What is Air Canada Flight 621?

Air Canada Flight 621

Summary
Date	July 5 1970
Cause	Crew error
Site	Toronto Pearson International Airport
Fatalities	109
Injuries	0
Aircraft
Aircraft type	McDonnell Douglas DC-8-63
Operator	Air Canada
Tail number	CF-TIW
Passengers	100
Crew	9
Survivors	0

The Toronto Pearson International Airport's worst accident took place on July 5, 1970, when Air Canada Flight 621, a Douglas DC-8 registered CF-TIW, was flying on a Montreal-Toronto-Los Angeles route.

The captain and first officer had flown on various flights together before, and had an ongoing discussion on when to engage the spoilers. They both agreed they did not like engaging them at the beginning of the final approach, fearing it could lead to an inadvertent spoiler activation. The captain preferred engaging them on the ground, whilst the copilot preferred engaging them during the flare.

The flare is executed just above the ground as the plane nose rotates up slightly, and the power (thrust) is reduced. Small planes flare until the wing stalls causing a very light touch down. Large planes like this DC-8 are flown onto the runway. The flare is used to both reduce speed and lift the nosewheel so it does not strike runway first. This gives a smooth touchdown for both small and large planes.

The pilots made an agreement that, when the captain was piloting the aircraft, the first officer would arm the spoilers on the ground, as the captain preferred, and when the first officer was piloting the aircraft, the captain would arm them on the flare as copilot preferred.

On this particular instance however, the captain was piloting the landing and said, "All right. Give them to me on the flare. I have given up." This was not their usual routine. Sixty feet from the runway, the captain began to reduce power in preparation for the flare and said, "Okay" to the first officer. The first officer immediately engaged the spoilers. The aircraft began to sink heavily and the captain, realising what had happened, pulled back on the control column and applied full throttle to all four engines. The nose lifted, but the aircraft still continued to sink, hitting the runway with enough force that the number four engine and pylon broke off from the wing. Realising what he had done, the first officer began apologising to the captain. The aircraft eventually managed to lift off for a go-around, but the lost fourth engine had torn off a piece of the lower wing plating and the aircraft was now trailing fuel, which ignited. The first officer requested a second landing attempt on the same runway but was told it was closed due to debris and was directed to another runway.

Two and a half minutes after the initial collision, the outboard section of the right wing above engine number four exploded, causing parts of the wing to break off. Six seconds after this explosion, another explosion occurred in the area of the number three engine, causing the pylon and engine to both break off and fall to the ground in flames. Six and a half seconds after the second explosion, another explosion occurred, destroying most of the right wing, including the wing tip. The aircraft then went into a violent nose dive, striking the ground at a high velocity and killing all 100 passengers and the nine crew members on board. The crash occurred in a field located in Brampton, Ontario.

External links

• Aviation Safety Network
• Cockpit voice recorder transcript
• Friends of Flight 621
• Super70s.com report on Flight 621
• Air Canada Flight 621 Memorial at Find-A-Grave