Ste. Therese De Blainville, QB Airliner Crashes, Nov 1963
Trans-Canada Air Lines (TCA) Flight 831 was a flight from Montréal–Dorval Airport (now Montréal-Trudeau) to Toronto International Airport (now Toronto-Pearson) on November 29, 1963. The aircraft was a four-engine Douglas DC-8-54CF airliner, registered CF-TJN. About five minutes after takeoff in poor weather, the jet crashed about 20 miles north of Montreal, near Ste-Thérèse-de-Blainville, Quebec, Canada, killing all 118 people on board: 111 passengers and 7 crew members. The crash was the deadliest in Canadian history at that time, and is still the third-deadliest in Canada behind Swissair Flight 111 and Arrow Air Flight 1285. It was also the worst crash of DC-8 at the time, and is currently the sixth worst.
The plane was too badly damaged to determine a definite cause. Canadian aircraft were not required to carry voice cockpit recorders or flight data recorders at this point, complicating the investigation into the crash of TCA Flight 831. The official report released in 1965 pointed to problems in the jet's pitch trim system (the device that maintains a set nose-up or -down attitude) as a possibility, since a pitch trim problem caused the similar crash of Eastern Air Lines Flight 304, another DC-8, three months later in 1964. Other possible causes were put forward that could not be ruled out: 1) Icing of the pitot system; and 2) Failure of the vertical gyro.