Trans-Canada Air Lines Flight 831

Trans-Canada Air Lines (TCA) Flight 831 was a scheduled Canadian flight from Montréal–Dorval International Airport to Toronto International Airport on November 29, 1963. About five minutes after takeoff in poor weather, the Douglas DC-8-54CF Jet Trader operating the flight crashed about 32 km north of Montreal, near Ste-Thérèse-de-Blainville, Quebec, Canada, killing all 111 passengers and seven crew members. The crash was the deadliest in Canadian history at the time. It was also the deadliest crash of a DC-8 at the time, and, as of 2025, the sixth-deadliest.

Sequence of events

At 6:28 p.m., the DC-8 began its takeoff roll on Dorval airport's Runway 06R. The crew reported back when they reached 3000 ft and were given clearance for a left turn. Shortly thereafter, the aircraft deviated from its expected flight path and began a quick descent. At about 6:33 p.m., the jet struck the ground at an estimated 470 – 485 kn while descending at about a 55-degree angle (± 7 degrees).

The aircraft plunged into a soggy field in Sainte-Thérèse, Quebec, about 100 m from the main highway that leads to the Laurentian Mountains. One witness said that he saw what looked like "a long red streak in the sky" just before the crash. The red-trimmed, silver jet dug a crater 6 ft deep and 150 ft wide in the ground that soon began to fill with rainwater. Although parts of the airplane were scattered over a wide area ahead of and separate from the crater, the commission of inquiry found that the aircraft was structurally intact when it struck the ground.