Airman 1st Class Randall Lewallen, 92nd Maintenance Squadron fuel systems apprentice, installs a pressure door on a KC-135 Stratotanker at Fairchild Air Force Base, Wash., Jan. 28, 2013. Installing a pressure door helps find the exit point of any fuel leaks to the aircraft. (U.S. Air Force photo by Airman 1st Class Janelle Patiño)