Moderators: richierich, ua900, PanAm_DC10, hOMSaR
Reheat is used on every take-off, its light-up sequence taking place on the roll as the engines accelerates up to full power – it needs the mass flow associated with an N1 of 81% or more to function. It is switched off at 500ft on a standard flight or at noise abatement cut-back where needed. For the transonic acceleration it is switched on at climb power at M0.95, then off again at M1.7 – a run of between 10 and 15 minutes dependent upon aircraft weight and outside air temperature
kalvado wrote:Reheat is used on every take-off, its light-up sequence taking place on the roll as the engines accelerates up to full power – it needs the mass flow associated with an N1 of 81% or more to function. It is switched off at 500ft on a standard flight or at noise abatement cut-back where needed. For the transonic acceleration it is switched on at climb power at M0.95, then off again at M1.7 – a run of between 10 and 15 minutes dependent upon aircraft weight and outside air temperature
https://www.heritageconcorde.com/concor ... e-re-heats
Since reheat runs at the very end of engine flow, I assume not many - if any - parts were exposed to temperature. Nozzle may be protected by colder flow areas.
tu144d wrote:kalvado wrote:Reheat is used on every take-off, its light-up sequence taking place on the roll as the engines accelerates up to full power – it needs the mass flow associated with an N1 of 81% or more to function. It is switched off at 500ft on a standard flight or at noise abatement cut-back where needed. For the transonic acceleration it is switched on at climb power at M0.95, then off again at M1.7 – a run of between 10 and 15 minutes dependent upon aircraft weight and outside air temperature
https://www.heritageconcorde.com/concor ... e-re-heats
Since reheat runs at the very end of engine flow, I assume not many - if any - parts were exposed to temperature. Nozzle may be protected by colder flow areas.
Interesting stuff. It always impressed me how Concorde engineers effectively used fuel as a heat sink to cool the fuselage and yet the Russians with the TU-144 couldn't get if figured out and used gigantic air conditioners that made so much nose normal conversation was impossible aboard it.
Yikes! wrote:tu144d wrote:kalvado wrote:https://www.heritageconcorde.com/concor ... e-re-heats
Since reheat runs at the very end of engine flow, I assume not many - if any - parts were exposed to temperature. Nozzle may be protected by colder flow areas.
Interesting stuff. It always impressed me how Concorde engineers effectively used fuel as a heat sink to cool the fuselage and yet the Russians with the TU-144 couldn't get if figured out and used gigantic air conditioners that made so much nose normal conversation was impossible aboard it.
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
Max Q wrote:I believe the maximum time in reheat was 15 minutes
kalvado wrote:Is that limited by fuel tank capacity?
Legs wrote:kalvado wrote:Is that limited by fuel tank capacity?
Certainly in military circles, afterburner limitations are mostly driven by heat management; nozzles, exhaust ducts, surrounding structure etc. I suspect that Concorde would be no different.
Yikes! wrote:tu144d wrote:kalvado wrote:https://www.heritageconcorde.com/concor ... e-re-heats
Since reheat runs at the very end of engine flow, I assume not many - if any - parts were exposed to temperature. Nozzle may be protected by colder flow areas.
Interesting stuff. It always impressed me how Concorde engineers effectively used fuel as a heat sink to cool the fuselage and yet the Russians with the TU-144 couldn't get if figured out and used gigantic air conditioners that made so much nose normal conversation was impossible aboard it.
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
GDB wrote:Yikes! wrote:tu144d wrote:
Interesting stuff. It always impressed me how Concorde engineers effectively used fuel as a heat sink to cool the fuselage and yet the Russians with the TU-144 couldn't get if figured out and used gigantic air conditioners that made so much nose normal conversation was impossible aboard it.
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
tu144d wrote:GDB wrote:Yikes! wrote:
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
Apparently the latter version of Tu-144D (D model) used a non-afterburning translating plug variable nozzle engine (Kolesov RD-36-51A). I posted a thread about this trying to more info but got no replies. It never flew pax and and there was a fuel line issue which caused a crash that promptly resulting in Aeroflot terminating the commercial flights even though those aircraft used different afterburning NK-144 turbojets. Either way they flew transcontinental test flights from Moscow to Khabarovsk in the fear east successfully a few times. I think that would make the TU-144D the first SST or any supersonic aircraft for that matter, to use a non-afterburning turbojet the first aircraft to supercruise. Can't verify this though. Shame, if it weren't for the oil-crisis and Aeroflot's lack of enthusiasm the Soviets might have been able to work out the kinks with a few more years.
kalvado wrote:Max Q wrote:I believe the maximum time in reheat was 15 minutes
Is that limited by fuel tank capacity?
Max Q wrote:kalvado wrote:Max Q wrote:I believe the maximum time in reheat was 15 minutes
Is that limited by fuel tank capacity?
Probably and perhaps an engine limitation, IIRC that was enough time to allow the acceleration from .95 at mid altitudes to 1.7 Mach around FL 450 after a steady accelerating cruise climb continuing at lower rate in dry power reaching M2 at FL500 then cruise climbing as fuel was burned off up to a maximum of FL600
I remember this 15 minute restriction from John Hutchinson’s excellent podcast on flying Concorde
He is a retired BA Captain who flew that aircraft for 15 years during a long career at that airline
It’s fascinating and educational, worth looking up
kalvado wrote:tu144d wrote:GDB wrote:
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
Apparently the latter version of Tu-144D (D model) used a non-afterburning translating plug variable nozzle engine (Kolesov RD-36-51A). I posted a thread about this trying to more info but got no replies. It never flew pax and and there was a fuel line issue which caused a crash that promptly resulting in Aeroflot terminating the commercial flights even though those aircraft used different afterburning NK-144 turbojets. Either way they flew transcontinental test flights from Moscow to Khabarovsk in the fear east successfully a few times. I think that would make the TU-144D the first SST or any supersonic aircraft for that matter, to use a non-afterburning turbojet the first aircraft to supercruise. Can't verify this though. Shame, if it weren't for the oil-crisis and Aeroflot's lack of enthusiasm the Soviets might have been able to work out the kinks with a few more years.
I suspect going through M=1.0 would still require an afterburner. I don't think any plane today can accelerate supersonic on turbojet/turbofan with no afterburn.
Supersonic cruise without an afterburner is the general goal.
On a separate note - is it delta wing that requires a lot of takeoff thrust that an afterburner was required on a runway for both SSTs?
GDB wrote:Yikes! wrote:tu144d wrote:
Interesting stuff. It always impressed me how Concorde engineers effectively used fuel as a heat sink to cool the fuselage and yet the Russians with the TU-144 couldn't get if figured out and used gigantic air conditioners that made so much nose normal conversation was impossible aboard it.
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
kalvado wrote:I suspect going through M=1.0 would still require an afterburner. I don't think any plane today can accelerate supersonic on turbojet/turbofan with no afterburn.
Supersonic cruise without an afterburner is the general goal.
mxaxai wrote:kalvado wrote:I suspect going through M=1.0 would still require an afterburner. I don't think any plane today can accelerate supersonic on turbojet/turbofan with no afterburn.
Supersonic cruise without an afterburner is the general goal.
Most modern fighter jets can accelerate to supersonic speeds without afterburner in a clean configuration. Some may need to dive and exchange altitude for speed during the transition. In general, you'd want to spend as little time as possible at transonic speeds for efficiency reasons, so either a shallow dive and/or afterburners are used to get to the more efficient supersonic (supercruise) regime.
mxaxai wrote:kalvado wrote:I suspect going through M=1.0 would still require an afterburner. I don't think any plane today can accelerate supersonic on turbojet/turbofan with no afterburn.
Supersonic cruise without an afterburner is the general goal.
Most modern fighter jets can accelerate to supersonic speeds without afterburner in a clean configuration. Some may need to dive and exchange altitude for speed during the transition. In general, you'd want to spend as little time as possible at transonic speeds for efficiency reasons, so either a shallow dive and/or afterburners are used to get to the more efficient supersonic (supercruise) regime.
Yikes! wrote:GDB wrote:Yikes! wrote:
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
Thanks for that. My recollection is from the notes I took in 1996 LHR-JFK. I was in 9A. I do recall hearing the fuel transfer pumps so perhaps my inflight hearing wasn't as bad as I recollect! I did get a visit to the flight deck as it seemed it was every passenger's rights back in the day. But the Skipper told me I was the only one that ASKED to visit the flight deck in flight - I was up there for nearly 10 minutes! Glad to hear you had multiple trips - I'm jealous. Just sayin'...!
GDB wrote:Yikes! wrote:GDB wrote:
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
Thanks for that. My recollection is from the notes I took in 1996 LHR-JFK. I was in 9A. I do recall hearing the fuel transfer pumps so perhaps my inflight hearing wasn't as bad as I recollect! I did get a visit to the flight deck as it seemed it was every passenger's rights back in the day. But the Skipper told me I was the only one that ASKED to visit the flight deck in flight - I was up there for nearly 10 minutes! Glad to hear you had multiple trips - I'm jealous. Just sayin'...!
It was a great part of many peoples experience that cockpit visit, especially during all those charters, though crew told me that getting most of the 100 pax a look on what was usually a shorter flight was a challenge.
After those deluded, mad, human hating specimens did Sept 11, that ended of course, I mentioned above a simulated full pax flight LHR-LHR, it was part of the return to service after the AF accident, as planned the flight turned at 30W and we landed back at LHR, as it turned out into a different world from what we took off from just 3.5 hours. Since the date was September 11th 2001.
I had been at BA 14 years when I joined BA Concorde Engineering in 1997, in November 1993, I got my first Concorde flight via staff concessions, IAD-LHR.
As were the other pax flights, save the last, longest, highest (60,000ft) on the longer leg to BGI.
Feeling the reheats come on at Mach 0.95, I cannot say I felt them come in despite knowing, due to the cabin bulkhead displays, when they were, with two exceptions, despite being in the forward cabin on that fateful 2001 flight, though being engaged two at a time also lessened feeling, as well as my last, that last one for G-BOAE to BGI in November 1993, then I was in the rearmost row.
I sad four pax flights, one actually had very few pax and was also LHR-LHR, since it was a post engineering test flight.
So I was lucky, in a right place/right time way.
GalaxyFlyer wrote:That’s how the SR did it—the dipsy-doodle off the tanker.
GDB wrote:Yikes! wrote:tu144d wrote:
Interesting stuff. It always impressed me how Concorde engineers effectively used fuel as a heat sink to cool the fuselage and yet the Russians with the TU-144 couldn't get if figured out and used gigantic air conditioners that made so much nose normal conversation was impossible aboard it.
Last thing first: normal noise on BA/AF Concorde during flight was so loud as to prohibit normal conversation - one had to raise their voice to be heard. I used ear plugs on my flight.
Re-heat (afterburner) was used only during takeoff, cancelled after entry into third segment climb, and then again, from the acceleration from M.090 to ~M1.7 then shutdown once a stable Mach climb was established. Acceleration to M2.0 and climb to apogee was strictly on engine thrust, no re-heat (afterburner).
Hoping that adds to your understanding.
I never had any trouble, not having to raise my voice on my 7 flights, 5 of which were standard pax, one was a full pax LHR-JFK simulation (LHR-LHR but same speed, altitude, duration), one was a pretty full retirement flight for G-BOAE to BGI, if you are going by You Tube videos note the cameras (pre smartphone too), accentuated cabin noise. As on conventional airliners.
Maybe a decent quality one of a professional film crew.
The TU-144 apparently was so loud pax had to pass written messages, however very few 'pax' flights flown, foreign journalists picked that up.
Had the noise been as loud as you claim, at least for most people, I accept some for various reasons might find it louder, then again some are more sensitive to aircraft motions too, well, BA would have struggled to keep all those regular pax for all those years.
Saying that, do you have, not intruding here I hope, sensitive hearing?
It was louder (as are all aircraft) on take off, down the back it was known as 'rocket class', again that just illustrates what one of the type's Chief Pilots said, 'it's just another aircraft only more so'.
accentra wrote:From experience, have to concur. If you were sat away from the rear then the noise levels in Concorde were pretty much the same as any other contemporary jet aircraft. Think that was one of the design goals? And even then it was really only on TO. It was all about supersonic being no different than the norm. There's a famous quote re one of the test flights/demos about something like (and I'm paraphrasing): 'it's not extraordinary' and 'yes, that was the hard part!'.