EIELSON AIR FORCE BASE, Alaska – U.S. Air Force Airmen assigned to the 335th Aircraft Maintenance Unit prepare to perform pre-flight checks on an F-15E Strike Eagle dual-role fighter aircraft assigned to the 335th Fighter Squadron, Seymour Johnson Air Force Base, N.C., prior to a sortie, May 3, 2017, at Eielson Air Force Base, Alaska, during NORTHERN EDGE 2017 (NE17). 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/Staff Sgt. Ashley Nicole Taylor)