A multipurpose tactical fighter/bomber capable of supersonic speeds, the F-111 was one of the most controversial military aircraft to ever fly, yet it achieved one of the safest operational records of any plane in United States Air Force history. The F-111 provided many firsts among weapons systems as well as being the first production aircraft with variable wings that could be swept back or brought forward to increase efficiency.

In early 1960, proposals that would lead to the development of the F-111 were issued to Boeing, Lockheed, Northrop, General Dynamics, Grumman, McDonnell, and Douglas Aircraft in dual response to the U.S. Navy’s need for a long-range carrier defense fighter to replace the F-4 Phantom and the F-8 Crusader, and the U.S. Air Force's requirement for a long range/high and low-altitude bomber.

The Air Force's Tactical Air Command expressed great desire for a fighter bomber with the ability to penetrate Soviet air defenses at extremely low altitude, but at the same time very high speeds to deliver nuclear weapons systems against crucial targets such as airfields, supply depots, and munitions dumps. Specifications for the request included a combat radius of nearly 900 miles, a low-altitude speed of Mach 1.2 and a high-altitude speed of Mach 2.5. The Air Force was not at first concerned with maneuverability, or cannon armament, but with good field performance and the ability to reach Europe without the need to refuel.

Meanwhile, the Navy had realized its own need for a high-endurance interceptor to defend aircraft carrier fleets against Soviet jet bombers that were being armed with nuclear anti-ship missiles capable of annihilating the large ships and their crews with an estimated zero survivability rate. The Navy required an aircraft with more load-carrying ability, a more powerful radar than the F-4 Phantom was designed for, and the capability to wield an array of long range weapons to intercept both bombers and missiles.

After a series of subsequent proposals the Department of Defense awarded the contract to General Dynamics in November of 1962, in part because the General Dynamics design promised to be more affordable and allow greater commonality with both requests.

General Dynamics presented an experimental aircraft in the 20-ton class with a maximum take-off weight of almost 50 tons. They had intended to use titanium for large portions of the fuselage to save weight, but this proved prohibitively expensive. The plane was powered by two afterburning Pratt & Whitney TF30-P-100 turbofans. Shoulder-mounted wings were attached to a pair of large pivots, allowing it to take off, land, loiter and cruise at high subsonic speeds with its wings forward, which offered the greatest surface area and amount of lift. When the wings were swept backwards the aircraft became streamlined for supersonic dashes at more than Mach 2. When landing, the wings would once again be spread, eliminating the need for a drag parachute or for reverse thrusting.

Largely at Navy insistence, the F-111 had a two pilot crew who were to be seated next to one another, and production versions did not have ejection seats but instead used a pressurized crew compartment that could be ejected as a self-contained escape capsule. When activated, explosive charges around the module would detonate and separate the cockpit from the aircraft and would then deploy a 70 ft parachute to bring the compartment safely to the ground. Airbags cushioned impact and helped to keep the module afloat in water. The module could be released at any speed or altitude, even under water. If the F-111 was put down into a body of water, the airbags raised the module to the surface after it had been severed from the plane.

The Aardvark could carry conventional as well as nuclear weapons, four mounted externally with two warheads and additional fuel in the internal weapons bay. External ordnance could also include combinations of bombs, missiles and fuel tanks. The weapon s nearest the fuselage on each side pivoted on anchors as the wings swept back, keeping ordnance parallel to the body of the craft. Weapons pylons near the tips of the wings did not pivot but could be jettisoned if supersonic speeds were needed with short notice.

A revolutionary automatic terrain-following radar system flew the craft at a constant altitude following the Earth's contours much like the cruise control system in a civilian vehicle manages speed. The system allowed the aircraft to fly in valleys and over mountains, day or night, and regardless of weather conditions. Should any of the system's circuits have failed, the aircraft automatically initiated a climb and the pilot would take manual control.

The first flight of the F-111A, as the Air Force version was designated, took place in December of 1964, and entered into service in July of 1967. The Navy never adopted an F-111 model, opting instead for the Grumman F-14 Tomcat which featured the same swept wing design, Pratt & Whitney TF30-P-100 turbofan engines, and weapons capabilities. The Tomcat entered service in 1968.

Able to fly in weather conditions that would ground most aircraft, the F-111 could also carry the equivalent ordnance load of four F-4 Phantoms and during the Viet Nam conflict although over 4000 missions were flown, only six combat losses occurred.

Commonly referred to as the "Aardvark" because of the elongated nose used to house its radar system, the F-111 was never officially given the name until its retirement ceremony to the United States Air Force Museum in 1992.

Length: 73 feet, 6 inches
Height: 17 feet, 1 1/2 inches
Wingspan: 63 feet full forward; 31 feet, 11 inches full aft
Speed: Mach 1.2 at sea level; Mach 2.5 at 60,000 feet
Ceiling: 60,000-plus feet
Range: 3,565 miles with external fuel tanks
Weight Empty: 47,481 pounds
Maximum Takeoff Weight: 100,000 pounds
Crew: Two, pilot and weapon systems officer