The competition to redevelop Torontos 70-acre former Downsview Airport Lands (known as YZD) has named CCxA, Field Operations, Michael Van Valkenburgh Associates, Sasaki, and SLA to its shortlist. The project forms the 'cornerstone' of a new 370-acre mixed-use development, one of North Americas largest.It is aimed at creating a new landscaped pedestrian corridor out of the airport's former runway and will be animated by year-round cultural programming and other public uses. A winner is expected to be announced by mid-summer this year. The entire redevelopment will reportedly cost $22 billion.