Template:FPS-117EPRProgram

Essential Parts Replacement Program (EPRP)
In 2011 the U.S. Air Force awarded Lockheed Martin $46.8 million in contract options to begin modernization of 29 long-range radars. Under the EPRP contract, Lockheed Martin was to modernize 15 radars in Alaska, 11 in Canada, and one each in Hawaii, Puerto Rico and Utah, all part of the Air Force's Atmospheric Early Warning System. The Utah radar was the FPS-117 at the Hill Air Force Base Radar Site.

By 2011 the FPS-117 radars, which were originally installed in the 1980s, suffered from excessive parts obsolescence and diminishing manufacturing sources. The EPRP program was established to eliminate obsolete components and to ensure continued supportability through 2025. The modifications also provided the hardware necessary for the eventual implementation of Mode 5 IFF.

The program replaced four major subassemblies on the FPS-117: the Maintenance and Control System, the Beacon system, the Uninterruptable Power Supply/Communications Rack, and Local Control Terminals, which allow remote monitoring, troubleshooting, and control of the radars. The modifications reduced the line-replaceable unit count by approximately 80 percent, easing maintenance and the number of parts on the shelf.

More than 25 radar systems were upgraded, including the Hill AFB Engineering Facility, the last site in Hawaii was returned to service in late June 2015 after all the site operations and maintenance personnel had been trained.