5th Sep 2010, 11:56
permalink Post: 217
In-Flight Reverse (A case of Bucket and See)
Capt Chambo
Concorde was, as EXWOK says, could use reverse in flight, on the inboard engines only, and only as far as reverse idle, the mechanism of which was quite complex and did on occasion not do work as advertised. Bear in mind here that the Rolls Royce Olympus 593 was a pure turbojet with no bypass, and so a hot stream reverser only had to be used; the reverser buckets acting directly on the efflux as it did any reverser in the 'old' days. Also the same buckets that were used for reverse were also progressively opened up between Mach 0.55 and wide open at Mach 1.1, this giving a vital control enhancement to the divergencing efflux. The overall effect of this was to give a true overall convergent/divergent nozzle assembly, the ideal for any supersonic aircraft.
As far as inflight reverse goes, the amount of HP compressor delivery air (P3) required to actuate the bucket airmotor in flight at an idle thrust settings, was quite minimal to say the least, and some help was definitely needed here. The moment that inflight reverse was selected (on the inboard engines only remember) the OUTBOARD engines would have their idle N2 automatically increased, and some of THEIR P3 air supply was also automatically ported over (via an isolation valve) to the inboard buckets. This whole process was required in order to give a little added muscle to the bucket airmotors, and give the system a fighting chance. Even this however was still not quite enough, the inboard travelling buckets required minimal air loading on their surface, and so the primary nozzles for the affected engines (the primary nozzle lived just aft of the LP turbine, aft of the reheat assembly) was automatically signalled wide open in order to assist matters here, by reducing gas velocity. One the buckets had reached full reverse the primary nozzle was then signalled full close (this applied for normal ground reverse also) and the automatic increased idle on the outboard engines was cancelled. To enable the described process to occur, provided all four engines were at idle, a solenoid latched button on the F/E's station could be selected. This signalled a circuit that enabled the selection of idle reverse on the inboard engines only, the opening of the P3 isolation valve, the raising of the outboard engine's idle and maximum primary nozzle angle for the outboards as soon as reverse was then selected..
The whole system was just a little fragile here; failure of either the extra air supply, or the raised idle on the 'other' engine was usually enough to stop the process working correctly.
EXWOK
While flying 'up front' I only ever experienced the use of inflight reverse once. (The captain was a bit of an Animal, if you flying guys see what I mean
). I would not say that it felt as if we'd hit a brick wall, as I'd expected the sensation to feel, more like we were flying into the dumped contents of a very large manure truck
. The whole operation was so slick, we'd dumped the required amount of IAS more or less within a second or two, and normal thrust was immediately selected. As so often happened with you guys, you made it look too easy.
As far as the speed of the airmotor goes, I seem to remember that it was something in the order of 80,000 RPM at max chat; as you say faster (around twice as fast) as the standby horizon motor.
The basic core airmotor (not the whole assembly) was the same Garrett unit used on the P&W JT9 as well as the RB-211.
Dude
Concorde was, as EXWOK says, could use reverse in flight, on the inboard engines only, and only as far as reverse idle, the mechanism of which was quite complex and did on occasion not do work as advertised. Bear in mind here that the Rolls Royce Olympus 593 was a pure turbojet with no bypass, and so a hot stream reverser only had to be used; the reverser buckets acting directly on the efflux as it did any reverser in the 'old' days. Also the same buckets that were used for reverse were also progressively opened up between Mach 0.55 and wide open at Mach 1.1, this giving a vital control enhancement to the divergencing efflux. The overall effect of this was to give a true overall convergent/divergent nozzle assembly, the ideal for any supersonic aircraft.
As far as inflight reverse goes, the amount of HP compressor delivery air (P3) required to actuate the bucket airmotor in flight at an idle thrust settings, was quite minimal to say the least, and some help was definitely needed here. The moment that inflight reverse was selected (on the inboard engines only remember) the OUTBOARD engines would have their idle N2 automatically increased, and some of THEIR P3 air supply was also automatically ported over (via an isolation valve) to the inboard buckets. This whole process was required in order to give a little added muscle to the bucket airmotors, and give the system a fighting chance. Even this however was still not quite enough, the inboard travelling buckets required minimal air loading on their surface, and so the primary nozzles for the affected engines (the primary nozzle lived just aft of the LP turbine, aft of the reheat assembly) was automatically signalled wide open in order to assist matters here, by reducing gas velocity. One the buckets had reached full reverse the primary nozzle was then signalled full close (this applied for normal ground reverse also) and the automatic increased idle on the outboard engines was cancelled. To enable the described process to occur, provided all four engines were at idle, a solenoid latched button on the F/E's station could be selected. This signalled a circuit that enabled the selection of idle reverse on the inboard engines only, the opening of the P3 isolation valve, the raising of the outboard engine's idle and maximum primary nozzle angle for the outboards as soon as reverse was then selected..
The whole system was just a little fragile here; failure of either the extra air supply, or the raised idle on the 'other' engine was usually enough to stop the process working correctly.
EXWOK
While flying 'up front' I only ever experienced the use of inflight reverse once. (The captain was a bit of an Animal, if you flying guys see what I mean
). I would not say that it felt as if we'd hit a brick wall, as I'd expected the sensation to feel, more like we were flying into the dumped contents of a very large manure truck
. The whole operation was so slick, we'd dumped the required amount of IAS more or less within a second or two, and normal thrust was immediately selected. As so often happened with you guys, you made it look too easy.
As far as the speed of the airmotor goes, I seem to remember that it was something in the order of 80,000 RPM at max chat; as you say faster (around twice as fast) as the standby horizon motor.
The basic core airmotor (not the whole assembly) was the same Garrett unit used on the P&W JT9 as well as the RB-211.
Dude
Last edited by M2dude; 5th Sep 2010 at 13:25 .
8th Oct 2010, 17:07
permalink Post: 536
Quote:
|
Originally Posted by
M2dude
Further development plans for the Olypus 593 included a large increase in dry thrust; the reheat being retained only for transonic acceleration. It is such a pity that it was not to be.
|
Reheat on the existing aircraft supplied about 25% extra "wet" thrust.
The Olympus 593 "B" engine was going to have about 25% more "dry" thrust, so the reheat could most likely have been deleted altogether.
This was achieved mostly by increasing the diameter of the LP compressor, hence increasing the mass flow, and adding a second LP turbine stage.
The "B" engine was destined for the "B" Concorde which, thanks to several aerodynamic improvements, would have had increased performance and more range, allowing direct flights from Frankfurt and Rome to New York.
Concorde #17 would have been the "prototype" for the "B" model... sadly, as M2dude says, it was not to be.
CJ
18th Nov 2010, 00:32
permalink Post: 719
Mr Vortex
First of all, 'welcome aboard'; I'll do my best to answer your queries.
The area of the primary nozzle Aj, was varied for 2 'primary' purposes
:
a) To act as a military type 'reheat' or 'afterburning' nozzle; opening up to control the rise in jet pipe pressure P7, as reheat is in operated.
b) To match the INLET TOTAL TEMPERATURE RELATED (T1) speed of the LP compressor N1 to the HP compressor N2 against a series of schedules, ensuring easch spool is as close as safely possible to its respective surge boundary, (with a constant TET, see below) and therefore at peak efficiency.
Now, in doing this a complex set of variables were in place. As the nozzle is opened there is a REDUCED pressure and temperature drop across the LP turbine. This has the effect of enabling a HIGHER N1,as less work is being done by the turbine. Also the change (in this case a decrease) in the temperature drop across the turbine will obviously affect the turbine entry temperature, TET. A closing down of the nozzle would obviously have the opposite effect, with a DECREASE in N1 and an INCREASE in TET.
In practice at a given T1 there was always an ideal N1 versus N2 on the control schedule (known as the E Schedule), the TET staying more or less constant from TAKE-OFF to SUPERSONIC CRUISE!!
As far as noise abatement went; when reheat was cancelled and power reduced after take-off, an E Schedule known as E Flyover was automatically invoked. This had the effect of driving the primary nozzle nearly wide open, reducing both the velocity of the jet efflux and in essence the noise below the aircraft.
The real beauty of this primary nozzle system was that it really did not care if the engine was operating dry or with afterburning ('it' did not even know). P7 was controlled against a varying compressor outlet pressure, the variable being controlled by a needle valve operated by the electronic engine controller. (If this is unclear I can post a diagram here that shows this control in action).
As soon as I receive back the majority of my technical notes that I have out on long-term loan (I've requested their return) I will post a schematic here. But for now; The tanks were vented to atmosphere via tandem vent galleries, the two vents openings being on the left hand side of the tail-cone. At an absolute static pressure of 2.2 PSIA (around 44,000') twin electrically operated vent valves, also in the tail-cone, would automatically close; the tanks now being pressurised via a small NACA duct on the right side of the fin. A tank pressure of around 1.5 PSIG was maintained by the action of a small pneumatic valve at the rear of the aircraft. There was massive protection built in to guard against over-pressure (eg. if a tank over-filled in cruise).
I hope this answers some of your queries
Best Regards
Dude
Quote:
|
1. I've heard that Concorde use the primary nozzle to modulate the noise and the speed of the N1 compressor. How does it work? and does it help to reduce the noise a lot?
2.Another thing about Primary nozzle. If i recall it correctly, the primary nozzle can also use to control the Inlet Turbine temperature. Is that true? How is that work |
The area of the primary nozzle Aj, was varied for 2 'primary' purposes
:
a) To act as a military type 'reheat' or 'afterburning' nozzle; opening up to control the rise in jet pipe pressure P7, as reheat is in operated.
b) To match the INLET TOTAL TEMPERATURE RELATED (T1) speed of the LP compressor N1 to the HP compressor N2 against a series of schedules, ensuring easch spool is as close as safely possible to its respective surge boundary, (with a constant TET, see below) and therefore at peak efficiency.
Now, in doing this a complex set of variables were in place. As the nozzle is opened there is a REDUCED pressure and temperature drop across the LP turbine. This has the effect of enabling a HIGHER N1,as less work is being done by the turbine. Also the change (in this case a decrease) in the temperature drop across the turbine will obviously affect the turbine entry temperature, TET. A closing down of the nozzle would obviously have the opposite effect, with a DECREASE in N1 and an INCREASE in TET.
In practice at a given T1 there was always an ideal N1 versus N2 on the control schedule (known as the E Schedule), the TET staying more or less constant from TAKE-OFF to SUPERSONIC CRUISE!!
As far as noise abatement went; when reheat was cancelled and power reduced after take-off, an E Schedule known as E Flyover was automatically invoked. This had the effect of driving the primary nozzle nearly wide open, reducing both the velocity of the jet efflux and in essence the noise below the aircraft.
The real beauty of this primary nozzle system was that it really did not care if the engine was operating dry or with afterburning ('it' did not even know). P7 was controlled against a varying compressor outlet pressure, the variable being controlled by a needle valve operated by the electronic engine controller. (If this is unclear I can post a diagram here that shows this control in action).
Quote:
3.Finally, does some one have a schematic or the fuel vent system?
|
I hope this answers some of your queries
Best Regards
Dude
18th Nov 2010, 03:13
permalink Post: 721
Hi M2 Dude
Thanks very very much for your long reply and good explanation.
- So once we select the Engine schedule to mode Hi or F/O the Prim nozzle will
open wider causing the pressure at the Prim nozzle to drop and hence the
higher flow of the exhaust through the LP turbine = Higher N1 RPM.
Am I understand it correctly?
- According to your reply, the E schedule that will provide the most thrust is
the Low mode since the prim nozzle area will be the smallest among all of the
other mode which mean the highest pressure and temperature.
Am I understand it correctly? And if so why do BA [as far as I know] told the FE
to use Hi mode? Because the higher thrust can be obtain with higher N1?
- Also does the the Hi mode can deliver the higher N1 RPM, does that mean
the Engine control unit must deliver the higher fuelflow rate in order to keep
N2 run at the constant speed [higher N1 speed => higher pressure => more resistance
=> higher Fuelflow require to keep N2 run at constant speed]
Thanks for all of your reply!
Best Regards
Vortex
Thanks very very much for your long reply and good explanation.
- So once we select the Engine schedule to mode Hi or F/O the Prim nozzle will
open wider causing the pressure at the Prim nozzle to drop and hence the
higher flow of the exhaust through the LP turbine = Higher N1 RPM.
Am I understand it correctly?
- According to your reply, the E schedule that will provide the most thrust is
the Low mode since the prim nozzle area will be the smallest among all of the
other mode which mean the highest pressure and temperature.
Am I understand it correctly? And if so why do BA [as far as I know] told the FE
to use Hi mode? Because the higher thrust can be obtain with higher N1?
- Also does the the Hi mode can deliver the higher N1 RPM, does that mean
the Engine control unit must deliver the higher fuelflow rate in order to keep
N2 run at the constant speed [higher N1 speed => higher pressure => more resistance
=> higher Fuelflow require to keep N2 run at constant speed]
Thanks for all of your reply!
Best Regards
Vortex
18th Nov 2010, 12:25
permalink Post: 724
Mr Vortex
More or less you are correct yes, but remember that schedule selection was more or less automatic. (
E Flyover
was armed prior to take-off, and
E-MID
during approach by the E/O, otherwise it was more or less a 'hands off' afair).
Oooo no, we are way adrift here I'm afraid. I'm trying not to get too 'heavy' with this explanation, and I've enclosed below the Rolls-Royce E Shedule diagram to try and help clarify everything. (I've edited out the exact equation figures in deference to Rolls-Royce). Where N1/√θ and N2/√θ is quoted, the term '
θ
' related to
T1 in degrees K/288
. (288 deg's K being 15 deg's C). The hotter things are the higher the spool speed scheduled is, and visa-versa for lower temperatures. Only at a T1 of 15 deg's. C (Standard day temperature) does N/√θ equate to N. (But remamber that T1 is TOTAL temperature, that varies with Mach Number).
The use of E LOW above 220KIAS was not only strictly inhibited by the automatics, if you over-rode the automatics and 'hard selected' E LOW , the aircraft would fall out of the sky when reheat was cancelled at Mach 1.7. This was because the low N1/√θ scheduled by E LOW would now invoke an N2/√θ limit (The E3 Limiter in the diagram) and claw off fuel flow by the tonne.
The most efficient schedule for supersonic cruise was E HI which again would be automatically selected.
E-MID was automatically selected during afterburning operation, to minimise the chance of an N1 overspeed on cancellation of reheat. E-MID could also be selected by the E/O for noise abatement approach.
E Flyover was as we discussed before used for take-off flyover noise abatement as well as subsonic cruise if desired. (If Mach 1 was exceeded with E Flyover still selected, a yellow NOZZLE light illuminated and E HI would be automatically selected.
I sincerely hope that this blurb is not clear as mud, feel free to ask away.
Nope, that is the beauty of it all. Because of the part choking of the LP turbine section of the engine, the pressure changes due to Aj variation were felt exclusively by N1 and not N2. (Clever, these Rolls-Royce guys
).
Regards
Dude
Quote:
| - So once we select the Engine schedule to mode Hi or F/O the Prim nozzle will open wider causing the pressure at the Prim nozzle to drop and hence the higher flow of the exhaust through the LP turbine = Higher N1 RPM. Am I understand it correctly? |
Quote:
| According to your reply, the E schedule that will provide the most thrust is the Low mode since the prim nozzle area will be the smallest among all of the other mode which mean the highest pressure and temperature. Am I understand it correctly? And if so why do BA [as far as I know] told the FE to use Hi mode? Because the higher thrust can be obtain with higher N1? |
The use of E LOW above 220KIAS was not only strictly inhibited by the automatics, if you over-rode the automatics and 'hard selected' E LOW , the aircraft would fall out of the sky when reheat was cancelled at Mach 1.7. This was because the low N1/√θ scheduled by E LOW would now invoke an N2/√θ limit (The E3 Limiter in the diagram) and claw off fuel flow by the tonne.
The most efficient schedule for supersonic cruise was E HI which again would be automatically selected.
E-MID was automatically selected during afterburning operation, to minimise the chance of an N1 overspeed on cancellation of reheat. E-MID could also be selected by the E/O for noise abatement approach.
E Flyover was as we discussed before used for take-off flyover noise abatement as well as subsonic cruise if desired. (If Mach 1 was exceeded with E Flyover still selected, a yellow NOZZLE light illuminated and E HI would be automatically selected.
I sincerely hope that this blurb is not clear as mud, feel free to ask away.
Quote:
|
- Also does the the Hi mode can deliver the higher N1 RPM, does that mean the Engine control unit must deliver the higher fuelflow rate in order to keep N2 run at the constant speed [higher N1 speed => higher pressure => more resistance
=> higher Fuelflow require to keep N2 run at constant speed] |
).
Regards
Dude
Last edited by M2dude; 18th Nov 2010 at 15:04 . Reason: I goofed.. (another sign of age)
1st Dec 2010, 14:04
permalink Post: 822
Well I have to say this is a brilliant thread.
I stumbled upon it by accident and been catching up on it when I had a spare moment and have found it completely riveting and it has whiled away many hours over the past month.
I\x92m ex-RAF and spent the last ten years working as an engine bloke on the T aeroplane & RB199. We were always told there were many parallels with Concorde & the Olympus 593 \x96 TBT/T7 Gauges, Optical Pyrometers, EPC Coils on-engine FCU\x92s, Vapour Core Pump for reheat fuel as well and the like. I attended the RR Manufactures course for two weeks at the Patchway Works and spent a day at the Concorde Museum seeing the similarities with the Electronic Control Units too though Lucas Aerospace made the MECU\x92s or GR1/4 (& DECU\x92s on the F3\x92s).
Also while on the course the distinguished RR Instructor Gent filled up in with various snippets of Engine History too such as the Vaporisers which were fitted to RB199 & the later models of Olympus 593 were originally Armstrong Sidderly designed for the Sapphire, also I learned the whole 15 Stage Sapphire Compressor was lifted completely and fitted to later Avon\x92s as it worked better.
I was at Leuchars in the early 80\x92s and the Open Golf peeps all arrived in one of these magnificent lady\x92s \x96 the visit was notable for several things; someone fired off an escape chute!!! \x96 What does this little handle do on the Main Oleo ??? whoosh ! and after the dusk take off the pilot beat the place up several times in full reheat !!!!
My last place of work before I was de-mobbed was at the RAF Marham Engine bay and I had the good fortune to meet an RR Technician called Phil (second name escapes me) but he was part of the team of RR Controls Engineers during the Hot & High Trials. He said they used to modify the three \x93Amps\x94 for each Engine control \x96 Lane1, Lane 2 & Reheat on the fly and the aircraft often flew with different schedules installed on all four engines \x96 I think the aircraft at Duxford has these still fitted in the racks (??M2Dude??) but that\x92s another Tonka thing too; three control lanes. Were all these Amps combined into one black box??
They are always Amps in RR Speak?? The Spey 202 had \x93Amps\x94 in its reheat system too.
I was lucky to find a job with the TVOC in 2001 until they ran out of money (as they do) and worked to have their flight worthy Olympus 20202\x92s tested at RR Ansty but left before that happened. In fact I don\x92t know if it did happen though it was a CAA requirement. While I was there we were working with Alan Rolfe & Mike Batchelor of the RR Historic Engine Department were offering support too. (593\x92s were their responsibility also !!! Historic !!!) but I think that was unofficial until there was an agreement about the costs.
After that I worked in industrial applications of Olympus (and Avon) and worked on many installed Olympus in power generation but based on the 200 Series \x96 I think the 300 was thought to be too fragile. But I did have a good look at Olympus 2008/003 Still in good working order in Jersey on the Channel Islands with it\x92s Bristol Sidderly Name plate on it. They didn't have Inlet Guide Vanes as the 300's had but just 6 Forward Bearing Supports, hollow with anti -Icing air blown though, controlled by a Garret Air Valve.
I never saw a DEBOW sort of function on the Industrials but there is a critical N1 speed which has to be avoided because the LP Turbine Disc can fail. The Trouble with that speed range is that it is right where the usefull power is produced!!! Was there any Normal Operating Range RPM's which had to be avoided on the 593 ?
Again thanks very much for all the fascinating information here\x92s to another 42 pages!!
Sorry to have rambled on so much
Howie
I stumbled upon it by accident and been catching up on it when I had a spare moment and have found it completely riveting and it has whiled away many hours over the past month.
I\x92m ex-RAF and spent the last ten years working as an engine bloke on the T aeroplane & RB199. We were always told there were many parallels with Concorde & the Olympus 593 \x96 TBT/T7 Gauges, Optical Pyrometers, EPC Coils on-engine FCU\x92s, Vapour Core Pump for reheat fuel as well and the like. I attended the RR Manufactures course for two weeks at the Patchway Works and spent a day at the Concorde Museum seeing the similarities with the Electronic Control Units too though Lucas Aerospace made the MECU\x92s or GR1/4 (& DECU\x92s on the F3\x92s).
Also while on the course the distinguished RR Instructor Gent filled up in with various snippets of Engine History too such as the Vaporisers which were fitted to RB199 & the later models of Olympus 593 were originally Armstrong Sidderly designed for the Sapphire, also I learned the whole 15 Stage Sapphire Compressor was lifted completely and fitted to later Avon\x92s as it worked better.
I was at Leuchars in the early 80\x92s and the Open Golf peeps all arrived in one of these magnificent lady\x92s \x96 the visit was notable for several things; someone fired off an escape chute!!! \x96 What does this little handle do on the Main Oleo ??? whoosh ! and after the dusk take off the pilot beat the place up several times in full reheat !!!!
My last place of work before I was de-mobbed was at the RAF Marham Engine bay and I had the good fortune to meet an RR Technician called Phil (second name escapes me) but he was part of the team of RR Controls Engineers during the Hot & High Trials. He said they used to modify the three \x93Amps\x94 for each Engine control \x96 Lane1, Lane 2 & Reheat on the fly and the aircraft often flew with different schedules installed on all four engines \x96 I think the aircraft at Duxford has these still fitted in the racks (??M2Dude??) but that\x92s another Tonka thing too; three control lanes. Were all these Amps combined into one black box??
They are always Amps in RR Speak?? The Spey 202 had \x93Amps\x94 in its reheat system too.
I was lucky to find a job with the TVOC in 2001 until they ran out of money (as they do) and worked to have their flight worthy Olympus 20202\x92s tested at RR Ansty but left before that happened. In fact I don\x92t know if it did happen though it was a CAA requirement. While I was there we were working with Alan Rolfe & Mike Batchelor of the RR Historic Engine Department were offering support too. (593\x92s were their responsibility also !!! Historic !!!) but I think that was unofficial until there was an agreement about the costs.
After that I worked in industrial applications of Olympus (and Avon) and worked on many installed Olympus in power generation but based on the 200 Series \x96 I think the 300 was thought to be too fragile. But I did have a good look at Olympus 2008/003 Still in good working order in Jersey on the Channel Islands with it\x92s Bristol Sidderly Name plate on it. They didn't have Inlet Guide Vanes as the 300's had but just 6 Forward Bearing Supports, hollow with anti -Icing air blown though, controlled by a Garret Air Valve.
I never saw a DEBOW sort of function on the Industrials but there is a critical N1 speed which has to be avoided because the LP Turbine Disc can fail. The Trouble with that speed range is that it is right where the usefull power is produced!!! Was there any Normal Operating Range RPM's which had to be avoided on the 593 ?
Again thanks very much for all the fascinating information here\x92s to another 42 pages!!
Sorry to have rambled on so much
Howie
5th Dec 2010, 06:11
permalink Post: 835
More Olympus stuff
Greetings.
Service Bulletin 0420 Industrial Olympus Gas Generator \x96 LP Turbine Disc Cracking Safety Related Operational and inspection requirements.
to paraphrase:
Avoid steady operations in the range 5450 to 5850 RPM I believe that 100% is 8000RPM so that equates to 68 \x96 73%. It is ok the accelerate through that range apparently.
There seems to be a lot of history about Olympus LP Discs:
Test House 40 \x96 I think - at RR Ansty still has the deep groves in the brickwork where an engine broke up during test.
From Wikipedia:
\x93XA894 flew with five Olympus engines, the standard four plus an underbelly supersonic Olympus 320 fed from a bifurcated intake starting just aft of the wing leading edge and inboard of the main intakes, in a mock-up of the BAC TSR-2 installation. This aircraft was destroyed on a fire on the ground on 3 December 1962\x94
I read the LP Disc did a QANTAS A380 and decided to leave the engine:
An Aviation Heritage story
So there\x92s nothing new in the world really
regards
HH93
Service Bulletin 0420 Industrial Olympus Gas Generator \x96 LP Turbine Disc Cracking Safety Related Operational and inspection requirements.
to paraphrase:
Avoid steady operations in the range 5450 to 5850 RPM I believe that 100% is 8000RPM so that equates to 68 \x96 73%. It is ok the accelerate through that range apparently.
There seems to be a lot of history about Olympus LP Discs:
Test House 40 \x96 I think - at RR Ansty still has the deep groves in the brickwork where an engine broke up during test.
From Wikipedia:
\x93XA894 flew with five Olympus engines, the standard four plus an underbelly supersonic Olympus 320 fed from a bifurcated intake starting just aft of the wing leading edge and inboard of the main intakes, in a mock-up of the BAC TSR-2 installation. This aircraft was destroyed on a fire on the ground on 3 December 1962\x94
I read the LP Disc did a QANTAS A380 and decided to leave the engine:
An Aviation Heritage story
So there\x92s nothing new in the world really
regards
HH93
Last edited by howiehowie93; 5th Dec 2010 at 07:19 .
8th Apr 2011, 18:33
permalink Post: 1285
Fatigue
I saw some questions earlier about performance but that's pretty well documented. I was wondering more about for how much longer ( if there had been no retirement )??
Was there a Fatigue Index as other aircraft of the same era \x96 I only know of the Tornado in this respect: a long calculation was made per flight taken of flight duration, G readings, TO weight, Landing weight etc leaving a small number of 0.0000x per flight. Then added to the current FI to give a forecast of life left. If anyone remembers the Tornado 25FI Update Program debacle in the 90's ???
So how was the Concorde's airframe life calculated ?? Flying hours or perhaps pressurisation cycles ? Did a higher altitude effect anything since there would be a higher differential pressure??
On the Engine side, I remember an Olympus Service Bulletin describing the calculation of Fatigue Cycles for the Oly 200:- There was a calculation with several parameters but instruction to disregard below a certain figure, 85% to Max RPM & back was a regarded as a cycle and the LP Turbine Disc was the component with the lowest number of cycles before the need for overhaul.Was this still the case with the 593 ??
Was there a Fatigue Index as other aircraft of the same era \x96 I only know of the Tornado in this respect: a long calculation was made per flight taken of flight duration, G readings, TO weight, Landing weight etc leaving a small number of 0.0000x per flight. Then added to the current FI to give a forecast of life left. If anyone remembers the Tornado 25FI Update Program debacle in the 90's ???
So how was the Concorde's airframe life calculated ?? Flying hours or perhaps pressurisation cycles ? Did a higher altitude effect anything since there would be a higher differential pressure??
On the Engine side, I remember an Olympus Service Bulletin describing the calculation of Fatigue Cycles for the Oly 200:- There was a calculation with several parameters but instruction to disregard below a certain figure, 85% to Max RPM & back was a regarded as a cycle and the LP Turbine Disc was the component with the lowest number of cycles before the need for overhaul.Was this still the case with the 593 ??