The F— 111 Multi‐Mission Fighter: An Introduction to the General Dynamics/Grumman F‐111 Variable Sweep Fighter Which is Being Developed for Service with the U.S.A.F., U.S.N., R.A.A.F., and possibly with the R.A.F.

THE General Dynamics)'Grumman F‐111 fighter is noteworthy on many counts: first, and most important in the context of coverage of variable sweep types in this issue, the F‐111 is the world's first variable sweep air‐craft to be designed and built for operational service. Second, the F‐111 represents the first successful attempt by the United States to design and build a multi‐mission aircraft suitable for service with both the United States Navy and the United States Air Force—obviously the F‐111 is not the first aircraft to become operational with more than one of the United States services (the McDonnell Phantom is currently in service with the U.S.A.F., the U.S. Navy and the U.S. Marines)—but it is the first to be designed from the initial concept to satisfy U.S.A.F. and U.S. Navy mission requirements. Thirdly, the existence of the F‐111 programme was directly responsible for the cancellation of the TSR‐2 programme because even though Britain's Government cur‐rently appear to be seeking an alternative replace‐ment for the cancelled TSR‐2 (in the form of an uprated Hawker Siddeley Buccaneer—designated the Buccaneer 2 Star—or an improved Dassault Mirage IV with two afterburning Rolls‐Royce Speys instead of the S.N.E.C.M.A. Atar turbo‐jets), it is doubtful if the TSR‐2 would ever have been cancelled had not the American Government offered Britain the opportunity of pur‐chasing the high‐performance multi‐mission F‐111 as a lower cost substitute. If the R.A.F. does re‐equip with the F‐111 instead of the TSR‐2 then in terms of performance, i.e. range, speed, weapons load, ability to survive at low level, ability to navigate to target in all weathers (day and night), ability to operate from short rudimentary airstrips and ferry range, the F‐111 should, with only mild reservations, fulfil all the mission profiles planned for the TSR‐2, and will offer attractive bonuses in addition. On the other hand, unless something approaching a complete redesign and rebuild of the Buccaneer or Mirage IV is carried out, neither aircraft can approach the performance of the TSR‐2.