1911-vintage Curtiss Model D pusher biplane had spanwise rectangular interplane ailerons of a similar nature to those on the final form of the Santos-Dumont 14-bis, but mounted on, and pivoted from the outer rear interplane struts instead. Another very late contestant included the American, William Whitney Christmas, who claimed to have invented the aileron in the 1914 patent for what would become the Christmas Bullet which was built in 1918. Both "Bullet" prototypes crashed during their first "flights" when their wings broke off in flight due to flutter as a result of being deliberately unbraced. Patents and lawsuits The Wright Brothers' Ohio patent attorney Henry Toulmin filed an expansive patent application and on May 22, 1906, the brothers were granted U.S. Patent 821393. The patent's importance lay in its claim of a new and useful method of controlling an airplane. The patent application included the claim for the lateral control of aircraft flight that was not limited to wing warping, but through any manipulation of the "....angular relations of the lateral margins of the airplanes [wings].... varied in opposite directions". Thus the patent explicitly stated that other methods besides wing-warping could be used for adjusting the outer portions of an airplane's wings to different angles on its right and left sides to achieve lateral roll control. John J. Montgomery was granted U.S. Patent 831173 at nearly the same time for his methods of wing warping. Both the Wright Brothers patent and Montgomery's patent were reviewed and approved by the same patent examiner at the United States Patent Office, William Townsend. At the time Townsend indicated that both methods of wing warping were invented independently and were sufficiently different to each justify their own patent award. Multiple U.S. court decisions favoured the expansive Wright patent, which the Wright Brothers sought to enforce with licensing fees starting from $1,000 per airplane, and said to range up to $1,000 per day. According to Louis S. Casey, a former curator of the Smithsonian Air & Space Museum in Washington, D.C., and other researchers, due to the patent they had received the Wrights stood firmly on the position that all flying using lateral roll control, anywhere in the world, would only be conducted under license by them. The Wrights subsequently became embroiled with numerous lawsuits they launched against aircraft builders who used lateral flight controls, and the brothers were consequently blamed for playing "...a major