In 1937 the Junkers company designed a jet powered speed record aircraft under the designation Rekord-EF. The aircraft was powered by two jet turbine engines hanging below and in front the wing.
Development of the engine, designated Jumo T1, was started in 1937 and the first prototype was run in 1939. It took to 1940 however before a flight capable prototype was ready. This engine, the T1-5a developed 350kg (770lb) of thrust.
The company developed the Rekord-EF as a private venture to promote the new engine and the only prototype flew on the 2nd of February 1940. The aircraft made a series of record breaking flights but because of the was these flight were kept secret from the world. Only long after the war the data was found and it transpired that the Rekord-EF flew at 966km/h (600mph) on the 8th of March 1940.
Not long after this flight the aircraft was destroyed when it crashed on landing, killing the pilot.
Despite the record breaking speed the RLM showed no interest in the aircraft but it did instruct Junkers to develop a larger version of the engine. This would eventually become the Jumo 004.