A Royal Canadian Air Force Canadair Harvard collides with a Trans-Canada Airlines Canadair North Star over Moose Jaw, Saskatchewan, killing 37 people.

The North American Aviation T-6 Texan is an American single-engined advanced trainer aircraft, which was used to train pilots of the United States Army Air Forces (USAAF), United States Air Force (USAF), United States Navy, Royal Air Force, Royal Canadian Air Force and other air forces of the British Commonwealth during World War II and into the 1970s.

On April 8, 1954, Trans-Canada Air Lines Flight 9, a Canadair C-4 North Star four-engine commercial propliner on a domestic regular scheduled flight, collided in mid air with a Royal Canadian Air Force (RCAF) Harvard Mark II single engine military trainer on a cross-country navigation exercise over Moose Jaw, Saskatchewan.

Trans-Canada Air Lines was a Canadian airline that operated as the country's flag carrier, with corporate headquarters in Montreal, Quebec. Its first president was Gordon Roy McGregor. Founded in 1937, it was renamed Air Canada in 1965.

The Canadair North Star is a 1940s Canadian development, for Trans-Canada Air Lines (TCA), of the Douglas DC-4. Instead of radial piston engines used by the Douglas design, Canadair used Rolls-Royce Merlin V12 engines to achieve a higher cruising speed of 325 mph (523 km/h) compared with the 246 mph (396 km/h) of the standard DC-4. Requested by TCA in 1944, the prototype flew on 15 July 1946. The type was used by various airlines and by the Royal Canadian Air Force (RCAF). It proved to be reliable but noisy when in service through the 1950s and into the 1960s. Some examples continued to fly into the 1970s, converted to cargo aircraft.