Crew chiefs and jet engine mechanics finish repairs on a C-17 Globemaster III engine thrust reverser Aug. 8, 2017, at Joint Base Lewis-McChord during Exercise Mobility Guardian. More than 650 international military personnel and 3,000 U.S. military service members have partnered together during the exercise to test the abilities of Mobility Air Forces to execute rapid global mobility missions in airlift, air refueling, aeromedical evacuation and mobility support. (U.S. Air Force photo by Tech. Sgt. Bryan Hull)