Quote, AAF EB-104 report: ". Elevator control forces are very heavy in a tight turn, requiring constant use of the elevator trim control."
-This tells me the evaluation of a wide turning radius was, as usual, made at full power, and heavy elevator forces seem to mean above 250 MPH:
http://img105.imageshack.us/img105/3950/pag20pl.jpg Quote , PJ_Godzilla: "I would add this, however. It's probably worse than you posit. Why? a prop works to produce thrust by creating a press decrease on the forward surface and that goes something like the square of the velocity of the prop foil relative to the ambient air. Given that the top half is moving relative to free stream SLOWER, should you not also see an attendant thrust increase - due to increased prop alpha (alpha being the angle determined by the resultant of the sum of the forward velocity vector plus the rotational velocity vector - at that radius point on the prop foil - right, it increases as we travel toward the tips) on that half of the disk, thus making it's "pitch" (in the ac frame of ref - not prop pitch) rotation harder? If so, you'd also see decreased thrust on the lower half, since it's forward motion relative velocity is greater -thus making it's prop alpha smaller."
Well, you have my congratulations sir, you are the FIRST to clearly agree with the basic premises of my theory (You probably don't agree about the short nose leverage theory, which I can accept is yet not an obvious certainty, but you do agree with the DOWTHROTTLING element helping in increasing the sustained low-speed turn rate if I understood you correctly)...
AND, though I did not go down that line here, I have also explained it once with a similar content to what you just did: The prop's center of thrust MOVES into the upper disc half, which means the BOTTOM disc half LOSES thrust while the thrust in the upper half INCREASES...
Since we now both agree that overcoming the prop's passive resistance to longitudinal twisting is a heavy burden, then it is not much of a stretch from now on to accept that overcoming it requires taxing the wing's available lift with a leverage force coming from the tail?
Which does mean that lowering power will reduce the depressing force on the wing all by itself, not just as an aerodynamic byproduct of lowering the speed (this is why in combat accounts the turn rate benefit seems INSTANTANEOUS rather than delayed by the time it would take a heavy airplane to slow down), which is what is being tirelessly argued against me...
Well I am glad I finally did not type all this for nothing! That we don't agree on the FW-190A's relative turn performance is not important: pilot accounts of the day all agree on its superiority to at least the Me-109, barring a handful of test pilots running things at full power...
I'll add a few links for your perusal about the FW-190A issue:
http://www.lonesentry.com/articles/ttt/russian-combat-fw190.html "inevitably offers turning combat at a minimum speed"
http://luthier.stormloader.com/SFTacticsIII.htm Note the "interaction" of FW-190As and Me-109s...
Turn times, a bit criptic, but having the FW at 19-23(?) s. minimum, vs 20.5 s. for the Me-109F and 22 s. for the Me-109G-2:
http://wio.ru/tacftr/ww2t.htm FW-190A being indeed better turning, relatively, at speeds BELOW 250 MPH, and much worse above:
http://img105.imageshack.us/img105/3950/pag20pl.jpg Note same crummy FW-190A high speed handling here, with on top of that the same "tendency to black-out the pilot" as link above, DESPITE "elongated" loop (a pitch-up stall-"mushing" towards the inside of the turn then outside, decelerating violently tail-down):
http://www.spitfireperformance.com/mustang/combat-reports/20-murrell-2dec44.jpg FW-190A beating in sustained low altitude flat turns a Spitfire Mk V that is running at "wide-open throttle", WITH post-war hindsight:
http://img30.imageshack.us/img30/4716/jjohnsononfw190.jpg The FW-190A's character in turns is so contrasted from below 250 MPH to above 250 MPH that I think this is why its turn performance has remained so clouded to this day... Both good and bad qualifications can apply to the FW-190A's turn ability...
Anyway, I am glad someone finally sees the prop effect I was refering to... You apology is well accepted! From the description you made of prop blades and their relative speed in the airflow, I would think you might be an engineer of some sort?
Gaston
FW-190A beating a Spitfire V running at full power in sustained low-altitude flat turns, and with post-war hindsight mind you...
