Flettner Fl 185
The development contract for the Fl 185 was issued by the RLM in February 1937; two SV-Types were planned. It was given the designation "Helicopter Conversion 184" in the Aircraft Development Program, because the planned Fl 184 V3 was used in the construction of the Fl 185 V1. The Fl 185 project was financed with the insurance sum received from the destroyed Fl 184 V1 and a grant of approximately RM 50,000 from the RLM. Mockup inspection took place in April 1937.
The Fl 185 was a gyroplane equipped with a three-blade rotor. Torque balance was achieved by means of variable-pitch pusher propellers driven by extension shafts located at the ends of outriggers mounted on each side of the fuselage. The starboard propeller produced backward thrust, the port forward, so that the total moment exerted on the fuselage balanced that of the main rotor. The centrally-mounted Sh.14A engine drove, in addition to the rotor and anti-torque propellers, a large cooling fan in the nose consuming about 14hp. The main gearbox was in the front part of the cockpit.
The sole prototype built was the Fl 184 V1 D-ELFT, which carried out a number of flights m 1938. The Fl.185, which had a three-wheeled undercarriage, was given only a few tests near the ground, and then abandoned in favour of the Fl.265, which embodied the intermeshing rotor system on which Flettner had now begun to work.