Despite severe material shortages, work on experimental design started in 1948, and the main designer became Bronisław Żurakowski (brother of test pilot Janusz Żurakowski), who designed a rotor and control system. It used simpler Hiller rotor type, with two auxiliary blades. A fuselage structure, tail boom, auxiliary rotor and tricycle undercarriage were designed by Tadeusz Chyliński. A power unit and final drive were designed by Zbigniew Brzoska. The design utilized some components left by the Germans, like a piston engine Hirth HM 504 (re-configured for vertical use), rear gear from a Zündapp motorcycle and wheels from a DFS Kranich glider's jettisonable landing gear.