Concorde question
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
Anyway, for modelers (not your case, I take it) a Munsell chip ref wouldn't be much use..... they'd need a Humbrol paint number !
"Matching colors" is a Concorde problem to this day....
A small group of enthusiasts is trying to re-paint F-WTSA (the French preprod Concorde, now at a small museum south of the Paris Orly airport) in the same paint scheme as in the olden days... ancient BA livery on one side, ancient AF livery on the other side.
Getting hold of all the paint color references is not obvious!
CJ
Join Date: Aug 2007
Location: San Mateo
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Performance Question
Could I ask a performance question of you folks?
I was watching the ITVV Concorde program the other day and a couple of things really stood out. The noise abatement take off from JFK looked pretty alarming from a climb rate point of view, looked like the aircraft tottered over the coastline with a pretty low rate of climb compared to the subsonic stuff. That being said she was supersonic 12 minutes after the thrust levers were advanced so she could certainly pick up her heels.
So the question is, if you were operating the aircraft out of somewhere with no climb or noise abatement restrictions (BGI?) on an average day with make take off weight what would be the typical time to M1? Course the 7 year old in me also want to know what the fastest time was that you saw on a revenue trip.
I was watching the ITVV Concorde program the other day and a couple of things really stood out. The noise abatement take off from JFK looked pretty alarming from a climb rate point of view, looked like the aircraft tottered over the coastline with a pretty low rate of climb compared to the subsonic stuff. That being said she was supersonic 12 minutes after the thrust levers were advanced so she could certainly pick up her heels.
So the question is, if you were operating the aircraft out of somewhere with no climb or noise abatement restrictions (BGI?) on an average day with make take off weight what would be the typical time to M1? Course the 7 year old in me also want to know what the fastest time was that you saw on a revenue trip.
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
It was a JFK-LHR BA Concorde which landed at Cardiff (in Wales) with some kind of tech problem. The paxs were ferried to LHR and the repairs were done at Cardiff.
Then the a/c was flown back to LHR. Since the take-off was over the sea (so no noise abatement needed), and the plane was empty, with only little fuel, she went "like a scalded cat" and hit Mach 1 in about 6 minutes.
Mr Hoppy,
I am aware it doesn't quite answer your question... I hope one of the pilots can answer that. But I doubt they would normally have kept specific records.
CJ
Join Date: Mar 2007
Location: Cardiff UK
Age: 69
Posts: 118
Likes: 0
Received 0 Likes
on
0 Posts
Great thread and I am still enjoying reading it over a year later. I was again watching ITVV Concorde DVD the other night and noticed the Heading/Track button on the A/P. I wondered how you could chose to fly in Track instead of Heading i.e. did you say have to push the button quickly twice to get the track mode?
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
Great thread and I am still enjoying reading it over a year later. I was again watching ITVV Concorde DVD the other night and noticed the Heading/Track button on the A/P. I wondered how you could chose to fly in Track instead of Heading i.e. did you say have to push the button quickly twice to get the track mode?
IIRC you had to push/pull the HDG/TRK SET button in or out to set either heading or track which would then show on the HSI.
This from memory only... I may well be wrong.
CJ
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
Nick Thomas
... I wondered how you could chose to fly in Track instead of Heading i.e. did you say have to push the button quickly twice to get the track mode?...
We should establish which button you mean, because there are two buttons, both associated with TRK/HDG, either of which might be the one you are referring to.
On the auto flight control panel there is a white push-button switch engraved with the letters TRK and HDG.
Photo courtesy of, and copyright to, Gordon Roxburgh, from his ConcordeSST.Com website.
When pressed, this will initiate the acquisition and subsequent hold of the preselected track or heading selected on the three digit counter beneath it (and repeated on the track/heading pointer on the HSI). This switch will illuminate White when this mode is engaged.
Photo courtesy of, and copyright to, Gordon Roxburgh, from his ConcordeSST.Com website.
So what determines whether this mode, if selected, would follow TRK or HDG? Beneath the three digit counter is a combined push-pull and rotary control, beside which is marked HDG PULL and TRK PUSH.
The rotary function of this control altered the reading in the counter and the Push/Pull function determined whether the entered number was a TRK demand or a HDG demand. With TRK/HDG illuminated on the push-button control, and with the rotary control pulled out (and thus in HDG mode), this little rotary control was effectively the steering wheel for the aircraft.
Why HDG and not TRK? Mainly because nearly all ATC vectors are HDG vectors. In practice TRK was rarely used, with the aircraft either in HDG or INS.
Best Regards
Bellerophon
... I wondered how you could chose to fly in Track instead of Heading i.e. did you say have to push the button quickly twice to get the track mode?...
We should establish which button you mean, because there are two buttons, both associated with TRK/HDG, either of which might be the one you are referring to.
On the auto flight control panel there is a white push-button switch engraved with the letters TRK and HDG.
Photo courtesy of, and copyright to, Gordon Roxburgh, from his ConcordeSST.Com website.
When pressed, this will initiate the acquisition and subsequent hold of the preselected track or heading selected on the three digit counter beneath it (and repeated on the track/heading pointer on the HSI). This switch will illuminate White when this mode is engaged.
Photo courtesy of, and copyright to, Gordon Roxburgh, from his ConcordeSST.Com website.
So what determines whether this mode, if selected, would follow TRK or HDG? Beneath the three digit counter is a combined push-pull and rotary control, beside which is marked HDG PULL and TRK PUSH.
The rotary function of this control altered the reading in the counter and the Push/Pull function determined whether the entered number was a TRK demand or a HDG demand. With TRK/HDG illuminated on the push-button control, and with the rotary control pulled out (and thus in HDG mode), this little rotary control was effectively the steering wheel for the aircraft.
Why HDG and not TRK? Mainly because nearly all ATC vectors are HDG vectors. In practice TRK was rarely used, with the aircraft either in HDG or INS.
Best Regards
Bellerophon
Join Date: Mar 2007
Location: Cardiff UK
Age: 69
Posts: 118
Likes: 0
Received 0 Likes
on
0 Posts
I was referring to the button in the top picture. On the DVD you can see the co-pilot moving the lower button but the camera view is from the side and below so it's not possible to see the button label. Thank your Bellerphon for your clear explanation and for going to the trouble of finding the photos.
Join Date: Feb 2001
Location: UK
Posts: 223
Likes: 0
Received 0 Likes
on
0 Posts
Re : 9min to mach 2.
Not sure you can get CG back that quickly.
In the (restored) Sim with a lightweight fuel load that will not get you anywhere and not bothering about the CG, the absolute minimum time to Mach 2 at 50,000ft on a pretty constant VMO chase is just over 15mins, so really unlikely that this was possible in real life....but will stand corrected if someone says other wise.
The A/C had diverted to cardiff as they had suffered a engine surge due to a double intake lane failure and had to slow to subsonic early. That coupled with additional time with engines running at JFK meant they were just not comfortable about coming to London and possibly declaring a fuel emergency.
Not sure you can get CG back that quickly.
In the (restored) Sim with a lightweight fuel load that will not get you anywhere and not bothering about the CG, the absolute minimum time to Mach 2 at 50,000ft on a pretty constant VMO chase is just over 15mins, so really unlikely that this was possible in real life....but will stand corrected if someone says other wise.
The A/C had diverted to cardiff as they had suffered a engine surge due to a double intake lane failure and had to slow to subsonic early. That coupled with additional time with engines running at JFK meant they were just not comfortable about coming to London and possibly declaring a fuel emergency.
Join Date: Apr 2011
Location: NL
Age: 38
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
Hello,
Because this is such an interesting plane, I have a few questions. Maybe someone can answer, would be interesting:
When a concord(e) is in supersonic cruise, is there one main compression/ expansion wave? If so, where is it located, on the longitudinal axis?
Also:
It is quite obvious that the plane doesn't have a horizontal tail. Now I know that a plane without a tail can be statically stable (I think), but is concorde dynamically stable?
If so, how is this achieved?
Because this is such an interesting plane, I have a few questions. Maybe someone can answer, would be interesting:
When a concord(e) is in supersonic cruise, is there one main compression/ expansion wave? If so, where is it located, on the longitudinal axis?
Also:
It is quite obvious that the plane doesn't have a horizontal tail. Now I know that a plane without a tail can be statically stable (I think), but is concorde dynamically stable?
If so, how is this achieved?
Join Date: Dec 2010
Location: Europe
Age: 88
Posts: 290
Likes: 0
Received 0 Likes
on
0 Posts
Two shock waves - the main one located on the nose, then an expansion field over the wing and a final shock at the tail where the flow was recompressed. [That is ignoring all the intake shocks!] The two compression shocks are what gives rise to the characteristic Boom-boom on the ground.
The aircraft was dynamically stable (just) because it had natural pitch damping, but in practice to give good handling qualities some artificial damping was required via the autostabiliser.
The aircraft was dynamically stable (just) because it had natural pitch damping, but in practice to give good handling qualities some artificial damping was required via the autostabiliser.
Join Date: Apr 2011
Location: NL
Age: 38
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
OK.. It is a FBW aircraft, right? Did the flight control software include this artificial damping?
I would not expect that it has a ,,direct law'' type FBW where a control deflection gives a control surface deflection, right?
Thanks CliveL
I would not expect that it has a ,,direct law'' type FBW where a control deflection gives a control surface deflection, right?
Thanks CliveL
Join Date: Dec 2010
Location: Europe
Age: 88
Posts: 290
Likes: 0
Received 0 Likes
on
0 Posts
One for Christiaan I think 
Sure it had electrically signalled controls, but this is 1960s technology - it was (sshhh) an analogue system. No "control laws", just a direct relationship between stick and surface - the autostabiliser signals (also analogue) were just added to the stick commands.
The only bit of digital control on the airplane was in the hybrid intake control system.
Sure it had electrically signalled controls, but this is 1960s technology - it was (sshhh) an analogue system. No "control laws", just a direct relationship between stick and surface - the autostabiliser signals (also analogue) were just added to the stick commands.
The only bit of digital control on the airplane was in the hybrid intake control system.
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by CliveL
One for Christiaan I think
So no, I don't have all the block diagrams and circuit diagrams in my head any more... I'll have to look through what I still have in the way of documentation.
i'll try to give some quick answers.
Da-20 monkey,
Yes, Concorde had "artifcial damping", or "autostabilsation" as we called it, on all three axes (pitch, roll and yaw), even if it could be flown without it.
On the prototypes there were three separate computers (one per axis).
On the preprod and production aircraft the A/S function was 'compressed' into a single unit (I still have one).
CliveL has given the basic answer.
Don't confuse the Concorde FBW (which we referred to as "electrical signalling") with the current "Airbus" digital FBW.
One, rather than in previous-generation aircraft, the pilot no longer pushed and pulled on cables and rods to move the control surfaces. Instead, when he moved the controls, those movements were translated into electrical signals that were sent to the electro-hydraulic control surface actuators (even if in the Concorde days there still was a mechanical back-up).
Two, the entire system was "analogue". A concept difficult to explain in these days, where nearly everything is digital.....
Very briefly, you can convert 'physical' data, like control positions, or altitude, or pitch or roll rate, or Mach number, into 'analogue' electrical signals. You can then perform all kinds of 'computations' on those signals, like filtering them, or add or subtract them, or even multiply them, using electronic circuits based on 'operational amplifiers'.
In digital systems you go one step further.... you convert all those data into digital values, and use a digital computer to perform all your calculations, in accordance with the 'system software', then convert all the results back into physical data, such as control surface commands.
In analogue systems there is no "software". The entire system is defined by 'control laws ' (not the same thing at all as in the Airbus FBW aircraft) that are fixed in terms of 'transfer functions' of the various control loops.
Those in turn are determined by the values of the components in the various electronic circuits (resistors and capacitors mostly). So in those golden days.... we didn't re-write and re-program software.... we changed resistor and capacitors, and re-wired logic circuits.
I admit, you almost have to have been there to understand it....
I'm not sure whether it's worth starting an entire new thread on 'analogue computing' (maybe there's something on wikipedia, I haven't looked)....
CJ