Aileron

An aileron is a hinged control surface built into the trailing edge of each of an aircraft's wings that, working in an opposed pair, one deflecting down as the other deflects up, changes the lift each wing produces to roll the aircraft around its lengthwise axis; the name comes from the French word for little wing. The English scientist Matthew Piers Watt Boulton described an aileron-like device in an 1864 paper and patented it in 1868, decades before powered flight was practical, and the Wright brothers obtained a 1906 patent covering their own method of lateral control, which led to years of patent litigation with the rival aviator Glenn Curtiss. The term aileron itself first appeared in French aviation writing around 1908, and by about 1915 ailerons had displaced wing warping and other earlier lateral-control methods to become the standard means of banking an aircraft, the role they still hold today.