Caudron C.561 was the last of the line of racers designed by Marcel
Riffard at Caudron in the 1930s. It was (with the 461 which has a six
cylinder engine) the most radical of all of them with the canopy
following the line of the fuselage, with no forward view for the pilot
and an inverted V12 air cooled Renault engine. Sadly, it was also the
least successful, as it failed to qualify for the 1939 Coupe Deutsch de
la Meurthe due to continuous engine reliability issues.