EIELSON AIR FORCE BASE, Alaska –A U.S. Air Force F-16 Fighting Falcon aircraft assigned to the 18th Aggressor Squadron, prepares to take off during NORTHERN EDGE 2017 (NE17), May 4, 2017, at Eielson Air Force Base, Alaska. NE17 is Alaska’s premier joint training exercise designed to practice operations, techniques and procedures as well as enhance interoperability among the services. Thousands of participants from all the services, Airmen, Soldiers, Sailors, Marines and Coast Guardsmen from active duty, Reserve and National Guard units are involved. (U.S. Air Force photo by Airman 1st Class Isaac Johnson)