The Su-47 (formerly S-37) “Berkut” (meaning “Golden Eagle” in Russian) is a Russian experimental jet aircraft, designed to test various composite materials, low observability technologies, thrust vectoring, and sophisticated control systems.
Its builder-Sukhoi Aviation Corporation designed it to exploit the benefits of forward-swept wings, which consequently grant the aircraft superb maneuverability, stability, high angles of attack (“alpha”-the angle between the chord line of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere), lower minimum flight speed, larger range, shorter takeoff/landing distances, reduced wing-bending and stall resistance! The usage of forward-swept wings was only enabled in recent years, since without today’s advanced strong composite materials, the pressure put on the wings (especially during rolls) might cause them to detach from the fuselage.
The Su-47 is derived from a 4.5 generation Russian fighter; the Su-37. As an all-weather fighter (prototype), the Su-47 was well equipped- it uses a multi-mode passive electronically scanned radar array, terrain avoidance, terrain mapping, a rear-facing radar, a fly-by-wire flight control system, and a somewhat unique characteristic: it is Russia’s first fighter with the Hands On Throttle and Stick (or HOTAS) system, and the first to use a side-stick.
Aside from being a technology demonstrator, the Su-47 is currently under consideration of Russian military and other foreign customers as a potential fighter. Even if it will not be battle ready, it still has to lay the foundations for the next generation of Russian fighters, which by demands, must be equal to, or even surpass the F-22 Raptor!
The Su-47 can withstand high g-forces, and maneuver extremely well using thrust vectoring, but even so, it offers its pilots poor visibility, a result of bad seating arrangement. To make things worse, the composite materials the aircraft is made of do not seem to suffice to resist strong rotational forces applied on the wings during high speeds (around mach 1.8). Those forces are strong enough to twist off the aircraft’s wings, a fact which might change Berkut’s design back to a conventional wing layout (which would probably affect Russia’s future fighter designs). Russia’s conclusion regarding forward-swept wings is similar to the Grumman’s, which reached it earlier, after experimenting with the (forward-swept wing) X-29. Making a forward-swept wing aircraft might have been a mistake, and Russia could easily avoid it by simply paying attention to what Grumman Aerospace Corporation learned 24 years ago.