Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Concorde question

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

Concorde question

Thread Tools
 
Search this Thread
 
Old 19th Nov 2010, 20:45
  #741 (permalink)  
 
Join Date: Jan 2008
Location: FL 600. West of Mongolia
Posts: 463
Likes: 0
Received 0 Likes on 0 Posts
Cron
The crews, the engineers and anyone 'hands on' with the aircraft would have known that they were involved with something very special. Moreso I detect from such posters that they seemed to have a relationship with the aircraft which went beyond the normal level of any professional working with interesting technology. Were these people such well balanced types that they shrugged and took in their stride or was there seething but repressed anger? Was there a feeling of personal loss that such a thing would never happen again?
You sure touched a nerve or two there Cron. I can only speak for myself, but to me Concorde was more than a job, far more than just 30 years of my life, she was (and still is) an amazing and astoundingly beautiful aircraft. She was flown by dedicated, highly professional crews, some of which I still regard as some of my best friends. She carried an enormous variety of people, from the wealthy and famous to old Granny having a chance of a lifetime birthday treat. She epitomised what dedicated men (and women too) can achieve in the field of adversity when there is sufficient talent and dedication available to overcome massive political and technical hurdles. These guys and gals produced what is to me simply avaiation perfection. There is another aspect of Concorde's life that is seldom mentioned, that of live organ transportation across the Atlantic (in both directions I might add). I wonder just how many lives were saved by this marvelous use of speed. (The organs were transported in refrigerated containers and the speedy transport from the aeroplane was both slick and professional. I could go on.... but will give instead my personal feelings regarding this 'world without Concorde. The real TRUE story of why Concorde was withdrawn from service is for another time (this story has already been alluded to several times in this thread), but I am stilll filled with feelings of sadness, of guilt (was there really nothing any of 'us' could have done?) but mainly a deep feeling of anger and revulsion towards a small handfull of nasty little individuals that managed to destroy something so wonderful, so unique and so special for ALL the wrong reasons. I just hope these characters look back and are truly proud of themselves; this aviation 'crime' is right up there with the TSR-2 cancellation in my view.
But life goes on, and I had to spend the next few years learning all about those Boeing things. (You know I never realised that it was possible to fly WELL BELOW the speed of sound ).

BN2A
PS - Was there ANYTHING on the Charger(ski) that was better or more advanced??
errrr nope.
Regards

Dude
M2dude is offline  
Old 19th Nov 2010, 21:00
  #742 (permalink)  
 
Join Date: Jan 2008
Location: FL 600. West of Mongolia
Posts: 463
Likes: 0
Received 0 Likes on 0 Posts
Mr Vortex
So if we select E Low at M>1.7 the N2 will ovespeed and hence higher fuelflow. Am I understand it right? Also, what E mode provide the
best config shape [lest sat suitable] that provide a con-di nozzle for
maximize thrust. [Not open to wide that exhaust can't reach M1 at the
throat of Prim nozzle].
Not quite; remember that the N1s and N2s in the E SCHEDULE graph are non-dimentional. ie. they vary with temperature. As the temperature rises (with increasing Mach Number) the scheduled spool speeds increase. What really happens (I did not explain it correctly first time) is that the much lower N1 demanded by the use of E LOW at high speed results in a much further closed primary nozzle than normal, pushing up TET (and EGT) and we run hard into the EGT limiter, which claws fuel flow off, to the extent that the ramps and spill doors come down to their preset limits, almost as if there is a flame-out. The net result is a huge reduction in thrust. The condi was formed as the primary nozzle naturally took up a near fully open position in supersonic cruise and the wide open secondary nozzle buckets completed the picture. The schedule used here was E HIGH. I've noticed a couple of errors on the graph, the main one being that E HIGH is used with reheat off but with Vc > 220 KIAS
And another quesrion here, the engine control unit use which parameter to control the thrsut. The EGT, or N2, or P7.
Apart from being set as a variable limit, EGT normally played no role in the control loops (there were 2 loops, the 'governor' and 'positioner' loops). P7 played no part whatsoever in any case, the main variables were; N2, throttle valve position, throttle transmitter position, T1, total pressure and static temperature..

Feathers McGraw
If you watch some of the more recent Concorde programmes, such as "Concorde's Last Flight", you'll hear and see the reaction of the various people (including our very own Dude) from the BA side of things as they talk about their charge.
Oh nooooo... I've been outed
Best regards

Dude

Last edited by M2dude; 20th Nov 2010 at 04:10.
M2dude is offline  
Old 19th Nov 2010, 22:50
  #743 (permalink)  
 
Join Date: Mar 2007
Location: Cardiff UK
Age: 69
Posts: 118
Likes: 0
Received 0 Likes on 0 Posts
I have just come back from the pub so am being more open than normal. So I have to come out of the closet to admit that Concorde is the only inanimate object that I find "so sexy". I also think that most people that have contributed to this thread would agree with me.
Regards
Nick
Nick Thomas is offline  
Old 20th Nov 2010, 01:16
  #744 (permalink)  
 
Join Date: May 2010
Location: Canada
Age: 73
Posts: 457
Received 6 Likes on 3 Posts
M2 Dude

Back in August of 1997 I had the privilege of a ride in G-BOAC out of CYYZ on a flight to now where ie east of JFK up to FL550 Mach 2.0 etc.
It was back in a gentler day with a visit to the flight deck and I can still remember it all is if it was yesterday. As you can tell by web name I am industry and I really appreciated the short time I had in the Flight Deck. Unfortuneatly I was one of 99 that day so I did not get a chance to ask all the questions but the fuel system and fuel pump mini lecture from the flight engineer was stunning.
Please accept my sincere thank you and to Christian as well.
Like the Avro Arrow the TSR-2 the Concorde will live long in our minds.
One last comment many years ago we were number 2 on 09R in LHR and Concorde takes off in front of us. We were in an L-1011 that day and it shook as if a metal saw was trying to cut us in two. The Flight Service Director came running in white as a ghost and his first words were "What the #@&*" was that.........................
Please keep writing your story and if I ever run across you on the other side of the "pond" the bitter is on me
a330pilotcanada is offline  
Old 20th Nov 2010, 16:04
  #745 (permalink)  
NW1
 
Join Date: Nov 2001
Location: UK
Posts: 171
Likes: 0
Received 0 Likes on 0 Posts
We've heard from Engineers, Pilots, Designers, 'Ambassadors'.... How about ATC??? Are there any out there with their memories?? Was life slightly different when "No Speed Restriction" was offered and Concorde hit 400 kts+ instead of the mere mortals at +/- 300 kts?? Anything unusual in their handling on the way into LHR/JFK/IAD/BGI etc for sequencing?? Any general anecdotes to recollect??
I remember once decending into JFK, still at about M1.7ish on the 001 and the 002 was climbing out having just accelerated. Through disruption to schedules (this would not usually happen) the AF pair were in the same state (one in, one out, both supersonic). I asked the controller (I *think* it was NY centre) if that was the first time he'd ever had four supersonic airliners, simultaneously, on his watch - the reply was effusive and summed up the really positive reaction that aeroplane engendered in people working with it in any field...
NW1 is offline  
Old 20th Nov 2010, 16:46
  #746 (permalink)  
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 71
Posts: 3,414
Received 3 Likes on 3 Posts
To the ATC question, one experience. I was flying a Falcon 10 into KIAD one afternoon, level in the mid-teens, indicated 300-ish, when the ATCO vectored us off the airway for overtaking traffic. Now, in 1980, the DA-10 was considered pretty hot stuff for biz jets. We asked for an increase in speed and offered 400 KIAS or better. We took the vector, to watch the Speedbird speed by. As magnificent as pictures are, in flight a couple of miles away it is stunning.

GF
galaxy flyer is offline  
Old 20th Nov 2010, 18:55
  #747 (permalink)  
 
Join Date: Jan 2008
Location: FL 600. West of Mongolia
Posts: 463
Likes: 0
Received 0 Likes on 0 Posts
a330pilotcanada
I'm so glad that the guys on Alpha Charlie looked after you so well on that flight. Meeting fellow aviators was always most pleasurable for my 'flying chums' and they's always wax lyrical with absolute pride. I can also only apologise on behalf of the enrire fleet for the underwear replacement that your Flight Service Director; the aeroplane DID look stunning from that close I know.
If the beers are on you my friend that will be great (but you can #make mine a Bud' if that's ok
Best Regards

Dude
M2dude is offline  
Old 21st Nov 2010, 01:07
  #748 (permalink)  
Guest
 
Join Date: Nov 1999
Location: In the shadow of R101
Posts: 259
Likes: 0
Received 0 Likes on 0 Posts
In 2000 I was on my way to Helsinki in a Finnair A321 at Heathrow taxying out towards 28R when looking out of the windows we realised that a Concorde was passing to the left of us. Just at that moment the ceiling screens folded down and the forward facing camera powered up, showing us the whole of the Concorde as it turned onto the runway and spooled up. The whole of the fuselage of our 'bus was rattling away, and then as the noise decreased we were cleared to line up ourselves and the screens showed rapidly receding reheat flames through a cloud of exhaust smoke. Despite being cleared to take off immediately, we were naturally left well behind, I could just see the Concorde climbing out to the west as we turned north and then east to head off across to the North Sea.

No prizes for guessing which flight I would have preferred to be on....
Feathers McGraw is offline  
Old 21st Nov 2010, 04:58
  #749 (permalink)  
 
Join Date: Nov 2010
Location: Beijing
Age: 30
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Thanks very much M2Dude for your answer.

I'm wonder if all 4 Olympus 593 all died in flight and unable to restart. Is it
possible to be able to land at the nearest airport?
I've heard some of the double delta fighter like saab 35 Draken suggested that
if engine was died inflight, ejection was recommend since it isn't possible to land
[maybe due to the enormous of drag create while aircraft approaching the
runway]. So if i'm wrong please correct me. I'm no expert in saab draken.

Thanks for all of yours reply.

Best regards

Vortex
Mr.Vortex is offline  
Old 21st Nov 2010, 11:06
  #750 (permalink)  
 
Join Date: Jan 2008
Location: YLIL
Posts: 250
Received 1 Like on 1 Post
Many thanks to Dude, Christiaan and all the others for a wonderful thread.

Yesterday, being in New York, I headed off to the Intrepid museum on the Hudson to see BOAD - I spent ages wandering around marvelling at this beautiful machine, people must have thought I was crazy ignoring the other exhibits!

Unfortunately, never had the chance to fly in Concorde, but did go out to see 002 when she flew into Melbourne in 1972 (I can still remember the experience in fine detail, even now - I must sort through my photos one day, I'm sure there are shots there somewhere).

Only other times I saw her were on the ground in Heathrow - always a highlight of my London visits!
triton140 is offline  
Old 21st Nov 2010, 14:37
  #751 (permalink)  
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 71
Posts: 3,414
Received 3 Likes on 3 Posts
Mr Vortex

An ejection was recommended because it was possible, not that was necessarily impossible to land a Draken dead stick. F-16s have done a number of them, I witnessed one at KTPA. There was a video of the HUD view of one at NAS Glenview, IL.

To your question, it would depend on distance to go to the airport, glide ratio (high but probably not terribly worse than any conventional airliner) and most importantly the capability of the RAT providing hydraulic power.

M2dude, any idea of the min IAS for the RAT to provide the juice and hydraulics? Would it be as low as Vapp minus some margin?

GF
galaxy flyer is offline  
Old 21st Nov 2010, 16:02
  #752 (permalink)  
 
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Mr.Vortex
I'm wonder if all 4 Olympus 593 all died in flight and unable to restart. Is it possible to be able to land at the nearest airport?
The "venom" is in the tail of your question.....
Best glide angle for Concorde is in the order of 1:10, so with an multiple failure at 40,000ft (7.5 miles) your "nearest airport" would have to be well within a distance of 75 miles.
(BTW, I think somebody earlier already mentioned that a large part of the actual descent from top-of-descent was with the engines barely above idle, so that it was much like a glide. It was during the final hold, approach and landing, that it was preferable to have a few engines left.....)

Four-engine surges have happened a few times during flight testing, but I don't think there ever has been a four-engine flameout.

Re the SAAB Draken, I would think a dead-stick landing would be possible, but only IF you could arrive 'overhead' at about 10,000ft and IF you were well aware of the horrendous sink rate 'on the back of the drag curve' once you committed to the final approach and landing.
Even the F-104G, not known for its gliding qualities, could be and has been landed dead-stick - there is a section on the subject in the flight manual. On the 104, things were further complicated by the fact that without an engine you also lost the "blown flaps", so your landing speed was a lot higher.

In Western Europe, with its densely populated areas on the one hand, and a lot of airbases on the other hand, there were certainly cases where you thought twice before 'punching out'.

CJ
ChristiaanJ is offline  
Old 21st Nov 2010, 17:21
  #753 (permalink)  
 
Join Date: May 2002
Location: UK
Posts: 140
Likes: 0
Received 0 Likes on 0 Posts
QUOTE]I'm wonder if all 4 Olympus 593 all died in flight and unable to restart. Is it
possible to be able to land at the nearest airport[/QUOTE]

As CristiaanJ says , it depends on how far the nearest airfield was away, but given that there was one close enough then yes in theory it was possible.

On Concorde there were two checklist to cater for a four engine failure that assumes the engine have flamed out but not seized thus the system can be fed by windmilling engines. The two drills are

4 ENGINE FAILURE ABOVE MACH 1.2

4 ENGINE FAILURE BELOW MACH 1.2

When above M1.2 the windmilling speed of the engines should keep the engine generators on line and you should have good hyd pressure also.
Therefore the main point of the drill at this speed is to try and relight the engines, by selecting relight on all 4 engines at the same time. You normally got the chance to go through 2 and some times 3 relight sequences before the speed dropped to Mach 1.2

At mach 1.2 with no engines then the windmilling speed is reaching a point where it is not sufficent to hold the generators on line so the drill concentrates on switching as much of the systems onto essential electrics which will be supplied by the hydraulically driven emergency generator.
To help support the yellow and green hyd system below M1.2 the ram air turbine is lowered. Engine relights will continue to be attempted but as you are on essential electrics now they can only be attempted individually.

If no relights and below 10,000ft then the c/list tells you to prepare the aircraft for landing by lowering nose/visor and gear by emergency systems with speed reduced now to 270 kts. To conserve hyd pressure being mainly derived now from the RAT for the flying controls the emerg gen is switched off during the approach and approch speed is 250 kts with min landing speed
of 200kts

During this all this descent the aircraft had to be flown and navigated, radio calls made along with PA and cabin briefing and all the normall descent checklist complied with so you can imagine it was quite a busy time

This drill used to be practised on the sim ,but the crew would normally find the engines started to relight before 10,000ft so as to give the crew confidence that the drill worked.

However after many years of operation there was some talk about doing away eith the drill as no one could envisage it ever happening. then the BA 747 lost all 4 engines in the volcanic ash cloud and all such talk stopped
Brit312 is offline  
Old 21st Nov 2010, 17:38
  #754 (permalink)  
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 71
Posts: 3,414
Received 3 Likes on 3 Posts
Thanks for the very complete answer, Brit312. As I gather, Mr Vortex is a relative novice (from the profile, I'm making an assumption), an additional point. As supersonic flight was overwater, the loss of all engines above M1.2 pretty much precluded a airport landing except for initial acceleration and final deceleration. And, at that, initial acceleration would require a 180 degree turnaround, probably reducing the time above M1.2. Over sovereign land, you would, I presume, be going directly to the slower than M1.2 drill and the possibility of an airport landing.

GF
galaxy flyer is offline  
Old 21st Nov 2010, 17:48
  #755 (permalink)  
 
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by galaxy flyer
As I gather, Mr Vortex is a relative novice (from the profile, I'm making an assumption), an additional point.
GF, that's another thing about Concorde....
I'm always amazed about how many people, who've never flown on Concorde, sometimes never even have seen her fly, still try to find as much about her as they can, even on technical issues they'd never bother with about for any aircraft (apart from maybe the SR-71).
It's worth passing on the heritage, I think.

CJ
ChristiaanJ is offline  
Old 21st Nov 2010, 19:11
  #756 (permalink)  
 
Join Date: Nov 2010
Location: Beijing
Age: 30
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Thanks for all of your reply.

As galaxy flyer said, I'm haven't met real Concorde in my life and neither see her
flying too. So I'm study about her for a while from flight simulator, manual,
some book, and this forum to get to know more about this amazing plane.
So if i'm bother you guys with a non sense question I'm apologize for that.

Best Regards

Vortex
Mr.Vortex is offline  
Old 21st Nov 2010, 19:44
  #757 (permalink)  
 
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Mr.Vortex
So if i'm bother you guys with a non sense question I'm apologize for that.
I'll answer that with an ancient remark...
"There are no such things as stupid questions. There are only stupid answers".
So no need to apologize.
We'll do our best to answer, and do our best to keep the Concorde story 'alive'.

CJ
ChristiaanJ is offline  
Old 21st Nov 2010, 20:21
  #758 (permalink)  
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 71
Posts: 3,414
Received 3 Likes on 3 Posts
More than that, ChristaanJ, there are only stupid mistakes!

Mr Vortex. At your age, I was doing the same thing, asking all sorts of questions that required knowledge and understanding before my years and experience. Keep doing so, it is the only way to expand your mind. And you never know when that obscure fact will come in handy

GF
galaxy flyer is offline  
Old 21st Nov 2010, 20:37
  #759 (permalink)  
 
Join Date: Jan 2008
Location: FL 600. West of Mongolia
Posts: 463
Likes: 0
Received 0 Likes on 0 Posts
galaxy flyer
any idea of the min IAS for the RAT to provide the juice and hydraulics? Would it be as low as Vapp minus some margin?
Well the RAT was 'advertised' to be able to maintain 4000 (ish) PSI on Green and Yellow systems down to around 200 KTS, so IN THEORY you'd be ok (ish), refering to Brit312's post. Incidently, one of the prime reasons that the engines were housed in twin nacelle pairs, rather than the original TU144 'monobloc' style was to eliminate the chance of a severe ripple surges flaming out all four engines. (But as the thing had half of the engine air passing over the massive stowed main undercarriage, they had other problems to worry about anyway).
I have to echo your point GF about carrying on asking questions, even if they may seem dumb at the time. It's all about how we all had to learn in the first place; Personally I'm happy to answer any questions at all here (the questions may not be stupid, but some of my answers...........).
Regards to all

Dude
M2dude is offline  
Old 21st Nov 2010, 21:14
  #760 (permalink)  
 
Join Date: Nov 2010
Location: Beijing
Age: 30
Posts: 43
Likes: 0
Received 0 Likes on 0 Posts
Thanks to all of your cheer up reply. I'm really appreciate that.

Best Regards

Vortex
Mr.Vortex is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.