Air Canada Flight 189
|Date||June 26, 1978|
|Summary||Mechanical failure, pilot error|
|Aircraft type||McDonnell Douglas DC-9-32|
|Flight origin||Toronto International Airport|
|Destination||Winnipeg International Airport|
During takeoff at 8:15 a.m. one of the McDonnell Douglas DC-9-32's tires burst and partially disintegrated, firing chunks of rubber into the landing gear mechanism. This set off an "unsafe gear" warning, prompting the pilot to abort the takeoff. However, the aircraft was already two thirds along the length of runway 23L and travelling at 154 knots (285 km/h). It could not stop before the end of the runway, and plunged off the edge of an embankment still travelling at 60 knots (110 km/h), eventually coming to a rest in the Etobicoke Creek ravine. The plane broke in three pieces, but despite its full load of fuel did not catch fire. The accident was visible from Highway 401, which runs alongside the south side of the airport.
The plane was destroyed and two passengers were killed: 73 year old J. Frank Scrase of Victoria died when a rib punctured his heart, and 45 year old Irwin Theodore Childs of North York died of suffocation when he was wedged beneath the seat in front of him. Both were seated at the site of the forward split in the fuselage. Most of the other 105 passengers and crew aboard were injured.
The subsequent investigation found multiple causes of the accident. It recommended greater scrutiny be given to the tires. The pilot, Reginald W. Stewart, delayed four seconds after the warning light came on before he chose to abort the takeoff; a more immediate decision would have prevented the accident. The investigators also criticized the level of training in emergency braking. The presence of the ravine at the end of the runway was also questioned, but nothing was done. This failure to expand the airport's overshoot zone was raised when Air France Flight 358 plunged into the same ravine 27 years later.
Although it is customary for airlines to retire a flight number after a major incident, Air Canada continues to use Flight 189 for its Ottawa-Vancouver route and it uses a Boeing 767-300 aircraft instead of a DC-9. However, the flight no longer has stopovers in Toronto and Winnipeg. 
- Palango, Paul (26 June 1978). "2 killed, 105 hurt in DC-9 crash". The Globe and Mail (Toronto). p. 1.
- Canadian Press (28 March 1979). "Jet's crash traced to 4-second delay in use of full brakes". The Globe and Mail (Toronto). pp. 1–2.
- Graham, Bob (28 March 1979). "4-second delay cost two lives report finds". The Toronto Star (Toronto). pp. A1–A2.
- Furness, Richard (7 October 1978). "Extend runway over creek, air crash jury urges". The Globe and Mail (Toronto). pp. 1–2.
- Priest, Lisa (3 August 2005). "Takeoffs and landings always pose risk of calamity, as history shows". The Globe and Mail (Toronto). p. A11.