The Wright Brothers Patent War - Prior Art

Prior Art

There are conflicting claims over who first invented the aileron as a method for lateral flight control. In 1868, before the advent of powered aircraft, English inventor Matthew Piers Watt Boulton patented the first aileron-type device for lateral control via 'flexed' wings. Boulton's patent, No. 392, awarded in 1868 some 40 years before ailerons were 'reinvented', became forgotten until the aileron was in general use. If the Boulton device had been revealed at the time of the Wright Brother's patent filings, they may not have been able to claim priority of invention for lateral control of flying machines.

New Zealander Richard Pearse may have made a powered flight in a monoplane that included small ailerons as early as 1902, but his claims are controversial (and sometimes inconsistent), and, even by his own reports, his aircraft were not well controlled.

Robert Esnault-Pelterie, a Frenchman, built a Wright-style glider in 1904 that used ailerons in lieu of wing-warping. Although Boulton had described and patented ailerons in 1868, no one had actually built them until Esnault-Pelterie’s glider, almost 40 years later.

The Santos-Dumont 14-bis airplane was modified to add ailerons in late 1906, though it was never fully controllable in flight, likely due to its unconventional surfaces arrangement. Henri Farman's ailerons on the Farman III were the first to resemble ailerons on modern aircraft, and have a reasonable claim as the ancestor of the modern aileron.

In 1908 U.S. inventor, businessman and engine builder Glenn Curtiss flew an aileron-controlled aircraft. However Curtiss had previously been a member of the Aerial Experiment Association, headed by Alexander Graham Bell. The Association had previously developed ailerons for their June Bug aircraft. The AEA members were later dismayed when Curtiss dropped out of their organization, patented their innovation and reportedly sold the patent to the United States Government.