I've just built an FT Commuter. For the hell of it, I've programmed flaperons. In a tx like the Futaba T6K the way you can do it is with the Air Brake function. Just set the ailerons to down... I haven't flown it so won't switch it on until I'm way up high...but judging by the posts, I doubt it is much of a good idea anyway for this plane so it will just be to experiment.