Generally, the flaps are dropped down somewhat for landing. Theoretically, this gives more drag and more lift and allows the plane to be landed at a slower speed. In practice, I have found this to be less than ideal however. Start with only a little bit of throw and try it at a high altitude for your first time. If you set it up with full throws and both ailerons drop down at full travel, the model may not be controllable. Generally, RC planes pitch down when the ailerons are dropped. Full sized planes have "real" flaps separate from the ailerons. These are always inboard of the ailerons and when deflected, the ailerons are still effective. Flaperons (as we call them) do not work as well, but they are fun to play around with.