nose having a live axle), for automatic use during gear retraction only.
Quote:
| 7) How many flying control modes were there? |
Quote:
| 8) How many positions of nose droop were there? |
Quote:
| 9) What was the first microprocessor application on the aircraft? |
Quote:
| 10) How many main electrical sources were there? |
There were a total of seven main power sources: 4 x 60KVA AC generators, one per engine, a single 40KVA hydraulically powered emergency generator and 2 lead acid (or ni-cad in the case of G-BOAG) main aircraft batteries. (Not a terribly Re-Volting question I hope).
I hope this quiz was fun and not too perplexing to any of you guys.
Dude
15th Oct 2010, 22:25
permalink Post: 574
Ze Concorde Quiz Mk 2 (Or is it Mach 2?).
As requested here is the second in the diabolical series of Concorde quizes. If you were never personally involved withe the aircraft you can leave out the really stinky questions if you want. Most answers can be found either in this thread, by looking at the many panel photos around or as usual by asking Mr Google
1) How many Concorde airframes were built?
2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.
3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).
4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).
1) How many Concorde airframes were built?
2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.
3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).
4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).
5) There were no less than FORTY SIX fuel pumps on Concorde. What was the breakdown for these? (Clue; don't forget the scavange pump
).
).
6) What was the only development airframe to have a TOTALLY unique shape?
7) This one is particularly aimed at ChristiaanJ. What was the total number of gyros on the aircraft?
8) How many wheel brakes?
9) What Mach number was automatic engine variable intake control enabled?
10) Above each bank of engine instruments were three lights, a blue, a green and an amber. What did they each signify?
11) At what airfied were the first BA crew base training details held?
12) What LHR runways did Concorde use for landing and take-off? (Trick question, not as obvious as it might seem).
13) What operator had serious plans to operate Concorde from SNN to JFK in the early 1980's?
14) What development aircraft did not exceed Mach 2 until fifteen months after her maiden flight?
Answers in 7 days, if further guidence (or clues) required then feel free to IM me.
Dude
Last edited by M2dude; 16th Oct 2010 at 08:00 . Reason: Addition of missing question... I am sooo nasty.
16th Oct 2010, 14:47
permalink Post: 577
questions
Humble SLF here, hope it is ok to have a stab at the questions, mods please feel free to delete if necessary.
1) How many Concorde airframes were built?
22, 20 that flew and 2 test frames
2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.
New York, Washington, Miami, Barbados, Toronto, Bahrain and Singapore, no British registered aircraft ever operated to or form Dallas, should not forget BAs most popular destination of all time-London
3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).
0930-Local
4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).
193 & 195 respectiveley
5) There were no less than FORTY SIX fuel pumps on Concorde. What was the breakdown for these? (Clue; don't forget the scavange pump ).
Pass
6) What was the only development airframe to have a TOTALLY unique shape?
101, G-AXDN
7) This one is particularly aimed at ChristiaanJ. What was the total number of gyros on the aircraft?
pass
8) How many wheel brakes?
8
9) What Mach number was automatic engine variable intake control enabled?
1.3
10) Above each bank of engine instruments were three lights, a blue, a green and an amber. What did they each signify?
Not sure here, best guess -green was part of the take-off moniter -red failure-blue reverse
11) At what airfied were the first BA crew base training details held?
Prestwick, shannon, and one in France
12) What LHR runways did Concorde use for landing and take-off? (Trick question, not as obvious as it might seem).
28L , 28R, 27L, 27R, 9L, 9R 10L 10R, 23
13) What operator had serious plans to operate Concorde from SNN to JFK in the early 1980's?
Fed-ex
14) What development aircraft did not exceed Mach 2 until fifteen months after her maiden flight?
214? G-BFKW
1) How many Concorde airframes were built?
22, 20 that flew and 2 test frames
2) As far as the British constructed aircraft went, name the destinations that were served?. Regular flight numbers only, excludes charters etc.
New York, Washington, Miami, Barbados, Toronto, Bahrain and Singapore, no British registered aircraft ever operated to or form Dallas, should not forget BAs most popular destination of all time-London
3) What was the departure time for the ORIGINAL morning LHR-JFK Concorde services? (Not called the BA001 then either).
0930-Local
4) Further to question 3 above, what WERE the original flight numbers for the BA001 and BA003? (The morning and evening LHR-JFK services?).
193 & 195 respectiveley
5) There were no less than FORTY SIX fuel pumps on Concorde. What was the breakdown for these? (Clue; don't forget the scavange pump ).
Pass
6) What was the only development airframe to have a TOTALLY unique shape?
101, G-AXDN
7) This one is particularly aimed at ChristiaanJ. What was the total number of gyros on the aircraft?
pass
8) How many wheel brakes?
8
9) What Mach number was automatic engine variable intake control enabled?
1.3
10) Above each bank of engine instruments were three lights, a blue, a green and an amber. What did they each signify?
Not sure here, best guess -green was part of the take-off moniter -red failure-blue reverse
11) At what airfied were the first BA crew base training details held?
Prestwick, shannon, and one in France
12) What LHR runways did Concorde use for landing and take-off? (Trick question, not as obvious as it might seem).
28L , 28R, 27L, 27R, 9L, 9R 10L 10R, 23
13) What operator had serious plans to operate Concorde from SNN to JFK in the early 1980's?
Fed-ex
14) What development aircraft did not exceed Mach 2 until fifteen months after her maiden flight?
214? G-BFKW