The Su-47 Berkut is an experimental fighter jet built by Russian company Sukhoi in 1997, it features a pair of fixed wings that sweep forwards. The high lift-to-drag ratio of the wing design provides the Su-47 with enhanced manoeuvrability at supersonic speeds (faster than sound). It is able to turn mid-air quickly and is much less likely to stall at high angles of attack. The main disadvantage of this design is the increased stress load on the wings.