Cobras, Mustangs, Thunderbolts, Eastern vs Western front, Franek vs ...

[Graham Boak]

I am afraid that it is you who is making such a judgement. I am not awared of Bari mock-up dog fight, but there is a substantial difference between and ad hoc organised combat and several days of tests with various pilots involved as Yugoslavs did. quote]

I do agree, though "several days of tests with various pilots" does not exactly imply great thoroughness. I thought that was much the point I was making, that looking at anecdotal or semi-anecdotal accounts, or even any single account, can be misleading, however genuine the participants. The only reliable source of data comes from organised series of tests done at the national flight test centres, and they rarely address direct comparisons. Even then they rarely are able to check "best current practice" on both sides but inevitably end up comparing their own national best versus the latest enemy that they could get their hands on. Always assuming the captured enemy can be made to work at optimum: the Russian test figures I've seen on the Bf 109F are clearly at fault above low altitudes, and the RAF initial figures on the Fw 190A have been criticised for not getting the maximum power from the engine. (Given that the early production BMW 801s were limited in power in German use, I'm not convinced that this was a genuine failing of the test.) There is a long and painful thread on this board(?) where one poster was clearly convinced that the performance gained from the British Bf 109G-6 was obviously affected by the retention of the gunpacks.

It would be interesting to know which engines were fitted to those Yugoslav Spitfires: there's no doubt on simple power/weight comparisons that the Yak 3 would climb away from a standard Mk.V - an M rated engine could be another matter. I'm not familiar with Yugoslav use of the Yak 3, thinking of them as Yak 9 users.