An AH-64 (Apache) Longbow fire control full size radar photographed during icing tests in the Icing Research wind tunnel. Built at the end of World War II, the Icing Research Tunnel is the oldest and largest refrigerated icing wind tunnel in the world. It can produce winds that travel up to 395 miles per hour and reach temperatures as low as -30 degrees Fahrenheit. The facility simulates ice formation during flight by spraying a cloud of super-cooled water droplets onto an aircraft component or model.