Originally posted by Saxman
Actually, I thought I saw somewhere our F4U's flaps aren't available until about 50mph SLOWER than per the manual (first notch kicks in at 250 in the game, thought I read the real bird could drop them at 300. Also I remember from another discussion, the real F4U could drop the flap lever a notch so that when airspeed decreased to the point flaps could deploy they would do so automatically, and blow back up again as speed increased). The aircraft's manual even indicates that the flaps can be used for maneuvering.
Here's the chart posted by F4UDOA showing the F4U's stall speeds:
As a point of comparison, per DOA the P-51B power off full flaps has an improvement of 7% in its stall speed. Power off stall without flaps is 101mph, full flaps 94mph. The Hog achieves this difference--at lower ACTUAL speeds, with two notches of flaps.
F4U stall speed power off no flaps is 94mph, 86mph power off full flaps. Power on, the differences in the Corsair's stall speed with and without flaps is even MORE significant.
Hi,
many planes could use their flaps at higher speeds, i talk about the relations here. I wrote that the F4U can use them "much more early" than others, not "to early".
Also regarding the stallspeed and lift behaviour i talk about relations. Although the F4U have a lower stallspeed, the lift efficiency can be rather bad. The stall speed is, next to other factors, related to max liftload and the liftload get infuenced by the wingarea and the F4U is more light wingloaded. btw, the F4U stallspeeds in that maual are made with almost dry tanks, so the wingload is very low, resulting in a rather low stall speed.
With that weight the wingload is 176kg/m², while the P51D with 75% fule still has 203kg/m².
That the stall speed of the F4U drop by using the flaps dont indicate that the lift increase that much over the whole speed range.
It is absolut normal for flaps that only a few degrees of flaps create more lift than full flaps, but of course at a different speed!! Full flaps result in a slowspeed airfoil, but a bad one, while the flapless parts of the wings already tend to stall. This conficuration is usefull for landing, but manouvering is not that good.
Normal Flaps are made to lower the stall speed and the aproach speed (drag) and to provide a better sight while landing(nose down behaviour). Flaps dont need to create more lift and in general they dont do that, they need to create the same lift at slower speeds.
Flaps in general tend to decrease the max lift, although the lift at a given AoA increase, the max AoA tend to decrease, resulting in a smaler max lift + much more drag.
As you can read in the manual 0-20° is the manouver flap setting and its good to slow the plane fast down. In AH i can manouver very good with full flaps. Tight turn with more than 45°-60° bank at 100mph(F4U-1D, 100% fuel), without a bad tendency to snaproll or spin. With 25% the turnspeed dont drop, but the radius, it feels more like a UL glider than like flying a heavy WWII fighter then. And no tendency to enter a spin at all.
Regarding this the F4U´s are real rooki planes.
Greetings,
Knegel
