The Arrow's cancellation was announced on 20 February 1959. The day became known as "Black Friday" in the Canadian aviation industry. Diefenbaker claimed the decision was based on "a thorough examination" of threats and defensive measures, and the cost of defensive systems. More specifically, the cost would have needed to be amortized over hundreds of manufactured models. At the time the trend was "away from conventional bombers" that the Avro Arrow could intercept and "towards atmospheric weapons like intercontinental ballistic missiles", according to Global News. As a result, the foreign demand for the Avro Arrow had declined substantially. Canada's alternative to the Arrow was to purchase some American McDonnell F-101 Voodoo interceptors and Bomarc B missiles.