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Concorde question

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Concorde question

Old 13th Mar 2011, 07:25
  #1241 (permalink)  
 
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Quax .95
The trick was to get as many hydraulic systems online ASAP during engine start/pushback, and that's where the sequence was defined. Now my tired/worn out/time-expired brain recollects that number TWO engine was started first, this gave us GREEN and YELLOW systems, followed by number THREE engine, which now gave us BLUE system. Once these engines were successfully started the 2 air start trucks (oh for that darned APU) could be disconnected and preliminary system checks, including full and free flying controls, could be carried out. After push-back the outboard engines were started by using adjacent engine cross-bleed (as BRIT312 quite correctly stated years ago, there was no 'cross the ship' cross-bleed duct), the remaining system checks would be carried out. After this the tow-bar would be disconnected, the nose lowered to 5 and our Concorde would taxi away ready to leap up into the heavens; the place that she truly belonged.

Best Regards
Dude
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Old 13th Mar 2011, 13:09
  #1242 (permalink)  
 
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It is easy [by looking in my book] to confirm the starting sequence was
3421 or for a Push Back it was 3 then 2 followed by 4 then 1, after pushback was complete

Now the hard part is to remember why, and perhaps it was because that is the way in BOAC/BA we had always started engines, but on previous aircraft I do remember there being a reason such as brake pressure or electrics, which was not the case on Concorde. However I seem to remember that the hydraulic pump layout on pre production Concordes was not always the same as the airline version, so this might have had some influence

However by starting 3 then 4 first it did allow engine start to commence with the passenger finger still in place. Now unlike the French the flying control checks were carried out by a pilot as engines were being started and it started with "Blue" being selected which was sourced from 3 and 4 engines.
Now I think this was only because 3 and 4 were the first engines to be started rather than the reason, but it was handy to speed things up.

Now I have heard a rumour you understand that sometimes when things were running late the 3 and 2 engines would be started at the same time, but you have to understand this is only a rumour
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Old 19th Mar 2011, 18:38
  #1243 (permalink)  
 
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Unlikely Information

Hi, Just caught this question on a search, a bit more info.

My Father was Project Manager for the testing of the engines. I remember spending a few weekends with him driving around to look at suitable railway tunnels. I didn't remember where it was but your post identified it.

Once the test-bed was set up dead birds were collected to be fired in to the engine. As stated it was to prove a disk destruction would be contained within the housing: it was.

There were problems with some break-ins, the company put up various hazard signs to scare away local youths (presumed responsible), it worked but then they had to take them down a reassure the local council there were no such hazards.

My Father was also responsible for the flying test bed, placing an Olympus in the bomb bay of a Vulcan bomber.

Hope this helps.
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Old 25th Mar 2011, 20:02
  #1244 (permalink)  
 
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Seats

Guys - not really a technical question but probably of interest.
Like ShaggySheepDriver I'm one of the guides on Alpha Charlie at Manchester. As part of the tour we always say where the Queen sat. But people always have questions about others.
e.g. - David Frost was always towards the back but was he actually at the back in R26 ?
Question is :- Are there any interesting people with quirky stories who sat elsewhere ? (As per that John Cleese story a few pages back).
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Old 25th Mar 2011, 22:19
  #1245 (permalink)  
 
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e.g. - David Frost was always towards the back but was he actually at the back in R26 ?
Concorde eradicates the tobacco habit - Business, News - The Independent
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Old 31st Mar 2011, 02:09
  #1246 (permalink)  
 
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Hi all,

Sorry for bump this tread but I'm just wonder why Tank 8 is bigger than Tank 6
which is sit left to the tank 8. Is there any specific reason for this?

Thanks for all of yours reply

Best regards
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Old 31st Mar 2011, 16:20
  #1247 (permalink)  
 
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I'm just wonder why Tank 8 is bigger than Tank 6
which is sit left to the tank 8. Is there any specific reason for this?
No specific reason that I know - just that the wing is a bit deeper in that area so same planform area holds more fuel.
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Old 1st Apr 2011, 18:48
  #1248 (permalink)  
 
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M2 dude
Firstly thanks for a very interesting thread. Regarding post 88 (I know it was last year) and the hydraulic systems, the use of M2V would also be required as the pipes were Titanium and Skydrol (ester) based fluids will cause hydrogen embrittlement in Titanium and cracking. For me I had a couple of years working on the aircraft at BA in the late 70's and was always reminded that the design was in the best British military design tradition and training as a gynacologist would have been handy when replacing any component! Good times.
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Old 3rd Apr 2011, 13:23
  #1249 (permalink)  
 
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I'm so glad and flattered at your comments, thank you very much spannersatKL. You are so right about working on the lady. It often seemed like gynacology, or even 'brain surgery 'for fun and profit' a lot of the time when changing stuff on 'The Rocket'.
M2V really was great stuff though, although now it is as rare as rocking horse excrement. (Got any spare)???

Best Regards
Dude
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Old 3rd Apr 2011, 13:29
  #1250 (permalink)  
 
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Dude/SpannersatKL

It often seemed like gynacology, or even 'brain surgery 'for fun and profit' a lot of the time when changing stuff on The Rocket'.
The old "fourteen fingers and rubber legs" syndrome? Been there, done that, got the bad joint pain to prove it.

Roger
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Old 3rd Apr 2011, 17:39
  #1251 (permalink)  
 
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Originally Posted by spannersatKL View Post
....the use of M2V would also be required as the pipes were Titanium and Skydrol (ester) based fluids will cause hydrogen embrittlement in Titanium and cracking.
Thanks for that snippet of info, spanners, I'll pass it on to whom it may concern.
...I was always reminded that the design was in the best British military design tradition
Hummm, half of it was French, and I can confirm they were quite good too at the kind of design you are referring to....
My own field was the AFCS, and one of my experiences was discovering, (quite recently) that the prototype Concorde AFCS controller had obvious family relations with the one on the VC-10 (so not military).
Logical, both were designed by Elliott.
.... and training as a gynacologist would have been handy when replacing any component! Good times.
Now 40 years ago in my case, so the scars have gone, but I do know what you are talking about! And yes, good times.

Originally Posted by M2dude
M2V really was great stuff though, although now it is as rare as rocking horse excrement. (Got any spare)???
Same question here....
Concorde always leaked as a sieve... (escept at Mach 2) and still does to this day. We collect the M2V in the drip pans, filter it, and re-use it, but a few uncontaminated drums or boxes would be very gratefully received.... never mind the "Best By" date.

CJ
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Old 3rd Apr 2011, 20:16
  #1252 (permalink)  
 
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Bellerophon

You call 3-2-1 Now, start your stopwatch, pre-set to countdown from 58 seconds, and slam the throttles fully forward till they hit the stops. Four RR Olympus engines start to spool up to full power and four reheats kick in, together producing 156,000 lbs of thrust, but at a total fuel flow of 27,000 US gallons per hour. A touch of left rudder initially to keep straight, as the #4 engine limiter is limiting the engine to 88% until 60 kts when it will release it to full power. The F/O calls Airspeed building, 100 kts, V1, and then, at 195 kts, Rotate. You smoothly rotate the aircraft, lift-off occurs at around 10 and 215 kts. You hear a call of V2 but you keep rotating to 13.5 and then hold that attitude, letting the aircraft accelerate.

The F/O calls Positive Climb and you call for the Gear Up. On passing 20 feet radio height, and having checked the aircraft attitude, airspeed and rate of climb are all satisfactory, the F/O calls Turn and you slowly and smoothly roll on 25 left bank to commence the turn out over Jamaica bay. Some knowledgeable passengers will have requested window seats on the left side of the aircraft at check-in, and are now being rewarded with a very close look at the waters of Jamaica Bay going by very fast! As you accelerate through 240 kts, the F/O calls 240 and you pitch up to 19 to maintain 250 kts and keep the left turn going to pass East of CRI.
I remember that -- the initial rotation was pretty normal other than being a bit faster, then from there it was brought up to a very steep climb (it feels worse than it is, but I was guessing it was around 22 or so degrees -- it has to do with eyeballing the angle of the horizon to the plane's current path -- 22.5 degrees is 1/4 the way up, 30 is 1/3, 45 is 1/2, 60 is 2/3's and so forth). Clearly I'm not a human ADI
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Old 3rd Apr 2011, 20:17
  #1253 (permalink)  
 
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How many shockwaves does the concorde's inlet produce? I've been told it was like 3 or so, but looking at some diagrams it looks like there are 7... two stronger ones, three weaker ones, a bendy stronger one, a gap and then the terminal shock.
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Old 4th Apr 2011, 14:26
  #1254 (permalink)  
 
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Regarding the engine start-up, was Two-Engine Taxi out ever considered/used in an effort to save some of the vast amound of fuel consumed before take-off.

Related I guess to the above, was there a minimum time limit after engine start before which full thrust could be applied?
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Old 4th Apr 2011, 19:33
  #1255 (permalink)  
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1. Yes ( of course if you have more then 2 )
2. Yes ( every engine, even the one in car or a motorbike etc. )
 
Old 5th Apr 2011, 07:23
  #1256 (permalink)  
 
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Jane-DoH
How many shockwaves does the concorde's inlet produce? I've been told it was like 3 or so, but looking at some diagrams it looks like there are 7... two stronger ones, three weaker ones, a bendy stronger one, a gap and then the terminal shock.
OK here we go:

1) The first shock was generated from the top lip of the intake

2) A second shock is generated from the fwd ramp hinge

3) A third isentropic fan shock is generated from the progressively
curved section of the fwd ramp

4) A 4th shock was generated fron the bottom lip
5) A terminal shock system is generated by the coalescence of
still supersonic and now subsonic air at the upper section of the ramp
area.



Hopefully these two diagrams will help. The first hand illustration above gives the 'theoretical' shock pattern and the second below gives an illustration of practical flows within the inlet. Both assume critical operation at Mach 2.


I hope all this blurb helps


Best regards
Dude

Last edited by M2dude; 5th Apr 2011 at 07:35.
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Old 5th Apr 2011, 16:27
  #1257 (permalink)  
 
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During the take off roll there was a power check called (by the FE, I think). I've heard this on recordings and videos variously as "power checked" and "Power set". Assuming they are one and the same check, which is correct?
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Old 5th Apr 2011, 17:09
  #1258 (permalink)  
 
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Dude, those are very nice illustrations, but I would make a small correction to the lower picture - the bleed flow is shown as entering the void at the front of the slot between the front and rear ramps whereas in reality it goes (sorry went :-( ) in at the rear behind the terminal shock. The increase in pressure behind that shock was the 'drive' for bleed flow.

Regards

CliveL
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Old 5th Apr 2011, 17:32
  #1259 (permalink)  
 
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During the take off roll there was a power check called (by the FE, I think). I've heard this on recordings and videos variously as "power checked" and "Power set". Assuming they are one and the same check, which is correct
?

I think you are referring to the 100kt call, when the F/E was expected to give a call as to the state of the powerplant [both engine and reheat] achieving desired power for take off. He was assisted in this decision by the illumination of 4 green lights [ one per engine] which came on if the engine power was OK. Should one green light fail then he would confirm the correct engine operation by observing that engine's N2 and Area position

If all OK at 100kts the F/E would call ---- "Power Set"
If not all Ok then he would call ----------" Engine Failure" which would
result in a rejected Take off

In the early days there was no concession and every take off had to have 4 green lights illuminated so the call then was " 4 Greens" , but when the concession came along that term would not fit so the change in call

The concession were
1] one green light out [seeabove]
2] and basically if weight, and airport conditions allowed it a take off could be continued even with one reheat failed at 100kts

Up to 60 kts the F/E could reselectt a failed reheat so hoping it would be
OK by 100kts
At 100kts the conditions in the above concessions applied
Above 100kts the take off would continue even if a reheat failed however
if another fails when below V1 the take off would be rejected

So finally to answer your question the correct call [well in 1998] was

" Power Set "
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Old 5th Apr 2011, 18:09
  #1260 (permalink)  
 
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CliveL
Dude, those are very nice illustrations, but I would make a small correction to the lower picture - the bleed flow is shown as entering the void at the front of the slot between the front and rear ramps whereas in reality it goes (sorry went :-( ) in at the rear behind the terminal shock. The increase in pressure behind that shock was the 'drive' for bleed flow.
Clive, thank you so much for your correction; I will ammend this diagram in my files immediately.
(As always you are of course 100% on the bal. And what do aerodynamisits know about aerodynamics anyway ).

Best regards
Dude
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