Air Canada Flight 621 was an Air Canada Douglas DC-8, registered as CF-TIW, that crashed on July 5, 1970, while attempting to land at Toronto Pearson International Airport. It was flying on a Montreal–Toronto–Los Angeles route. It crashed in Toronto Gore Township, now part of Brampton. All 100 passengers and 9 crew on board were killed, and at the time it was Canada's second-deadliest aviation accident. Aircraft The aircraft involved was a Douglas DC-8 60 series, powered by four Pratt & Whitney JT3D engines and delivered new to Air Canada just three months prior to the accident. At the time of the incident the aircraft had accumulated only 453 hours of flight time. The aircraft was registered CF-TIW and was the 526th DC-8 built at the Long Beach assembly plant. The 60 series was a stretched version of the DC-8 that was 36.7 feet longer than the DC-8 series models 10 through 50. History Captain Peter Cameron Hamilton and First Officer Donald Rowland had flown on various flights together before, and had an ongoing discussion on when to arm the ground spoilers. They agreed that they did not like arming the spoilers at the beginning of the final approach, as specified in the checklist, fearing it could lead to an inadvertent spoiler deployment. The captain preferred not arming them at all, but directly deploying them once on the ground, while the co-pilot preferred arming them during the landing flare. Neither procedure was approved, as the spoilers should have been armed in the pre-landing check. The flight engineer, Harry Gordon Hill, correctly called for the spoiler deployment as evidenced in the CVR transcript. When executed just above the runway, the landing flare procedure arrests the aircraft's descent just prior to touchdown. By raising the aircraft's nose (pitching up), lift momentarily increases, reducing the descent rate, and the main wheels may then gently contact the runway. During the flare, pilots normally retard the throttles to idle to reduce engine thrust. A squat switch within the main landing gear then signals the touchdown and automatically deploys the spoilers, if armed. This destroys any remaining lift and helps the aircraft slow down. The pilots made an agreement that, when the captain was piloting the aircraft, the first officer would deploy the spoilers on the ground as the captain preferred, and when the first officer was piloting the aircraft, the captain would arm them on