If you do it... move the ailerons UP not down, (spoilerons technically) and mix in up elevator. You will be pushing the nose up, and the "reflexed" ailerons will kill lift. Presenting the bottom of the wing to the airstream will slow it down quick. Get the relationship of elevator to reflex correct and you won't gain altitude (but it will drop like a rock when it slows down too much)


You don't want to use full span flaperons on a flat bottom wing. You would be inviting tip-stall and spin.