FAIRCHILD AIR FROCE BASE, Washington --   U.S. Air Force Airman 1st Class Mark Arroyo, 436th Civil Engineer Squadron water and fuels system maintainer, Dover Air Force Base, Delaware, fills out in-processing forms to participate in Exercise Mobility Guardian 2019 at Fairchild Air Force Base, Washington, Aug 16, 2019. Exercise Mobility Guardian is Air Mobility Command’s premier, large-scale mobility exercise during which more than 2,500 Mobility Airmen will participate. (U.S. Air Force photo by Staff Sgt. Dustin Mullen)