The Canadair North Star was a 1940s Canadian development of the Douglas DC-4 aircraft. Instead of radial piston engines found on the Douglas design, Canadair used Rolls-Royce Merlin engines to achieve a faster cruising speed. The prototype flew on July 15th 1946 and the type was used by various airlines and by the RCAF. It provided reliable, if noisy, service through the 1950s and into the 1960s. Some examples continued to fly into the 1970s, converted to cargo aircraft.