U.S. Air Force crew chiefs from the 354th Expeditionary Fighter Squadron perform maintenance on a U.S. Air Force A-10 Thunderbolt II attack aircraft engine during a theater security package deployment to Lask Air Base, Poland, July 9, 2015. The U.S. and Polish air forces will conduct training aimed to strengthen interoperability and demonstrate the countries' shared commitment to the security and stability of Europe. (U.S. Air Force photo by Staff Sgt. Christopher Ruano/Released)
