ELLSWORTH AIR FORCE BASE, S.D. - Airmen of the 28th Maintenance Squadron aerospace ground equipment section work on various projects, Sept. 7. Aerospace ground equipment technicians service, inspect, troubleshoot, repair and perform preventive maintenance on motor and engine-driven generator sets, air conditioners, hydraulic test stands, air compressors, bomb lifts, heaters and other similar support equipment. (U.S. Air Force photo/Staff Sgt. Marc I. Lane)