Hi Kweassa,
>I'm aeronautically impaired, and have always wondered just exactly what Carson was so wrong about.
Carson's approach is to declare the Me 109 aerodynamically inferior to the Supermarine Spitfire because of the latter's lower zero-lift drag coefficient.
However, as both types historically were quite similar in their top speed, that would have required the Me 109 to compensate the higher drag with higher power.
Assuming that the Me 109 had just 10% more drag than the Spitfire, the Meesserschmitt would have needed 33% more power just to achieve the same top speed as the Spitfire (at the same altitude).
For an example, let's say both aircraft's top speed at sea level is 480 km/h.
Now what happens in manoevring combat at 240 km/h? Due to the cubic relationship mentioned above, at 1/2 of the top speed, our planes need only 1/8 of the top-speed power to overcome parasitical drag. Let's assume a Spitfire with 1000 HP and a Me 109 with 1330 HP - the Spitfire would have 875 HP excess power at 300 km/h, while the Me 109 would have 1164 HP excess power available.
This is an advantage of 289 HP which - assuming a 10% weight advantage for the Me 109 because they always were lighter than Spitfires - would translate into a climb rate advantage of about 1550 fpm.
Wow! :-) That's more like the difference between the Me 109 and the P-40 - the Spitfire compared much more favourably!
Lesson learned: Given the choice between a draggy but powerful fighter and a sleek but weak fighter, we'll always go for the drag monster :-) Obviously, the drag monster will rule at low speeds where the significance of drag greatly decreases.
I hope that explains why the Me 109 would have been greatly superior to the Spitfire in a close encounter if Carson's claim about its high drag were correct. ("Like golf scores, the lower the better, and no fudging.") As you know, the Spitfire did very well in close encounters!
The truth is, the Me 109 generally had about as much power available as the Spitfire (it changed with altitude, so it's hard to nail down), and reached about the same top speeds, too.
For the Me 109E vs. Spitfire I comparison, which I have analysed in some detail, it actually looks as if at the same power, the Me 109E should have been a bit faster than the Spitfire I. The excess power advantage accordingly resided with the Spitfire, at least at those altitudes were the Merlin could exploit the 100 octane fuel.
(Reality of course is more complex than I could describe in this space, with induced drag, exhaust thrust, propeller efficiency and everything else ... but still, as a rule of thumb - pick the drag monster :-)
Regards,
Henning (HoHun)
