W.S. Buttrill, formerly senior vice president of program operations at Loral Defense Systems-Arizona, has been named senior vice president of program operations at Loral Aeronutronic, Newport Beach. He will manage production programs and manufacturing operations. He joined the defense- electronics and space-communications company in 1989 after serving as an assistant director for Hughes Aircraft Co.'s missile systems group. In addition, Paul Siconolfi, previously vice president of the programs office, has been appointed vice president of business development.