Heinkel had developed the turbojet engine and the testbed aircraft, the Heinkel He 178 V1, in great secrecy.
They were kept secret even from the German air force and the Reichsluftfahrtministerium.
On 1 November 1939, after the German victory in Poland, Heinkel arranged a demonstration of the jet for officials, which Herman Goering, commander in chief of the Luftwaffe, did not attend.
Ernst Udet and Erhard Milch, Minister of Aircraft Production and Supply watched the aircraft perform, but were unimpressed.
While a technical success but speeds were limited to 598 kilometres per hour (372 mph) even when fitted with more powerful HeS 6 1,300lb thrust engines and combat endurance was only 10 minutes.
Location probably Warnemünde HQ of Heinkel