Members of the 931st Maintenance Squadron unwrap a KC-135 Stratotanker F108 engine during a unit training assembly at McConnell Air Force Base, Kan., April 11, 2015. With more than 60 Stratotankers assigned, McConnell operates and maintains the Air Force's largest air refueling fleet, conducting worldwide military operations. (U.S. Air Force photo by Tech. Sgt. Abigail Klein)