During the 1960s, aeronautical designers looked to variable geometry designs to gain the maneuverability and efficient cruise of straight wings with the speed of swept-wing designs. Great Britain and France initiated the AFVG (Anglo French Variable Geometry) project in 1965, which ended with French withdrawal in 1967. In 1968, Germany, Holland, Belgium, Italy, and Canada, facing the retirement of the F-104, formed a working group to examine replacements, initially called the Multi Role Aircraft (MRA), and later called the Multi Role Combat Aircraft (MRCA). Britain joined the MRCA group in 1968, and a memorandum of agreement was drafted between Britain, Germany, and Italy.

The program was intended to produce a single-seat replacement for the F-104G, and a 2-seat strike craft for Britain and Germany. Canada and Belgium pulled out in 1969. The four remaining partner nations - United Kingdom, Germany, Italy, and the Netherlands, formed Panavia Aircraft GmbH on 26 March, 1969, though the Netherlands would pull out in 1970. The United Kingdom and Germany each had a 42.5% stake, with the remaining 15% going to Italy. The scope of work for production was also agreed upon - the front fuselage and tail assemby in England, the center fuselage in Germany, and the wings in Italy. A separate multinational company, Turbo Union, was formed in June 1970 to develop and build the RB199 engines for the aircraft, with ownership similarly split 40% Rolls-Royce, 40% MTU, and 20% FIAT.

At the conclusion of the project definition phase in May 1970, the concepts were reduced to two designs; a single seat Panavia 100 which Germany initially preferred, and the twin seat Panavia 200 which the RAF preferrend and which would become the Tornado. At this point, the aircraft was intended solely for the low-level strike mission. The RAF decided it needed an air defence fighter, and initiated the F2 variant. Though seriously flawed, its shortcomings were quickly corrected for the F3.

The Tornado was originally designed as a low-level supersonic ground attack bomber, capable of taking off and landing in short distances. This requires good high-speed and low-speed flying characteristics. In general, an aircraft which is designed to fly at high speeds usually has poor low-speed characteristics. In order to achieve the desired high-speed performance, an aircraft has a highly swept or ‘delta’ wing platform. However, these wing designs are very inefficient at low speeds where unswept wing planforms are required. In order for an aircraft to be operated efficiently at both high and low speeds, variable wing sweep is a desirable feature; this was incorporated into the Tornado design.



When the wings are swept back, the Tornado GR4 increases its high-speed low-level capability by reducing drag. When sweeping, the wings partially slide into the fuselage, reducing the exposed wing area. This gives the aircraft a low gust response in turbulent low-level winds. This not only makes flight much more comfortable for the aircrew but makes the aircraft a more stable platform from which to aim and deliver unguided weapons at low level.

The aircraft was designed to be land-based and operate from large airfields that were considered to be vulnerable to aerial attack. Therefore, during the development of the aircraft, short field landing capability was considered essential in order to enable the aircraft to operate from short strips on potentially damaged runways and taxiways. With the wings swept fully forwards the Tornado GR4 generates greater lift because of the increased exposed wing area and the utility of full-span flaps and slats. This gives greater lift at lower speeds, reducing the minimum landing speed required and therefore giving shorter landing distances.

In general, when the pilot wants to fly at low speed, they sweep the wings forward (through a selection lever in the cockpit) to maximise lift, and when flying faster they sweep the wings further back. The Tornado GR4 flies at one of 3 levels of wing sweep: 25, 45 and 67 degrees of sweep. There is a corresponding speed range that is appropriate for each level of wing sweep; these change with the configuration of stores on the aircraft, as they directly affect the lift and drag characteristics.