for close coupled planes... sometimes the pitch effect of the flaps acting on the WING can overpower the elevator. When the flaps go down, the nose goes down and the elevator doesn;t have the authority to overcome the flaps.

(we had a discusion about this with a Slow Poke owner that set up flaperons...)

The answer?... deflect the flaps the SAME direction as the elevator so that you have ELEVONS on the wing, amplifying the elevator's pitch action for some AMAZINGLY tight loops.

Its a question of what is the ratio of the wing chor to the separation of the wing TE from the elevator hinge line... and then the aspect ratio of the wing is a bit of a factor. And then the chord of the aileron as a percentge of wing chord. (all kinds of variables as to if this works...)

The Slow Poke (and Lil' Poke.. its Park Flyer "little brother") can have pitch controled by the ELEVON action of the flaperons with more authority than by the elevator. These things will pitch with the flap function and the elevator just CAN'T overpower the flaps in pitch control. These models approach being "stabilized flying wings"

I have seen combat models that were stabilized flying wings using this to very good effect. (One was a R A cores Gremlin with a small horizontal added with the horizontal stab LE actually over the elevons. the stab/elevator had 5% as much area as the main wing and was split 50-50 fixed and moveable.) the small elevator and stab just AIDED the elevons in making the thing do tighter turns... and reduced the reflex needed on the elevons for level flight (higher top speed and less trim needed with speed change)