Michael Ferrel was appointed general manager of WGMS-AM/FM (570/103.5) this week. He replaces Jerry Lyman, who was promoted to president of RKO General Inc.'s radio division.

Ferrel, 35, has spent his entire radio career at WGMS, which is owned by RKO. A native of Buffalo, he joined the sales department in 1973 and has been the general sales manager for six years. "I met Jerry socially, and he found out I was an English major and thought I could work on ad copy," recalls Ferrel, laughing. "I told them I could type, but I couldn't, and I used to waste pounds of correctotype."

WGMS, the area's leading classical music station, ranks 17th in the Washington market, with a 2.3 share of listeners, according to the summer Arbitron ratings. It is one of the most successful and visible classical stations in the country. "We have broadened the appeal of the station," says Ferrel. "On most stations you have a dead sound of a few seconds after the music, and then someone with an 80-degree body temperature says, 'That was Mozart.' " He doesn't plan any changes. "The commitment is 110 percent to what WGMS is, and only to improve on it."

Lyman, 43, was the station's general manager for 12 years, and also RKO's vice president for government relations. He takes over immediately from former president Robert J. Williamson, and is expected to work from the Rockville station until next spring.

The changes at WGMS occurred during a shake-up last week of the network's top executives. Since 1965, the network's financial reports, trade practices and qualifications to be a licensee have been under investigation by the Federal Communications Commission and the Securities and Exchange Commission. It lost one television station on the grounds of "lack of candor," according to a Washington court of appeals judgment, and its other properties are tied up in the ongoing legal action.