Concorde question
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It would appear so....but I wonder if Vref+10 came about as a result of earlier experience and that was the source of the story?
I get what you mean about the height response at the cockpit vs flightpath response....but given that we're talking about landing, then it's the height of the undercarriage that matters.
FWIW, like all long-bodied aircraft, a last-minute pull has the capacity to drive the u/c into the ground harder because the pitch change happens before the flightpath change. That could well be exaggerated by 'negative elevator' effect.
A video of a landing could be quite telling if you could see the elevons - there's a very marked and increasing 'up' input to counter the pitch down from ground effect. I suspect that, in ground effect, this negative elevator effect would be swamped by all the other things that are happening.
I get what you mean about the height response at the cockpit vs flightpath response....but given that we're talking about landing, then it's the height of the undercarriage that matters.
FWIW, like all long-bodied aircraft, a last-minute pull has the capacity to drive the u/c into the ground harder because the pitch change happens before the flightpath change. That could well be exaggerated by 'negative elevator' effect.
A video of a landing could be quite telling if you could see the elevons - there's a very marked and increasing 'up' input to counter the pitch down from ground effect. I suspect that, in ground effect, this negative elevator effect would be swamped by all the other things that are happening.
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I think we are pretty much on the same page.
Since the cg is generally close to the landing gear longitudinally, to all intents and purposes the height changes are the same on most aircraft. Pitch change before flight path change is an essential part of the negative lift effect.
But I agree, there is so much happening that it is difficult to separate out individual effects.
Since the cg is generally close to the landing gear longitudinally, to all intents and purposes the height changes are the same on most aircraft. Pitch change before flight path change is an essential part of the negative lift effect.
But I agree, there is so much happening that it is difficult to separate out individual effects.
I hope that has answered CliveL and Megan's questions somewhat?
Why would the +7 approach be deemed "unstable" today. Actually, thank you to all the contributors, fascinating stuff.
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A slightly tongue-in-cheek comment, Megan.
The BA Ops Manual requires an approach to be fully stable at 1000'R. It used to be slightly more relaxed, but even then a 'reduced noise' approach was an exception to the policy.
Basically we flew at a higher speed (190kts) until 800', then reduced speed to achieve final approach speed at 300'.
This had two benefits - thrust required at 190kts was a lot less than 160kts so flew a quieter and less-thirsty approach, and the portion between 800' and 300' was quieter still.
Vref+7 gave better control and performance margins at the end of this manoeuvre - I'll try to find a reference as to why +7 came about (I recall there was a specific reason for that number, but not the detail).
The BA Ops Manual requires an approach to be fully stable at 1000'R. It used to be slightly more relaxed, but even then a 'reduced noise' approach was an exception to the policy.
Basically we flew at a higher speed (190kts) until 800', then reduced speed to achieve final approach speed at 300'.
This had two benefits - thrust required at 190kts was a lot less than 160kts so flew a quieter and less-thirsty approach, and the portion between 800' and 300' was quieter still.
Vref+7 gave better control and performance margins at the end of this manoeuvre - I'll try to find a reference as to why +7 came about (I recall there was a specific reason for that number, but not the detail).
Thread Starter
looking at the Concorde instrument panel lately brings up a couple more questions:
Why is the radar altimeter positioned where the altimeter is normally placed ?
Did the designers decide it was more important for the radalt to have a more
prominent position in the pilots scan for a particular reason ?
While on the subject of radar altimeters Concorde has a fairly unique VSI, at least
for civil aircraft, it's vertical strip presentation is a clever way of saving space in
a compact, crowded panel.
But in the era that Concorde was designed a popular option on other jet transports was a vertical strip radar altimeter.
The radalt, after all is an instrument that is only used very briefly at the final stages of the approach and landing and is
situated accordingly, easily seen but not part of the classic 'T' airspeed, attitude, altimeter, HSI, of primary instrumentation
But in Concorde it literally has the most 'prime location'
For some reason I wasn't consulted on cockpit design despite going to school
with John Cochrane's son but surely a more conventional design would have had:
Altimeter, top right , VSI bottom right in their usual place and a vertical strip radalt
taking the place of the vertical strip VSI.
Curious as to the design choices, anyone with further insight ?
Why is the radar altimeter positioned where the altimeter is normally placed ?
Did the designers decide it was more important for the radalt to have a more
prominent position in the pilots scan for a particular reason ?
While on the subject of radar altimeters Concorde has a fairly unique VSI, at least
for civil aircraft, it's vertical strip presentation is a clever way of saving space in
a compact, crowded panel.
But in the era that Concorde was designed a popular option on other jet transports was a vertical strip radar altimeter.
The radalt, after all is an instrument that is only used very briefly at the final stages of the approach and landing and is
situated accordingly, easily seen but not part of the classic 'T' airspeed, attitude, altimeter, HSI, of primary instrumentation
But in Concorde it literally has the most 'prime location'
For some reason I wasn't consulted on cockpit design despite going to school
with John Cochrane's son but surely a more conventional design would have had:
Altimeter, top right , VSI bottom right in their usual place and a vertical strip radalt
taking the place of the vertical strip VSI.
Curious as to the design choices, anyone with further insight ?
I'll always bow out to the pros did the actual design and flying - but this book quote may be one insight.
The Concorde, Christopher Orlebar, 2017, p. 55
From the point of view of the most critical phase of human piloting, the radio altimeter was far more important in the scan than the baro altimeter. Baro altitude was generally a problem for the automated part of the envelope, or the FE, while the guys up front needed only spare it a glance (most of the time) only twice a minute or so (or less often?)
As the flight deck is over 35 feet above the runway on main wheel touchdown, of key assistance in landing is the radio altimeter. Concorde has two radio altimeters, and on this occasion [early test flight] both failed, so the landing at Fairford....had to be done by eye. It was a 'firm' landing. As Brian Tubshaw put it later: 'We arrived about a half second early.'
From the point of view of the most critical phase of human piloting, the radio altimeter was far more important in the scan than the baro altimeter. Baro altitude was generally a problem for the automated part of the envelope, or the FE, while the guys up front needed only spare it a glance (most of the time) only twice a minute or so (or less often?)
Thread Starter
Thanks for that, useful information.
Another question, there is what appears to be a fixed red line marked on the airspeed indicator opposite or pointing to around 190Kias.
Anyone know what this was for ?
Another question, there is what appears to be a fixed red line marked on the airspeed indicator opposite or pointing to around 190Kias.
Anyone know what this was for ?
It's actually a window, with a red warning annunciator/flag behind it, that flags a problem with the functioning of the Vmo needle (yellow and black "speed-limit" barber pole.)
See section 4 on this web page: Heritage Concorde
On the extreme right - microscopic explanatory type (sorry!)
Since one of its triggering events is a loss of electrical power, the red flag will be showing unless the aircraft electrical system is powered up (my guess). So it shows red in most cockpit photos.
See section 4 on this web page: Heritage Concorde
On the extreme right - microscopic explanatory type (sorry!)
Since one of its triggering events is a loss of electrical power, the red flag will be showing unless the aircraft electrical system is powered up (my guess). So it shows red in most cockpit photos.
stilton
...there is what appears to be a fixed red line marked on the airspeed indicator opposite or pointing to around 190Kias...
Could you please show us which picture you are looking at, as there was no such red line on the ASI on BA aircraft and I can't think what purpose such a line might serve?
The only thing I can think of is that there was a VMO Failure Flag window, cut into the face of the ASI dial, adjacent to 190kts.
When the flag was displayed, this indicated a failure of the VMO pointer, something that was very important on Concorde.
This flag had an all red background and bore the letters VMO on it in black.
I just wonder if perhaps what you are looking at might be the edge of the VMO Pointer Failure Flag which has not fully retracted into its window, leaving just its lower red edge displayed, which could look like a red line.
...there is what appears to be a fixed red line marked on the airspeed indicator opposite or pointing to around 190Kias...
Could you please show us which picture you are looking at, as there was no such red line on the ASI on BA aircraft and I can't think what purpose such a line might serve?
The only thing I can think of is that there was a VMO Failure Flag window, cut into the face of the ASI dial, adjacent to 190kts.
When the flag was displayed, this indicated a failure of the VMO pointer, something that was very important on Concorde.
This flag had an all red background and bore the letters VMO on it in black.
I just wonder if perhaps what you are looking at might be the edge of the VMO Pointer Failure Flag which has not fully retracted into its window, leaving just its lower red edge displayed, which could look like a red line.
Thread Starter
That's certainly possible, I was looking at the picture of the Captains instrument panel taken in level cruise at FL600.
It appears as a thin red line on the face of the instrument itself opposite 190 knots
approximately.
The picture i'm referring to is on page 4 of this thread reply #66 posted by yourself !
And on further examination I think I can see what you're saying, it does look like
the lower red edge of the warning flag just visible in that window.
Thanks again BP and for the person that did the very useful indexing which made finding that picture a breeze.
It appears as a thin red line on the face of the instrument itself opposite 190 knots
approximately.
The picture i'm referring to is on page 4 of this thread reply #66 posted by yourself !
And on further examination I think I can see what you're saying, it does look like
the lower red edge of the warning flag just visible in that window.
Thanks again BP and for the person that did the very useful indexing which made finding that picture a breeze.
Last edited by stilton; 29th Apr 2017 at 06:28.
stilton
I'd forgotten I'd posted that photo, but now that I've looked at it again, it is indeed the bottom (red) edge of the VMO failure flag that you saw.
A thread you started nearly 7 years ago has now reached 100 pages, generated nearly 2,000 replies and been read roughly 900,000 times.
Who knew a question about an APU would start all that!
Kudos
I'd forgotten I'd posted that photo, but now that I've looked at it again, it is indeed the bottom (red) edge of the VMO failure flag that you saw.
A thread you started nearly 7 years ago has now reached 100 pages, generated nearly 2,000 replies and been read roughly 900,000 times.
Who knew a question about an APU would start all that!
Kudos
Thread Starter
Thanks for the clarification BP and for your many informative and fascinating
replies enlightening all of us on this incredible and unique aircraft.
I didn't think a simple question about an APU would take off into a
delightfully detailed account of Concorde's technical achievements and even
better, personal accounts of operating her 'on the line'
Thank you, I feel fortunate that I asked !
Best wishes
replies enlightening all of us on this incredible and unique aircraft.
I didn't think a simple question about an APU would take off into a
delightfully detailed account of Concorde's technical achievements and even
better, personal accounts of operating her 'on the line'
Thank you, I feel fortunate that I asked !
Best wishes
Last edited by stilton; 2nd May 2017 at 06:13.
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Departure & Arrival
Couldn't get this to post as an embedded video. May have been posted before and may even feature a PPruner or three. Beautiful...
https://youtu.be/1bjzoh3iQJc
https://youtu.be/1bjzoh3iQJc
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Only slightly envious of doing circuits in Concorde!! 
https://youtu.be/ZqCO1qBUY88
Or this little jolly....
https://youtu.be/fB-smagT0O4
https://youtu.be/ZqCO1qBUY88
Or this little jolly....
https://youtu.be/fB-smagT0O4
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Thanks for the clarification BP and for your many informative and fascinating
replies enlightening all of us on this incredible and unique aircraft.
I didn't think a simple question about an APU would take off into a
delightfully detailed account of Concorde's technical achievements and even
better, personal accounts of operating her 'on the line'
Thank you, I feel fortunate that I asked !
Best wishes
replies enlightening all of us on this incredible and unique aircraft.
I didn't think a simple question about an APU would take off into a
delightfully detailed account of Concorde's technical achievements and even
better, personal accounts of operating her 'on the line'
Thank you, I feel fortunate that I asked !
Best wishes
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It's not exactly elegant, but if you have Firefox you can select 'reader view' on the right hand side of the url box. This will basically give you a printable version of just text. You could then print and scan.
It's not ideal, but may be of help.
It's not ideal, but may be of help.
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PPruNe has an archive where more posts are displayed per page.
So below you can get the whole thread in just 8 pages.
Concorde question [Archive] - PPRuNe Forums
Why do you want a pdf, for your ebook reader? Guess it doesn't work with just saved html.
In Google Chrome you can save pages as PDF via the printing dialog.
Font is a bit small though.
There are also some webservices that can convert a web page to pdf. Have never used them though.
This may be overtaken by later postings, but a couple of reasons why n5692s's explanation might not work:-
I read this in The Concord Stick and Rudder Book, though my summary of the explanation may not do the author justice.
Good Evening Stilton, M-2 Dude and others.
I am having a nostalgia evening as 20 years ago today I had a flight in G-BOAC from CYYZ to “no-where”.
Actually, it was down to New York out over the ocean for around 30 minutes at FL 550 and Mach 2. For one in the “industry” it was a real treat to be able to have a flight in such an iconic aircraft.
Things I will always remember going out of “reheat” (a more elegant description then afterburner) after noise abatement from being pushed back into one’s seat to being momentarily weightless, the brilliance of the sky at FL 550, the cabin windows being hot at Mach 2 and seeing the gap between the flight engineers panel and the bulk head at Mach 2 due to the aircraft heating. I could go on about the engineering, observing the crew coordination from the cockpit visit (sadly pre-9/11) and there is a certain story about how our group sweet talked our way into the first-class lounge in YYZ and drained all the bubbly British Airways had in the fridge that day but…….
Reading the thread on this aircraft has been fascinating and thank you to all that has contributed to this wonderful story a sincere thank you.
I am having a nostalgia evening as 20 years ago today I had a flight in G-BOAC from CYYZ to “no-where”.
Actually, it was down to New York out over the ocean for around 30 minutes at FL 550 and Mach 2. For one in the “industry” it was a real treat to be able to have a flight in such an iconic aircraft.
Things I will always remember going out of “reheat” (a more elegant description then afterburner) after noise abatement from being pushed back into one’s seat to being momentarily weightless, the brilliance of the sky at FL 550, the cabin windows being hot at Mach 2 and seeing the gap between the flight engineers panel and the bulk head at Mach 2 due to the aircraft heating. I could go on about the engineering, observing the crew coordination from the cockpit visit (sadly pre-9/11) and there is a certain story about how our group sweet talked our way into the first-class lounge in YYZ and drained all the bubbly British Airways had in the fridge that day but…….
Reading the thread on this aircraft has been fascinating and thank you to all that has contributed to this wonderful story a sincere thank you.