Concorde question
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Originally Posted by M2dude
You would not wind up on the brakes either, the carbon brakes were extremely sensitive to overtorquing.
None but a blockhead
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Club Concorde seems very bullish about its plan to moor G-BOAB in the Thames outside the London Eye. I asked around the office here (just down the river in Southwark); nearly everyone thought it was a fabulous idea.
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Quax .95
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?
What makes you think they would not have any brakes?? When performing any engine runs always set the brakes & chock the wheels.
Just think back to the A340 that was written off in France when the brakes were released & the aircraft jumped the chocks.
tristar 500
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?
What makes you think they would not have any brakes?? When performing any engine runs always set the brakes & chock the wheels.
Just think back to the A340 that was written off in France when the brakes were released & the aircraft jumped the chocks.
tristar 500
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When performing any engine runs always .... chock the wheels.
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Quax .95
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?
What makes you think they would not have any brakes?? When performing any engine runs always set the brakes & chock the wheels.
Just think back to the A340 that was written off in France when the brakes were released & the aircraft jumped the chocks.
tristar 500
Looking at the pic of G-BOAB in the detuner brings me to the question how they performed the run-up. No brakes, just chocks?
What makes you think they would not have any brakes?? When performing any engine runs always set the brakes & chock the wheels.
Just think back to the A340 that was written off in France when the brakes were released & the aircraft jumped the chocks.
tristar 500
The question is less odd than it seems....
With full take-off power plus reheat, Concorde could not be held on brakes alone (hence the various procedures at take-off).
Maybe somebody has the full story.... in the light of chocks being less than perfect....
CJ
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I cannot imagine any requirement for more than one engine (with or without reheat) to be run at full power when parked in the detuners. Thus there would be very little chance of exceeding the brake torque limits.
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I was at Heathrow on last Sunday, 15th May; G-BOAB is still in the location detailed by Heritage Concorde. Also I can confirm that the detuner where you can see G-BOAB parked in the other picture, has now been completely demolished.
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ZimmerFly said
I cannot imagine any requirement for more than one engine (with or without reheat) to be run at full power when parked in the detuners. Thus there would be very little chance of exceeding the brake torque limits.
Brake torque us only one of the things you have to think about when running at high power.
Consider running an engine on one side with all the others at idle or even shut down, what do you do when the aircraft starts to slide sideways?
The engine run drills call for "balanced" power. What this means is that you have to balance the power which means running the opposite engine at high power also.
Been there, done that!!
tristar 500
I cannot imagine any requirement for more than one engine (with or without reheat) to be run at full power when parked in the detuners. Thus there would be very little chance of exceeding the brake torque limits.
Brake torque us only one of the things you have to think about when running at high power.
Consider running an engine on one side with all the others at idle or even shut down, what do you do when the aircraft starts to slide sideways?
The engine run drills call for "balanced" power. What this means is that you have to balance the power which means running the opposite engine at high power also.
Been there, done that!!
tristar 500
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I know we seem to be straying a little off topic, but having two engines at high power against brakes set to park and all wheels chocked is going to produce a lot less torque than say a sudden stop from 30 knots at RTOW.
[I am too lazy to attempt the sums !]
[I am too lazy to attempt the sums !]
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.... brakes set to park and all wheels chocked
4 years ago Spanner Turner came to my rescue on ground runs with -
Quote below is from the Maintenance Manual. (a 747 manual, but you get the picture).
C. Prepare for Engine Operation.
(1) Check that airplane is parked in clean area with wheels on areas
that are free of oil, grease, or other slippery substances.
(2) Make sure the wheel chocks are installed at the main landing gear
wheels and ground locks are installed.
(a) Do these steps if you will operate the engines for a high power
engine run.
1) Make sure that the forward wheel chock is six to twelve
inches in front of the tires.
NOTE: This will cause the thrust of the engine to be held
by the frictional force between the airplane tires and the
ground, and not the wheel chock. The wheel
chocks do not have the same frictional force as the
tires. If the tires touch the wheel chock, some of
the frictional force between the tires and the
ground is lost, and the airplane can skid. The
wheel chocks are only used to prevent the airplane
from rolling if the airplane brakes were
accidentally released before or after the engine run.
maybe not the proper place but I wanted to share this very nice and supposedly recent photo gallery on the topic...
Last edited by atakacs; 23rd May 2011 at 20:15. Reason: typo
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CJ & rodlittle
Photoshop, most of it, I would say.
Still, well done.
CJ
Still, well done.
CJ
it does say cgi if you look
rod
rod
I saw that, but the images are just the ones you would like to have taken ............ if you wouldn't have been arrested if you'd tried to. 
Roger.
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Landroger,
What triggered my remark was merely that I don't think there's any record of a BA and AF Concorde flying in formation near to the LearJet....
But yes, we would all want to have taken photos like that.
And all of us still hope that there is a video somewhere, somehow, of one of Jean Franchi's barrel rolls.....
CJ
What triggered my remark was merely that I don't think there's any record of a BA and AF Concorde flying in formation near to the LearJet....
But yes, we would all want to have taken photos like that.
And all of us still hope that there is a video somewhere, somehow, of one of Jean Franchi's barrel rolls.....
CJ
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Firsty, i would like to say a big "hello" and "thanks" to everyone who has contributed to this fantastic record of Concorde development and Service!!
I grew up in South Oxfordshire, and on weekday mornings, at what i remember to be a bit after 11am, we would hear the "roar", and run outside into the garden to look up as she passed overhead. The most wonderful racket ! A perfect white arrow, spearing off to exotic destinations, we used to try to guess who might be aboard ;-)
Certainly one of the things that made me interested in engineering, and something to be proud of ;-)
So, here's 2 questions that i hope someone might be able to answer:
1) roughly, how many people worked on the complete development program?
and
2) How many total passenger miles did the fleet clock up over it's service life??
As someone who is now an automotive controls engineer, i have serious respect for the people who built and tested Concorde. We now take for granted being able to log and analyse data over 100's of channels at kHz rates with just a laptop and a small input conditioning box. Having been round 101 at Duxford, and seen the size and capabilites of the engineering flight recorders fitted (and the 1000's of wires linked to them) i tip my hat to anyone trying to get that all to work ;-)
I grew up in South Oxfordshire, and on weekday mornings, at what i remember to be a bit after 11am, we would hear the "roar", and run outside into the garden to look up as she passed overhead. The most wonderful racket ! A perfect white arrow, spearing off to exotic destinations, we used to try to guess who might be aboard ;-)
Certainly one of the things that made me interested in engineering, and something to be proud of ;-)
So, here's 2 questions that i hope someone might be able to answer:
1) roughly, how many people worked on the complete development program?
and
2) How many total passenger miles did the fleet clock up over it's service life??
As someone who is now an automotive controls engineer, i have serious respect for the people who built and tested Concorde. We now take for granted being able to log and analyse data over 100's of channels at kHz rates with just a laptop and a small input conditioning box. Having been round 101 at Duxford, and seen the size and capabilites of the engineering flight recorders fitted (and the 1000's of wires linked to them) i tip my hat to anyone trying to get that all to work ;-)
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Ground Running Concorde
I've been away 'cruising' for a few weeks (lecturing about Concorde) and thought it was time I popped back into this wonderful forum.
There were a few questions regarding ground running Concorde, so here are some 'facts' as far as I recall (Wrinkled old brain permitting).
Concorde was ALWAYS ground run in the detuners at the BA Engineering base at Heathrow, with the parking brake ON. (Save idle runs on the ramp after, say, replacing a PNC actuator etc. on departure. The required high power nozzle trim run could be deferred until the aircrafts return to LHR). Sadly I can confirm that the Concorde 'Hush House' was being demolished when I was last over the engineering patch a few weeks ago, and is probably all gone now.
The detuner chocks were like nothing else you could imagine. They were HUGE steel affairs that needed wheels to be wound down in order to move into position (took a couple of guys at least to move). Once in position forward and aft of the undercarriage, the wheels would be retracted and these 'chocks' would be tension chained together. Believe me, nothing was going to move these suckers!!
Engines WERE NOT run in symmetrical pairs, but the adjacent engine always was run at idle power. The reason for this was so that there was airflow over the T1 probe of the adjacent engine, a winding in this being used by the alternate engine control lane if needs meant it might be required if the main lane failed during the engine run. The way that the aircraft was tethered meant that symmetrical high power running was not any sort of issue.
We were very mean too. In the summer the hangar doors of TBK opposite would invariably be open during the day, the challenge was to see how long it took for us to make them close the doors to shut out the din. (Like I said, Concorde engineers were mean
).
Good to be back
Best regards to all
Dude
There were a few questions regarding ground running Concorde, so here are some 'facts' as far as I recall (Wrinkled old brain permitting).
Concorde was ALWAYS ground run in the detuners at the BA Engineering base at Heathrow, with the parking brake ON. (Save idle runs on the ramp after, say, replacing a PNC actuator etc. on departure. The required high power nozzle trim run could be deferred until the aircrafts return to LHR). Sadly I can confirm that the Concorde 'Hush House' was being demolished when I was last over the engineering patch a few weeks ago, and is probably all gone now.
The detuner chocks were like nothing else you could imagine. They were HUGE steel affairs that needed wheels to be wound down in order to move into position (took a couple of guys at least to move). Once in position forward and aft of the undercarriage, the wheels would be retracted and these 'chocks' would be tension chained together. Believe me, nothing was going to move these suckers!!
Engines WERE NOT run in symmetrical pairs, but the adjacent engine always was run at idle power. The reason for this was so that there was airflow over the T1 probe of the adjacent engine, a winding in this being used by the alternate engine control lane if needs meant it might be required if the main lane failed during the engine run. The way that the aircraft was tethered meant that symmetrical high power running was not any sort of issue.
We were very mean too. In the summer the hangar doors of TBK opposite would invariably be open during the day, the challenge was to see how long it took for us to make them close the doors to shut out the din. (Like I said, Concorde engineers were mean
).Good to be back
Best regards to all
Dude
Last edited by M2dude; 4th Jun 2011 at 19:03.
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What was the minimum maneuvering speed for Concorde
- At a typical takeoff weight?
- At MTOGW?
Also what was the typical climb speed
- At lift-off?
- Once 240 kts is achieved?
- At minimum maneuvering speed at typical takeoff weight?
- At MTOGW?
- At a typical takeoff weight?
- At MTOGW?
Also what was the typical climb speed
- At lift-off?
- Once 240 kts is achieved?
- At minimum maneuvering speed at typical takeoff weight?
- At MTOGW?
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What was the minimum maneuvering speed for Concorde
It was expressed in the flight manual as "Lowest Authorised" speed, Vla, and didn't depend on weight. 0-15,000' Vla=V2 or Vref as appropriate, 15,000'-41,000' Vla=250kias, 41,000'-60,000' Vla=300kias
Also what was the typical climb speed I'm guessing you mean rate of climb rather than IAS?
- At lift-off? From memory Vr was around 200kts, V2 around 220kts and if restricted to 250kts (way below min drag) you'd get pretty poor rates of climb - about 1000fpm if you were lucky and IIRC - you'd quickly want to lower the nose, just barely climb and get her up to 400kts when she'd really fly...
- Once 240 kts is achieved? see above - but once you got her up to min drag (about 400kts at MTOW) things went better - about 4000fpm without reheat
- At minimum maneuvering speed at typical takeoff weight? At V2 she staggered up due the the drag of the slender delta wing at low IAS - but climb performance on three engines (in contingency reheat) at V2/MTOW was better than a conventional subsonic jet on three / MTOW / V2 due to conservative certification requirements of the TSS
- At MTOGW? Does the above answer your Q? Happy to add more if you need...
Edited to add, most transatlantic takeoffs were at MTOW - around 185 tonnes - and due to the slender delta aerodynamics, weight didn't affect performance as much as a conventional wing anyway because induced drag was the bigger player at slow speeds - and I've just completely exhausted my very limited grasp of aerodynamic engineering!!
It was expressed in the flight manual as "Lowest Authorised" speed, Vla, and didn't depend on weight. 0-15,000' Vla=V2 or Vref as appropriate, 15,000'-41,000' Vla=250kias, 41,000'-60,000' Vla=300kias
Also what was the typical climb speed I'm guessing you mean rate of climb rather than IAS?
- At lift-off? From memory Vr was around 200kts, V2 around 220kts and if restricted to 250kts (way below min drag) you'd get pretty poor rates of climb - about 1000fpm if you were lucky and IIRC - you'd quickly want to lower the nose, just barely climb and get her up to 400kts when she'd really fly...
- Once 240 kts is achieved? see above - but once you got her up to min drag (about 400kts at MTOW) things went better - about 4000fpm without reheat
- At minimum maneuvering speed at typical takeoff weight? At V2 she staggered up due the the drag of the slender delta wing at low IAS - but climb performance on three engines (in contingency reheat) at V2/MTOW was better than a conventional subsonic jet on three / MTOW / V2 due to conservative certification requirements of the TSS
- At MTOGW? Does the above answer your Q? Happy to add more if you need...
Edited to add, most transatlantic takeoffs were at MTOW - around 185 tonnes - and due to the slender delta aerodynamics, weight didn't affect performance as much as a conventional wing anyway because induced drag was the bigger player at slow speeds - and I've just completely exhausted my very limited grasp of aerodynamic engineering!!