The Avro Canada CF-100 Canuck (affectionately known as the "Clunk") is a Canadian twinjet fighter-interceptor designed and produced by aircraft manufacturer Avro Canada. It was the only Canadian-designed fighter to have entered mass production.
Work commenced in October 1946 in response to a Royal Canadian Air Force (RCAF) specification calling for a new jet-powered interceptor/fighter aircraft suitable for long-distance patrol missions and all-weather operations. On 19 January 1950, the CF-100 Mark 1 prototype, 18101, had its maiden flight, powered by a pair of Rolls-Royce Avon RA 3 turbojet engines. Pre-production and production series aircraft were powered by the domestically-developed Avro Orenda engine instead. Flight testing proved the CF-100 to possess a relatively short takeoff run and a high climb rate, making it well suited to its role as an interceptor. On 18 December 1952, Squadron Leader Janusz Żurakowski, the Avro company chief development test pilot, took the CF-100 Mk 4 prototype up to Mach 1.10 in a dive from ,Page 1981, p. 64. making the type the first straight-winged jet aircraft to achieve controlled supersonic flight.
The CF-100 principally served with the Royal Canadian Air Force and Canadian Armed Forces; it was also procured in small numbers by Belgium to equip the Belgian Air Force. Introduced in 1952 during the Cold War, the CF-100 was typically deployed at NATO bases in Europe, and in North America as part of North American Aerospace Defense Command (NORAD). In addition to use by frontline squadrons, it was also supplied to operational training units and frequently used for secondary duties, including aerial reconnaissance and electronic warfare roles. In the early 1950s, the Avro Canada CF-103, an advanced derivative of the CF-100 with a swept wing and capable of transonic speeds, was cancelled during its development. Concepts explored for the CF-103 ultimately led to the CF-105 Arrow.
From 1961, RCAF CF-100s were withdrawn from the interceptor role, replaced by the McDonnell-Douglas CF-101 Voodoo; some were reallocated to support roles. In 1981, all remaining CF-100s were withdrawn from service. They were replaced in training and electronic warfare roles by the Canadair CT-133 Silver Star and the CC-117 Falcon respectively.
Design and development Background Amid the final years of the Second World War, officials in Canada had concluded a self-sufficient indigenous military aviation industry would be of considerable national value, and that the new field of jet propulsion held considerable promise. As early as July 1944, Canada commenced work on a turbojet engine programme, producing the experimental Avro Canada Chinook powerplant.Dow 1997, pp. 62-63. During the late 1940s and early 1950s, events such as the Korean War and Soviet atomic bomb project contributed to the rising international tensions of what would become known as the Cold War. The Canadian government responded by greatly increasing defense expenditure.Dow 1997, pp. 66-70. The Royal Canadian Air Force (RCAF) accounted for 46.6% of overall defense expenditure during FY 1951–1952, some of which is attributable to several major procurement programmes.Dow 1997, p. 70.
The RCAF had a strong interest in acquiring its own fleet of jet-powered combat aircraft. It identified a need for a new jet-powered interceptor/fighter aircraft capable of patrolling the vast Canadian north and operating in all-weather conditions. Envisaged as a two-seat fighter crewed by a pilot and navigator, it would adopt two powerful engines along with a relatively advanced radar set and fire control system housed in its nose that would enable all-weather and night flying. These requirements were formalized by a RCAF specification that was issued during 1946. According to RCAF air marshal Wilfred Curtis, no existing aircraft satisfied the specification, nor was there any suitable aircraft already in development elsewhere. Thus, it was necessary for Canada to develop such a fighter itself.Dow 1997, pp. 64-65.
On 3 November 1945, an agreement was struck to develop a prototype jet-powered fighter on behalf of the RCAF; on 13 October 1946, the issuing of government contracts to aircraft manufacturer Avro Canada enabled the company to commence the associated design work.Dow 1997, p. 63-65. From these efforts emerged the XC-100, a prototype all-weather fighter, developed to meet the outstanding specification. Work was initially overseen by Edgar Atkin, Avro Canada's chief engineer. A key contributor to the programme was ex-de Havilland aircraft designer John Frost, who was appointed chief design engineer for military projects and thus responsible for the CF-100's development.Dow 1997, p. 69. At one stage Frost, along with Avro's chief aerodynamacist Jim Chamberlin, extensively reworked the original design of the fuselage. On 17 May 1949, in response to the programme's progress, an additional agreement was reached to produce ten pre-production fighters along with 30 Avro Orendas, an indigenously-developed turbojet engine.
Flight testing The CF-100 Mark 1 prototype, 18101, emerged from the factory painted gloss black, with white lightning bolts running down the fuselage and engines. On 19 January 1950, the CF-100 prototype flew its maiden flight from Malton, Ontario with Gloster Aircraft Company chief test pilot squadron leader Bill Waterton (on loan from Gloster, then also part of the Hawker Siddeley group) at the controls.Rossiter 2002, p. 63. The Mark 1 was powered by a pair of Rolls-Royce Avon RA 3 turbojet engines, each capable of a maximum thrust of 28.9 kN (2,950 kgp / 6,500 lbf) thrust. During July 1950, the second prototype, 18102, performed its first flight. On 5 April 1951, the second prototype was lost in an accident that killed test pilot Bruce Warren. According to aviation author James Dow, this loss resulted in the programme being placed on indefinite hold and questions raised over Avro Canada's competency.
In response to the accident, Avro Canada dismissed several members of the design team and established a special working group to rectify a major structural design error. A straightforward modification that could be easily retrofitted into the pre-production aircraft was devised to solve the problem. While both prototypes had been powered by Avon engines, pre-production and production aircraft used the locally-designed Orenda powerplant instead, the first of which flew in June 1951. Delays during the Orenda's development disrupted the CF-100 programme timetable. Dissatisfied with the pace of development, Cabinet Minister C. D. Howe instructed Avro to suspend its other projects to focus entirely on completing the CF-100.Dow 1997, pp. 70-72.
Five pre-production Mk 2 test aircraft (serial numbers 18103-18107) were produced, all fitted with Orenda 2 engines; one was fitted with dual controls and designated a Mk 2T trainer. According to pilot Jacqueline Cochran, the Orenda engine responded noticeably smoother than the British or American-built jet engines she had previously flown.Dow 1997, p. 73. Initial issues with the pre-production aircraft were soon resolved. The first production version, designated Mk 3, made its first flight during October 1952. The Mk 3 incorporated the APG-33 radar and was armed with eight .50 caliber Browning M3 machine guns. The Mk 3CT and Mk 3DT were dual control versions supplied to operational training units.
During mid-January 1955, a CF-100 arrived at Eglin AFB, Florida, for cold-weather tests in the climatic hangar. A seven-man RCAF team, headed by flight lieutenant B. D. Darling, which had previously conducted tests at Namao Air Base, Alberta, were part of the climatic detachment of Central Experimental and Proving Establishment. Testing commenced the following month."Eglin Will Test New All-Weather RCAF Interceptor". The Okaloosa News-Journal, Crestview, Florida, Volume 41, Number 3, 20 January 1955, p. 6. In March 1956, four CF-100 Canucks were dispatched to Eglin AFB to conduct comparative armament trials, where the type was flown by several United States Air Force (USAF) crews."ADA-Arrow Pilots: Jan Zurakowski." Avroarrow.org. Retrieved: 31 October 2011. The operational suitability tests, dubbed Project Banana Belt, were carried out by the 3241st Test Group (Interceptor) of the APGC's Air Force Operational Test Center, in conjunction with a project team belonging to the RCAF."Eglin Tests Latest Canadian Jet Model". The Okaloosa News-Journal, Crestview, Florida, Volume 42, Number 14, 5 April 1956, p. 20.
Production During September 1950, the RCAF placed an initial production order for 124 Mk 3 aircraft, the first entering service in 1953. This model was armed with eight .50 caliber machine guns. The definitive rocket-armed Mk 4A was based on the prototype Mk 4 (a modified Mk 3), which first flew on 11 October 1952. The nose housed the much larger APG-40 radar, while the wings were equipped with wingtip pods, each containing up to 29 Mk 4/Mk 40 "Mighty Mouse" folding-fin aerial rocket, to be used in addition to the guns. During 1954, the last 54 of an order for the Mk 3 were swapped for the more advanced Mk 4, the total orders for the Mk 4 rose to 510. The Mk 4B version was furnished with more powerful Orenda 11s.
Five versions, or marks, were produced. The high-altitude Mk 5 was the final variant, production of which commenced during 1955. This model featured a -longer wingtip and enlarged tailplane, along with removal of the machine guns. The proposed Mk 6 would have been equipped with Sparrow II missiles and afterburning Orenda 11IR engines. It was intended as an "interim" fighter until development of the advanced Avro Canada CF-105 Arrow concluded, though the Arrow was also cancelled. An advanced derivative of the CF-100 was the CF-103, which was equipped with a swept wing and projected to be capable of transonic speeds; a mock-up was made in 1951, but it was considered obsolete even before the CF-100 performed a dive that exceeded the speed of sound. On 18 December 1952, squadron leader Janusz Żurakowski, the Avro company chief development test pilot, took the CF-100 Mk 4 prototype to Mach 1.0 in a dive from , becoming the first straight-winged jet aircraft to achieve controlled supersonic flight.Whitcomb 2008, p. 89.
Operational history
Amongst RCAF pilots, the Canuck was affectionately known as the "Clunk".Dow 1997, p. 74. The nickname has been attributed to noise produced by the forward landing gear as it retracted into its well after takeoff. Another common nickname was the "Lead Sled", alluding to its heavy controls and low maneuverability; this nickname was shared by numerous 1950s aircraft. Others included CF-Zero, the Zilch, and the Beast, all references to an aircraft many pilots considered less glamorous than RCAF day fighters like the Canadair Sabre."CF-100 Veterans Reunite." Comox Valley Echo, 18 September 1998. Retrieved: 7 February 2010.
Many CF-100s functioned under the US–Canadian North American Air Defense Command (NORAD), which protected North American airspace from Soviet intruders, particularly by nuclear-armed bombers. Between 1956 and 1962, as part of the North Atlantic Treaty Organization (NATO), four CF-100 squadrons were based in Europe with 1 Air Division; for some time, the CF-100 was the only NATO fighter capable of operating in zero visibility and poor weather conditions.Baglow pp 101-113