The Dornier Do 10, originally designated Dornier Do C4 was the name given by the Reichsluftfahrtministerium (RLM) of a pre-World War II German aircraft. A two-seat parasol-wing monoplane intended to be used as a fighter. Two prototypes were built in 1931 to fulfil a requirement for a two seat fighter. Having failed to gain a production order the Do C4 / Do 10 was used to test a tilting engine installation and propellers to suit, for STOL tests