Airman 1st Class Terre Camille, an avionics technician assigned to the 28th Maintenance Squadron, installs an amp into a Line Replaceable Unit at Ellsworth Air Force Base, S.D., Dec. 6, 2016. An LRU is a modular component of complex electronic systems for aircraft that can be replaced quickly, and generally with a minimum of tools. (U.S. Air Force photo by Airman 1st Class Donald C. Knechtel)