Vulcan XH 558 Threads (merged)
From the Vulcan 558 website:
It is with great sadness that VTST have to announce that due to technical problems XH558 will not be appearing at Siverstone or Goodwood this weekend . Fuller details will be posted later today
Put a note in my diary today. Simply wrote "BUGGER IT!!"
It is with great sadness that VTST have to announce that due to technical problems XH558 will not be appearing at Siverstone or Goodwood this weekend . Fuller details will be posted later today
Put a note in my diary today. Simply wrote "BUGGER IT!!"
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Fron the Web Site
The reason for the cancellations of the display flights this weekend is that we have been monitoring the engines during this season by the means of magnetic chip detectors fitted to the sump of each of the engines. These give the team the ability to foresee any potential change to the internal parts of the engine by the collection of magnetic debris and No2 engine has been showing signs over the last 6 hours of some change. Following consultation with MA and Rolls Royce this morning the team has been advised to change No2 before the next Display, Please note this is a precautionary engine change and we will keep you informed of our progress.
The reason for the cancellations of the display flights this weekend is that we have been monitoring the engines during this season by the means of magnetic chip detectors fitted to the sump of each of the engines. These give the team the ability to foresee any potential change to the internal parts of the engine by the collection of magnetic debris and No2 engine has been showing signs over the last 6 hours of some change. Following consultation with MA and Rolls Royce this morning the team has been advised to change No2 before the next Display, Please note this is a precautionary engine change and we will keep you informed of our progress.
Forgive my ignorance but I was under the assumption that the current engines in 558 were 'zero' hour ones, is that correct?
If so, isn't it a bit soon to be talking about changing one of them, the aircraft has hardly broken sweat this year what with numerous cancellations.
This is not a dig, just interested to know that's all.
Forgive my ignorance but I was under the assumption that the current engines in 558 were 'zero' hour ones, is that correct?
If so, isn't it a bit soon to be talking about changing one of them, the aircraft has hardly broken sweat this year what with numerous cancellations.
This is not a dig, just interested to know that's all.
What a shame and just as the weather was starting to be stable in the UK for an Indian summer...... Talk about having headwinds during this show season.
Out of interest, just how long does it take to change a donk on the Vulcan assuming that there aren't any peripheral issues ?
Regards
SHJ
Out of interest, just how long does it take to change a donk on the Vulcan assuming that there aren't any peripheral issues ?
Regards
SHJ
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Are the engines interchangeable?
Or do they have one spare for each of the four positions? If the latter, then given that the engines apparently cannot be overhauled, this is presumably the loss of an eighth of their available engine hours, which isn't a good thing, but isn't a disaster. Plus the loss of two potentially vital and high profile displays, which is a disaster.
If they have one spare engine per slot then it's a catastrophe, though - they have just irretrievably lost 50% of their maximum available flying hours, demonstrated the very high engineering related risk inherent in sponsoring the project and are now one similar failure away from being grounded permanently, wherever they happen to be at the time or manage to get themselves back onto the ground...
Oops!
I assume it must be the former, because you'd need to have rocks in your head to have ever started a project that had such a high risk of total and ignominious technical failure so soon after inception!
If they have one spare engine per slot then it's a catastrophe, though - they have just irretrievably lost 50% of their maximum available flying hours, demonstrated the very high engineering related risk inherent in sponsoring the project and are now one similar failure away from being grounded permanently, wherever they happen to be at the time or manage to get themselves back onto the ground...
Oops!
I assume it must be the former, because you'd need to have rocks in your head to have ever started a project that had such a high risk of total and ignominious technical failure so soon after inception!
Engine Overhaul and (over)regulation
"given that the engines apparently cannot be overhauled"
Is this really the case? If so, this must be the final nail in the coffin. Perhaps somebody who has experience of working on similar engines can explain.
Is it that the (rightly ??) tight regulation in this Country is making this project almost impossible? Or at least too expensive? Suppose XH558 was in South Africa with the four Lightnings, would it cost less and spend more time in the air?
Chris
Is this really the case? If so, this must be the final nail in the coffin. Perhaps somebody who has experience of working on similar engines can explain.
Is it that the (rightly ??) tight regulation in this Country is making this project almost impossible? Or at least too expensive? Suppose XH558 was in South Africa with the four Lightnings, would it cost less and spend more time in the air?
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Please forgive me for reposting this, but as I'm sure you'd agree, you'd not want to be posting this from scratch again either!!
Hi all,
Having caught up with this and many other topics on this subject, I can hopefully offer a little insight into the situation, and an explanation of a few matters, hopefully without stepping on anybody's toes. As many of you may be aware, I am a former RAF Propulsion/Airframe engineer with 10 years RAF experience and an ex TVOC Prop/Airframe engineer. I am going to try an answer the majority of questions in one here, so stay with me, and I'll apologise in advance if you think I'm waffling.
As has been mentioned many times before, quite correctly, All Gas Turbine engines are fitted with Magnetic Chip Detectors which are usually placed in the Scavenge, or Return lines of the engine oil system, however, on more modern engines they are also fitted in the Pressure, or Feed lines of the system to detect pump failure. These detectors are there to magnetically attract any large metallic particles which are present in the oil. As you can imagine, there are hundreds of areas across a rotating Gas Turbine engine where metal is meeting metal, in many cases with only a high pressure film of oil acting as a 'shock absorber' if you will, to prevent these areas from coming into contact. There are also many different bearings, spinning at several thousand RPM which are utterly reliant on their oil supply in order to remain lubricated and cooled enough to do their job. Should any one of these areas fail to recieve that lubrication, or start to break down through fatigue, then small metallic particles will begin to be deposited in the oil as the component breaks down. These metallic particles will be carried along in the flow of oil until they reach the Mag chips, whereby they will be attracted by those chips. Periodically, the chips are removed from the aircraft and sent to the Early Failure Detection Cell (EFDC) for examination. This involves the 'Washing' the chips in solvent to remove all traces of oil, then using a small amount of transparent tape, similar to Sellotape, collecting the particles from the chip end. This is then magnified and examined to deduce the material, size shape and concentration of the metal particles. All engines have particle residues upon a chip change, and wear is totally expected, as you'd imagine, however, any increases in this wear are investigated to ensure that things are OK.
All engines have their typical wear rate charted, and this is often referred to as the "Trend Graph". This trend is proven over the course of the engines type life by regular EFDC examination and this is another reason that EFDC is carried out so frequently. Unfortunately, over the years, the Trends for the Olympus 200 series have been discarded or lost, as you'd expect for an engine that has been out of mainstream service for over 20 years, so upon the restoration to flight, studies were carried out, involving our own Alan Rolfe who was working for Rolls Royces legacy engine division at the time, and an agreement was made between Rolls Royce and TVOC that the EFDC trends would be monitored and the graphs rewritten, so to speak. In the meantime Rolls Royce decided to use the Olympus 593 engine as a guide to wear rates for the Olympus 200. This was a little unfair on the 200 series used by XH558, as the 200 series is a far sturdier engine than the 593 which tended to suffer quite badly from rear turbine bearing failure, and had its own unique failure rates, but unfortunately, as that is all there was, that had to do. As you can imagine, Rolls are an extremely safety based organisation, and so will always err on the side of caution, this means that they will obviously be FAR less tolerant of any anomalies than in the Vulcans heyday, as they have a worldwide reputation to protect of building safe engines. Unfortunately for XH558, this has meant that the microscope has been trained on her, and in effect RR have been looking a little hard for problems.
As has been stated here many times, Build Debris is an issue that affects all recently serviced Gas Turbine engines. As you can perhaps imagine, Gas Turbines are constructed such that they rely on large chunks of metal rotating at high speeds and at close tolerances in order to produce their power. These same engines are also constructed and bolted together by human beings, and in a steady, static 'shop floor' environment. Although every care is taken to ensure that all tolerances are rigorously adhered to (trust me, I have built engines too) a tolerance on a static engine under a constant 1'g' is different to an engine turning at many thousands of RPM, with a 3'g' loading. This is where your "Build Debris" comes in. Usually, after an engine change, an overhauled engine recieves a full "Post Installation Ground Run" which takes the new engine through a full range of speed and handling tests and then has the 'Chips' changed and sent for EFDC. The engine will then have the same chips for aroung 20 - 30 hours in order for the build debris to accumulate and for any 'spikes' in a material type to settle down. As you can imagine, some metals are harder than others, and so will hold off from breaking down longer than others, and will thus produce spikes in the graph at difering stages. When the chips are removed after 30 hours, they usually resemble Christmas Trees, such is the volume of metallic deposits on them, however, this is expected.
A good Propulsion engineer will tell you that it takes around 50-75 hours before build debris spikes settle down, and that's not accounting for engines that have been sat in a desiccant bag for 26 years, with microscopic deposits accumulating in nooks and crannies.
Unfortunately, RR have insisted upon Mag Chip changes at unrealistic intervals of around 6 hours or so, and in many cases, the chips have required replacement after every flight in order to not exceed the RR hourly limitations. This, as you can imagine has not allowed the build debris to settle and 'spike' correctly. I am not alone in this judgement, as this is an opinion shared by myself, Alan Rolfe, and the Waddington EFDC cell, however, Rolls are inclined to err on the side of caution and this can be perhaps understood. This does not mean by any token that the engine is U/S and I would stake my own mortgage on the fact that the engine is 100% serviceable, however, this is the engine that is causing RR to have doubts, so the fastest and safest route is to replace the engine. Please bear in mind that the plan has always been to rotate the engine at 25 hr intervals, and this is not that far off, so hopefully, if this engine is left for a while, the trends of the other engines may well show that all is well with this engine, and it will rejoin the replacement cycle and fulfil its expected life. No two engines are ever the same, and all display different wear characteristics whilst still remaining totally serviceable, however, bear in mind that there is nothing to compare XH558 to any longer, and as she is the only aircraft airborne in the world on Olympus engines, she will have to re-write the rules.
I hope that helps, and thank you for staying with me!
Flipflopman
Hi all,
Having caught up with this and many other topics on this subject, I can hopefully offer a little insight into the situation, and an explanation of a few matters, hopefully without stepping on anybody's toes. As many of you may be aware, I am a former RAF Propulsion/Airframe engineer with 10 years RAF experience and an ex TVOC Prop/Airframe engineer. I am going to try an answer the majority of questions in one here, so stay with me, and I'll apologise in advance if you think I'm waffling.
As has been mentioned many times before, quite correctly, All Gas Turbine engines are fitted with Magnetic Chip Detectors which are usually placed in the Scavenge, or Return lines of the engine oil system, however, on more modern engines they are also fitted in the Pressure, or Feed lines of the system to detect pump failure. These detectors are there to magnetically attract any large metallic particles which are present in the oil. As you can imagine, there are hundreds of areas across a rotating Gas Turbine engine where metal is meeting metal, in many cases with only a high pressure film of oil acting as a 'shock absorber' if you will, to prevent these areas from coming into contact. There are also many different bearings, spinning at several thousand RPM which are utterly reliant on their oil supply in order to remain lubricated and cooled enough to do their job. Should any one of these areas fail to recieve that lubrication, or start to break down through fatigue, then small metallic particles will begin to be deposited in the oil as the component breaks down. These metallic particles will be carried along in the flow of oil until they reach the Mag chips, whereby they will be attracted by those chips. Periodically, the chips are removed from the aircraft and sent to the Early Failure Detection Cell (EFDC) for examination. This involves the 'Washing' the chips in solvent to remove all traces of oil, then using a small amount of transparent tape, similar to Sellotape, collecting the particles from the chip end. This is then magnified and examined to deduce the material, size shape and concentration of the metal particles. All engines have particle residues upon a chip change, and wear is totally expected, as you'd imagine, however, any increases in this wear are investigated to ensure that things are OK.
All engines have their typical wear rate charted, and this is often referred to as the "Trend Graph". This trend is proven over the course of the engines type life by regular EFDC examination and this is another reason that EFDC is carried out so frequently. Unfortunately, over the years, the Trends for the Olympus 200 series have been discarded or lost, as you'd expect for an engine that has been out of mainstream service for over 20 years, so upon the restoration to flight, studies were carried out, involving our own Alan Rolfe who was working for Rolls Royces legacy engine division at the time, and an agreement was made between Rolls Royce and TVOC that the EFDC trends would be monitored and the graphs rewritten, so to speak. In the meantime Rolls Royce decided to use the Olympus 593 engine as a guide to wear rates for the Olympus 200. This was a little unfair on the 200 series used by XH558, as the 200 series is a far sturdier engine than the 593 which tended to suffer quite badly from rear turbine bearing failure, and had its own unique failure rates, but unfortunately, as that is all there was, that had to do. As you can imagine, Rolls are an extremely safety based organisation, and so will always err on the side of caution, this means that they will obviously be FAR less tolerant of any anomalies than in the Vulcans heyday, as they have a worldwide reputation to protect of building safe engines. Unfortunately for XH558, this has meant that the microscope has been trained on her, and in effect RR have been looking a little hard for problems.
As has been stated here many times, Build Debris is an issue that affects all recently serviced Gas Turbine engines. As you can perhaps imagine, Gas Turbines are constructed such that they rely on large chunks of metal rotating at high speeds and at close tolerances in order to produce their power. These same engines are also constructed and bolted together by human beings, and in a steady, static 'shop floor' environment. Although every care is taken to ensure that all tolerances are rigorously adhered to (trust me, I have built engines too) a tolerance on a static engine under a constant 1'g' is different to an engine turning at many thousands of RPM, with a 3'g' loading. This is where your "Build Debris" comes in. Usually, after an engine change, an overhauled engine recieves a full "Post Installation Ground Run" which takes the new engine through a full range of speed and handling tests and then has the 'Chips' changed and sent for EFDC. The engine will then have the same chips for aroung 20 - 30 hours in order for the build debris to accumulate and for any 'spikes' in a material type to settle down. As you can imagine, some metals are harder than others, and so will hold off from breaking down longer than others, and will thus produce spikes in the graph at difering stages. When the chips are removed after 30 hours, they usually resemble Christmas Trees, such is the volume of metallic deposits on them, however, this is expected.
A good Propulsion engineer will tell you that it takes around 50-75 hours before build debris spikes settle down, and that's not accounting for engines that have been sat in a desiccant bag for 26 years, with microscopic deposits accumulating in nooks and crannies.
Unfortunately, RR have insisted upon Mag Chip changes at unrealistic intervals of around 6 hours or so, and in many cases, the chips have required replacement after every flight in order to not exceed the RR hourly limitations. This, as you can imagine has not allowed the build debris to settle and 'spike' correctly. I am not alone in this judgement, as this is an opinion shared by myself, Alan Rolfe, and the Waddington EFDC cell, however, Rolls are inclined to err on the side of caution and this can be perhaps understood. This does not mean by any token that the engine is U/S and I would stake my own mortgage on the fact that the engine is 100% serviceable, however, this is the engine that is causing RR to have doubts, so the fastest and safest route is to replace the engine. Please bear in mind that the plan has always been to rotate the engine at 25 hr intervals, and this is not that far off, so hopefully, if this engine is left for a while, the trends of the other engines may well show that all is well with this engine, and it will rejoin the replacement cycle and fulfil its expected life. No two engines are ever the same, and all display different wear characteristics whilst still remaining totally serviceable, however, bear in mind that there is nothing to compare XH558 to any longer, and as she is the only aircraft airborne in the world on Olympus engines, she will have to re-write the rules.
I hope that helps, and thank you for staying with me!
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Thank you Flipflopman for a very interesting and informative explanation. Would one get the feeling that "industry" would prefer that the Vulcan did not fly in the UK?
Engines, Flipflopman etc
My thanks also to Flipflopman for the superb, detailed explanation. Does anybody have an answer to my other point? If the aircraft was operated in, say, South Africa, could the owners do more or less what they like and not be tied by close regulation? Whether or not that would be a good idea is another matter...
Chris
Chris
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Thankyou for a well informed and presented post FFM 
I was a simulator engineer (hence the handle), and we had a slightly different way of doing things. Although we did have mag chips in our hydraulic system, the only thing we did with them was to periodically replace them. We used to take periodic oil samples. We would take a fixed volume of oil and pass it through different grades of filter paper, which we would then mount on microscope slides. We would then count the number of particles per unit area on each, and if they exceded our reference levels, we would then take another sample and take it to the EFDC chaps. I seem to remember a pokey room with two wise men and a load of magnets.
I am curious to know why there would be different techniques. The only anvantage I can think of for our method is that it would also catch non-ferromagnetic particles (rubber from seals, phosphor bronze from bushes etc).
Your thoughts appreciated.
I was a simulator engineer (hence the handle), and we had a slightly different way of doing things. Although we did have mag chips in our hydraulic system, the only thing we did with them was to periodically replace them. We used to take periodic oil samples. We would take a fixed volume of oil and pass it through different grades of filter paper, which we would then mount on microscope slides. We would then count the number of particles per unit area on each, and if they exceded our reference levels, we would then take another sample and take it to the EFDC chaps. I seem to remember a pokey room with two wise men and a load of magnets.
I am curious to know why there would be different techniques. The only anvantage I can think of for our method is that it would also catch non-ferromagnetic particles (rubber from seals, phosphor bronze from bushes etc).
Your thoughts appreciated.
I don't own this space under my name. I should have leased it while I still could
skeeler, engine change, not long if it was an ECU change not an engne change.
An engine needs to be removed with all its ancilliary machinery. This is then removed, fitted to the new engine, which is then installed, ground run, and then authorised for an 'en route' air test. Ie if it works when the aircraft is airborne the aircraft will continue its sortie. Usually fitted today, flown tomorrow.
An ECO or engine change unit has all the ancilliaries already fitted. You remove one, replace with the new one, and then carry on as before. It could easily be done in a day.
The key is the engneering support and team.
More than one engine usually dictated a dedicated air test. Engine change to flight status would then be Monday - Wednesday for instance.
That is from an aircrew perspective, been there done that, but over 40 years ago
An engine needs to be removed with all its ancilliary machinery. This is then removed, fitted to the new engine, which is then installed, ground run, and then authorised for an 'en route' air test. Ie if it works when the aircraft is airborne the aircraft will continue its sortie. Usually fitted today, flown tomorrow.
An ECO or engine change unit has all the ancilliaries already fitted. You remove one, replace with the new one, and then carry on as before. It could easily be done in a day.
The key is the engneering support and team.
More than one engine usually dictated a dedicated air test. Engine change to flight status would then be Monday - Wednesday for instance.
That is from an aircrew perspective, been there done that, but over 40 years ago
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...as the 200 series is a far sturdier engine than the 593 which tended to suffer quite badly from rear turbine bearing failure,
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Thanks Flip Flop Man, great explanation.
How many spare engines does TVOC have?
Probably a daft question but are the basic core components changeable with the core components of the Marine Olympus which power various frigates & destroyers?
How many spare engines does TVOC have?
Probably a daft question but are the basic core components changeable with the core components of the Marine Olympus which power various frigates & destroyers?
I don't own this space under my name. I should have leased it while I still could
Gainsey, I was on the Ark a couple of weeks ago, I believe she has 500 series Olympus, ie Concorde, not Vulcan. Don't know about the rest.
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How many spare engines does TVOC have?
They intend to rotate all the engines in and out of the aircraft every so often.
Probably a daft question but are the basic core components changeable with the core components of the Marine Olympus which power various frigates & destroyers?
Aircraft engines need to be made as light as possible whereas the marine ones don't, so the metals used are different. (AFAIK)
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Probably a daft question but are the basic core components changeable with the core components of the Marine Olympus which power various frigates & destroyers?
Aircraft engines need to be made as light as possible whereas the marine ones don't, so the metals used are different. (AFAIK)
Gainsey, I was on the Ark a couple of weeks ago, I believe she has 500 series Olympus, ie Concorde, not Vulcan. Don't know about the rest.
I was on the Ark a couple of weeks ago, I believe she has 500 series Olympus, ie Concorde
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