Canadair North Star

The Canadair North Star is a 1940s Canadian development of the Douglas DC-4 for Trans-Canada Air Lines, which asked for it in 1944. Instead of the DC-4's radial piston engines, Canadair used Rolls-Royce Merlin V12 engines to reach a cruising speed of 325 mph (523 km/h), against 246 mph for the standard DC-4. It was more than an engine swap: the North Star had the DC-6 nose and landing gear and a fuselage shortened by 80 inches, a DC-4 tail and wing tips, C-54 middle fuselage and wing sections, cabin pressurisation and a standardised cockpit. The prototype flew on 15 July 1946. Canadair built 71 of what it officially called the Canadair Four, under the names North Star, DC-4M, C-4 and C-5, and the single C-5 had Pratt and Whitney R-2800 engines. Trans-Canada Air Lines, the Royal Canadian Air Force, Canadian Pacific Airlines and BOAC, which called it the Argonaut, were the main operators. It proved reliable but noisy through the 1950s and 1960s, and some flew on into the 1970s as freighters.