ORIGINAL: tnewman
If the model was warped and or the rudder trim was off it would act the same upright and inverted.
Not true! A given yaw input reverses the right/left direction of the aircraft path when changing from upright to inverted. That is from the RC pilot’s perspective on the ground observing and controlling the aircraft. Trying to trim out a yaw problem caused by rudder or engine thrust with aileron input causes a nasty problem when flying inverted.