The Sukhoi Su-47 Berkut (Russian: ??-47 "??????" - golden eagle), also designated S-32 and S-37 during initial development, is an experimental supersonic jet fighter developed by Sukhoi Aviation Corporation. The NATO reporting name for this aircraft is "Firkin". A distinguishing feature of the aircraft is its forward-swept wing, similar to that of the Grumman X-29. Although the Berkut has been referred to as the Su-47 since 2002, suggesting that it is a ready-for-production warplane, it ...