OOK 6th Brigade under Skrzhinskii designed the A-12 wingless autogiro.  The A-12  was a direct-control rotor derived from the previous A-7 version.  The A-7 had a similar engine drive before takeoff.  With Roll controlled by only the rotor, the tail and central rudder and two Scheibe fins on strut-braced tailplane with elevators.  Cautious taxiing and hops on the 10^th of May, 1936 by A.P. Charnyavskii, eventually 17h 55mins in 43 flights until rotor blade came of on the 23^rd of May, 1937 killing I.Kozyrev.  The cause was never found, but ascribed fatigue almost halted work on the autogiro.