Aileron

An aileron (French for 'little wing') is a hinged flight control surface usually attached to the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll, or movement around the aircraft's longitudinal axis, which normally results in a change in heading due to the tilting of the lift vector. Movement around this axis is called 'rolling' or 'banking'.

Even though there was extensive prior art in the 19th century for the aileron and its functional predecessor, wing warping, in 1906 the United States granted an expansive patent to the Wright Brothers of Dayton, Ohio for the invention of a system of aerodynamic control that manipulated an airplane's control surfaces. Much litigation ensued over the legal issues of lateral roll control, until World War I compelled the U.S. Government to legislate a legal resolution.

In the present day ailerons have become highly refined in their designs and performance, with multiple types created to suit the various fixed wing aircraft in existence.