Operation Yellow Ribbon () was commenced by Canada to handle the diversion of civilian airline flights in response to the September 11 attacks in 2001 in the United States. Canada's goal was to ensure that potentially destructive air traffic be removed from United States airspace as quickly as possible, and away from potential U.S. targets, and instead place these aircraft on the ground in Canada, at military and civilian airports primarily in the Canadian provinces of Nova Scotia, Newfoundland, and British Columbia. Yukon, New Brunswick, Alberta, Manitoba, Ontario, Northwest Territories, and Quebec also took in aircraft so that any malicious or destructive potential threats could be better contained and neutralized. None of the aircraft proved to be a threat, and Canada hosted thousands of passengers who were stranded until U.S. airspace was reopened.
Canada commenced the operation after the U.S. Federal Aviation Administration (FAA), implementing Security Control of Air Traffic and Air Navigation Aids (SCATANA), grounded all aircraft across the United States, an unprecedented action. The FAA then worked with Transport Canada to reroute incoming international flights to airports in Canada.
During the operation, departing flights—with the exception of police, military, and humanitarian flights—were cancelled, marking the first time that Canadian airspace had been shut down. In total, as a result of Operation Yellow Ribbon, between 225 and 240 aircraft were diverted to 17 different airports across the country.
Deployment of emergency measures
Immediately after the attacks on the World Trade Center (WTC), both Transport Canada and Nav Canada, the Canadian air navigation agency, activated their emergency measures.
Transport Canada
Transport Canada activated its situation centre (SitCen) in Ottawa at 09:21 EDT (13:21 UTC), 18 minutes after the second plane hit the WTC.
The SitCen is Transport Canada's emergency operations center (EOC), originally constructed to deal with earthquakes along the British Columbia Coast. It had been used several times prior to September 11, 2001, including the January 1998 North American ice storm and after Swissair Flight 111 crashed off the coast from Peggy's Cove, Nova Scotia, on September 2, 1998. As personnel staffed the SitCen, key organizations such as Nav Canada, the Department of National Defence, the Royal Canadian Mounted Police (RCMP), Canadian Security Intelligence Service (CSIS), Citizenship and Immigration Canada (CIC), and Canada Customs and Revenue Agency (CCRA) were also involved in SitCen operations. One of the tasks of the SitCen was to maintain contact with other members of the Canadian aviation community, such as the Air Transport Association of Canada and local airport authorities. Their counterparts in the FAA (United States) and other international civil aviation authorities were also kept apprised.
Nav Canada
Nav Canada set up two command centres, the Strategic Command Centre (SCC) and the Tactical Command Centre (TCC).
The SCC, located at the head office in Ottawa and headed by Andy Vasarins, vice-president of operations, oversaw the entire crisis and ensured that information and resources were effectively shared amongst the TCC and other parties.
The TCC was originally a training institute in Cornwall, Ontario, and headed by Kathy Fox, assistant vice-president of air traffic services. Its role in the crisis was to disseminate information amongst airports and control towers. To facilitate this, general managers from across Canada were present. After the immediate crisis passed, the TCC was relocated to the head office and its operations were merged with the SCC.
The operation
The operation officially began at 09:45 ET (13:45 UTC), when Ben Sliney, working in his first day in his position as the U.S. Federal Aviation Administration's (FAA) National Operations Manager, ordered all U.S. airspace to be shut down as a result of the attacks.
Actions taken by Transport Canada
After learning that the FAA had closed down U.S. airspace, David Collenette, the Canadian Transport Minister, gave orders that Canadian airports be open only for outgoing police, military, and humanitarian flights, and incoming U.S. bound international flights. This was the first time Canada had shut down its airspace.