TempestNutOne post. No other answer makes any sense. This is an aviation forum, not any other kind. I agree with Aurthur about condolences. Other forums are able to deal with this without the morale high ground being high jacked all the time, and great dollops of immature personal attacks on one and other. And they post eye witness accounts and observations, photos and videos etc. Often we have no clue to the significance of the person involved, so those that do know and are able to should post information. That way we all learn and gain something.
TempestNutOK, we are heading into the realms of speculation now.
Lets stick to some facts:
The accident has killed a well respected figure in the warbird community, who was in fact responsible for building the aircraft in which he was killed.
The aircraft was a replica aircraft, built to original specifications – not that that has any bearing on the accident.
Let us use this thread as an opportunity to pass on our sympathies to the families of those affected and not to speculate on the causes please.
Bruce
Bruce no one is speculating. I am trying to make the point that we humans are curious types and in adversity we have a “need to know” a “search for information” call it what you like and this is perfectly normal and in my view should not be suppressed. I am not just speaking for myself but others expressed similar views to me.
If people on the forum react to one piece of information that may or may not be incorrect it may leave an incorrect impression. I have just indicated to people that there may be a more informed and adult view in other places, that may satisfy their needs without this unhealthy suppression of discussion that will only lead to what I know you are trying to avoid actually worse.
By the way thanks for the information about the aircraft, I did not know it was a replica, not that that it makes any difference to the fact that Gerry lost his life, but it helps us all understand who Gerry was and demonstrates his skills to those who care about these things. More information about Gerry and what he did would be very helpful to those reading this forum.
TempestNutGuys, plenty of eye witness accounts to be read in the US. Not sure they were landing “in formation”. Looks like the P51A came in with the D unsighted, or that he expected the D to be further down the runway. What ever I’m sure its not as per the impressions from the first news reports.
TempestNutCan I suggest that the Moderators please do something about the crass and insensitive post by Steve964 above.
The deceased pilot’s family are coming to terms with the death of a loved one, as are his colleagues. Many of those who witnessed this tragedy will have been traumatised by what they have seen.
Now is most assuredly NOT the time to be making comments about ‘pilot error and bravado.’ Now is NOT the time to be concerned about the loss of an aircraft, but about the loss of the pilot. The fullness of time and investigation by trained expert investigators will reveal the cause and make recommendations should any be necessary.
Regards,
kev35
Kev35, Steve 964 has expressed an opinion, and I detect in that opinion frustration at what he perceives as a needless loss of life. He will be feeling no less a loss or no less sympathy for the families than you or anyone else is feeling at the moment. But everyone is different and as human beings we need to express our frustration and feelings as part of the healing process. That a person gets “shot down” for doing so, is not nice in my opinion. I know it is a fine line in what is tasteful to everyone; but I find the obsessive “we must not speculate or comment at all costs” mentality here is truly unhelpful at times.
If you go to a motor racing forum and a drive has been killed people speculate and pick over what happened over and over. For some it helps for others it doesn’t. We should be more tolerant of those that comment when there is a tragedy with a Warbird. It has been bad couple of weeks in the US and perhaps questions need asking. Perhaps not; we certainly don’t know do we.
TempestNutI’d also expect better of you, Mark V. A relative of mine is a scientist who works in the Arctic in the ‘summer’ each year, and has done for a decade or so. The melt is real; argue as some might about why. Likewise the effects are going to affect us more in the future, and the P-38s are going to be metal kippers in the bottom of any remaining ice well after most of our cities are under water.
Back to the topic.
And we could all say we expect the press to be better informed. The climate may be warming, but not at the apocalyptic rate the press would have us believe and it most definitely is NOT predominantly caused by CO2.
Check out what the experts are now saying, and the Scientific facts for your selves not the complete load of rubbish from the press.
http://www.sciencebits.com/CosmicRaysClimate
http://mysite.verizon.net/mhieb/WVFossils/Carboniferous_climate.html
TempestNutDB605A Compression ratios
Ok I managed to have a quick browse around my references and can add a bit more. The only engines to feature the asymmetric compression ratios were the DB605 and 603 (and all of their double derivatives) As I mentioned above the most likely reason for this arrangement was oil getting into the combustion chamber and causing detonation. Now the one feature of the DB engines that contributed to this and differentiated them from say the Jumo200 series was the lubrication system and in particular the caged roller bearings used on the big-ends. These bearings and the gallery type lubrication system resulted in large amounts of oil being thrown about by the rotation of the crankshaft and more of it ending up on the LB rather than the RB.
A lot has been written about German engineering, but design wise the DB 600 series where not particularly noteworthy despite a number of neat features, and they where not nearly as robust as the Merlin and Griffon or the American Radials, and were way past being state of the art.
TempestNutI am sure that the answer to this question is to do with oil scavenging and the fact that one side of the engine got more oil into the combustion chamber than the other, and this reduced the detonation limit. To mitigate this issue the engines had a lower compression ratio on one side. This was an issue that the inverted V engines built by Daimler Benz had. I do not have my detailed references to hand but I doubt that the offset supercharger could cause this.
The detonation limit was a problem that vexed all the large Piston Engine Manufacturers and its obvious when looking at the German approach to getting power out of their engines that they ran higher compression ratio’s with lower boost, whereas the British ran lower compression and higher boost and I guess this left the German engines more susceptible to oil in the combustion chamber reducing the detonation limit. This is a complicated issue and I’m sure there were multiple issues that contributed to the asymmetric compression ratios
TempestNutAside from the political/historical/peace aspects, don’t forget the “green” aspect.
It would take a lot of corporate carbon credits to make up for what would be seen by a large part of the public as a fuel extensive, polluting and noisy public appearance…and seen by a relative few.
Ummm I think most thinking people who have actually looked at the science are realising carbon is not the cause of climate change. If the entire human race contributes 0.017% per annum to greenhouse gases the Vulcan is going to contribute b….all. Perhaps we can ask Gordon to divert some of the money raised in airport taxes to get the Vulcan back in the air. 😎
TempestNutThat itty bitty little Allison looks lost in there!
I was wondering what the difference in power is between an Allison and a Jumo 213?
Jumo 213 was the same cubic capacity as the Sabre and Griffon, slightly less in fact at 35 litres vs 36 litres of the allied units, and had a normal output of 1800hp. This was the same as a Merlin 66 at plus 18lbs or the single stage Griffon in the Spit MkXII or Seafire XV and XVII.
The wartime Allison’s produced 1100 to 1400hp, and it was not until the twin Mustang that they produced 2000hp.
The Jumo 213 could be rated up to 2200hp with MW50 but 2000hp was a more often used high rating. The Jumo revved to 3,200rpm at full power which was high for a production V12 of this size.
The Griffon could go to 2500hp @25lbs and the Sabre was rated at 2600hp and 3055 hp on special fuels. The small 27litre Merlin66 produced 2000hp @25 lbs boost on a regular basis and the 100 series replacement for the 66 was certified for service use @ 2,200hp @ 30lbs before the war ended and orders cancelled.
TempestNutRe 757
Would one of the pilots on this forum please explain how that RANZF B757 recovers from that almost verticle climb. 😮
TempestNutDid the Mossie use left and right Merlins….??
In which case it might not be so easy as that…..unless the Merlin crank etc can be swopped a la Allison…?
Or was it just the Hornet that had left/right rotation….??
Just the Hornet, but the engines were identical and rotated in the same direction; it was an idler in the reduction gearing that reversed the direction of the prop.
TempestNutIt seems like there were more than a few occasions where substituting a radial engine for an inline produced a superior airplane. The ki 100 comes to mind. I think you could also argue the Typhoons were better with the Centaurus than the Sabre.
Could the radial be improved? How about using magnesium cooling fins like the BMW 801 and direct fuel injection, removing the mechanical supercharger entirely and going with turbo-charging only, four valve heads. What else? Maybe maximize oil cooling? Shrink the entire engine diameter as much as possible. Could an 18 cylinder radial of about 2000 cubic inches produce 2000 reliable horsepower?
Look at the state of modern air-cooled motorcycle engines. 4 valve heads air-cooling and forced induction all live happily together in a microscopic package.
If not, what would a modern radial look like from a clean sheet of paper? I guess it could be liquid cooled but I’m not crazy about that.
This subject is infinitely more complicate than your simple analogies would suggest, and it is not true that the radial engine improved aircraft when it replaced an inline engine. My best suggestion is your read Allied Piston Engines of WWII by Graham White.
By the way the Typhoon was never powered by a Radial engine, only the Napier Sabre, an unashameably military engine. This 36 litre engine produced 2600hp on a regular basis during late war combats operations , and 3000hp was a possibility. The Centaurus produced 2500hp from 57 litres. Both were sleeve valve engines, again a technology developed to produce more power, and only persisted with. Both engines were difficult to fully develop and both suffered from vibration issues that were not present in earlier engines with fewer cylinders.
What would a clean sheet engine look like? Who knows, what is the role? And what are the key requirements. Maybe an air-cooled inline turbo diesel with common-rail fuel system and power recovery turbine. All off the shelf commercially available stuff.
TempestNutNow that I have moved down to West Sussex I hope to see her fly one day, as she just down the road. Bit of a trek back to DX now though
TempestNutThe Napier Sabre’s fitted to Typhoons used in Normandy suffered dreadfully from wear caused by the very fine gritty dust found in the region, some engines had so much bore/sleeve that they were way down on power and used large amounts of oil.
Cant remember where but recall reading about squadrons being recalled to New Forest airfields to have new engines fitted. before returning to France, think Vokes designed a better filter.
The Merlin suffered in the same way as the Sabre with dust, but many Spitfires where already being manufactured with the revised air intake that could be retrofitted or was already fitted with an air filter. This came as a result of experience in the Middle East. No such body of experience with the Typhoon existed although three aircraft had gone to Egypt for tropical trials.
TempestNutHello all,
I just got back from the Reno air races.The Unlimited Gold races were dominated by Hawker Sea Furies.Of course these had all been re-engined with either Wright R-3350 or Pratt and Whitney R-4360 radial engines.As fine as these planes perform with these engines.Its just not right to have a 4 bladed prop on a Sea Fury.They look oh so right with the 5 bladed( Rotol?)unit used with the Centaurus engine.So I got to thinking,Why not have a British backed,British built,Bristol Centaurus engined Unlimited Air racer and team?They Yanks say that they replaced the Bristol engines due to lack of usable spare parts and that they always need repair/maintenance.Ok ,maybe this is true for day to day purposes but maybe not so for a purpose built racer.Surely the parts and needed knowhow must exist somewhere in England?.Show the world that Napier and Bristol werent both chasing dead ends with sleeve valve technology.Someone must have the skills needed to build a monster Centaurus powerplant.Remember ,the UNLIMITED air races are truely UNLIMITED as far as engine mods go.Added cooling with spraybars,added manifold pressures,A.D.I.,Nitrous oxide,etc,etc.This would be the chance for some determined Brits to wave the flag and show them Yanks that they were wrong about Bristols finest reciprocating engine.It wouldnt be cheap nor easy but what good is?It can be done.All that is needed is the will.
Nice idea but apart from all the supply difficulties and knowledge of the engine being thin on the ground I don’t think the Centaurus lends itself to being modified in a way that would allow huge increases in power. This is due to the unusually long stroke of the engine. If you look at all of Roy Feddens Bristol engine designs they have a long stroke. Under normal circumstances this would increase the diameter of the engine but because the Hercules and Centaurus had no overhead valve gear they were compact for their Cubic capacity. This gave the engine great torque but at the same time piston speeds were already high compared to R2800’s R3350’s and R4360’s (same cylinder as R2800) This means that increased revs to increase hp would not be an option and increased boost would be the only option, increasing the risk of detonation, the usual cause of most big Reno failures. If my memory serves me correctly, in simplistic terms the Centaurus was a Hercules with 4 additional cylinders and a inch added to the stroke. Bore remained the same.
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