Canada's Cold War Sentinel: The "Clunk"

By Jon Guttman

From Volume 23 Issue 2 (March 2016)

 The prototype A.V. Roe Canadaa CF-100 serial No. 18101 made its maiden test flight from Malton, near Toronto, on January 19, 1950. (Association of Medical Faculties Of Canada)

The prototype A.V. Roe Canadaa CF-100 serial No. 18101 made its maiden test flight from Malton, near Toronto, on January 19, 1950. (Association of Medical Faculties Of Canada)

The Cold War that arose between the Western Allies and the Soviet Union after the Second World War got a bit hotter — at least under the collar — in 1949, when the North Atlantic Treaty Organization (NATO) became aware that the Soviet Union had successfully tested its own nuclear weapon, along with the equally unwelcome news that it had a delivery system in the form of the Tupolev Tu-4, essentially a reverse-engineered copy of the Boeing B-29. One response from the North American Aerospace Defense Command (ADC) was a phalanx of radar across the Arctic approaches known as the Distant Early Warning (DEW) Line, backed by a new generation of radar-equipped jet interceptors capable of operating under all conditions of weather and visibility.

The United States had already put its considerable resources to the matter of air defence back in 1946, and by 1948 it was evaluating the big, four-engine Curtiss XF-87, whose failure doomed Curtiss-Wright to bankruptcy, and the slimmer twin-engine Northrop F-89 Scorpion. When the latter’s development underwent setbacks and delays, the U.S. Air Force hedged its bets with two other fighters based on proven airframes. Lockheed’s F-94 Starfire was essentially a radar and missile equipped version of its two-place T-33 trainer, while the single-seat North American F-86D was an enlarged F-86A Sabre jet with a prominent radar nose and a retractable tray of Mickey Mouse rockets. 

On August 15, 1952, these three American stopgap aircraft found themselves serving alongside unexpected company when a fourth all-weather interceptor arrived at ADC North Bay, Ontario. Canada’s first indigenously designed jet fighter, the CF-100 Canuck, was taking its place along the DEW Line.

As with the United States, Canada’s military and industrial capacity had grown exponentially during World War II, including the establishment of A.V. Roe Canada at Malton, Ontario. And as the Americans had done in response to the game-changing challenges of the jet age and the Cold War, Royal Canadian Air Force Air Vice-Marshal Wilfred A. Curtis called upon the new firm to produce a jet interceptor, the CF-100, as well as the CF-101 jet trainer and the CF-102 airliner.

It seemed like expecting a child to sprint after barely having begun crawling to expect something that sophisticated from so new a company, but Avro Canada’s personnel devoted 450,000 man-hours to the challenge (compared to the 42,000 man-hours it took to design the North American P-51 Mustang), at a cost of $150 million before the prototype even took to the air. Besides the airframe, the company was creating its own engine, the Orenda, on top of which templates, jigs, dies and machine tools had to be assembled for mass production and space made available for the vast facilities in which to house them all — all on what, for Canada, was an unprecedented scale.

Chief Edgar Atkins initially headed the XC-100 project, but his design was subsequently handed off to former de Havilland engineer John Frost and Avro chief aerodynamicist Jim Chamberlin, who reworked the fuselage. On January 19, 1950, some three years after the project was launched, Squadron Leader Bill Waterton, chief test pilot for Gloster Aircraft, took the prototype CF-100 Mark I, serial No. 18101, up for its first flight using Rolls-Royce Avon RA3 engines, since the Orendas were not yet ready. The ill-fated second prototype, 18102, crashed on June 23, 1951 — the very day it was delivered to the RCAF — but the first, initially painted gloss black with white lightning bolts, but later reverting to more conventional RCAF livery, faithfully performed preliminary flight tests and rocket firing exercises for 15 years before being retired to a disposal depot. Ten pre-production Mark 2s followed, but the breakout of the Korean War in June 1950 induced the Canadian government to order 124 CF-100s — a number greatly raised in February 1951, after the commitment of Chinese troops escalated the conflict.

On August 15, 1952 the RCAF accepted its first CF-100 Mark 3, armed with eight 12.7mm Colt-Browning machine guns in an innovative tray-like gun pack that could, when ammunition was expended, be replaced outright, minimizing ground time. Powered by two Orenda 8 turbojets producing 6,000 lbs. of static thrust each, the first Mark 3s entered service with No. 445 (All-Weather) Fighter Squadron and No. 3 (AW) Operational Training Unit at ADC North Bay. The Mark 3 was only an interim model and only 70 were built before it was superseded by the improved Mark 4 — the prototype for which, 18112, actually flew on October 11, 1952, the same day as the first Mark 3. As training and testing proceeded, on December 18 a CF-100 diving from 30,000 feet is believed to have become the first straight-wing combat plane to exceed the speed of sound.

The CF-100 Mk 4 replaced the smooth nose of its predecessors with a more bulbous one housing a Hughes MG-2 fire control system and PG-40 airborne gun-laying radar in place of the Mark 3’s APG-33. Its Orenda 9 engines produced 6,335 lb. of thrust each, and its wing tips could mount rocket pods, each housing 29 70mm folding-fin projectiles, in lieu of auxiliary fuel tanks. Additionally, the framed canopy was replaced by a one-piece, rearward-sliding blister canopy that afforded the crew unobstructed vision.

After 147 CF-100 Mk 4As were produced, the first of a total of order of 194 Mk 4Bs was accepted in November 1955, which featured Orenda 11s, each with 7,275 lb. of static thrust and the option of a ventral rocket pack in place of the machine guns. By mid-1955 CF-100 Mk 4s were equipping Nos. 409, 419, 423, 425, 428, 432, 423, 440 and 445 Squadrons. On March 25 three CF-100s became the first Canadian-designed jets to cross the Atlantic as they flew to Britain, where the decision was made early in 1956 to provide NATO with much-needed all-weather capability by assigning CF-100 squadrons to each fighter wing in Europe. These were 445 Squadron serving 1 FW at Marville, France, 423 Squadron with 2 FW at Gros Tenquin, France, 440 Squadron with 3 FW at Zweibrücken and 419 Squadron with 4 FW at Baden-Soellingen, the last two bases being in the German Federal Republic.

 CF-100 Mark 4Bs of 445 Squadron, the first unit to receive Canucks, and on November 4, 1956, the first to arrive in France to be NATO's first all-weather fighter squadron. (DND)

CF-100 Mark 4Bs of 445 Squadron, the first unit to receive Canucks, and on November 4, 1956, the first to arrive in France to be NATO's first all-weather fighter squadron. (DND)

Officially designated the Canuck but more popularly called the “Clunk” for the distinctive sound its landing gear made as it retracted, the CF-100 swiftly distinguished itself, even against the Orenda-powered Canadair Sabres that patrolled European skies by day while six Canucks stood at constant readiness for the night shift. “The normal European weather (if there is such a thing) had a visibility of about three miles in haze and some clouds,” noted 4 FW’s Pictorial History Record. “In winter, thick fog and/or an overcast cloud layer are the norm. Under these conditions, the all-weather capabilities of the CF-100 team soon became apparent….”

The principal CF-100 variant, the Mark 5, first flew in September 1954 and production began on October 12, 1955. Besides 279 of that type, the last 50 production Mark 4Bs were converted to Mark 5 standard. A projected Mark 6 did not go into production. Featuring a wingspan (over rocket pods) of 60 feet, 10 inches – 6 feet more than previous models — a 591 square-foot wing area and enlarged tail surfaces, the Mark 5 had a length of 54 feet and 2 inches, a height of 15 feet and 6½ inches, an empty weight of 23,100 lb., and a normal loaded weight of 33,600 lb. Its two Orenda Mark 11s and, later, Mark 14s of similar power but improved operational characteristics, gave it a maximum speed of 650 mph at 40,000 feet, a cruising speed of 480 mph, climb to 50,000 feet in 8 minutes, a 54,000-foot service ceiling and a 700-mile combat radius, which could be maximized to 2,300 miles with wingtip tanks. In the event of a bailout, the pilot and radar operator/navigator each had a Martin-Baker 2E ejector seat.

From 1947 the RCAF judged a head-on attack with machine guns or rockets to be an outmoded and unsuitable means of interception, and the Defence Research Board set out to develop a guided air-to-air missile, culminating in 1950 with the Velvet Glove, four of which were carried by the CF-100 Mark 4B. In 1956 the Velvet Gloves were replaced by more effective American-developed Douglas AAM-N-3 Sparrow IIs.

In addition to the RCAF, the Force Aérienne Belge acquired 53 Mark 5s through an American aid programme. From December 1957 these were operated by the 1e Wing de chasse tout
temps. Boasting NATO’s first all-weather fighters, the Canadian and Belgian squadrons served in the vanguard of Western Europe’s defences until 1961, when obsolescence began the Canuck’s gradual phasing-out in favour of the McDonnell-designed CF-101 Voodoo, followed in 1962 by the Lockheed-developed CF-104 Starfighter. The Belgians gave up their last CF-100s in 1964.

Neither Avro Canada nor Orenda were to survive the one-two punch of the cancellation of the CF-105 Arrow programme in 1959 and CF-100’s phase-out from first-line service. The Canucks soldiered on as trainers and target tugs, and No. 414 Squadron kept them operating in the combined reconnaissance, training and electronic countermeasures roles from whence their saga began, Canadian Forces Base North Bay, until 1981.

Representing several firsts and a significant era in Canadian aviation history, 27 CF-100s of various marks are known to survive in museums or on static display. Three are in the United States and one in Brussels, Belgium, to remind the world at large of the contribution they made at a critical juncture in the Cold War.