Aircrew personnel from the 37th Bomb Squadron prepare for a training mission during the Green Flag exercise at Ellsworth Air Force Base, S.D., April 29, 2015. Green Flag is a large force exercise designed to provide combat training to joint and coalition warfighters in the art of air-land integration and the joint employment of airpower at the U.S. Army National Training Center at Fort Irwin, Calif. (U.S. Air Force photo by Senior Airman Anania Tekurio/Released)