The Canadian-built, Canadair Argus was a unique hybrid that employed the wings, tail surfaces and undercarriage of the British designed Britannia transport, married to a completely new unpressurized fuselage of Canadian design and equipped with different American-designed engines. Work on the CL-28 began in April 1954 and at the time it was the largest aircraft built in Canada. The first CL-28 came off the assembly line on December 21, 1956 and flew on March 28 1957, with the delivery of the first CL-28 to the RCAF in September 1957.

In March, 1957, the prototype Argus, 20710, flew for the first time, with test pilot Bill Longurst at the controls. Thirteen Mark Is, from 710 to 722, were built, while 20 Mark IIs, from 723 to 742, were delivered. Two Mark Is - 710 and 711, were oddballs in that they didn't have a freight door. The difference between Marks was primarily in the radar set. The Mark Is had an American radar system the APS-20, similar to that in the Neptune, while the Mark IIs had a British system the ASV-21, similar to the Shackleton. The last Argus to fly, 742, was originally delivered in 1960. Now in the National Aviation Museum in Ottawa, it was a favorite air show aircraft which the crews would pull up at steep angles to impress crowds. The Argus had the same wingspan as the B-29, but was 33,000 pounds heavier.The Argus used the highest octane fuel ever used outside the Reno races for piston aircraft. The growing scarcity of the fuel eventually helped to kill the Argus. Capable of carrying 28,000 pounds of fuel, the Argus could fly for 22 hours at normal power settings burning 300 gallons an hour. When the aircraft landed, it normally had 4,000 pounds of fuel on board as a residual margin for error. Take-off weight for the Argus throughout its operational career was 157,000 pounds, not 148,000 as generally reported.

One of the most effective anti-submarine warfare aircraft of it's day, the Argus was a mainstay for the RCAF in the maritime role. The Argus replaced the Lancaster and Neptune aircraft types previously flown in the maritime roles and eventually, the Argus was itself to be replaced by the current CP-140 Aurora aircraft.