What was the world's first jet aircraft?

The Heinkel He 178 was the world's first aircraft to fly under turbojet power, and the first practical jet aircraft. It was a private venture by the German Heinkel company in accordance with director Ernst Heinkel's emphasis on developing technology for high-speed flight. It first flew on 27 August 1939, piloted by Erich Warsitz. This flight had been preceded by a short hop three days earlier. The aircraft was a success; however, speeds were limited to 598 kilometres per hour (372 mph) at the proposed service altitude, and combat endurance was only 10 minutes.