Sud-Est SE.3101 / SE.3110
The first all-French helicopter to be designed and built after World War 2, SNCA du Sud-Est's single-seat SE.3101 was powered by an 85hp Mathis engine and flew for the first time on 1 June 1948.
This experimental helicopter was to study the placing of auxiliary rotors intended simultaneously to provide torque correction and longitudinal control. Two rotors, with compressed wood blades 1.6m in diameter, were placed symmetrically at 45°, one on each side of a V-shaped beam at the end of the fuselage, which was made of soldered tubes without a skin covering. These variable-pitch airscrews enabled the aircraft to be steered by varying their pitch differentially.
There then followed the 2-seat SE.3110 (F-WFUE), which had a 200hp Salmson 9 NH piston engine.