Development.

During the 1950s jet aircraft replaced slower, propeller-driven planes. In the military the change was swift; in civilian aviation it took place more slowly. World War II forced the United States government to accelerate research and development of highperformance jet aircraft in order to counter the German air force's jet fighters. While American pilots never flew jets during the war, the air force tested a number of jetand rocket-powered planes from 1942 onward.

Background.

The jet age arrived on 27 August 1939 when Erich Warsitz flew a turbojet-powered Heinkel 178 aircraft at Marienehe airfield in Nazi Germany. German officials shrugged indifferently. In the United States, Bell Aircraft's XP-59 Airacomet jet made its debut on 1 October 1942 over Muroc, California. Neither plane was substantially faster than its piston-engine counterpart, and while both aircraft served as prototypes and training models for later, more-advanced jet aircraft, early jet engines only hinted at...