Dornier Do 10

The Dornier Do 10, originally designated Dornier Do C4, was a pre-war German aircraft named by the Reichsluftfahrtministerium. It was a two-seat parasol-wing monoplane intended as a fighter, and two prototypes were built in 1931 to meet a requirement for a two-seat fighter. It failed to win a production order, and the Do C4 and Do 10 were then used to test a tilting engine installation with matching propellers for short take-off and landing experiments. The source notes that information on this model is difficult to find and that the relationship between the C1, C4 and Do 10 is not fully resolved.