Trans-Canada Air Lines Flight 810-9 was a Canadair North Star on a scheduled flight from Vancouver to Calgary (continuing to Regina, Winnipeg, and Toronto). The plane crashed into Mount Slesse near Chilliwack, British Columbia, Canada, on 9 December 1956 after encountering severe icing and turbulence over the mountains. All 62 people on board died, making it one of the deadliest airline crashes ever as of that date; it still ranks as the sixth deadliest air disaster in Canadian history.

Due to the remoteness and difficulty of the terrain, the crash site was not located until the following May, when it was discovered by mountaineers Elfrida Pigou, Geoffrey Walker, and David Cathcart. Among the victims were five professional Canadian football players on their way home from the annual Shrine Game between the East and West all-stars in Vancouver.

The remains are located in a highly inaccessible area and are protected from disturbance.