Did the never produced Russian Su-47 'Berkut' fighter accomplish anything of significance?
It is an interesting question, given that the not-so-stealthy aircraft was intended to push the technological curve of possibility with greater maneuverability, range and improved anti-spin characteristics.
A case can be made for what the demonstrator aircraft introduced, explaining why it is often described as a precursor to Russian’s much stealthier 5th Generation PAK FA Su-57 fighter jet.
The Sukhoi Su-47s most notable or often-discussed attribute is its swept forward wing, a design configuration credited for helping to bring improved attack angles and flight path adjustments while maintaining maneuverability. It only had a speed of Mach 1.6, compared with the Su-57s Mach 2, however, the Su-47 did have a high lift-to-drag ratio, 9g capability, improved stall resistance and added stability at high-angles of attack, according to a report from Airforce-technology.
A swept forward wing configuration, like that visible on the Su-47, is known for its impact upon airflow and drag, aerodynamic characteristics which of course greatly impact maneuverability. A so-called swept forward wing generates an inward airflow over the rear of the aircraft, a phenomenon said to decrease stall conditions and improve “roll control” of the wings. A forward-swept wing reverses the airflow direction over the rear of the aircraft by driving it closer to the fuselage or root of an airframe.
However, despite being able to improve “roll” characteristics on an aircraft with greater aileron control, a forward-swept wing can increase “yaw” concerns and move left-to-right, something which could impair flight stability, according to an interesting 2015 NASA essay about the similarly-configured, 1980s Darpa-Northrop X-29 demonstrator. NASA and the U.S. Air Force built and flew two Northrop-Grumman built X-29s, which also had a forward-swept wing, in the mid-1980s.
The Su-57 and F-22, by contrast, are built with rear-swept wings. At the same time, what is interesting is that some of the Su-47 and Su-57 design features clearly appear as an effort to mimic the F-22’s dual-engine rear configuration. In this respect, the Su-47 could very well have informed or greatly influenced the development of the Su-57, which as a 5th-Gen fighter is reported to be capable of a high degree of maneuverability.
While the F-22’s thrust vectoring, supercruise speed and dog-fighting superiority may not have been known as well by Russian rivals 15 or more years ago, its shape and capabilities likely did cause concern among Russian weapons developers interested in countering it. Does a Su-57 parallel or counter an F-22? Could the Su-47 have laid some kind of foundation for the maturation of this possibility?
Perhaps, although the shape of the Su-47 reveals many sharp edges, steep inclines and protruding structures, the back end of its fuselage does look a lot like an F-22 with its dual exhaust cylinders and vertical tails. The front end of the Su-47, however, looks quite different and much closer to a 4th-generation aircraft such as an F-15. In fact, reports say the Su-47s forward fuselage and landing gear were taken from Russia’s 4th-Gen Su-27 family for cost-saving reasons, something which might explain its less-stealthy forward shape.
Nonetheless, there may be little way of knowing that a Su-47 or even a Su-57 can truly rival an F-22.
Kris Osborn is the Defense Editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.