SCAR, thanks for the quick reply. As a matter of fact, the picture I posted is not my plane. I modified my plane to allow mounting the wing with bolts instead of rubber bands. The wing s secured by two bolts - one in front and one in the rear of the wing.

Other modelers who experience this "Bee Tuck" have attributed it to flying too fast. They say the plane was designed as a slow flyer and at high speeds, the main wing turbulance reduces the effectiveness of the horizontal stab and elevator. That is somewhat beleivable, but I thought I would try for a more technical explaination from the experts here on RCU.