A number of airplanes (gliders in particular) have ailerons which are
connected with the flaps and move with them. In these planes, the main idea
is to be able to reduce drag with negative deflection of the ailerons
together with the flaps. But I'd hesitate to call them flaperons in this
case, where the wing also has separate flaps.

Gliders with connected but separate flaps and ailerons are commonly referred to
as having interconnected flaps and ailerons. This is a very common system on
gliders that have flaps, not all do.

In the negative flap position the entire trailing edge is at a negative
setting. This reduces drag and increases performance. When applying positive
flap the ailerons also drop with the flap so that the entire trailing edge is
at a positive flap setting. The ailerons still work as ailerons separately from
the flap on some gliders.

On a glider such as the ASW-20 you have to see the interconnect system to
believe it. As the flaps go to positive positions so do the ailerons then as
the flap is put further down to the landing position the ailerons go back up to
a neutral or almost neutral setting thus reducing the angle of attack at the
tips and allowing for better lateral control during the landing roll. When the
control stick is moved laterally, for roll, the flaps and ailerons deflect
together but at different rates. Truly an amazing system and I always think of
it whenever someone mentions how "simple" gliders are.

Robert Mudd