OOK 6th Brigade under Skrzhinskii designed A-10 six-seat transport autogyro with M-22 in 1934 but dropped this in favour of high-speed wingless machine with fully controllable rotor. Design in parallel with small A-14 which flew first and assisted perfection of A-12 wingless autogyro. Direct-control rotor derived from A-7, with similar engine drive before takeoff. Roll control by rotor only, tail with central rudder (extension of fuselage) and two Scheibe fins on strut-braced tailplane with elevators. Shavrov loosely describes fuselage and engine as I-16 (fighter); in fact steel tube with fabric, and engine cowl with gills. Two-position Hamilton prop, single-seat cockpit, very strong main gears with oleo struts and wide-track spatted wheels with toe brakes. Cautious taxiing and hops 10 May 1936 by A.P.Charnyavskii, eventually 17h 55min in 43 flights until rotor blade came off 23 May 1937 killing I.Kozyrev. Cause never found but ascribed fatique; almost halted autogyro work.
Bill Gunston "The Osprey's Encyclopedia of Russian Aircraft", 2000
Technical data for A-12
Engine: 1 x 670hp Wright Cyclone (later M-25), rotor diameter: 14.0m, length: 6.3m, weight empty: 1343kg, fuel+oil: 165+17kg, weight loaded: 1687kg, max speed: 245km/h, min speed: 52km/h, ceiling: 5570m, endurance: 1.5h, take-off run: 25m, landing run: 5-10m