Originally Posted by
Pilot DAR
Happily, I have no combat experience, so I'm unqualified to comment on combat flying techniques. My experience with many engine and propeller changes on many small civil types has shown me that airplane handling may be effected by the propeller, if the propeller is managed/mismanaged during maneuvering. Also, when installing an engine of a different mass, or at a different location (I've done both), the handling of the plane could be affected. If ballast is needed in the tail, more so. So, certainly, there could be expected to be a difference in handling between airplanes changed from inline to radial engines.
WwII fighters mostly all had tail ballast, and this tail ballast was changed when altering radically from inline to radial, which was rare. The centre of gravity was always kept the same at about two thirds of the wing’s chord.
There is nothing in any model known that explains an improvement in slow speed sustained turn handling for heavier radials of similar power. The obvious explanation is internal leverages are affecting the wingloading, but there is no model for that either.
Not only is there no model for these particular rare and esoteric issues, but even a question as basic as: Does more power improve the maximum available sustained speed rate of turn? This basic question is still answered today as yes, more power increase the sustainable speed rate of turn, yet not one single wwII combat account I have found supports this in 25 years of searching for it. The implications of this alone are enormous; it means, for these specific configuration/weight/power, there is an interaction going on between prop load and wing load, an absolutely foreign concept to current flight physics.
It seems to me the prop effects that are well known are all easy to detect minor roll and yaw effects. Since there are huge vertical to fuselage forces in play that are cancelling each other out, gravity/momentum on one side and lift on the other, there is plenty of room inside those two immense forces to hide massive smaller forces that also cancel each other out, but alter the assumed outcomes of the two larger vertical forces.
If you assume the smaller forces hiding within the bigger forces are not there, they are never going to come out and tell you of their existence (other than by indirect means like competing turn rates)
As I said, precise vertical prop load variations in turns, or wing bending measurements in turns, for these old types, would instantly reveal these forces, but if you never do these tests on these particular types, how would you ever know 20 000 lbs of forces are cancelling each other out? the airframe will perhaps groan a little more than you expect, but it won’t really complain in an obvious way if you don’t dogfight everyday... Yes I do think something that gigantic could easily be hiding in plain sight of decades of air show flying, since that is all they do.