The most innovative aspect of the design was the variable-incidence wing which pivoted by 7° out of the fuselage on takeoff and landing (not to be confused with variable-sweep wing). This allowed a greater angle of attack, increasing lift without compromising forward visibility. This innovation helped the F-8's development team win the Collier Trophy in 1956. Simultaneously, the lift was augmented by leading-edge flaps drooping by 25° and inboard flaps extending to 30°. The rest of the aircraft took advantage of contemporary aerodynamic innovations with area-ruled fuselage, all-moving stabilators, dog-tooth notching at the wing folds for improved yaw stability, and liberal use of titanium in the airframe. The armament, as specified by the Navy, consisted primarily of four 20 mm (.79 in) autocannons; the Crusader happened to be the last U.S. fighter designed with guns as its primary weapon. They were supplemented with a retractable tray with 32 unguided Mk 4/Mk 40 Folding-Fin Aerial Rocket (Mighty Mouse FFARs), and cheek pylons for two guided AIM-9 Sidewinder air-to-air missiles. In practice, AIM-9 Sidewinder missiles were the F-8's primary weapon; the 20mm guns were "generally unreliable". Moreover, it achieved nearly all of its kills with Sidewinders. Vought also presented a tactical reconnaissance version of the aircraft called the V-392.