U.S. Air Force aircrew assigned to the 340th Expeditionary Air Refueling Squadron await takeoff on a KC-135 Stratotanker at Al Udeid Air Base, Qatar, April 8, 2016. As of April 4, U.S. and partner nation aircraft have flown an estimated 88,667 sorties in support of operations in Iraq and Syria. (U.S. Air Force photo by Staff Sgt. Corey Hook/Released)