Su 47 Sukhoi Berkut

The Sukhoi Su-47 Berkut (Russian: Су-47 Беркут - Golden Eagle), also designated S-32 and S-37 during initial development, is an experimental supersonic jet fighter developed by Sukhoi Aviation Corporation. A distinguishing feature of the aircraft is its forward-swept wing, similar to that of the Tsybin's LL-3.[1] Its NATO reporting name is "Firkin". The sole aircraft produced is an advanced technology demonstrator prototype and manufacture of a planned second flying prototype is under question due to recent MIG developments of 5th generation Jet fighters.




Development
Originally known as the S-37, Sukhoi redesignated its advanced test aircraft as the Su-47 in 2002. Officially nicknamed Berkut (Golden Eagle), the Su-47 was originally built as Russia's principal testbed for composite materials and sophisticated fly-by-wire control systems. The aircraft makes use of forward-swept wings allowing superb maneuverability and operation at angles of attack up to 45° or more.

TsAGI has long been aware of the advantages of forward-swept wings, with research including the development of the Tsibin LL and study of the captured Junkers Ju 287 in the 1940s. Forward-swept wings yield a higher maximum lift coefficient, reduced bending moments, and delayed stall when compared to more traditional wing shapes. At high angles of attack, the wing tips remain unstalled allowing the aircraft to retain aileron control. Unfortunately, forward sweep also induces twisting (divergence) strong enough to rip the wings off an aircraft built of conventional materials. Only recently have composite materials made the design of aircraft with forward-swept wings feasible.

The project was launched in 1983 on order from the USSR AF. But then, with the crash of the USSR funding was frozen and development continued only being funded by Sukhoi. Like its US counterpart, the Grumman X-29, the Su-47 is primarily a technology demonstrator, one intended to lay the foundation for the next Russian fighter. Such a fighter must not only be as advanced as the US F-22 Raptor, but must also compete for funding with the more conventional MiG 1.44. However, Sukhoi is now attempting to market the Su-47 to the Russian military and foreign customers as a production fighter in its own right