Sukhoi Su-47 Berkut (Russian: Сухой Су-47 Беркут, lit. 'Golden Eagle') (NATO reporting name Firkin), also designated S-32 and S-37 (not to be confused with the twin-engined delta canard design offered by Sukhoi in the early 1990s under the designation Su-37) during initial development, was a Russian experimental supersonic jet fighter developed by the JSC Sukhoi Company.
A distinguishing feature of the aircraft was its forward-swept wing that gave the aircraft excellent agility and maneuverability. While serial production of the type never materialized and the configuration was not further pursued, the sole aircraft produced served as a technology demonstrator prototype for a number of advanced technologies later used in the 4.5 generation fighter Su-35 and current fifth-generation jet fighter Su-57.
