To try and keep on point here, LS-6, LS-10, LS-3, PIK 20 D, Ventus C,
ASW-17 come to mind as having full span flaperons. The entire
trailing edge moves the same amount when moved as flap or aileron.
ASW-20, PIK 20B, Zuni, SGS 1-35, HP Series, 301 Libelle, Diamants,
Ventus A/B, Kestrel, etc do NOT have full span flaperons. They have
flaps and ailerons, and varying degrees of interconnection between the
two.

Only plane I know of that had a full span flap that was used at large
deflections (greater than 30 degrees) was the HP-17. Notice, it did
not have full span flaperons. It had spoilers for roll control. And
I understand the contestants had a great time watching Schreder take
off with it, as he went from tip to tip, side to side on the runway
until he finally got the plane into the air. This was likely due to
the fact that you could only reduce the lift a bit on the high wing
and add drag to it to try and pick up the down wing.

Full span, large deflection flaperons will likely provide very poor
roll control at any deflection beyond about 30-45 degrees, as the flap
will be likely be stalled, and the main thing you will get is
differential drag or a yawing moment when you moved the stick to try
and roll the plane. Oh, and I don't consider the Ventus A/B, Mini
Nimbus, or Mosquito to have drag flaps. They have cruise flaps and
trailing edge air brakes. Drag flaps have you looking out the top of
the canopy at where you are going to land when you put them full on.
You are still looking out the front of the canopy at where you are
going to land with trailing edge air brakes.

The ASW-20 was the first to get the ailerons back up as the flaps went
on down, getting the plane into what a previous poster said is called
"crow mode" in the model world. I think the biggest thing it does is
makes it so the ailerons won't stall once you are on the ground in two
point, tail low attitude. I don't think it was done for added drag or
improved in flight handling. You already get ENORMOUS geometric twist
when your inboard flap is down 50 degrees and your ailerons are still
down 8. However, these flapped ships like to have the ailerons up
when sitting two point on the ground in order to have aileron
authority, and Schleicher got this (among so many other things) right
by putting them back up so you can leave the flaps all the way down
after you land. That way, your left hand doesn't have to keep jumping
around in the cockpit grabbing different handles. Set the flaps, use
the dive brakes and land. No more needed hand changes.

Steve Leonard