The Wright Flyer (also known as the Kitty Hawk, Flyer I or the 1903 Flyer) made the first sustained flight by a manned heavier-than-air powered and controlled aircraft—an airplane—on December 17, 1903. Invented and flown by Orville and Wilbur Wright, it marked the beginning of the pioneer era of aviation. The aircraft is a single-place biplane design with anhedral (drooping) wings, front elevator (a canard) and rear rudder. It used a 12 horsepower gasoline engine powering two pusher propellers. Employing 'wing warping' it was relatively unstable and very difficult to fly. The Wright brothers flew it four times in a location now part of the town of Kill Devil Hills, about south of Kitty Hawk, North Carolina. The airplane flew on its fourth and final flight, but was damaged on landing, and minutes later powerful gusts blew it over, wrecking it. The aircraft never flew again but was shipped home and subsequently restored by Orville. The aircraft was initially displayed in a place of honor at the London Science Museum until 1948 when the resolution of an acrimonious priority dispute finally allowed it to be displayed in the Smithsonian. It is now exhibited in the National Air and Space Museum in Washington, D.C. Design and construction The Flyer was based on the Wrights' experience testing gliders at Kitty Hawk between 1900 and 1902. Their last glider, the 1902 Glider, led directly to the design of the Wright Flyer. The Wrights built the aircraft in 1903 using spruce for straight members of the airframe (such as wing spars) and ash wood for curved components (wing ribs). The wings were designed with a 1-in-20 camber. Since they could not find a suitable automobile engine for the task, they commissioned their employee Charlie Taylor to build a new design from scratch, a lightweight gasoline engine, weighing , with a fuel tank. A sprocket chain drive, borrowing from bicycle technology, powered the twin propellers, which were also made by hand. In order to avoid the risk of torque effects from affecting the aircraft handling, one drive chain was crossed over so that the propellers rotated in opposite directions. According to Taylor: The long propellers were based on airfoil number 9 from their wind tunnel data, which provided the best "gliding angle" for different angles of attack. The propellers were connected to the engine by chains from the Indianapolis Chain Company, with a sprocket gear