role in the lack of growth and aviation industry competition in the United States comparative to other nations like Germany leading up to and during World War I". Years of protracted legal conflict ensued with many other aircraft builders until the U.S. entered World War I, when the government imposed a legislated agreement among the parties which resulted in royalty payments of 1% to the Wrights. Ongoing controversy There are still conflicting claims today over who first invented the aileron. Other 19th century engineers and scientists, including Charles Renard, Alphonse Pénaud, and Louis Mouillard, had described similar flight control surfaces. Another technique for lateral flight control, wing warping, was also described or experimented with by several people including Jean-Marie Le Bris, John Montgomery, Clement Ader, Edson Gallaudet, D.D. Wells, and Hugo Mattullath. Aviation historian C.H. Gibbs-Smith wrote that the aileron was "....one of the most remarkable inventions... of aeronautical history, which was immediately lost sight of". In 1906 the Wright brothers obtained a patent not for the invention of an airplane (which had existed for a number of decades in the form of gliders) but for the invention of a system of aerodynamic control that manipulated a flying machine's surfaces, including lateral flight control, although rudders, elevators and ailerons had previously been invented. Flight dynamics Pairs of ailerons are typically interconnected so that when one is moved downward, the other is moved upward: the down-going aileron increases the lift on its wing while the up-going aileron reduces the lift on its wing, producing a rolling (also called 'banking') moment about the aircraft's longitudinal axis (which extends from the nose to the tail of an airplane). Ailerons are usually situated near the wing tip, but may sometimes also be situated nearer the wing root. Modern airliners may also have a second pair of ailerons on their wings, with the two positions distinguished by the terms 'outboard aileron' and 'inboard aileron'. An unwanted side effect of aileron operation is adverse yaw—a yawing moment in the opposite direction to the roll. Using the ailerons to roll an aircraft to the right produces a yawing motion to the left. As the aircraft rolls, adverse yaw is caused partly by the change in drag between the left and right wing. The rising wing generates increased lift, which causes increased induced drag. The descending wing generates reduced lift, which causes reduced induced drag. Profile drag caused