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Concorde question

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Concorde question

Old 27th Aug 2010, 19:02
  #141 (permalink)  
 
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Originally Posted by chksix View Post
YouTube - Concorde breaking the sound barrier
I feel the need to post this clip.
It IS a nice one....
There's a longer one with more of the story, but this is the essence.

TESGO is the designation of one of the waypoints on the Concorde route from CDG to JFK, shortly beyond the point where Concorde goe ssupersonic on its way over the Atlantic.
At the occasion of one of the last Air France CDG-JFK flights, a small group of French enthusiasts hired a boat to get a record of the overflight and the sonic bang, and they succeeded beyond expectations.

There can't be many Concorde friends, who haven't already seen this clip....

CJ
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Old 27th Aug 2010, 19:41
  #142 (permalink)  
 
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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
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Old 27th Aug 2010, 20:15
  #143 (permalink)  
 
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Thanks Brit312 and ChristiaanJ.

Living in Bristol we used to see her go over on the way in to LHR and on a quiet day with the wind in the right direction we could sometimes here a very faint version of the "BaBoom" that was in the linked video.

Such a shame that they didn't keep at least one in a relatively easier to restore to flight condition and send it on the air show circuits with the Vulcan. With the talk of analogue FBW and PFCUs it reminded me of some of the Vulcan controls that I have read about, was there much technology transfer from the Vulcan to Concorde in the design stage?
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Old 27th Aug 2010, 20:32
  #144 (permalink)  
 
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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
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Old 27th Aug 2010, 21:12
  #145 (permalink)  
 
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Notfred
Love the lightning story, hadn't heard that one before.
I was in the Air Training Corps in Bristol in the late 80s and flew in the Chipmunks based at Filton. Used to see the spare Concorde sitting there outside the hangar.
That would have been production series test aircraft G-BBDG, A/C 202 before a purpose built hangar (more shed really) was built to house her, with fin and U/C removed. This aircraft has now been beautifully restored at Brooklands museum.
And a question of my own - I've heard that the engines were pretty powerful even at ground idle, so powerful that if all 4 were running then a tug would not be able to push her back. Any truth to this? Were just 2 started, pushback and then start the remainder? Also heard that the pilots had to watch the brake temps whilst taxiing out to takeoff - was this also due to the power?
You are quite correct about the pushback, not having an APU (THAT story again ) meant that a one engine in each nacelle pair had to be started on the gate, and the other in each nacelle started after push. Having a symetrical pair started enabled all 3 hydraulic systems, and hence most of the critical systems to be checked puring pushback.
Brake temperatures always had to be monitored; they really could get very hot. If a wheel was still too warm after T/O, then the gear would be left down just a little longer to aid cooling. (Each brake also had an electric cooling fan).
Idle thrust was always a problem in that it was too high; there was a 'lo idle' setting, but depending on the temperature of the day the difference was not that big. You could not just reduce idle some more because of a malady known as rotating stall. This can plague any engine, but the Olympus 593 was particularly susceptible. At very low idle speeds, pockets of air 'rotate' around the first few compressor stages and can completely alter the airflows through the engine. It is important that the engine is always accelerated quickly through this zone on start-up, because serious damage can occur if the engine runs for any period of time in the rotating stall region. If the engine DOES operate in this zone, then the combustion process can even occur in the last few stages of the HP compressor, causing extreme damage. This damage, although malignant, can result in blade failure and the subsequent damage to the combustion chamber and turbine areas. This can occur within a few flights of the event, so just cranking down the idle was never an option.
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Old 27th Aug 2010, 21:25
  #146 (permalink)  
 
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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
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Old 27th Aug 2010, 21:39
  #147 (permalink)  
 
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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
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Old 28th Aug 2010, 02:16
  #148 (permalink)  
 
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Digital on board computer

In the late 60 a major computer manufacturer prototyped a miniaturized version of one of its products dedicated to real time process control. The original beast was bigger than an american fridge, while the prototype and its memory were as small as two shoe boxes.

It was proposed to the Concorde project, but never seriously considered.
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Old 28th Aug 2010, 02:37
  #149 (permalink)  
 
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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

Last edited by twochai; 28th Aug 2010 at 03:05.
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Old 29th Aug 2010, 14:10
  #150 (permalink)  
 
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@twochai

No idea who you are but THAT is what I would call first class treatment ! Except allowing you to barrel roll it I don't what more they could do

All other: as may other lurkers I immensely enjoy this thread - keep it up
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Old 29th Aug 2010, 17:57
  #151 (permalink)  
 
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I know that other planes such as the 747 had INS; so in a way this question is not specifically related to Concorde. With the radio navigation update was the lat and long of appropiate radio beacons hard wired into the system and then based on the assumed position the nearest beacons would automatically be tuned or did the pilots enter the lat and long of the beacons that they would then manually tune?
I guess there were three INS units to allow for drift etc and it would be easier to spot if one unit was less accurate than the other two. So when radio updating was not possible ie over the atlantic was it possible for the automatics to weigh against one rouge reading
Finally as Concordes ground speed was over double that of other aeroplanes was there any need to take this into account when designing and building the INS system(other than the speed display that would have to show an extra digit)?
Thanks
Nick

Last edited by Nick Thomas; 29th Aug 2010 at 18:00. Reason: punctuation
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Old 29th Aug 2010, 18:51
  #152 (permalink)  
 
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Hi Nick,

On 707s in early 70s I can only remember 2 INS sets on the centre console. (Where was the third?) They were independent of each other, but we could load up to 9 new way points into both sets simultaneously using the "REMOTE" buttons. There was no automatic radio position updating.

The best we could do was press the "HOLD" button when we were over a VOR, compare the displayed position with the published, and update the position if it was in significantly in error. (In practice we hardly ever did it because determining the overhead position was always a bit iffy). All radio Nav aids had to be manually tuned. Navigation was done using Heading select, whilst comparing Cross Track Error and Desired Track, Dist to Go etc.

Later, with the introduction of FMS (on L1011) we had 3 INS, Tripple MIX, Radio position updating using DME/DME, ETA prediction etc. PFM.

Since INS was developed initially for Intercontinental Ballistic Missile Guidance and the Apollo Space programme, I don't think Mach 2 or less was a problem.

I've enjoyed reading this Concorde thread more than anything else that's been posted. Please tell how the Nav displays evolved during their service.

Regards, RRR
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Old 29th Aug 2010, 20:47
  #153 (permalink)  
 
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twochai
It is wonderful that you have such fond flying memories of Concorde;in the pre-911 days there was a fairly liberal open door policy for flight deck visits (Although all passengers were made to feel really special, it is so great that the guys had you up front for so long on that flight. You just never lose those sort of memories, I know).
On descent over the U.K. and passing through 10K' abeam Southampton, as I remember it we got a yellow 'Radiation' caution
The Radiation Meter was an interesting addition to Concorde's collection of avionics kit. It was primarily designed to detect solar proton, as well as neutron radiation, (the detector element lived behind the fwd r/h wardrobe as I remember and was a total pain in the 'you know where' to get at). The indicator displayed the dose rate in millirems/hour, with amber and red triggers, triggering a master alarm. (The amber was a mere caution, whereas the red was a warning. I can't quite remember any figures, but a descent was required with a genuine red warning. I think I'm correct in saying that no such descent was ever required, at least in the UK). There was a huge amount of concern initially about crews long term exposure to radiation, after all there is a fairly linear relationship between solar radiation and altitude. In reality however Concorde crews received far less radiation than subsonic crews; although the dose rates may have been higher, the sector times were a fraction of a lot of the subsonic routes. (Even a subsonic LHR-JFK is WELL over twice the sector length). Nuisance ambers were not uncommon, a certain 'facility' in Berkshire would often register as the aircraft over-flew, as well as MANY years ago, Three Mile Island itself. I remember that there were long term plans to replace the radiation meter with a portable 'carry on' device that was being trialled. (Spares for the detector were becoming very difficult to obtain).

Dude

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Old 29th Aug 2010, 21:26
  #154 (permalink)  
 
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Nick Thomas
You really do have a great selection of queries Nick .
With the radio navigation update was the lat and long of appropiate radio beacons hard wired into the system and then based on the assumed position the nearest beacons would automatically be tuned or did the pilots enter the lat and long of the beacons that they would then manually tune?
Although Concorde was wired for full area navigation, with autotuning nav radio selectors, this was never fully implemented, and the autotuning selectors replaced with fairly conventional units at entry into service. (Although on route proving trials, G-BOAC did fly with the autotuning selectors).
HOWEVER, a really neat 'next best thing' system evolved: Originally the INS's had an optical card reader for inputting waypoints etc. (when 'island dodging' flying supersonic over the Mediterranean, to avoid booming the populous, it was said to be almost impossible to add waypoints quick enough manually). This card reader was really quite poor; when you inserted the card it was a lottery whether it came out of the reader in one piece, or even at all. Eventually a fairly sophisticated system was developed, and the card readers done away with altogether, and a navigation database was added to the INS units. This database would be updated a couple of times a year, and had to be loaded into each of the three units separately, USING A CASSETTE TAPE!!! All the 'normal' collection Concorde of routes were stored in the database, although the INS core memory could still only handle 9 waypoints at a time. (A light flashed when it was time to 'turn the page' and with a simple push of a button the next bank of waypoints were automatically uploaded into INS core memory. DME co-ordinates were also stored, along with the co-sited VOR frequency that had to be manually dialled for that station; ideally the left and right INSs would use two differing DMEs for best accuracy, and INS3 would use the mean. (Another simple button push would nominate and select the DME to be used by the INS). So, when flying within range of a VOR, the INS position would be refined with the co-sited DME slant range, but when flying oceanic, the 3 INSs would 'triple mix' their inertial positions to give a mean position. A 'rogue' INSs position would be rejected by the other two however, so as not to be sent to the moon because of a bad unit.
Rudderrudderrat
Nowhere near as sophisticated as the FMS system on the Tristar as you can see, but it seemed to work absolutely beautifully. (And when the system was DME updating, we even got an indication from an RNAV light, originally fitted for Area Navigation.
Since INS was developed initially for Intercontinental Ballistic Missile Guidance and the Apollo Space programme, I don't think Mach 2 or less was a problem.
Actally there was a problem of sorts, above 900 KTS G/S, the original DELCO INS would generate an error (after all, WHO would ever want to travell at more than 900 KTS; something must be wrong here ?). A special 'supersonic mode' had to be enabled by the way of pin programming in the INS rack, which inhibited this warning.
Really glad you are enjoying the ravings of us supersonic nutters.

Dude

Last edited by M2dude; 30th Aug 2010 at 04:12.
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Old 29th Aug 2010, 22:59
  #155 (permalink)  
 
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Thanks for your comment M2dude, am just SLF with an interest in design, due to being a member of the profession accused by the Prince of Wales "of doing more damage to this country than the Luftwaffe"!
This may seem a trival question but on the ITVV video Capt Rowlands is checking the pitch trim and the sound made is as he says "rather like a french bicycle bell" and he suggests that it may indeed be made by such a bell. I rather like that idea; but was it so?
I remember in the early eighties loading programmes into my ZX81 using cassettes; and not having much success! Mind you a cassette tape would be far better than an 8 track as an 8 track would keep reloading the route and you would end up flying in circles!
There is a serious point here and that is if you are designing such a complex machine as Concorde, if you can use proven technology in some areas then do so. It appears that all the people involved did so and didn't waste time on "reinventing the wheel" or complicating things just for the sake of it. Good design is about finding the most appropiate solution and Concorde is a fine example of that.
Once again thanks
Nick
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Old 30th Aug 2010, 03:27
  #156 (permalink)  
 
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Nick Thomas
SLF keep the rest of us in business, your input is so very welcome here. Nick, the 'French Bike Bell' is exactly what it was, as the electric pitch trim wheen ran up or down a striker would impact this tiny bell and make the sound that you describe. 'Pitch Trim' sounds like a strange term, after all the aircraft had no trim tabs or tailplane as we all know. What varying the pitch trim used to do was to alter the neutral setting of the artificial feel unit, the control column following this neautral datum.
ZX81, takes me back here. The tape loading that was used on the INS took around 45 minutes per navigation unit, that's two and a quarter hours total for the system. (There was no cross-loading). If Concorde had remained in service, new legislation meant that a more accurate primary navigation system would have been required. One of the systems under consideration was a Litton 82 [email protected] INS with GPS refinement. (As well as DME updating also).

Dude
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Old 30th Aug 2010, 10:30
  #157 (permalink)  
 
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Having only dropped in on this thread and wasted about two hours of supposedly work time reading it....
I have to recommend this piece of _homage_ to Concorde and the plane that unfortunately(!) beat it.
Like him or lump him - Dickinson's "everything goes to 11" does describe her beautifully...

Part 1: YouTube - Flying Heavy Metal Episode Three: Size Matters-Part 1 HQ
Part 2: YouTube - Flying Heavy Metal Episode Three: Size Matters-Part 2 HQ
(The clip starting at 1:38 always makes me smile...)
Part 3: YouTube - Flying Heavy Metal Episode Three: Size Matters-Part 3 HQ
(4:01 - fuel flow...)
(4:40 - An apology to concorde

My name say who I am, so back to lurking....
Darragh
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Old 30th Aug 2010, 18:11
  #158 (permalink)  
 
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No idea who you are but THAT is what I would call first class treatment
Other than being a regular customer of BA at the time, I was nobody. It certainly was First Class treatment, but as M2Dude said:

all passengers were made to feel really special, it is so great that the guys had you up front for so long on that flight.
On the other hand, among the really important people that I recognized on that same flight included:
Boutros Boutros Ghali sitting in row 1 with his security detail
Paul Newman sitting directly behind me, reading my sports car magazines and asking why I was the one who got to ride up front
John McEnroe down the back, but uncharacteristically quiet!
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Old 30th Aug 2010, 19:51
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Just wondering: does anyone know if a Concorde driver ever flew the Koncordski (Tu-144) ?
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Old 30th Aug 2010, 22:05
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Lurking SLF
An interesting post Darragh, but with the greatest respect I think that you may have missed the whole point of this thread. As wonderful as the Boeing 747 is (personally I think that the 744 is one of the finest commercial aircraft ever built), I think anyone would agree that there is no comparison at all, as far as technical achievement goes, between the 747 and Concorde. So many boundaries had to be crossed with the Concorde design, and technical problems were overcome that had defeated many of the world's leading designers. I do have a vague idea what I am talking about here; although I was directly involved with Concorde for 30 years, I am also licensed on both the 744 AND the 777, and although I hold Boeings with the greatest respecect and admiration, nothing so far in the realms of commercial aviation can really compare with the technological marvel that was Concorde.
I think that most of the posters here will be sorrry that you felt you wasted 2 hours reading through these pages, I feel most of us have thoroughly enjoyed reading each others posts.
The YouTube links were great though.
atakacs
To the best of my knowledge no. The original TU144 was an extremely crude attempt by the Soviets at commercial supersonic aviation, and the political climate at the time would not have permitted such a thing. The TU144D used in the 1990's as a joint NASA/Russian experiment was a different beast altogether however, with far better engines and systems, but as far as I am aware the only western pilots to fly it were American chaps.

Dude
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