Canadair CL-44 - Design and Development

Design and Development

In the 1950s, Canadair had acquired a licence to build the Bristol Britannia airliner. Their first use of the licence was to build the heavily modified Canadair CL-28 Argus patrol aircraft, that combined the Britannia's wings and tail sections with a new fuselage and engines. The resulting aircraft had lower speed and altitude, but had two bomb bays and greatly extended loiter times.

With an RCAF requirement for a replacement for its C-54GM North Star (an extensive redesign of the Douglas C-54 Skymaster, that among many changes, was powered by Merlin engines) fleets, Canadair began work on a long range transport primarily intended to provide personnel and logistics support for Canadian Forces in Europe. In January 1957 Canadair received a contract for eight aircraft, later increased to 12. The RCAF designation for the new design was the CC-106 Yukon, while the company's civilian variant was known as the CL-44-6. In company parlance the CL-44 was simply "the Forty-Four."

The RCAF had specified the CL-44 to be equipped with Bristol Orion engines. When the British Ministry of Supply canceled the Orion program, the RCAF revised the specifications to substitute the Rolls-Royce Tyne 11. The CL-44 fuselage was lengthened making it 12 ft 4 in (3.75 m) longer than the Britannia 300 with two large cargo doors added on the port side while the cabin was pressurised to maintain a cabin altitude of 2,400 m at 9,000 m (30,000 ft). The design used modified CL-28 wings and controls. The Yukon could accommodate 134 passengers and a crew of nine. In the casualty evacuation role it could take 80 patients and a crew of 11.

The rollout of the Yukon was a near-disaster when the prototype could not be pushed out of the hangar since the tail was unable to clear the hangar doors. The first flight took place 15 November 1959 at Cartierville Airport. During test flights many problems were encountered from complete electrical failure to engines shaking loose and almost falling off. Rolls-Royce had problems delivering engines resulting in the sarcastically named "Yukon gliders" being parked outside Canadair as late as 1961.