The first contract for full-scale development of the Hornet was placed on January 22, 1976, for 11 aircraft of which two were to be two-seat combat capable training versions (TF-18A).  The F/A-18 was designated to carry an air-to-air armament of AIM-7 Sparrow AAMs, plus AIM-9 Sidewinders at the wing-tips, and Hughes AN/APG-65 multi-mode radar for air-to-air and air-to-ground use.  Air-to-ground missiles, such as the AGM-84 Harpoon and AGM-65 Maverick, could be carried underwing in place of the Sparrows, so that the F/A-18 was suited to replacing the F-4 Phantom in the US Navy and Marine squadrons as an escort fighter/interceptor and to replace the Navy A-7 and Marine A-4 as an attack aircraft, using pod-mounted FLIR and laser tracker. (source: United States Navy Aircraft since 1911 by Gordon Swanborough and Peter Bowers)