When it comes to aircraft there is a difference of performance between unarmed light protos compared to production series combat aircraft. I came to this problem when gathering info about Bf 109 B or "Bruno". Most sources give it max. speed of 460 - 470 km/h at altitude of 4000 meters, however Soviets tested one from Spain captured "Bruno" and it did make max. only 422 km/h. Was this really "muy rapido" or "very fast" plane endorsed by Legion Condor pilots on spring 1937? Of course it was "muy rapido" compared to Heinkel 51 but not so fast compared to some other monoplanes like I-16 at the time.
It has been also stated that Bf 109 B was so fast that it forced German pilots to adopt more flexible formations (Rotten & Schwarmen). Really? Finnish fighter pilots noted the advantages of flexible pair-flying already in 1934 with Gloster Gamecock biplanes flying max. speed of approx. 250 km/h. Rotten could well be invented without the max. speed of over 400 and something of Bf 109 B. And why did not the Soviets invent the Rotten with quite fast I-16? Maybe Rotten & Schwarmen has less to do with Bf 109 than with other innovative thinking.
As I have not Radinger & Schcik 1997 as reference (and is it so precise on this matter?), I wonder if someone more enlightened could give more exact performance numbers of "Bruno" and "Dora" (Bf 109 D). With Bruno one has to take in account that the Soviet tested example seemed to have fixed Schwarz prop. How much it made difference when the plane was equipped with variable VDM Hamilton prop?
The true performance of early Bf 109?
Re: The true performance of early Bf 109?
Soviets had an A-0 with fixed pitch propeller. At least for me it's unknown which engine was fitted. Even if it has a Jumo 210D engine it may not be fully rated as these were very early production engines (or even late prototypes) used in the A-0 series.