Two Hawker Typhoon Restorations
Two Hawker Typhoon Restorations
Hawker Typhoon RB396 – Restoration Update | Vintage Aviation News (warbirdsnews.com)
Anyone know anything about the Canadian example or the viability of making a Napier Sabre airworthy?
Anyone know anything about the Canadian example or the viability of making a Napier Sabre airworthy?
Are you referring to typhoon Legacy as being the Canadian one? If so they have videos on YT which shows their progress and including info about two the two Sabres they have got. One is a wreck having been salvaged from a crash but the other is a part sectioned but largely complete engine which I assume gives them a fighting chance of a rebuild.
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All about the engine
The critical element would be getting a 'reliable' engine/prop combination that could function long enough to see an airframe off the ground and back again.
It would not have to be used at max power or flown at max speeds and weight, but it would HAVE to be suitable to get 20 mins (at a time) of flight for demo purposes. The airframe side of things would be less of a challenge as the weight could be kept down and it is not as if is has to rocket Tanks and take flack. Their problem is the lack of available product knowledge re what are normal operating limits, but modern technology could help there with sensors assisting to pick up issues BEFORE they become failures. The all important gear train and drives can also be sensor protected to avoid running in a range that gives premature wear leading to failures. There is no doubt that the use of modern materials in critical components could also reduce running issues. Many years ago I took a serviceable exhaust valve* from a pre-war radial engine to a specialist provider of valves to the racing car fraternity for an opinion of its suitability. Without even going into detail of material they condemned the part as unsuitable and said they would make a replacement (that would never break). They did and they have never failed since and are now a common 'fix' on this type of engine. That is how I would approach anything to do with a Sabre, as we have some wonderful materials now that were not available when they were new.
* I used to suffer valve failure in the display world (and transits) which 'could' wreck the engine if not chopped immediately. During a display it was less critical because there was somewhere to land, but it was less than helpful on a transit in poor weather !!!!.
Decades ago Pobjoy was on a gliding course at Swanton Morley and a couple of the instructors had flown Typhoons/Tempest. During a break in flying the conversation got around to engines (and reliability) and the CFI related that you had to fine tune the engine by 'feel and sound' to find the best rev range for smooth running. Although the manual would give a suggested rev/power range he said it was only a guide as subtle change either up or down by a 100 revs would suddenly give a much smoother run, and then you used that for that machine.
It would not have to be used at max power or flown at max speeds and weight, but it would HAVE to be suitable to get 20 mins (at a time) of flight for demo purposes. The airframe side of things would be less of a challenge as the weight could be kept down and it is not as if is has to rocket Tanks and take flack. Their problem is the lack of available product knowledge re what are normal operating limits, but modern technology could help there with sensors assisting to pick up issues BEFORE they become failures. The all important gear train and drives can also be sensor protected to avoid running in a range that gives premature wear leading to failures. There is no doubt that the use of modern materials in critical components could also reduce running issues. Many years ago I took a serviceable exhaust valve* from a pre-war radial engine to a specialist provider of valves to the racing car fraternity for an opinion of its suitability. Without even going into detail of material they condemned the part as unsuitable and said they would make a replacement (that would never break). They did and they have never failed since and are now a common 'fix' on this type of engine. That is how I would approach anything to do with a Sabre, as we have some wonderful materials now that were not available when they were new.
* I used to suffer valve failure in the display world (and transits) which 'could' wreck the engine if not chopped immediately. During a display it was less critical because there was somewhere to land, but it was less than helpful on a transit in poor weather !!!!.
Decades ago Pobjoy was on a gliding course at Swanton Morley and a couple of the instructors had flown Typhoons/Tempest. During a break in flying the conversation got around to engines (and reliability) and the CFI related that you had to fine tune the engine by 'feel and sound' to find the best rev range for smooth running. Although the manual would give a suggested rev/power range he said it was only a guide as subtle change either up or down by a 100 revs would suddenly give a much smoother run, and then you used that for that machine.
It's a lovely idea - a fabulous idea but if we can't keep Centrurii running these days (with a some supply of parts and a continuing, unbroken though thready supply of expertise ) what realistic hope is there for an airworthy Sabre with none of either? Theybstruggled to keep the thing running even in the day, and binned it the instant it became unnecessary to the war effort.
I'd guess we might yet see a couple of brave but futile test flights at prodigious expense only to see the aircraft grounded and condemned to static museum status.
I just can't imagine a Sabre in today's risk-averse climate allowing more than that to happen, even if they manage the incredible feat of getting one into airworthy status in the first place.
I hope i'm wrong.
I'd guess we might yet see a couple of brave but futile test flights at prodigious expense only to see the aircraft grounded and condemned to static museum status.
I just can't imagine a Sabre in today's risk-averse climate allowing more than that to happen, even if they manage the incredible feat of getting one into airworthy status in the first place.
I hope i'm wrong.
The Sabre was produced under a rather (we need it mentality) and never really sorted when it entered service. Like most very complex and complicated engines HOW it was operated also makes a substantial contribution to keeping it serviceable. Given the advances in cnc type production quality and the knowledge that this is not an engine for rapid throttle movements the challenge is how much 'out of the box thinking' will help enable the 'reliability factor' to be improved. Bringing in expertise from todays top racing guys could really help with this. For myself I only had exhaust valve issues, but sleeve vales did live on in later engines, and I suspect that the older technology could be improved enough to keep an example running good enough for demo purposes. They may have to be carefully 'warmed up' and power fed in smoothly, but then that is all part of keeping history alive as opposed to just being a static exhibit. Lots of interesting comments on the Sabre story in Rod Banks book plus the comments that despite all the problems and production issues (with engine and airframe) their part in the Normandy campaign justified the effort (just). Of course in Normandy they also had to contend with sucking in a very damaging dust before being retrofitted with better filters. The average Typhoon 'life' was such that the engines never really gained much of a chance to be improved by strip down inspections. They certainly are not a jump in pull the choke and shoot off type.
The engine ended up in Target tugs at Sylt so must have had some sort of serviceability rate for that job.
The engine ended up in Target tugs at Sylt so must have had some sort of serviceability rate for that job.
Originally Posted by POBJOY
The engine ended up in Target tugs at Sylt so must have had some sort of serviceability rate for that job.
I have often pondered the wisdom of using the Tempests as TT a/c post war and the only conclusion I have ever come to was that they must have had hundreds (perhaps thousands) of brand new sabre engines languishing in stores to either scrap or use up - so if they had any serious engine problems on a TT Tempest they could just demand a new engine and swap it out
Absolute engineering madness of an engine.
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You really don't like the Sabre or the Centaurus do you? You refer to them both as engineering madness at every opportunity.
They both became very successful engines with the Sabre remaining in service until the early 50s and the Centaurus until the late 60s.
They both became very successful engines with the Sabre remaining in service until the early 50s and the Centaurus until the late 60s.
Originally Posted by DHfan
You really don't like the Sabre or the Centaurus do you? You refer to them both as engineering madness at every opportunity.
They both became very successful engines with the Sabre remaining in service until the early 50s and the Centaurus until the late 60s.
They both became very successful engines with the Sabre remaining in service until the early 50s and the Centaurus until the late 60s.
.As I posted above - probably the only reason they survived into the 50's was a ready supply of spare/new engines in 'stores' - '' here Bert this here sabre sounds like a bag of nails - thats ok Alf we will just demand another one from stores - theres plenty left''.
regards LR
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There's no way of finding out now but I very much doubt there was a ready supply of Sabres. Some certainly but too expensive to buy hundreds of spare engines just in case.
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That seems an unlikely number considering there were only a little over 4000 airframes produced in total, Typhoons and Tempests together, that had a Sabre fitted.
One of the Typhoon projects reputedly acquired a zero hours Sabre, possibly crated but that's from memory so not sure, from a museum somewhere.
One of the Typhoon projects reputedly acquired a zero hours Sabre, possibly crated but that's from memory so not sure, from a museum somewhere.
We have to remember that these 'so called ' hyper engines' were the hoped for power plants for bombers rather than a fighter.
Rolls gave up with the Vulture, and that used existing technology, and then binned the Eagle. It is always easy to be clever 'after the event', but with a war to win and a serious amount of catch up to do there is no doubt that the Sabre was a very neat package, but ahead of the available materials that it really needed. I suspect that its shere power and in such a tight confinement was always going to be a problem if just one component failed. It really was an F1 engine in a van, not helped by issues with the van. At the end of the day when needed it did actually perform in the very hostile low level regime, and therefore played its part just in time. I doubt if the RAF were keen to look for more use for it as they had the Griffon by then which of course saw them into the Shackleton days. I think 'engineering madness' is not far off the mark, but also its power/size/weight was an amazing package for its time, and the 'compressed' development rather pushed it into service before the issues solved. I never fail to be impressed that they got all those gears,rods,and an oil system to work at all, and would love to hear one run and possibly fly.
Rolls gave up with the Vulture, and that used existing technology, and then binned the Eagle. It is always easy to be clever 'after the event', but with a war to win and a serious amount of catch up to do there is no doubt that the Sabre was a very neat package, but ahead of the available materials that it really needed. I suspect that its shere power and in such a tight confinement was always going to be a problem if just one component failed. It really was an F1 engine in a van, not helped by issues with the van. At the end of the day when needed it did actually perform in the very hostile low level regime, and therefore played its part just in time. I doubt if the RAF were keen to look for more use for it as they had the Griffon by then which of course saw them into the Shackleton days. I think 'engineering madness' is not far off the mark, but also its power/size/weight was an amazing package for its time, and the 'compressed' development rather pushed it into service before the issues solved. I never fail to be impressed that they got all those gears,rods,and an oil system to work at all, and would love to hear one run and possibly fly.
Last edited by POBJOY; 27th Mar 2023 at 20:01.
