JtD

I found one test from the VVS concerning a Merlin 66 Spitfire IX. Not much, if that's really all. I know of another one which gave 642 km/h, but overall I don't care enough to actually search for anything. 404 mph +/- 3% is absolutely fine with me, and I'd be surprised if Supermarine invested a lot of effort into making their planes better than specified, it goes against commercial necessities.

Maybe you can get a head start and present all the tests you have seen? Evidence makes it much easier to built a case.

If you were to look for serial production aircraft performance, you'd have to look at serial production aircraft testing, not development and type testing. Not much of those around for the Mk.IX, I'm afraid, and also not really the point of this topic.

It's good then - you don't have to uphold that anything faster than 404 was a testbed and everything slower was serial production, seeing that now you're rightfully putting SU pump mod and 25lbs boost mod into the same category, whichever label it may carry. I'd label both of them testbeds, but that's just me.

Yes, but not of Spitfire JL.165. Just pointing out that JL.165 was either a testbed for 25lb testing, or 25lb was serial production standard at the time, can't have both. Same thing as with the SU pump.

The 388 you quote were measured by the AAE and the aircraft was also tested by Rolls Royce, but not the manufacturer. It's interesting nonetheless that you claim that 25lb boost came with serial production machines in October 1943 already, as opposed to the tested example being a testbed for the modifications.

Given that JL.165 was only tested at 25lb boost, are you sure you want to insist that it was a serial production machine?

I don't think so, since the LF IX with Bendix carburettor was the most numerous model produced in 1944. I also think this topic is less about relative performance, and more about the misconception of a P-47 being able to maintain load factors in excess of 3g at 20000 feet, where the true figure is somewhere around 2g. Odd relative performance is just a result of that.

A 13234 lb P-47 would either need twice the power it had or propeller and wing efficiencies in excess of 100% in order to maintain a load factor of near 2.5g at 30000 feet. Your calculation is again wrong, proper figure is in the region of 1.8g. The Spitfire IX, even the L.F. version, can still turn inside the P-47 and stay there, but this relative performance is also evident from your own chart.

I've made two quick estimates for the P-47 turning at 20k feet myself. Input data may vary a little bit from the quoted figures above. Wrongly using EAS (as in TAS=EAS, sea level) I end up at 3.2g, correctly using TAS I end up a little over 2g. So clearly, EAS / TAS is the key issue in the debate.

No, it refers to a dynamic pressure equivalent to that obtained at a speed at sea level. If I fly 165 knots EAS at 20k feet I'm not at sea level.

You're either saying you can't fly 165 knots EAS at 20k feet or you can't answer a simple question which is for which altitude you gave your performance figure. Which is it?

And why are you telling me?

:doh: An aircraft can very well fly 165 knots EAS at an altitude not sea level.

How do a longer nose and a longer tail "hurt turning performance"?

No, it wasn't standard equipment. The rear tank came with the A-8 as standard equipment. And it was used for C3 fuel, not MW50, on all except for a few trial models, including the A-9. I'm not aware that the increased boost of 1.82 ata required MW-50.

I don't think the A-9 used MW50. It's the same plane as the A-8, just with a different engine. No change in the fuel system or any additional equipment.

Production quality would be a very interesting subject if modelled, but not good for any gaming purposes. Where's the fun in having a wing fall off for no reason?

It was a problem for the engines used with B4 fuel, yes. I'm not aware that the C3 engines could not reach their higher performance when using the same boost as the B4 engines.

You develop engines for the fuel available. DB605 existed in C3 and B4 variants since its beginning. Had there been C3 in unlimited quantities, the DB605 would have made good use of it. However, as opposed to the BMW801, it did manage to get good performance from lower quality fuel as well, which is why it was deemed acceptable to keep using B4 with it.

Not all of the Luftwaffe aircraft were fighters, so this statement does in fact not contradict the statement you labelled as "extremely wrong." In fact, German fighters were good for about 30% of the Luftwaffe front line units, and I take it you know how many times you can fill up a 109 for one full fuel load of a 111. B4 was the Luftwaffe standard fuel well into the war.

Clipped wings were a late war thing commonly found on all versions. They were not exclusive to LF models and not all LF's had them.

I was asking for one primary source. Not transcripts. Not empty blabber. All I ever asked for, for pages, nothing delivered but excuses, insults and arrogance. I'd ask again, but then you'd just do the tenth iteration of empty blabber. As for you lying - you stated that eight years ago you had supported you case with an article with "a list with more than 60 primary sources on the bottom which support the authors point of view - plans, technical feasibility, factory tests, field tests, service introduction, service use. All there, documented.". And there is NOTHING like that. Maybe you fail to deliver what I expect because you and I clearly have a different opinion on "relevant", seeing that I consider clearances, orders and logs relevant, whereas you consider transcripts from books that state some plans you'd like to believe has become true as relevant. To each his own, I guess. Over and out.

Not shown here. Not shown here. Shown here. You seem to mistake me for someone who cares about the issue. Fact, in a conclusive 1000 page encyclopedia of the WW2 air war, the use or not use of 1.98 ata for a few minutes by a few aircraft of a few groups for a few days well after the air war was lost, wouldn't even be worth a footnote. Which is how much I care about it. I don't even have decided on an opinion, because the issue isn't worth the effort of a well thought out decision. I care about you insulting other historians, because they disagree with you. You claim you've made an article that contains 60 primary sources, equivalent to their work on another issue, but that's an outright lie. You've managed an article that is based on a mere handful of secondary sources and a couple of pictures. I don't know what in the world you think gives you the right to insult others, in particular when they clearly know their job better than you.

We have a better level there, because we have primary sources about plans, decisions and fuel shipments. Plenty of them. Imperfect still, but beats a few snippets from secondary sources by a mile.