Russian's S-37 forward-swept-wing fighter prototype is being used as a test bed for the technologies of the next Russian heavy fighter. (Russia expects to build a heavy fighter to counter the F-22 Raptor and a lightweight fighter to counter the Joint Strike Fighter.) The S-37 is large as fighters go, with a 55-foot wingspan supporting an overall length of 74 feet. While the next real fighter probably won't have forward-swept wings, the materials developed for the S-37 will certainly be used in future aircraft. The composite structure can bend without twisting, which is good because twisting would impose unbearable loads and tear the aircraft apart. The forward-swept wings cause the air flowing over the thin wings to flow toward the body, preventing the wingtips from stalling at high angles of attack. The forward-swept wings maintain constant airflow over the ailerons, maintaining high maneuverability even at high speeds. The next Russian fighter will certainly use its multi-circuit fly-by-wire technology. The S-37 has completed "about 100 flights" so far and is moving into supersonic testing. --Stephen V Cole