ELLSWORTH AIR FORCE BASE, S.D. -- (Right) Senior Airmen Brandon Bolden and Christopher Harris, 28th Civil Engineer Squadron heating, ventilation and air conditioning repair journeymen, replace vent coverings on an air conditioning unit after performing general maintenance, April 12. The 28th Civil Engineer Squadron provides the necessary assets and skilled personnel to prepare and sustain installations throughout the world during current deployment operations. (U.S. Air Force photo/Airman 1st Class Matthew Flynn)