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No doubt that the D0-335 was the cleanest of all two engine designs (except possibly one with a counterrotating prop, but I don't know any designs that uses that combination. Several single engine planes tried it, but it was complex).Hi Davparlr,
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The aerodynamical advantage of the Do 335 is evident from the height differential for roughly equal top speed since at low altitude, it is handicapped by the greater drag of the denser air. If you look at speed over altitude diagrams of WW2 fighters, speed invariably increases with altitude until the full through height of the engine is reached. (Since many engines had two supercharger speeds, they had two full-throttle heights, giving the familiar "sawtooth" look of so many curves.)
In short, if you provide the Do 335 with an engine of equal power but greater full throttle height that matches those of the fighters it's compared against, it will be faster than it was at 21000 ft, where it was as fast in terms of true airspeed as the others at 25000 ft.
All I can say is that I have calculated it carefully, and don't mean it to be the final word on the type anyway. I just thought quoting an actual figure I personally consider realistic would be better than simply writing "It would have been very, very fast"
Also, It would have been nice to have a SL top speed.
SL - sea level? If yes, then its 580 km/h (360 mph).
Is your data good? Is it the last version, I think, the A?
Do you have any more performance numbers for the Do-335?
But the 15mm MG 151 would have to be explicity stated as the 15 mm version (MG 151/15). All references to MG 151 in wartime docs of at least 1944 (maybe even 1943) pointed to the then-standard MG 151/20.
You are correct, the Pfeil did not have a "service record", as no units ever reached operational status before the end of the War.
However, on at least one well-documented occasion, a Do-335 was able to "walk away" from a flight of P-51's, without the Mustangs even managing to get in a shot, due to the -335's superior speed. As I said, the smart LW pilot would've used the Pfeil's advantages to his benefit, not gotten tangled up in a furball with a bunch of more manueverable Mustangs.
SoD - one I recall was Lerche's account in LW Test Pilot - You can bet the 51's had probably full load of internal fuel and ammo and the 335 was light - but even so - in most combats the dead never saw the living guy, and airplanes don't run around in constant full boost.
If the 335 was 20+ mph faster in many regimes, so what? Mustangs weren't immune from 190A7/A8 or 109Gs and had a similar speed advantage.
And the main reason the LW was "dog meat" in '45 was superior Allied numbers, not necessarily superior tactics or superior hardware; anybody who is outnumbered 10-to-1 is probably going to lose, I don't care how good you are. In '40, the French were "dog meat" to the LW due to the LW's superior numbers; you do the math.
There actually was a direct comparison in a recent issue of a German aircraft magazine (Flugzeug Revue??), maybe someone's got the issue? I seem to recall the data for the Do 335 was all projected though.Hi Davparlr,
>I just have no idea of the thrust profile of the engine. Also, It would have been nice to have a SL top speed.
Unfortuntely, there are not many well-documented data points for the Dornier Do 335 around, and the speeds I have seen mentioned often do not specify the power settings.
I think that the 762 km/h top speed figure must have been reached on emergency power, so it's possible to reverse-engineer the Do 335 speed curve from the engine power curve as given in von Gersdorff et al. - result attached.
(Additionally, there is quite a bit of variation in the Do 335 data as the early development planes were all configured a bit differently, and as their role was it to work the bugs out, not all were up to full performance either.)
Accordingly, my curve can be seen only as a rough analysis.
(I have included a speed curve for the Ta 152H-1 from a German WW2 chart as that's the comparison suggested by the thread title
Regards,
Henning (HoHun)