Originally Posted by
mashp39
On another site it was suggested to raise both ailerons a couple degrees and this will help the tip stall. Anybody ever try this?.
Yes, yes, yes! Reflexing both ailerons up a few degrees at neutral and at this point with that airplane is the key to its survival.
First let me say it is my belief that the so called 'tip stall' is the most over used catch phrase in model aviation. In the full scale world it is rarely used. A stall is a stall it can also be an Accelerated stall as described by one of the responders above. The term tip stall is merely used to describe a stall that starts at the wingtip and propagates inward toward the wing root. Now a stall can also start at the wing root and propagate outward toward the tip. This last is not a tip stall.
Always if one is going to stall the airplane it is most desireable for the stall start at the wing root not the wing tip. The reason for this is to delay the loss of aileron control up to the point that the 'entire' wing becomes stalled.
The reason in your situation getting perhaps slower on landing approach that when the stall occurs it starts at the wing tip and aileron control is lost then if power is being maintained to control the approach or is increased for go around at the point of the stall the torque will tend to roll the airplane left at the break and the "P" factor will case the Yaw to the left.
Now normally this problem (and the problem is making the wing root stall first) is handled by several methods and the most common is first the actual airfoil itself of the wing and the second is a built in twist of the wing with the wing tips at a lessor angle of attack than the wing roots intended to cause the stall to start at the roots.
Two other methods that are easy for us to do is simply reflex the ailerons up full time. Also another it to simply tape short pieces of triangle stock to the wing roots the idea here is the sharp leading edge will trip the stall at the wing root first.
Now in the RC jet world since most turbine airplanes have dedicated flaps (not flaperons) it is common to mix in aileron up reflex when the flaps are applied. This does indeed work.
I have indeed used the stall tripper strips and or aileron reflex on P-40's of some folks I was helping and indeed these airplane were tending to tip stall. I do not recall which brand ARF's they were.
Please do not fly the airplane agine until you at least adjust so up reflex of both ailerons perhaps two to three degrees .
John