Air Force pilots and crew chiefs conduct a preflight maintenance check before a mission at Al Udeid Air Base, Qatar, Jan. 11, 2017. The pilots and crew chiefs are assigned to the 340th Expeditionary Air Refueling Squadron. The 340th Expeditionary Air Refueling Squadron conducts tactical refueling operations, which extend capabilities across Southwest Asia. Air Force photo by Senior Airman Jordan Castelan