VFAX

VFAX for Naval Fighter Attack Experimental was actually two specifications for two US Naval fighter projects. The first was for a low cost lightweight complement for the F-111B which could replace the F-4 Phantom II for air superiority, escort, and ground attack missions in the early 1960s. This role was dropped in favor of the VFX aircraft, which emerged as the F-14 Tomcat. The second VFAX evolved when the VFX proved too costly to replace all existing fighters and attack aircraft, and the Navy was invited to take part in the USAFs Lightweight Fighter Program (LWF). The Navy chose the "loser" of the LWF contest for its VFAX role, which was redesigned to become the F/A-18 Hornet.

VFAX was essentially the Navy counterpart to the Air Force's FX study which eventually led to the F-15 Eagle air superiority fighter. The F-111B had no rear visibility and was found to be too heavy and ungainly in a dogfight. It was not even slated to carry a simple gun or AIM-9 Sidewinder normally carried by air superiority fighters like the F-8 Crusader. Even the F-4 Phantom II did not achieve the success that the US enjoyed over Korean MiGs. It was thought that a mix of F-111B and lighter advanced fighter bombers could handle all anticipated threats in close and long range combat.

As a company project, Grumman was well aware of the limitations of the F-111B, but their approach to the VFAX was the Grumman 303 design. It essentially transplanted the engines and AWG-9/AIM-54 Phoenix weapons system of the F-111B into an agile airframe with the same tried and proved components of the A-6 Intruder, such as the landing gear and primary attitude reference. It would have to be capable of defeating the Soviet MiG-17 'Fresco' and MiG-19 'Farmer' fighters encountered by Navy pilots after 1965 over Vietnam. After 1967, it would also have to defeat the next generation Soviet fighters as well. By 1966, the Navy had been persuaded that a single VFAX could meet the specification if it were large enough to carry the AWG-9/Phoenix weapons system. The VFAX was quickly dropped in favor of a hastily rewritten VFX specification which was largely built around the 303. The VFX, it was thought, was a better and cheaper alternative to a fleet of F-111B FADF (fleet air defence) dedicated interceptors and lighter fighter bombers. Needless to say, this greatly accelerated the need to cancel the now superfluous F-111B.

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Wikipedia