Avro Canada CF-100 Canuck

The Avro Canada CF-100 Canuck (affectionately known as the "Clunk") is a Canadian twinjet interceptor/fighter designed and produced by aircraft manufacturer Avro Canada. It has the distinction of being the only Canadian-designed fighter to enter mass production.
Work commenced during 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", conducted its maiden flight, powered by a pair of Rolls-Royce Avon RA 3 turbojet engines. Both pre-production and production series aircraft were powered by the indigenously-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 , 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 Component. Introduced during 1952 amid the Cold War, the CF-100 was typically deployed at both NATO bases in Europe and in North America as part of North American Aerospace Defense Command (NORAD). In addition to the type's use by frontline squadrons, it was also supplied to operational training units and frequently used for other secondary duties, including aerial reconnaissance and electronic warfare roles. During the early 1950s, the Avro Canada CF-103, an advanced derivative of the CF-100 that adopted a swept wing and was capable of transonic speeds, was in development, but was terminated. Further development of these concepts ultimately led to the Avro Canada CF-105 Arrow.
During 1981, all of the remaining RCAF CF-100s were withdrawn from service, having been succeeded by newer fighters such as the McDonnell Douglas CF-18 Hornet.
Design and development.
Background.
Amid the final years of the Second World War, officials in Canada had concluded both that the development of 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 had commenced work on its own turbojet engine programme, producing the experimental Avro Canada Chinook powerplant. During the late 1940s and early 1950s, events such as the Korean War and Soviet atomic bomb project had contributed to the rising international tensions of what would become known as the Cold War; the Canadian Government decided to respond by greatly increasing defense expenditure. The Royal Canadian Air Force (RCAF) was a major recipient of the expanded budget, reaching 46.6% of overall defense expenditure during FY 1951-1952, some of which is attributable to several major procurement programmes that were conducted.
During this period, the RCAF had a strong interest in acquiring its own fleet of jet-powered combat aircraft. Specifically, the service had identified a need for a new jet-powered interceptor/fighter aircraft that would be able to patrol the vast areas of Canada's north and operate in all weather conditions. Envisaged as a two-seat fighter, to be 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 the aircraft to be operated in all-weather or night conditions. These requirements were formalized by a RCAF specification that was issued during 1946. According to RCAF Air Marshal Wilfred Curtis, there was no existing aircraft that could satisfy the specification, nor was there any suitable aircraft already in development elsewhere, thus it was deemed necessary for Canada to develop such a fighter itself.
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. Out of this effort would emerge the "XC-100", a prototype all-weather fighter, which was 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. 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 overall with white lightning bolts running down the fuselage and engines. On 19 January 1950, the CF-100 prototype flew its maiden flight 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. The Mark 1 was powered by a pair of Rolls-Royce Avon RA 3 turbojet engines, each capable of generating 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 loss and issues encountered, Avro Canada dismissed several members of the design team and established a special working group to rectify a major structural design error identified. To address the latter, a straightforward modification was developed that could be easily retrofitted into the pre-production aircraft. While both prototypes had been powered by Avon engines, the subsequent pre-production and production series aircraft used the locally developed Orenda powerplant instead, the first of which flying during June 1951. As a result of delays encountered in the development of the Orenda, its selection unavoidably impacted the CF-100 programme's timetable as well. Dissatisfied with the pace of development, Cabinet Minister C. D. Howe informed Avro to suspend work on all other projects and focus its efforts on completing the CF-100.
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 any of the British or American-built jet engines that she had previously flown. Initial teething 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 again 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 during the following month. In March 1956, a batch of 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. 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.
Production.
During September 1950, the RCAF placed an initial production order for 124 Mk 3 aircraft, the first of which 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" was to have mounted Sparrow II missiles and been powered by afterburning Orenda 11IR engines; this was intended to be adopted as an "interim" fighter prior to the introduction of the more advanced Avro Canada CF-105 Arrow, which was then under development. 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; this was built in mock-up form during 1951, but was considered obsolete even before the CF-100's demonstrated ability to exceed the speed of sound in a dive. 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.
Operational history.
Amongst RCAF pilots, the Canuck was affectionately known as the "Clunk", the name has been attributed to the noise produced by the forward landing gear during retraction into its well after takeoff. Another common, less attractive, nickname was the "Lead Sled", a reference to its heavy controls and general lack of maneuverability, a nickname that was shared with a number of other 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.
Operationally, many CF-100s functioned under the US–Canadian North American Air Defense Command (NORAD), which protected North American airspace from Soviet intruders, particularly the threat posed by nuclear-armed bombers. Additionally, 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 that was capable of operating in zero visibility and poor weather conditions.
Around the start of the Korean War in the early 1950s, the United States Air Force (USAF) found itself in urgent need of a jet-propelled, all-weather, interdiction/surveillance aircraft. This urgency was so great that the USAF was willing to consider two foreign designs: the CF-100 and the English Electric Canberra. Following an evaluation, the CF-100 was rejected due to its insufficient range and payload capabilities; the rival English Electric design was selected and developed into the Martin B-57 Canberra.
At its peak, the CF-100 served with nine RCAF squadrons in the mid-1950s. Four of these squadrons were deployed to Europe under the NIMBLE BAT ferry program, replacing multiple NATO RCAF squadrons equipped with Canadair Sabre day fighters to provide all-weather defense against Soviet intruders. While flown in the North American theatre, the CF-100 would typically retain a natural metal finish; however, those flying overseas were given a British-style disruptive camouflage scheme: dark sea gray and green on top, light sea gray on the bottom.
During his Avro Canada years, the Chief Development Pilot, S/L Żurakowski, continued to fly as an aerobatic display pilot, with spectacular results, especially at the 1955 Farnborough Airshow where he displayed the CF-100 in a "falling-leaf." He was acclaimed again as the "Great Żura" by many aviation and industry observers who could not believe a large, all-weather fighter could be put through its paces so spectacularly. His performance has been credited with Belgium's decision to purchase the CF-100 for the Belgian Air Force. Additional efforts were made to sell the Canuck to several other nations, including the United States, but no other export customers for the type would be secured. Dow reasoned that the Canuck's poor overseas sales performance caused officials to have little confidence for exporting other aircraft, including the CF-105 Arrow.
During the type's production life, 692 CF-100s of different variants were manufactured, including the 53 aircraft that were delivered to the Belgian Air Force. Although originally designed for only 2,000 flight hours, it was found that the Canuck's airframe could serve for over 20,000 hours before needing to be withdrawn. The Belgian aircraft were either scrapped after storage or written off in crashes. Consequently, though the Canadian CF-100 would be replaced in its front line role by the faster CF-101 Voodoo, the Canuck continued to serve with 414 Squadron of the Canadian Forces, based at CFB North Bay, Ontario; during its later years, the type was tasked with aerial reconnaissance, training and electronic warfare missions. It was finally withdrawn from service during 1981. After the CF-100 was retired, a number of aircraft still remain across Canada (and elsewhere) as static displays.
During the late 1950s, an advanced supersonic interceptor, CF-105 Arrow along with the sophisticated Orenda Iroquois engine, was under development by Avro Canada as an intended successor to the CF-100. However, during 1959, work on the CF-105 was terminated following a controversial decision by the Canadian government.