In fact the possibility of delaying the accelerations felt by the pilot at high speed and low altitude (penetration mission) makes possible the selection of larger wings which leads to an improvement of the aircraft qualities in the Air-to-Air dog fight (air superiority mission). A certain number of new FCS functions, as for instance gust alleviation, are decisive for multi-role aircraft. The selection of negative static margin thus made, a canard dimension linked to the selection of the aircraft c.g. It has been proved in combat simulation that the negative static margin obtained, thanks to the fly-by-wire controls, which was optimum, depends on the optimum limit of maneuver. It is the mastery of longitudinal balance that guarantees high maneuverability throughout the flight envelope. This configuration enahles excellent wing efficiency, especially at high angles-of-attack, due to deflection of the air flow on the wing by the foreplane, and extensive control of the aircraft's centre of gravity, thanks to the aerodynamic center effect created by the canard. The advantages of the delta moving canard configuration such as it is on the RAFALE are multiple. This gives back stability to the aircraft and enables more traditional flying control. The MIRAGE 4000 aircraft is equipped with fixed canard fins, designed to improve its maneuverability, which can be disengaged in caso of multiple failure of the flight control system. Then in 1979 it was the MIRAGE 4000 aircraft and in 1982 the MIRAGE III NG aircraft. This latter configuration dates from the "MILAN" aircraft which, in 1969 with its retractable "nose fins", was the first attempt within DASSAULT to decrease the relatively high approach speed of MIRAGE III aircraft (180 kts). The Rafale configuration is in line with the family of delta wing aircraft which started with MIRAGE III aircraft and which, later, gave birth to MIRAGE 2000 aircraft then to the "canard + delta wing aircraft". Every effort has been made for the sake of tactical flexibility to obtain balanced performance between subsonic and supersonic regimes, either in heavy or lighter air-to-air configurations. The choice of the close-coupled canards / delta wing configuration was decisive to ensure that the new fighter would offer the highest levels of performance during air-combats: even at high angles of attack, the RAFALE remains superbly agile, and its operational range for strikes at very long distances with incredibly heavy weapon loads is unmatched for such a compact design. In-house research in computational fluid dynamics has shown the specific benefits of close coupling between the wings and the canards: it ensures a wide range of centre of gravity positions for all flight conditions as well as benign handling throughout the whole flight envelope. The RAFALE features a delta wing with close-coupled canards.
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