Ugly Stik aileron differential.
 

Hi,

I'm flying a Great Planes Bik Stik (Original Ugly Stik size). It has a couple of inches of dihedral to avoid the “drooping wing” effect. Motor is an OS 91 Surpass four stroke. I have lots of differential in the ailerons. It is hard to control when inverted. What can be done to make it friendlier to handle when it is upside down? I realize the shoulder wing and dihedral don’t help but there must be something that can be tried. I have individual aileron servos and a computer radio.

Thanks for the help,



John in Kalifornia

What is the point of all the differential? We have a rudder, learn to use it.

A little differential is a good thing, maybe 3/32" more up throw then down throw is about all that is needed. A shoulder wing airplane really does not need dihedral, the biggest gain would be to cut the wing apart and put it back together flat. Some other things to look at is the wing and stab incidence. You want then both at zero just the same as the engine thrustline. If these are not right then make them right. Once the differential is reduced, the incidence and thrustlines have been verified/fixed do a test flight with zero elevator trim. If it requires up trim ( most likely will ) then move the CG back until it no longer needs any trim. After all this I promise the inverted performance will be much improved.