AA5BY, what I believe is happening is that the left aileron trim (right aileron down) causes the lower right wing to produce enough lift to want to roll the plane to the left but with both wheels still on the ground the plane cannot roll. Also remember that this is happening before the tail comes up. So the plane does a hard left ground loop. As I said before, if I was lucky enough to get the plane into the air it would fly straight and level with the amount of left trim I had dialed in.

So the question is, what causes the plane to fly straight and level in the air with a give trim setting and then do ground loops when on the ground with the same trim settings?? I believe the answer is that GROUND EFFECT is stronger on the lower wing than on the upper wing hence producing more lift on the lower right wing of the plane than on the upper left wing.

The wings are standard balsa/spruce double D-box construction with capped ribs. As such they are very rigid and it would be easer to build a new wing than try to remove the warp in the present wing. The aluminum pop-can trim tab on the upper wing is by far much easer and works surprisingly well.

Applying this theory to my biplane has eliminated all my ground handling problems and the plane flies very well. If you have a squirrelly bipe, try it, you may like it.

Oldbob