No project combined radical innovation and political furore quite like the F-111 program. It was intended as the world's biggest, most expensive defence procurement plan when it began in 1962. The aim was 'commonality'; the equipment of the USAF, US Navy and several foreign customers with a single type of fighter. It produced a superb strike aircraft which played a crucial role in three conflicts and was the only aircraft specifically mentioned by Moscow in the SALT disarmament talks that preceded the end of the Cold War. Its successors, the F-15E Eagle, B-1B Lancer and Panavia Tornado owe much to the experience gained on the F-111 Aardvark.<br><br>The variable-sweep wing and the turbofan jet engine enabled a large, heavily armed, two-seat fighter-bomber to operate from aircraft carriers and 3,000 ft unpaved runways with sufficient fuel economy to fly very long-range nuclear interdiction or combat patrol missions at speeds up to Mach 2.5. Contract negotiations always favoured the USAF's priorities. The weight of the Navy version, the F-111B soon made it impossible to operate it from aircraft carriers and it was abandoned. The USAF, meanwhile persisted with its F-111A version to replace the F-105 Thunderchief. Massive cost increases and design issues delayed and disrupted their use for a decade.<br><br>The F-111A's return to Vietnam in September 1972 showed the aircraft to be extremely successful in pin-point attacks on targets in all weathers, mainly at night, using its terrain following radar and heavy loads of external ordnance. It was used in 1986 for a long-range punitive attack on Libya, and in Operation Desert Storm both F-111 wings were the principal strikers against Saddam Hussein's planes and tanks. With ECM and pioneering digital avionics versions, the sheer variety of F-111 sub-types, all built in comparatively small numbers that partly caused its eventual withdrawal from USAF use in the late 1990s for cost reasons. The Aardvark's career ended in 2010.<br><br>Despite its uncertain start the F-111 proved to be one of the most successful and influential designs of the 1960s. Its radical 'swing wing' was adopted by the F-14 Tomcat, Panavia Tornado and Rockwell B-1B Lancer while its turbofan-type engines became standard in many combat aircraft. F-111 crews pioneered tactics using terrain-following and laser targeting devices that made the F-15E Eagle's missions possible. Its 4,000 low-altitude penetration missions during Operation Linebacker in Vietnam proved that solo aircraft deliver crippling blows to enemy capability with impunity.<br><br>The F-111's retirement appears to have created a surge of interest in the type. Visually dramatic in appearance, the F-111 versions have appeared in a variety of colour schemes. Some had striking nose art and some of my unique collection of these images could appear in colour for the first time.