The Story of the Anglo-French Variable Geometry (AFVG) Aircraft Project

The advent of the jet engine brought about a revolution in military aircraft the likes of which had not been seen since the Wright Brothers trialled fitting a machine gun to their revolutionary Wright Flyer. Aircraft were becoming faster, could fly higher and carry more weapons than ever before. It literally rewrote the book on aerial warfare but in the early days, like in most technological revolutions, it was wrought with difficulties. Designing the new aircraft to make the most of the jet engine particularly at high speeds resulted in compromised slower speed performance. If we look at the English Electric Lightning, it was designed to climb very high very quickly and accelerate to beyond Mach 2. To achieve this the design team created an aircraft with minimal drag and long sharply swept back wings but this resulted in an aircraft with very poor slow speed, low altitude performance. By comparison the Blackburn Buccaneer was designed to operate at its best at low level and so had very thick wings with rather modest sweep that blessed it with good low level performance but was a relative slouch higher up.

Lightning Red Top

The Lightning was designed for speed and nothing else

Designing aircraft this way was all well and good if it was to have just one mission in mind but the advancement of weapons technology coupled with the increasing costs of fielding fleets of combat aircraft tailored to one role meant that by the advent of the 1960s air forces were increasingly becoming interested in the concept of multi-role aircraft. These aircraft could be configured to attack an enemy airfield one day, carry out reconnaissance the next day and still be adept enough at air-to-air combat to defend itself. It was not an entirely new concept with most fighter aircraft during World War II being used in the ground attack role at some point although they were not as effective as dedicated attack aircraft.

Just how such an aircraft should be designed was the problem facing aerospace engineers of the day. Should it emphasize high speed and altitude performance with a sharply swept, possibly delta, wing or should emphasis be on low level performance where the speeds aren’t as high and so a less sharply swept wing offers the best performance? The answer, many thought, lay in a wing that could change its level of sweep to suit the flight parameters that were required of it at any given time. Where speed was needed the wings could be swept fully back to improve aerodynamic performance but at slower speeds the wings could be swept forward to improve handling. Additionally, the wings could be swept fully forward for landing and take-off to produce the maximum lift thus reducing take-off distance and landing speeds.

Messerschmitt Me P.1101

Messerschmitt P.1101 (

This was the birth of the golden age of variable-geometry wings known more commonly as “swing wings” and there were many proposals for their application in military aircraft. In Britain, a very early leap in to the world of variable-geometry wing technology began when Westland produced the Westland-Hill Pterodactyl experimental aircraft in the 1920s and 1930s that had pivoting wing tips. The Germans took a far greater interest in variable-geometry technology producing the Messerschmitt Me P.1101 although its wings could not be altered in-flight. Instead the aircraft had to be configured on the ground for the type of flight it was expected to undertake. After the war the P.1101 project was transferred to the United States and Bell Aircraft developed the X-5 test aircraft based on Messerschmitt’s research. Back in the UK, the famed inventor of the Vickers Wellington bomber and the “bouncing bomb” used by the Dambusters, Barnes Wallis, proposed a number of tailless designs with variable geometry wings for airliners and bombers but even his genius found stiff opposition from more conservative elements within the Air Ministry.

The problem was the technology for variable-geometry winged aircraft was still very primitive and faced a number of obstacles the biggest one being the sheer weight of the mechanisms used for pivoting the wings. This necessitated a large design with very powerful engines to get it airborne and still have performance comparable to more conventional aircraft. Then there were the problems of having pivoting pylons for weapons so that as the wings swept back they would keep facing forwards; something Soviet engineers didn’t really address with their variable-geometry aircraft until the Sukhoi Su-24. Nevertheless, aircraft technology and research in variable-geometry wings continued through the 1950s at an almost breakneck pace.

Canberra PR.7

GOR.339 sought a replacement for the Canberra medium bomber

In 1957, the British Ministry of Supply issued General Operational Requirement 339 (GOR.339) to Britain’s plethora of aviation companies. The requirement recognised the impending obsolescence of the English Electric Canberra medium bomber in the face of the new high performance Surface-to-Air Missiles (SAMs) being fielded by the Soviet Union and sought a replacement. The requirement went further than simply replacing the Canberra however. It outlined a highly advanced aircraft capable of carrying out several types of combat and reconnaissance (including electronic reconnaissance) missions in the face of a dense threat environment at very low level and high speed. In the typical British pluckiness of the 1950s, Britain’s aviation companies which were revered around the world for their technical skill rose to the challenge.

But 1957 would prove a bad year for manned aircraft development in the UK.

The ink was barely dry on the papers outlining the requirement when the Conservative Government Defence Minister, Duncan Sandys, issued his now notorious 1957 White Paper that brutally cancelled nearly all manned aircraft development on the belief that within the following decade, guided missiles would render them obsolete. GOR.339 managed to survive the chopping board, it possibly being seen as something of a stop-gap until such missiles were made ready, but it was not left unscathed and it was clear that no company’s submission would be taken seriously if it were not in partnership with another. The reasoning behind this was that with few-to-no orders in the foreseeable future the remaining companies would have to settle for shares in all future aircraft projects if they wanted to survive. It was the beginning of the so-called “rationalisation” of the British aviation industry.


BAC TSR.2 (commons.wikimedia)

One such company that responded to GOR.339 was Vickers-Armstrong with whom Barnes Wallis had carried out a lot of his research in to variable-geometry wing technology. Vickers-Armstrong examined ways that the technology could be applied to an aircraft that met the requirements of GOR.339 but when the company was absorbed in to the British Aircraft Corporation or BAC in 1960 the decision was eventually taken to adopt an advanced thin wing design put forward by English Electric in to what became the BAC TSR.2.

However, this was far from the end of the story. BAC still had an interest in variable-geometry wings spurred on by events in the United States where the sophisticated General Dynamics F-111 was taking shape. With TSR.2 set to replace the Canberra, BAC decided to start work on developing an aircraft that could replace the RAF’s fleet of fighter-bombers and light attack aircraft such as the Hawker Hunter FGA.9 that would make use of variable-geometry wings. Designated the P.45 the project did not have official government backing instead being carried out on BAC’s own time and money. Two proposals were put forward for powering the aircraft the first of which saw it powered by two RB.172 turbofan engines based on the French Adour fitted with an afterburner that would have produced around 13,500lbs of thrust for the aircraft. The other proposal called for it to be powered by a single afterburning RB.168 Spey low-bypass turbofan engine which promised even more power but was still under development when BAC approached the government with their project in 1964 (early versions of the engine were only just being fitted to the BAC 1-11 at the time).


BAC P.45 proposal (North West Heritage)

BAC’s timing could not have been worse.

In October 1964, Harold Wilson’s Labour government took power and very quickly began mopping up the survivors of their Conservative predecessor’s 1957 cull of British aircraft development. Within a year the TSR.2 was taken outside and shot; quite literally as some of the completed airframes were used to test the effects of bullets on modern combat aircraft. Not having been financed by the government in the first place the P.45 project survived but without any real financial support was left in limbo.

TSR.2 ii

Scrapped TSR.2s (Key)

Just as British military aircraft development appeared to be coming to an end the new government put forward a vision for its future and that lay in collaborating with other countries. There were a number of benefits to such a policy the biggest being of course the cost. Britain could work with a partner nation on developing an aircraft to suit its needs but only have to contribute a portion of the development and manufacturing costs. This would keep the aviation industry alive and generate a modest return in export sales. It would also have political advantages by strengthening ties both industrially and militarily with the partner nation.

The ideal choice for a partner nation would have been the United States but in the mid-1960s the US economy was booming and this fuelled a defence policy still traumatised by the Cuban Missile Crisis. The US had little to gain from collaborating on defence projects with the UK or anyone else but had plenty to gain from exporting its aircraft to her allies under the Mutual Assistance Program (MAP). Therefore, the UK turned to both an old ally and even older rival; France.

Compared to the UK the French military aviation scene was alive and well thanks in no small part to Dassault’s legendary Mirage III series of supersonic fighter-bombers. The Mirage III, while it certainly looked advanced for its day, was actually a relatively primitive aircraft when compared to the latest US warplanes and while the Mirage did sell reasonably well in Europe it was clear the Americans were leading the pack in sales. What France needed was to develop a technologically advanced but affordable aircraft to meet its own needs and challenge US supremacy in Europe and so Britain and France found themselves turning to one another to start what was an unprecedented aviation partnership. The two countries began looking at their requirements to find those that matched so that work could begin on developing an aircraft to meet both needs. One such project called for an advanced weapons trainer and light attack aircraft and this would lead to the superlative SEPECAT Jaguar while in the civil sector a new project began to show off just what European ingenuity could achieve; a supersonic airliner.

In this new spirit of cooperation work on the P.45 was finally given government support when on May 17th 1965 the two countries signed a Memorandum of Understanding setting out the guidelines for a new European variable-geometry combat aircraft. It was to be called the Anglo-French Variable-Geometry (AFVG) aircraft and a lot was expected of it to say the least. The French were satisfied that their skies were safe with their fleet of Mirage IIIs backed up by NATO and so wanted the aircraft tailored more closely to the strike role. In the UK however the need for a replacement for the English Electric Lightning interceptor fleet was a high priority and so the British wanted an advanced interceptor armed with Beyond Visual Range (BVR) weapons. The French Navy also had a requirement for a carrier capable version tailored primarily for the fighter role although by this time the Royal Navy had settled on the McDonnel Douglas F-4 Phantom II fitted with British engines for its needs.

BAC worked with the French company Breguet Aviation on what would become the SEPECAT Jaguar on the understanding that Breguet would have the lead in the project. As compensation, the French agreed that the UK and BAC should take the lead on the AFVG project working with Dassault Aviation. For the head of Dassault Aviation, Marcel Dassault, this was intolerable. A stout nationalist and aggressive industrialist, Dassault felt his company was going to be weakened by having to play second-fiddle to the British losing both prestige and a percentage of profits from export sales. Even more crucially his company had initiated work on their own variable-geometry aircraft the year before the Anglo-French agreement and wanted to pursue that to meet the French requirements and export overseas.

Dassault Mirage IVA

Dassault Mirage IV (

Dassault would be momentarily silenced in to cooperation however when the position his company was forced in to with BAC had a potentially profitable side effect. The cancellation of TSR.2 left a void in the RAF’s plans for the future which Harold Wilson’s government wanted to fill by buying the expensive and sophisticated General Dynamics F-111K which would be built in the US. With the government not having signed the contract for them yet, BAC turned to Dassault and proposed developing Dassault’s Mirage IV bomber to meet the requirement. The anglicised Mirage IV (known as Mirage IVK or Mirage IV* depending on the source) would be powered by Rolls-Royce Spey engines and feature a weapons package based on that developed for the TSR.2. BAC believed the aircraft could carry out virtually all the roles expected of the TSR.2 and still undercut the American F-111K project as well as keeping BAC employees working until AFVG production ramped up. There were rumours that the French air force was also interested in their own version powered by the more advanced and capable Spey.

Wilson and his Secretary of State for Defence, Dennis Healey, were having none of it however. With the criticism they had received for the cancellation of TSR.2 fresh in their minds they weren’t about to start funding development of another aircraft for the role even one based on an existing airframe already in service with a trusted ally. There were also political considerations to address such as the consequences of apparently preferring a French aircraft over an American one and what that might do to Anglo-US relations especially when the role envisioned was part of the US-led Single Integrated Operational Plan (SIOP) for dealing with the Soviets which meant carrying nuclear weaponry. BAC and Dassault were told in no uncertain terms to drop the idea and concentrate on the AFVG. This only further angered Marcel Dassault which in turn increased his resentment of his company’s position within the AFVG partnership.

AFVG 1965

Early AFVG sketch (commons.wikimedia)

Regardless of Dassault’s objections, the British and French went to work on the aircraft trying their best to reach some kind of agreement on specifications that would suit both British and French needs. As the project went on in to 1966 the aircraft was finally beginning to shape up on paper at least. It was broadly in the same class as the McDonnel Douglas F-4 Phantom II in terms of projected size and weight and similarly would have a crew of two; a pilot and navigator/weapons operator to handle the advanced weapon systems.

Just as BAC and Dassault collaborated on the airframe, Bristol-Siddeley and SNECMA collaborated on the powerplant. The engine chosen was the Bristol-Siddeley/SNECMA M453G turbofan of which there would be two mounted in the rear fuselage with air fed from two intakes mounted forward of the main wing spar. These were unmistakably of Dassault origin resembling those fitted to the Mirage including the distinctive half-shock cone inlets. The M453G was based on a civil engine that was partly funded by the West German government who wanted it to power the VFW-Fokker 614 twin-engined jetliner. The M453G was listed as being rated at 7,100lbs of thrust increasing to 12,230lbs when the afterburner was engaged. The design team believed that with this engine the aircraft would have a service ceiling of 60,000ft and a maximum speed of Mach 2.5 both of which were quite lofty goals for the time.

As the AFVG was gathering momentum however, events outside of the design team’s control began to interfere. By the start of 1966, France’s position in NATO was reaching breaking point. French President, Charles de Gaulle, had grown increasingly frustrated with US dominance within the alliance and on the European continent in general and had instigated a policy of making France free of US influence. This included France building its own nuclear deterrent but when NATO rejected France’s increasing demands for more authority within the alliance as well as trying to coax NATO to support their actions in their former African colonies the French took the drastic step of withdrawing from NATO. US forces based in France were ordered to leave in March 1966 and while French pride may have had a sudden boost its armed forces were worried by the resultant weakening of their defence particularly in the air. Consequently, the French started to look at the AFVG more as a fighter rather than a strike aircraft as they had originally conceived it.

RAF Phantom FGR.2 AIM-9L

RAF Phantom (

This should have played in to the design team’s hands since now they had a much narrower set of requirements to work with since the British and the French Navy had entered the project on the basis of building a missile armed interceptor. However, across the English Channel the Royal Air Force was now finding itself being handed a number of surplus Phantoms from the Royal Navy as Wilson’s government began to decimate the carrier force. The first RAF Phantoms, diverted from a Royal Navy order, were to be based in the UK supporting the Lightning force in the air defence role. This in turn led to the RAF deciding to acquire more Phantoms for use in the close air support and strike roles in Germany until the mid-1970s when they would adopt the fighter role completely from the Lightning. The RAF would therefore need a strike aircraft to replace the strike-role Phantoms in Germany during the 1970s and began to look at the AFVG as the answer to this requirement (ultimately the Jaguar would fulfil this role).

Therefore, somewhat incredibly both countries had reversed their position on just what role they wanted the AFVG to undertake in less than a year with the French now wanting a fighter and the British wanting a strike aircraft. This only further delayed development work as the specifications were revised again and again. Even worse, the UK government was blundering its way through its F-111K acquisition with the Americans and there was talk of rather than the AFVG supporting the F-111K it was going to have to replace it which increased Britain’s requirements for the type even further only to have it then denied and the previous requirements reinstated.

It was madness.

If there didn’t already seem like there was a conspiracy to collapse the project, it was then revealed that Dassault had been building a prototype of their own variable-geometry aircraft the Mirage G as well as working on the AFVG with BAC. This was in-effect a technology demonstrator proving the variable-geometry concept could work and was intended to lay the groundwork for future all-French aircraft just as Marcel Dassault had wanted from the start. The British sensed treachery but the French government insisted it remained committed to the AFVG.

BAC Dassault AFVG

Full-scale mock-up of the AFVG under construction

In order to throw off the stigma of the AFVG being a paper design, BAC began work on the first full scale mock-up to display in 1967 but despite their promises the French were already showing signs of pulling out due to a combination of projected costs spiralling and the increasing criticism of AFVG by junior partner, Dassault Aviation. With the mock-up almost completed, France finally withdrew from the AFVG project in June 1967 citing cost grounds. It came as little surprise to those involved in the project from BAC who had known for a while that the French had lost any genuine interest in it. For the RAF, and certainly Britain’s reputation, worse was to come in November 1967 when the F-111K was cancelled forcing them to absorb more of the Royal Navy’s hand-me-down aircraft such as the Blackburn Buccaneer and McDonnel Douglas Phantom to at long last replace the ageing Canberra.

Feeling somewhat numbed by the whole appalling affair there were mutterings of BAC going it alone and trying to complete the AFVG aircraft as an all-British design. The AFVG title was dropped, replaced by the rather unimaginative name UKVG standing for United Kingdom Variable-Geometry but funding only trickled down it being just enough to keep it alive at least in research form. Despite the shambolic partnership with the French, which to be fair both sides have to share a certain amount of blame, the British government once again told BAC that they had to find European partners if they wanted to turn the UKVG in to an operational aircraft.

The initial response from Europe was far from encouraging but in 1968 fortune finally began to favour the project’s prospects. In what had been dubbed the “sale of the century”, the Lockheed corporation in America had sold vast numbers of their F-104 Starfighters to European nations in the late 1950s and early 1960s. Soon the aircraft was going to need replacing and a research program comprising of a number of F-104 operators such as Belgium, Canada, Italy, the Netherlands and West Germany was set up to look in to developing and building a common NATO-oriented multi-role aircraft to replace the Starfighter. Although not an F-104 operator, Britain managed to negotiate itself in to the study with the intention of submitting the UKVG as a contender. The pitch worked and on March 26th 1969 the UK, West Germany, Italy and the Netherlands (who would later wihdraw) formed a multi-national consortium to develop what was now termed the Multi-Role Combat Aircraft (MRCA) and the starting point was the work carried out on the AFVG and UKVG. Thus, from the ashes of the AFVG rose a phoenix in the form of the Panavia Tornado.

RAF Tornado GR4The Tornado has secured itself a place in British military history as one of the greatest aircraft ever fielded by the RAF proving exceptionally capable in the low-level strike role and being able to adopt a wide array of roles. The RAF even adopted a dedicated fighter variant in the form of the Tornado F.3 which has now been replaced by the Typhoon, another European aircraft built on the foundations laid by Tornado. The Tornado continues in British service today in its highly upgraded GR.4 form and while it may be in the twilight of its career it is still defending the realm battling Islamic State in the Middle East using precision guided weapons.

While the Tornado bears only a superficial resemblance to the AFVG/UKVG it would not have been possible without it.


15 responses to “The Story of the Anglo-French Variable Geometry (AFVG) Aircraft Project

  1. Pingback: Defence of the Realm – Technology | Defence of the Realm

  2. Pingback: Defence of the Realm – Royal Air Force | Defence of the Realm

  3. Pingback: Typhoon a step closer to replacing Tornado GR.4 as RAF’s primary strike platform | Defence of the Realm

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