Royal Saudi air force Staff Sgt. Khalid Alhawsawi, 362nd Training Squadron F-15 crew chief apprentice course student, removes and installs the nose landing gear tire at Sheppard Air Force Base, Texas, March 12, 2019. Tires are usually changed every other month, but unexpected complications (i.e. bad runways, punctured during the mission, etc.) would cause the crew chiefs to change them sooner. (U.S. Air Force photo by Airman 1st Class Pedro Tenorio)