The United States Air Force and Navy were both seeking new aircraft when Robert McNamara was appointed U.S. Secretary of Defense in January 1961.

[1] The aircraft sought by the two armed services shared the need to carry heavy armament and fuel loads, feature high supersonic speed, twin engines and two seats, and probably use variable geometry wings.

[3] In June 1961, Secretary McNamara ordered the go ahead of Tactical Fighter Experimental (TFX) despite Air Force and Navy efforts to keep their programs separate.

The evaluation group found all the proposals lacking, but Boeing and General Dynamics were selected to submit enhanced designs.

[5] In November 1962, McNamara selected General Dynamics' proposal due to its greater commonality between Air Force (F-111A) and Navy (F-111B) versions.