PAINLESS,

I wasn't assuming that we would necessarily be limited to using existing ailerons. Even so, it may well be possible to get enough extra lift to be worthwhile even from a partial-span flaperon. My main worry with that would be causing a problematical early stall toward the tip, where ailerons are most likely to be. Certainly, it would be ideal to have more span to work with, and more toward the root. If there is no problem with aileron authority, I would be tempted to place the flaperons near the root, like traditional flaps, and leave the tip alone, to get some natural tip-stall protection.

I don't know anything about the rules, that's why I asked whether this idea would be legal. I would not assume that current designs are as optimal as possible under the current rules, though. There is usually some kind of improvement that can be made, unless they completely lock down the airframe you can use.

banktoturn