The Heinkel He 178 made, on 27 August 1939, the first flight of an aircraft powered exclusively by a turbojet engine, inaugurating the jet age. Its importance lies not in being an operational aircraft — it was an experimental prototype — but in demonstrating that the new form of propulsion could sustain a complete airplane flight. The engine was designed by Hans Joachim Pabst von Ohain; the airframe, by Ernst Heinkel's team. With it, the history of aviation enters a technologically new phase.