Student of the Moscow Technical College (МВТУ), Борис Николаевич Юрьев (Boris Nickolaevich Yurev) was the inventor of an automatic pitch-control mechanism, but because of lack of funds this full scale model was built without an engine nor pitch-control mechanism. Later however, a 30 hp Anzani radial was installed yet the machine remained without the poorly working pitch-control, which was used only on rotating tests. Considered to be the first modern helicopter with a single main rotor and a tail rotor.