Quote:
Originally Posted by IvanK
The RAE chart on its own shows sustained G over the complete speed range at 12,000ft altitude.
Its the a similar but more detailed chart to Crumpps.
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RAE's calculation also using estimated/guessworked stall speeds, Clmax and rather questionable power values for both the Spit and 109 (the latter probably understood with the effect of engine thrust). That's the problem with these charts in general - there's such a margin of error with the base values, that the results are all over the place. (estimated) Propeller effiency can vary results by 5-10% alone, drag values are unknown, the wing's oswald effiency factor is unknown (directly shifts the results, since its a multiplier in the equation), Cl max is unknown.
Just to make it clear I don't doubt the Spit had a sustained turn advantage at lower speeds, but OTOH I am pretty sure the situation reverses at higher speeds (for the 6 1/2 lbs version) at lower altitudes, since the 109E has both less drag and more power.
I am also curious about the effect of the two speed prop on turn capacity. Having 990 HP at the prop shaft is nice, but its all for naught if the two pitch prop can't properly convert it into thrust at turning speeds.