Originally posted by MiloMorai
As if the 109 did not have protrusions, Issy.
Bulges for the cowl mgs, bulges for the wheels, numerous other little bulges and scoops, an air intake sticking out from the side of the fuselage, 3 radiators (2 coolant, 1 large oil), ADF loop, a retractable tail wheel that was sometimes locked down, extended tail wheel strut, gondola guns hung from the wings, . . . . . . .
The point is not that the 109 never degraded aerodynamically during it`s development and when getting new stuff installed. The point is that it was later ALWAYS improved again. The Spit didn`t, as being said the ONLY aerodynamic improvement was the retractable tailwheel, that managed to get a few mph extra, and was used only on very few planes...
As for the 109s, it got two major aerodynamic facelift during it`s development, once in 1940 with the 109F, and in 1943 with the 109K. Which would explain you why it turned out that while in 1940 the Spitfire I was as fast with somewhat less HP, in 1944 it was 60 km/h slower with the same HP...
And just some comment on those drag factors... bulges for HMGs, yes, 9 km/h lost, which wouldn`t matter much in air combat, but the plane was now carrying effective MGs, instead of just ballast like the Spit did until 1944 with those .303s. And then in 1944 those HMG bulges gone.. The Spit had nice big bulges for the cannons through it`s service, THANK YOU desingers who designed a thin wing so much unsuited for bigger weapons, THANK YOU weapon developers in Britain who couldn`t came up with a cannon of their own, and forced the designers to put an large French cannon designed for rigid engine mounts and not flexible wings which cause them to jam.
bulges for the wheels, of course they had it, from 1943, the Spitty had them too, from 1941.
"numerous other little bulges and scoops", yeah, sure they existed somewhere if you say it.

an air intake sticking out from the side of the fuselage
"an air intake sticking out from the side of the fuselage" - that`s the best one Milo, you are actually critisizing a better aerodynamic solution that reduced the drag..

Yep, sticking out the air intake was putting it out of the airstream, which meant an undistrupted boundery layer around the fuselage, the same reason the Mustang did the same with it`s radiator (perhaps because it`s designer was also a former Mtt engineer..)
3 radiators, WOW, Milo, getting desperate, huh?

It ain`t the number of them counting, it`s the shape. The 109`s was sunken into the wings, having some 40mm sticking out in the front, the whole thing heavily profiting from the meredith effect.. On the Spit, it`s at least half a meter, I STILL don`t get who was that idiot who could design such a monstrosity onto a fighter.. literally drag bags they are, and aerodynamic test show they have serious turbulance inside as a bonus. Again the problem is not that.. the problem is it just worser and worser during the development!
ADF loop, yeah. That`s a classic. Huge drag I guess.

"a retractable tail wheel that was sometimes locked down," - hmm, yeah. I guess you mean that whereas the 109 had their retractable t/w *sometimes* locked down, the Spit never really had this problem, as it couldn`t retract the tail wheel in the first place. I wonder though what effect it had on the Spit`s tailwheel drag that it wasn`t lockable either.. lots of turbulance there again.
Gondola guns hung from the wings, yep,
optional, raising firepower to a level a Spitfire never had, at a horrific loss of 5 mph. Now for comparison tropicalized Spits lost some 10-15 mph, and that was quite common. Their air intakes were on the nose chin, being as big as the oil cooler on the 109, nicely createing a lot of turbulance all the way behind,
smarty positioned at the spot they can eat the most dust from the ground, which meant they needed a filter constantly used which added even more drag, and even then it was useless, the Soviets found the Spit IXs so sensible to dust that they only operated them from the well built airstrips of the PVO in the rear areas..
Mitchel put that plane very nicely together in the mid-1930s... very nice clean fuselage, good for it`s time, nice features, nice characteristics.. but from there it was a downhill run, the whole development can be described with two words : ad hoc.