Background From 1945 onwards, Britain conducted a number of studies into the properties and use of
variable geometry wings. The noted British engineer and inventor
Sir Barnes Wallis began exploring the concept during the
Second World War and became an early pioneer and advocate for the variable geometry wing, conceiving of an aircraft consideration that lacked conventional features such as a
vertical stabiliser and
rudder, instead using variable geometry wings to provide primary controllability in their place. In 1946, Wallis published a paper upon this research, which was quickly hailed as being a major scientific breakthrough in the aviation industry. The
Ministry of Supply and
Ministry of Defence arranged for a series of tests to demonstrate the application of the technology to
projectiles, both for research purposes and a potential form of
anti-aircraft defence; while Wallis worked upon this research programme, he continued to promote the concept of a manned variable geometry aircraft. In 1951, the Ministry of Supply issued
Specification ER.110T, which sought a piloted variable geometry aircraft that would be suitable for research flights; however, ER.110T would be cancelled without an order due to urgent demands for more conventional
transonic combat aircraft. At one point, Wallis examined the prospects of producing a variable geometry submission for
Specification OR.330, which sought a
supersonic aerial reconnaissance/
strategic bomber aircraft. He conceived of a large aircraft equipped with a moveable
delta wing configuration, which he dubbed
Swallow; however, midway through scale model free-flight testing, the funding for Wallis' studies was terminated by the Ministry in June 1957. In 1958, research efforts were revived in cooperation with the
Mutual Weapons Development Programme of
NATO, under which all of Wallis' variable geometry research was shared with the Americans. In 1964, the newly formed
British Aircraft Corporation (BAC) decided to harness Vicker's earlier variable geometry work on a new design study, designated as the BAC P.45. The conceptual BAC P.45 was designed as a 'light strike' and two-seat trainer aircraft. BAC had strongly advocated for a government order for the type to equip the
Royal Air Force (RAF), being one of a number of proposed designs that were produced by several rival manufacturers to meet
Specification AST.362. According to aviation author Derek Wood, in spite the P.45 design being "the obvious choice", the
Secretary of State for Defence Denis Healey dismissed it in favour of a prospective cooperative arrangement with
France for a joint-project based on the Br.121 ECAT ("Tactical Combat Support Trainer") proposal from
Breguet Aviation instead.
Anglo-French collaboration Starting in 1964, a series of in-depth discussions took place between the governments of France and UK on prospective collaborative military aviation programs; these involved talks between Handel Davies, the co-chairman of an Anglo-French committee, and his French counterpart,
Ingénieur-General Lecamus, negotiating the launch of two new military combat aircraft. According to these negotiations, the French would take the lead role in developing a new light ground-attack/trainer, while the British were to assume the leadership of a multirole fighter project. The AFVG was to be jointly developed by BAC and
Dassault Aviation, the proposed
M45G turbofan engine to power the aircraft was to also be jointly developed by
SNECMA and
Bristol Siddeley. The AFVG was to have a maximum speed of 800 knots at sea level and
Mach 2.5 at altitude. It was required to possess a minimum combat radius of 500 nautical miles, a ferry range of 3,500 nautical miles, and the nose-mounted
aircraft interception radar was to have a minimum range of 60 nautical miles. In RAF service, the AFVG had originally been intended to serve as a fighter, replacing the
English Electric Lightning in the interceptor mission. However, following the decision to procure the American-built
McDonnell Douglas F-4 Phantom II instead, the AFVG's expected role was changed in 1966 to supplementing the F-111K strike aircraft in replacing the
English Electric Canberra and the
V bomber force. The AFVG was to be powered by a pair of SNECMA/Bristol Siddeley M45G
turbofans, which were to be fed by Mirage-style half-
shock cone inlets. The engine development programme contract was to be issued by the French government to a SNECMA/Bristol Siddeley
joint venture company registered in France. After less than a year, Dassault began to actively undermine the AFVG project, working on two competing "in-house" projects: the variable geometry
Mirage G and the
Mirage F1. According to Wood, both Dassault and the French Air Force had been unenthusiastic for the project from the start, the latter wanting to pursue its own indigenous aircraft equipped with variable geometry wings, while the former had determined that the AFVG did not confirm with any of its future equipment plans. The collapse of the AFVG programme was considerably troubling to the British position, having chosen to rely on Anglo-French collaboration and American-designed combat aircraft to meet its needs. Up to this point, Britain had spent £2.5 million on the AFVG for practically no gains. In order to justify the absence of any new strike aircraft following the failure of multiple projects to develop or procure one, Healey decided to entirely dismantle the requirement for one. Thus, in 1968, Prime Minister
Harold Wilson, alongside Healey, announced that British troops would be withdrawn in 1971 from major military bases in South East Asia, the
Persian Gulf and the
Maldives, collectively known as '
East of Suez'. ==Redesign==