The Wright Flyer (often retrospectively referred to as Flyer I or 1903 Flyer) was the first successful heavier-than-air powered aircraft. It was designed and built by the Wright brothers. They flew it four times on December 17, 1903, near Kill Devil Hills, about four miles south of Kitty Hawk, North Carolina, US. Today, the airplane is exhibited in the National Air and Space Museum in Washington D.C.The U.S. Smithsonian Institution describes the aircraft as "the first powered, heavier-than-air machine to achieve controlled, sustained flight with a pilot aboard." The flight of Flyer I marks the beginning of the "pioneer era" of aviation.