The U.S. Air Force's KC-10 air refueling fleet has been in operation since 1981 without significant modernization. The Air Force is considering upgrades to the KC-10 in several areas: avionics, command and control, multipoint refueling, defensive systems,
Anthony D. Rosello,Sean Bednarz,David T. Orletsky,et al. Upgrading the Extender: Which Options Are Cost-Effective for Modernizing the KC-10?. 2011-01-01.