In Active Service

Number 6 Squadron was formed in 1939, equipped with Anson aircraft, and based in New South Wales. After reequipping with Hudsons, the squadron moved to Milne Bay, New Guinea. Later, with Beaufort bombers, the squadron took part in the air bombardment of captured New Guinea. After the war, Lincoln bombers were used during the atomic weapons trials off Western Australia for tracking radioactive clouds. Canberras replaced the Lincolns, and in 1970 Phantoms in turn replaced the Canberras. Today, the unit is based at RAAF Amberley along with No. 1 Squadron.

Role

Contrary to the views quite often expressed by the media, the F-111C is not a fighter. In fact, the RAAF’s F-111s are specialised bomber aircraft fulfilling the strike role. The aircraft was developed for strategic and tactical strike missions, with single aircraft flying below the enemy radar at very high speeds to drop weapons accurately on targets of strategic or tactical importance. Additionally, the RAAF operates its aircraft in the maritime strike role, where a number of aircraft are directed to, or locate and destroy seaborne targets. Four aircraft are usually employed, often directed by a P-3 Orion, and attack the target in a precisely timed tactic from different directions in order to saturate enemy defences. Only one pass at the target is made.

On a typical strike mission, the aircraft takes off and climbs to a fuel-efficient transit altitude of 15,000 to 25,000 feet until it approaches the fringes of the enemy radar range. Then the F-111 descends to 500 feet and engages the terrain following the radar (TFR) system until the run-in, taking advantage of natural obstructions that aid in “hiding” the aircraft from radar. After bombing the target, the F-111 may fly on to a second target if necessary before returning to base. If necessary, the aircraft can fly at supersonic speeds in the TFR mode, where virtually no fighter today can catch it.

In 1979/80, four F-111C aircraft were fitted with a General Dynamics reconnaissance package, tailored to AMF specifications, providing a day and night reconnaissance capability far superior to that of the Canberras, Mirages and Orions which also have facilities for photo-reconnaissance.

Perhaps more than any other RAAF aircraft, the F-111 is a crew aeroplane; the pilot and navigator must function as a team in order to efficiently operate the aircraft. Each mission is planned thoroughly, and timing accuracy for each flight is expressed in terms of ± 5 seconds. Number 1 Squadron is totally responsible for all operational strike missions, while Number 6 Squadron carries out the operational strike training for both squadrons and also operates reconnaissance missions. Before conversion to F-111s, prospective crews complete a 10-week fighter conversion course on Mirage 111-Ds at 2 OCU, RAAF Williamstown. All aircraft are pooled with Number 284 Maintenance Squadron, who carry out maintenance of the F-111Cs exclusively.

The Aircraft

The F-111 was the world’s first operational and variable geometry or swing-wing aircraft. The General Dynamics proposal for a tactical fighter was originally known as the TFX, until November 1962 when the United States Government selected the General Dynamics design over its Boeing competitor to become the F-111. An initial contract for 23 developmental aircraft was placed, of which 18 were for the USAF and five for the US Navy. The USAF F-111A was developed as a tactical fighter bomber, the F-111B as a Navy carrier-based fighter, the F-1110 and E as updated F-111As, the F-111F another USAF version, the FB-111A as a strategic bomber, and the RF-111A reconnaissance aircraft. In addition, the British Government originally ordered 50 F-111K versions but cancelled the order after two aircraft had been completed. These aircraft were re-assigned to the USAF.

Twenty-four F-111C versions were produced as two-seat strike aircraft, specifically for the Royal Australian Air Force, and are outwardly similar to the FB-111A. The C is powered by two Pratt and Whitney TF30-P-3 turbofans (as in the F-111A), each of 18,500 lb (8390 kg) with afterburning. Fuel is stored in the wings and fuselage, and the aircraft has air-air refuelling capabilities. Additionally, fuel can be carried externally. The wing has a sweepback variable from 16° to 72°, controlled by a lever on the left side of the cockpit. Six underwing hardpoints enable the aircraft to carry a multiplicity of external weaponry. The four inboard pylons pivot as the aircraft wing sweeps back to keep the stores parallel with the fuselage. A multi-barrel 20 mm cannon is carried in an internal weapons bay, but is virtually redundant in the strike role. The pilot and navigator are accommodated side-by-side in an air-conditioned and pressurised cabin. A zero speed – zero altitude (including underwater) rocket-propelled module, developed by McDonnell Douglas, provides the crew with a unique escape system. The capsule is buoyant and provides a survival shelter. The loaded aircraft weighs over 91,000 lbs (41,000 kg), or roughly three times that of a loaded Mirage. The F-111 is 73 ft 6 in (22. 4 m) in length and has a wing span that varies from 70 ft (21. 34 m), extended for low-speed manoeuvrability, to 33 ft 11 in (10. 34 m), swept for high speed, low drag.

The aircraft is fitted with an automatic terrain following a radar system, enabling the aircraft to fly at up to supersonic speeds (Mach 1. 2), with afterburner, and as low as 200 feet, with hard, medium and soft ride. At height, the F-111 can fly at speeds up to Mach 2. 5 and has a maximum range on internal fuel of over 3000 miles (5000 km).

The four reconnaissance RF-111C aircraft were fitted with an $8 million sensor package. The fit involved replacing the gun in the weapons bay with a sensor assembly containing a television view-finding system, an infra-red line scan, high altitude radar altimeter, high and low-altitude panoramic cameras, and split vertical cameras. A Photographic Processing and Interpreting Facility was established for the RF-111C programme. The reconnaissance aircraft do not lose any strike capability with the fit.

The RAAF hopes to operate its F-111 fleet for many years to come, and despite the age of the aeroplane, it remains the most capable strike aircraft in the world. One of the fastest aircraft at low level, and an aircraft with the lowest operational wastage rate. It has also earned a place in the history books as the first variable geometry combat aircraft.