An airplane or aeroplane (informally plane) is a powered, fixed-wing aircraft that is propelled forward by thrust from a jet engine or propeller. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spectrum of uses for airplanes includes recreation, transportation of goods and people, military, and research. Most airplanes are flown by a pilot on board the aircraft, but some are designed to be remotely or computer-controlled.In 1799, Sir George Cayley set forth the concept of the modern airplane. He was building and flying models of fixed-wing aircraft in 1803, and he built a successful passenger-carrying glider in 1853. Between 1867 and 1896 the German pioneer of human aviation Otto Lilienthal developed heavier-than-air flight. The Wright brothers flights in 1903 are recognized as "the first sustained and controlled heavier-than-air powered flight". Following WWI, aircraft technology continued to develop. Airplanes had a presence in all the major battles of World War II. The first jet aircraft was the German Heinkel He 178 in 1939. The first jet airliner, the de Havilland Comet, was introduced in 1952. The Boeing 707, the first widely successful commercial jet, was in commercial service for more than 50 years, from 1958 to 2010.