Grumman Navy F-111B Swing Wing (Naval fighters No. 41)

In 1960, both the U.S. Air Force and the U.S. Navy were developing requirements for new fighters. The Air Force was planning to replace the F-105 with a long-range, low-level supersonic, all-weather Tactical Strike Fighter to be operated from unpaved runways of 3,000 feet or less in length and capable to transatlantic ferry without refueling. The Navy needed an all-weather, carrier-based Fleet Defense Fighter with a big radar and six long-range air-to-air missiles. In 1961, these similar "Fighter" requirements were merged by the Secretary of Defense into one program, TFX, to save development costs and operating costs.