by Jim Flemming
As early as 1949, the Royal Australian Air Force (RAAF) began planning for a replacement jet fighter for the locally-built Commonwealth Aircraft Company (CAC) version of the North American P-51D/K Mustang and DeHaviland Vampire, then in service with the RAAF. Several designs were under consideration including the Grumman F9F Panther, Hawker P.1081, and their own CA-23 twin-jet, all-weather interceptor. However, none of these designs would win out in the end.
When the Korean War broke out on 25 June 1950, the Australian government committed No. 77 Squadron to the conflict as part of the United Nations forces. The squadron was equipped with Mustang fighters. Because of the growing threat from Soviet MiG-15 jet fighters in the skies over Northwest Korea, the Mustangs were soon replaced with Gloster Meteor Mk. 7 twin-jet fighters. But the Meteors were no match for the speedy MiG-15 either.
The answer that the RAAF found was the same one that the US Air Force realized during the late months of 1950 - the North American F-86 Sabre. In May 1951, plans were finalized for the CAC, who already had a good working arrangement with North American, to build a modified version of the (then) brand new F-86F Sabre. The redesign would feature two major changes - the engine and the armament.
In place of the standard General Electric J47-GE-27 engine, which offered
5910 lbs. of thrust, the CAC engineers installed a Rolls Royce Avon RA-7 engine which was rated at 7520 Ibs. of thrust. However the installation of the Avon engine called for enlarging the intake opening. To preserve the aircraft center of gravity, the engine was moved further aft in the fuselage due to the fact that it was some 400 lbs lighter in weight. Movement of the engine installation also meant that the real fuselage engine service 'break' had to be changed
In addition, the cockpit layout was modified and the fuselage fuel tankage was changed. CAC engineers estimate that some 60% of the airframe had been changed over the original F-86F design. And that didn't include the new armament.
The F-86F was armed with six M3 .50 caliber machine guns. But pilots in Korea complained that the .50 caliber guns weren't heavy enough to knock down the MiGs they encountered, despite the final 10-1 victory ratio in favor of Sabre pilots. The CAC engineers opted to install a pair of Aden 30mm cannons, which had a rate of fire of 1200 rounds per minute. There was one problem, which was also encountered with the re-armed F-86F-2 GUNVAL Sabres that had T160 20mm cannons installed - a lack of space for ammunition. The small Sabre fuseage would only hold 162 of the 30mm rounds. A type A-4 gunsight was used, which was very similar to the one in the F-86F.
Flight controls remained as on the F-86F, including the 'all flying tail' as well as the standard F-86F wing with leading edge slats. The '6-3 hard wing' came later. The new `super' Sabre prototype known as the Sabre Mk. 30 and designated by CAC as CA-26, serial A94-101, was completed in July 1953. RAAF Flt Lt W. Scott made the first flight on 3 August 1953. A94-101 went to the Air Research Development Unit in 1955, and later was used at Wagga for airframe instruction, before finally being used to test ejector seats. A94-101 now resides in the CAC museum at Melbourne.
Production aircraft were designated CA-27 Sabre. The first production aircraft, serial A94-901, flew on 13 July 1954. This aircraft was my personal aircraft when I commanded No. 76 "Black Panther" Squadron at Williamstown. Twenty two CA-27 Sabre Mk. 30s were built. All were powered by imported Avon RA-7 engines, and had the standard Sabre wing with leading edge slats. The Sabre Mk. 31 waspowered by a CAC-built Avon Mk 20 engine and had the new '6-3 hard wing' that North American had developed for the F-86F-25/-30 Sabre. CAC built a total of 20 Mk. 30s.
The final version of the CAC Sabre was the Mk.32. The major difference was introduction of the strengthened wing that had an additional pair of `hard points' to carry extra underwing fuel tanks or ordnance. CAC built a total of 69 Mk. 32 Sabres. In 1960, two additional hard points and wiring were added inboard of the main landing gear. This allowed installation and capability to fire the AIM-9 Sidewinder air to air missile.
The CAC-built Mk. 26 Avon engine was retrofitted to all Sabre Mk. 30/31/32 models, along with the new wing, which effectively brought the entire force to Mk. 32 standard. The last of 112 CAC Sabres, serial A94-973, was delivered on 19 December 1961. The entire CAC Sabre production was delivered to RAAF forces.
The first production aircraft were delivered to the Sabres Trial Flight that was part of No. 2(F) OTU based at RAAF Williamstown on 1 November 1954. The first squadron equipped with the Sabre Mk. 30 was No. 75 Squadron, that became combat operational on 4 April 1955. Before the end of its career with the RAAF, six squadrons were operational with the Avon Sabre - five fighter squadrons and an Operational Conversion Unit.
When the communists attempted a takeover in Malaysia in the late 1950s, the RAAF committed several squadrons to the conflict under the provisions called for in the South-East Asia Treaty Organization (SEATO) agreements. Beginning in early 1959, Nos. 3 and 77 Squadrons flew ground attack and counter-insurgency missions, ending their involvement in mid-1960.
On 1 June 1962, eight Avon Sabres deployed to Ubon Royal Thai AFB to counter the growing communist threat in Southeast Asia. The detachment was formed into No. 79 Squadron, and remained on alert status at Ubon until August 1968. Their mission was flying top cover over the Thai air bases that were supporting the ongoing war against North Vietnam.
Beginning in 1964, the Avon Sabre squadrons were phased out and replaced with Mirage III aircraft. As the Sabres were phased out, several were put up for sale, with both Mayasia and Indonesia purchasing many of the Avon Sabres from RAAF inventories. Finally, on 31 July 1971, the RAAF officially retired the Commonwealth Aircraft Company CA-26/-27 Sabre from service.
No portion of this article may be used or reprinted without permission from the President of the F-86 Sabre Pilots Association or the editor of Sabre Jet Classics magazine.
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