Can the ground effect lift on the lower wing override the aerodynamic lift of the upper wing? I have a bipe that is a ***** to take-off and land. The plane will taxi nice and straight and will roll out straight during take-off until it reaches a certain speed then it turns hard left (ground loop) just before reaching full flying speed. If I time the rudder input just right I can get it in the air with a very ugly take-off. On landing the approach is straight down the runway and just after touchdown, as the plane slows it will again turn hard left. It seems that the take-off and landing hard left turn happen at about the same speed.

The upper wing is swept back with no ailerons and the lower wing is straight with ailerons. There is a very slight warp in the upper wing that should bank the plane right so the ailerons are trimmed to the left for straight flight. With the ailerons trimmed for left roll the right aileron is down a bit more than the left aileron and as such counteracting the warped upper wing. This is all well and good while the plane is flying, but on the ground it may be a different story.

I do not know the lift factor of ground effect so my question is, is it strong enough to cause the lower right wing to lift more than the upper left wing and turn the plane left when it is on the ground??

Has anyone else had this experience?

Oldbob