CFS2 Dewoitine D-510 French low-wing monoplane fighter with fixed landing gear developed from D.501 in 1936. The D.510 was the first production fighter to reach an operating speed of 250 mph. This model represents a Spanish Civil War version which replaced the Hispano-Suiza engine with a Russian M-100, salvaged from a SB-2. By C.M. Carlson.