Nicholas Communications, a video production company in Alexandria, has appointed Edward O. LeRoy director of operations and Mark McMullen marketing director. LeRoy, a retired lieutenant colonel in the Marines, had been director at the Fairfax County YMCA and was in retail sales with Woodward & Lothrop. McMullen was formerly audiovisual coordinator for Equity Programs Investment Corp.

Garrett Corp., one of The Signal Cos. Inc., based in Los Angeles, announced two promotions in its Washington office. Michael S. Rachlin was named vice president of international government relations, a newly created position. Rachlin joined Garrett in 1952 as a preliminary-design engineer, and has served as director of NASA space program activities, sales engineer and both director and vice president of U.S. government relations. R. M. "Rob" Chapman, formerly manager of Navy programs in the Washington office, has been promoted to vice president of U.S. government relations, replacing Rachlin. Prior to coming to Garrett in 1977 as a market development executive, Chapman held several government positions, including executive secretary of the National Academy of Science's Naval Studies Board. He also served with the Defense Advanced Research Projects Agency and the Defense and Engineering Office in the office of the secretary of Defense.

John Gardner recently was appointed president and chief executive officer of Buvermo Management Inc., a Rosslyn-based real estate investment and management firm. Gardner previously was a senior vice president with The Kaempfer Co., a Washington-area real estate development firm. Before that, he was vice president in charge of shopping centers for B. F. Saul Real Estate Investment Trust. Gardner replaces Harrison Wehner, one of the founders and the first chief executive officer of the company. Wehner will become chairman of the board.

DCS Corp., an Alexandria-based high-tech firm, has appointed David Rubin to a senior management position. Rubin, previously a vice president with Syscon Corp., will head several major government projects.