A flaperon on an aircraft's wing is a type of control surface that combines the functions of both flaps and ailerons. Some smaller kitplanes have flaperons for reasons of simplicity of manufacture, while some large commercial aircraft such as the Boeing 747, 767, 777, and 787 may have a flaperon between the flaps and aileron. The 787 has a configuration known as a SpoileFlaperon that combines the action of spoilers, flaps and ailerons into one control surface.
Boeing 777 flaperon
Flaperons on a Denney Kitfox Model 3, built in 1991
Flaperons (Junkers style) on an ICP Savannah Model S, built in 2010
Work of the flaperon of Boeing 777
An aileron is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll, which normally results in a change in flight path due to the tilting of the lift vector. Movement around this axis is called 'rolling' or 'banking'.
An aileron and roll trim tab of a light aircraft
Boulton's 1864 paper, "On Aërial Locomotion" describing several designs including ailerons
A 1912 Farman HF.20 biplane with single acting ailerons hinged from the rear spar. The ailerons hang down when at rest and are pushed up into position when flying by the force of the air, being pulled down by cable to provide control.
A Yak-52 using ailerons to roll counter-clockwise during an aerobatic maneuver
