A B-52 Stratofortress from the 2nd Bomb Wing participates in Vigilant Shield 15 Oct. 24, 2014, at 5 Wing Goose Bay, Newfoundland and Labrador, Canada. The Vigilant Shield field training exercise is a bi-national North American Aerospace Defense Command exercise that provides realistic training and practice for American and Canadian forces. NORAD ensures U.S. and Canadian air sovereignty through a network of alert fighters, tankers, airborne early warning aircraft, and ground-based air defense assets cued by interagency and defense surveillance radars. (U.S. Air Force photo/Senior Airman Justin Wright)