The General Dynamics F-111 "Aardvark" was a medium-range interdictor and tactical strike aircraft that also filled the roles of strategic bomber, reconnaissance, and electronic warfare in its various versions. Developed in the 1960s by General Dynamics, it first entered service in 1967 with the United States Air Force. The Royal Australian Air Force (RAAF) also ordered the type and began operating F-111Cs in 1973.
The F-111 pioneered several technologies for production aircraft, including variable-sweep wings, afterburning turbofan engines, and automated terrain-following radar for low-level, high-speed flight. Its design influenced later variable-sweep wing aircraft, and some of its advanced features have since become commonplace. During its initial development the F-111 suffered a variety of problems, and several of its intended roles, such as naval interception, with the F-111B, failed to materialize.
General characteristics
- Crew: 2 (pilot and weapons system operator)
- Length: 73 ft 6 in (22.4 m)
- Wingspan:
- Spread: 63 ft (19.2 m)
- Swept: 32 ft (9.75 m)
- Height: 17.13 ft (5.22 m)
- Wing area:
- Spread: 657.4 ft² (61.07 m²)
- Swept: 525 ft² (48.77 m²)
- Airfoil: NACA 64-210.68 root, NACA 64-209.80 tip
- Empty weight: 47,200 lb (21,400 kg)
- Loaded weight: 82,800 lb (37,600 kg)
- Max takeoff weight: 100,000 lb (45,300 kg)
- Powerplant: 2 × Pratt & Whitney TF30-P-100 turbofans
- Dry thrust: 17,900 lbf (79.6 kN) each
- Thrust with afterburner: 25,100 lbf (112 kN) each
- Zero-lift drag coefficient: 0.0186
- Drag area: 9.36 ft² (0.87 m²)
- Aspect ratio: spread: 7.56, swept: 1.95
Performance
- Maximum speed: Mach 2.5 (1,650 mph, 2,655 km/h) at altitude
- Combat radius: 1,330 mi (1,160 nmi, 2,140 km)
- Ferry range: 4,200 mi (3,700 nmi, 6,760 km)
- Service ceiling: 66,000 ft (20,100 m)
- Rate of climb: 25,890 ft/min (131.5 m/s)
- Wing loading:
- Spread: 126.0 lb/ft² (615.2 kg/m²)
- Swept: 158 lb/ft² (771 kg/m²)
- Thrust/weight: 0.61
- Lift-to-drag ratio: 15.8
Armament
- Guns: 1× 20 mm (0.787 in) M61 Vulcan 6-barreled gatling cannon in weapons bay (seldom fitted)
- Hardpoints: 9 in total (8× under-wing, 1× under-fuselage between engines) plus 2 attach points in weapons bay with a capacity of 31,500 lb (14,300 kg) and provisions to carry combinations of:
- Bombs:
- Bombs:
- Free-fall general-purpose bombs
- Mk 82 (500 lb/227 kg)
- Mk 83 (1,000 lb/454 kg)
- Mk 84 (2,000 lb/907 kg)
- Mk 117 (750 lb/340 kg)
- Cluster bombs
- BLU-109 (2,000 lb/907 kg) hardened penetration bomb
- Paveway laser-guided bombs, including 2,000 lb (907 kg) GBU-10, 500 lb (227 kg) GBU-12 and GBU-28, specialized 4,800 lb (2,200 kg) penetration bomb
- BLU-107 Durandal runway-cratering bomb
- GBU-15 electro-optical bomb
- AGM-130 stand-off bomb
USAF F-111 variants were retired in the 1990s with the F-111Fs retired in 1996 and EF-111s retired in 1998. In USAF service, the F-111 has been effectively replaced by the F-15E Strike Eagle for medium-range precision strike missions, while the supersonic bomber role has been assumed by the B-1B Lancer. The RAAF was the last operator of the F-111, with its aircraft serving until December 2010.
The F-111 was an all-weather attack aircraft, capable of low-level penetration of enemy defenses to deliver ordnance on the target. The F-111 featured variable geometry wings, an internal weapons bay and a cockpit with side by side seating. The cockpit was part of an escape crew capsule. The wing sweep varied between 16 degrees and 72.5 degrees (full forward to full sweep). The wing included leading edge slats and double slotted flaps over its full length. The airframe was made up mostly of aluminum alloys with steel, titanium and other materials used in places. The fuselage was made of a semi-monocoque structure with stiffened panels and honeycomb sandwich panels for skin.
The F-111 used a three-point landing gear arrangement with a two-wheel nose gear and two single-wheel main landing gear. The landing gear door for the main gear was positioned in the center of the fuselage and also served as a speed brake in flight. Most F-111 variants included a terrain-following radar system connected to the autopilot. The aircraft was powered by two Pratt & Whitney TF30 afterburning turbofan engines. The F-111's variable geometry wings, escape capsule, terrain following radar, and afterburning turbofans were new technologies for production aircraft.
Armament
Weapons bay
The F-111 featured an internal weapons bay that can carry bombs, a removable 20 mm M61 cannon, or auxiliary fuel tanks. For bombs the bay could hold two 750 lb (340 kg) M117 conventional bombs, one nuclear bomb or practice bombs. The F-111B was to carry two AIM-54 Phoenix long-range air-to-air missiles in the bay. The cannon had a large 2,084-round ammunition tank, and its muzzle was covered by a fairing. However, it was rarely fitted on F-111s.
The F-111C and F-111F were equipped to carry the AN/AVQ-26 Pave Tack targeting system on a rotating carriage that kept the pod protected within the weapons bay when not in use. Pave Tack featured a forward looking infrared (FLIR) sensor, optical camera and laser rangefinder/designator. The Pack Tack pod allowed the F-111 to designate targets and drop laser-guided bombs on them. Australian RF-111Cs carried a pallet of sensors and cameras for reconnaissance use.
The FB-111 could carry two AGM-69 SRAM air-to-surface nuclear missiles in its weapons bay. General Dynamics trialed an arrangement with two AIM-9 Sidewinder air-to-air missiles carried on rails in a trapeze arrangement from the bay, but this was not adopted. Early F-111 models had radars equipped to guide the AIM-7 Sparrow medium-range air-to-air missile, but it was never fitted.
External ordnance
Each wing was equipped for four underwing pylons. The inner two pylons on each wing would rotate to align with the fuselage, while the outer two were fixed. Each pylon had a capacity of 5,000 pounds (2,300 kg). Various bombs and missiles could be carried on the pylons. Auxiliary fuel drop tanks with 600 US gallons (2,300 L) capacity each were also able to be carried.
The design of the F-111's fuselage prevents the carriage of external weapons under the fuselage. But two stations are available on the underside for electronic counter-measures (ECM) pods, and/or datalink pods; one station is on the weapon bay, and the other on the rear fuselage between the engines. The F-111's maximum practical weapons load was limited, since the fixed pylons could not be used with the wings fully swept.
Tactical F-111s were fitted with shoulder rails on the four inner swiveling pylons to mount AIM-9 Sidewinder air-to-air missiles for self-defense. Australian F-111Cs were equipped to launch the AGM-84 Harpoon anti-ship missile, and the AGM-142 Popeye stand-off missile. FB-111As could carry the same conventional ordnance as the tactical variants, but their wing pylons were more commonly used for either fuel tanks or strategic nuclear gravity bombs. They could carry up to four AGM-69 SRAM nuclear missiles on the pylons.
Later swing wing aircraft
The F-111 was the first production variable-geometry wing aircraft. Several other types have followed with similar swing-wing configuration, including the Soviet Sukhoi Su-17 "Fitter" (1966), Mikoyan-Gurevich MiG-23 "Flogger" (1967), Tupolev Tu-22M "Backfire" (1969) and Tupolev Tu-160 "Blackjack" (1981), the U.S. B-1 Lancer bomber (1974), and the European Panavia Tornado (1974). The Soviet Sukhoi Su-24 "Fencer" (1970) was very similar to the F-111. The U.S. Navy's role intended for the F-111B was instead filled by another variable-geometry design, the F-14 Tomcat.
