The General Dynamics F-111 Aardvark is a retired supersonic, medium-range, multirole combat aircraft.
Production variants of the F-111 had roles that included ground attack (e.g., interdiction), strategic bombing (including nuclear weapons capabilities), reconnaissance and electronic warfare.
Developed in the 1960s by General Dynamics, the F-111 entered service in 1967 with the United States Air Force (USAF).
The Royal Australian Air Force (RAAF) also ordered the type and began operating the F-111C variant 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.
The F-111 suffered a variety of problems during initial development.
A fighter variant, the F-111B, was not accepted for production.
The F-111B was intended to perform aircraft carrier-based roles with the US Navy, including long-range interception.
USAF F-111s were retired during the 1990s with the F-111Fs in 1996 and EF-111s in 1998.
The F-111 was replaced in USAF service 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 continued to operate the type until December 2010, when the last F-111C was retired.
The name Aardvark was derived from perceived similarities of the aircraft to the animal of the same name: a long nose and low-level, terrain-following capabilities.
The word aardvark originated in the Afrikaans language, as a contraction of “earth-pig”, and this was the source of the F-111’s nickname of “Pig”, during its Australian service.
The F-111 was an all-weather attack aircraft, capable of low-level penetration of enemy defences 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 aluminium alloys with steel, titanium and other materials used in places.
The fuselage was made of a semi-monocoque structure with stiffened panels and honeycomb structure panels for skin.
The horizontal stabilizer was an all-moving stabilator.
The F-111 used a three-point landing gear arrangement, with a two-wheel nose gear and two single-wheel main landing gear units.
The landing gear door for the main gear, which was positioned in the centre of the fuselage, 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.
The F-111A was the initial production version of the F-111.
Early A-models used the TF30-P-1 engine.
Most A-models used the TF30-P-3 engine with 12,000 lbf (53 kN) dry and 18,500 lbf (82 kN) afterburning thrust and “Triple Plow I” variable intakes, providing a maximum speed of Mach 2.3 (1,450 mph, 2,300 km/h) at altitude.
The variant had a maximum take-off weight of 92,500 lb (42,000 kg) and an empty weight of 45,200 lb (20,500 kg).
The A-model’s Mark I avionics suite included the General Electric AN/APQ-113 attack radar mated to a separate Texas Instruments AN/APQ-110 terrain-following radar lower in the nose and a Litton AJQ-20 inertial navigation and nav/attack system.
The terrain-following radar (TFR) was integrated into the automatic flight control system, allowing for “hands-off” flight at high speeds and low levels (down to 200 ft or 61 m).
Total production of the F-111As was 159, including 30 pre-production aircraft that were later brought up to production standards.
42 F-111As were converted to EF-111A Ravens for an electronic warfare tactical electronic jamming role.
In 1982, four surviving F-111As were provided to Australia as attrition replacements and modified to F-111C standard; these were fitted with the longer-span wings and reinforced landing gear of the C-model.
Three pre-production F-111A were provided to NASA for various testing duties.
The 13th F-111A was fitted with new wing designs for the Transonic Aircraft Technology and Advanced Fighter Technology Integration programs in the 1970s and 1980s.
It was retired to the United States Air Force Museum at Wright-Patterson Air Force Base in 1989.
The remaining unconverted F-111As were mothballed at Aerospace Maintenance and Regeneration Center at Davis-Monthan Air Force Base in June 1991.
The F-111B was to be a fleet air defence (FAD) fighter for the U.S. Navy, fulfilling a naval requirement for a carrier-based fighter aircraft capable of carrying heavy, long-range missiles to defend aircraft carriers and their battle groups from Soviet bombers and fighter-bombers equipped with anti-ship missiles.
General Dynamics, lacking experience with carrier-based aircraft, partnered with Grumman for this version.
The F-111B suffered development problems and Navy requirements changed to an aircraft with manoeuvrability for dogfighting.
The swing-wing configuration, TF-30 engines, AIM-54 Phoenix air-to-air missiles and AWG-9 radar developed for this aircraft were used on its replacement, the Grumman F-14 Tomcat.
The Tomcat would be large enough to carry the AWG-9 and Phoenix weapons system while exceeding both the F-111’s and the F-4’s manoeuvrability.
Seven aircraft were completed for testing, but the model never entered fleet service.
The F-111C is the export version for Australia, combining the F-111A with longer F-111B wings and strengthened FB-111A landing gear.
Australia ordered 24 F-111s and, following delays, the Royal Australian Air Force accepted the aircraft in 1973.
Four of these were converted to the RF-111C reconnaissance variant in 1979–80.
Australia also purchased four ex-USAF F-111As and converted them to C standard.
In the 1990s, F-111C aircraft underwent a comprehensive digital avionics upgrade (known as the AUP) which introduced new nav/attack systems (PAVE TACK Laser /infrared targeting system) and flight control computers.
The RAAF retired its last F-111Cs in December 2010.
The F-111D was an upgraded F-111A equipped with newer Mark II avionics, more powerful engines, improved intake geometry, and an early glass cockpit.
The variant was first ordered in 1967 and delivered from 1970–73.
The F-111D reached initial operational capability in 1972.
Deliveries were delayed due to avionics issues. 96 F-111Ds were built.
The sole operator of this variant was the 27th TFW stationed at Cannon AFB, New Mexico.
The F-111D used the new Triple Plow II intakes, which were located four inches (100 mm) further away from the airframe to prevent engine ingestion of the sluggish boundary layer air that was known to cause stalls in the TF30 turbofans.
It had more powerful TF30-P-9 engines with 12,000 lbf (53 kN) dry and 18,500 lbf (82 kN) afterburning thrust.
The Mark II avionics were digitally integrated microprocessor systems, some of the first used by the USAF, offering tremendous capability, but substantial problems.
The Rockwell Autonetics digital bombing-navigation system included inertial navigation system, AN/APQ-130 attack radar system and Doppler radar.
It also included digital computer set and multi-function displays (MFDs).
The terrain-following radar was the Sperry AN/APQ-128.
The attack radar featured a Doppler beam-sharpening, moving target indication (MTI), and Continuous-wave radar for guiding semi-active radar homing missiles.
It took years to improve the reliability of the avionics, but issues were never fully addressed.
According to Crandall, “The truth is that the D model didn’t work.
They parked every single one of them in Fort Worth for several years as they worked to fix the bugs”.
The F-111D was withdrawn from service in 1991 and 1992.
A simplified, interim variant ordered after the F-111D was delayed, the F-111E used the Triple Plow II intakes, but retained the F-111A’s TF30-P-3 engines and Mark I avionics.
The weapon stores management system was improved, and other small changes made.
Crandall described the F-111E as “all analogue, just like the A model, but It worked”.
The E-model was first ordered in 1968 and delivered from 1969–71.
It achieved initial operational capability in 1969.
The variant’s first flight occurred on 20 August 1969.
94 F-111Es were built.
Many F-111Es were assigned to the 20th TFW at Upper Heyford, UK until 1991.
The avionics were upgraded on some E-models as part of an Avionics Modernization Program.
The variant served in 1990-91 during the Gulf War.
Some F-111Es received improved TF30-P-109 engines in the early 1990s.
All F-111Es were retired to AMARC by 1995.
Crandall described the F-111F as “the Cadillac of the F-111 force”.
It was the final variant produced for Tactical Air Command, with a modern, but less expensive, Mark IIB avionics system.
The USAF approved development of the variant in 1969.
It also included the more powerful TF30-P-100 engine and strengthened wing carry-through box. 106 were produced between 1970 and 1976.
The F-111F’s Mark IIB avionics suite used a simplified version of the FB-111A’s radar, the AN/APQ-144, lacking some of the strategic bomber’s operating modes but adding a new 2.5 mi (4.0 km) display ring.
Although it was tested with digital moving-target indicator (MTI) capacity, it was not used in production sets.
The Mark IIB avionics combined some Mark II components with FB-111A components, such as the AN/APQ-146 terrain-following radar.
The F-111E’s weapon management system was also included.
The F-model could reach Mach 1.2 at sea level on full afterburner.
It used the Triple Plow II intakes, along with the substantially more powerful TF30-P-100 turbofan with 25,100 lbf (112 kN) afterburning thrust, 35% more thrust than the F-111A and E.
An adjustable engine nozzle was added to decrease drag.
The P-100 engine greatly improved the F-111F’s performance.
The engines were upgraded to the TF30-P-109 version, later in the 1985–86 timeframe.
In the early 1980s, the F-111F began to be equipped with the AVQ-26 Pave Tack forward looking infrared (FLIR) and laser designator system, which provided for the delivery of precision laser-guided munitions and was mounted in the internal weapons bay.
The Pacer Strike avionics update program replaced analogue equipment with new digital equipment and multi-function displays.
The last USAF F-111s were withdrawn from service in 1996, replaced by the McDonnell Douglas F-15E Strike Eagle.
The British government cancelled the BAC TSR-2 strike aircraft in 1965, citing the lower costs for the TFX and ordered 50 F-111K aircraft in February 1967 for the Royal Air Force.
The F-111K was to be supplemented later by the Anglo-French Variable Geometry Aircraft then under development.
The F-111K was based on the F-111A with longer F-111B wings, FB-111 landing gear, Mark II navigation/fire control system, and British supplied mission systems.
Other changes included weapons bay modifications, addition of a centreline pylon, a retractable refuelling probe, provisions for a reconnaissance pallet, and a higher gross weight with the use of FB-111A landing gear.
In January 1968, the United Kingdom terminated its F-111K order, citing higher cost; increased costs along with devaluation of the pound had raised the cost to around £3 million each.
The first two F-111Ks (one strike/recon F-111K and one trainer/strike TF-111K) were in the final stages of assembly when the order was cancelled.
All of the components that had been assembled for the production of the main F-111K fleet that shared commonality were diverted to the FB-111A program, while the two aircraft under construction were re-designated as YF-111As with the intention that they be used as test aircraft in the F-111A program.
Ultimately however, the two F-111Ks were never operated as test aircraft in July 1968, almost exactly a year after the first airframe began construction, the US Air Force decided not to take them over, and General Dynamics were ordered to use them for component recovery.
73 ft 6 in (22.40 m)
63 ft (19 m)
32 ft (9.8 m) swept
17 ft 1.5 in (5.220 m)
657.4 sq ft (61.07 m2) spread, 525 sq ft (48.8 m2) swept