A jet engine uses a fan to suck air into a cylindrical chamber and a second turbine fan to compress it. Then fuel is mixed with this high-pressure air and ignited. The hot expanding burning gasses then blast out of a nozzle at the rear of the engine thrusting the engine forward, and the aircraft it is usually attached to, with great force.
The independent coinventors were the English aviation engineer Sir Frank Whittle (1907-1996) and the German airplane designer Dr. Hans von Ohain (1911-1998). Chain's engine was tested in the Heinkel He178, flying first in August 27, 1939. Whittle's first engine, the Whittle Unit (WU), was completed in 1937 and subsequently fitted to an aircraft called the Pioneer (E.28/39), built by the Gloster Aircraft Company. The first flight was on May 15, 1941.
World War II saw swift developments of the jet engine and airplane. The United States's Bell XP-59 flew in September 1942, and by 1944 both the Messerschmitt Me 262 and the Gloster Meteor were being mass-produced. Jet-to-Jet dogfights were taking place during the Korean War in 1950. By 1952 BOAC were using the de Havilland Comet jetliner on their London to Johannesburg route.
Jet engines work most efficiently at altitudes of between 6 and 9 miles (10 and 15 km). Here, modern aircraft have cruising speeds of between 420 and 580 miles (680 and 900 km) per hour, this being about 80 percent the ambient speed of sound. Propeller powered aircraft have to fly at much lower altitudes and fly much more slowly. Also propeller engines are much more costly to manufacture and maintain.
