Originally
known as the S-37, Sukhoi redesignated its advanced test aircraft as
the Su-47 in 2002 reflecting the decision to market the design as a
production fighter rather than as an experimental prototype. Also
commonly referred to as the Berkut (Golden Eagle), the Su-47 was
originally built as Russia’s principle testbed for composite materials
andsophisticated 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. The advantages of forward sweep
have long been known as such wings offer lower wave drag, reduced
bending moments, and delayed stall when compared to more traditional
wing shapes.
Unfortunately, forward sweep also induces significant
wing twist that would shear most wings off the aircraft. To solve this
problem, the Su-47 makes use of composite materials carefully tailored
to resist twisting while still allowing the wing to bend for improved
aerodynamic behavior. To reduce development costs, the S-37 borrowed the
forward fuselage, vertical tails, and landing gear of the Su-27 family.

Nonetheless, the aircraft includes reduced radar signature features
(including radar absorbent materials), an internal weapons bay, and
space set aside for an advanced radar.
Though similar in overall
concept to the American X-29 research aircraft of the 1980s, the Su-47
is about twice the size and far closer to an actual combat aircraft than
the US design.
Su-47 has shown far superior manuvering in the air to any aircraft known to this date.
Like
the X-29 though, the Su-47 was 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 and Eurofighter
Typhoon, but must also compete for funding with the more conventional
MiGs. 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. Initial reaction was not good, but the aircraft’s performance
has been so impressive that the Russian government has made funds
available for further testing of the design.
Still, the low budgets
of the Russian military and the aircraft’s high price tag make it
unlikely that the Su-47 will be purchased any time in the near future.