U.S. Air Force Airman 1st Class Jacob Brown, 633rd Civil Engineer Squadron water fuels apprentice, practices land navigation during Prime Base Engineer Emergency Force training at Joint Base Langley-Eustis, Virginia, July 19, 2018. The Airmen learned to navigate terrain without technology, so they are prepared to operate in conditions where it may not be available. (U.S. Air Force photo by Staff Sgt. Areca T. Bell)