Douglas Aircraft Company (Canadian Pacific Airlines) - Douglas DC-8-43

N9604Z "Empress of Montréal" / On 21.8.1961, this aircraft broke the sound barrier at Mach 1.012 (660 mph/1,062 km/h) while in a controlled dive through 41,000 feet (12,497 m), and maintained that speed for 16 seconds. The flight was to collect data on a new leading-edge design for the wing, and while doing so, the DC-8 became the first civilian jet – and the first jet airliner – to make a supersonic flight. The aircraft was already painted in Canadian Pacific livery, and was delivered to CP shortly after this test flight (registered as CF-CPG).