Originally Posted by shdw

Apply your knowledge of differential ailerons, why do we use them?

Background: The downward deflection of the ailerons is about 15 degrees and the upward is about 20 degrees in most trainer aircraft.

Now think about the size of a surface. If we have a 3 foot long aileron going down, will it have to deflect more or less than a 6 foot long aileron to achieve the same result? Apply your answer to the flaps combined with the ailerons for turning.

Finally, apply what you have learned in weight and balance about arm. Do flaps have more or less arm than ailerons? So would they effect adverse yaw more or less, that is, would they have a greater moment?

Hope that helps.