Charles H. Evans, 79, who worked at Pepco's Benning Power Plant for 43 years before retiring as plant engineer in 1967, died of cardiac arrest Saturday at Montgomery General Hospital in Olney. He had lived in Rossmoor Leisure World in Silver Spring since 1967.

In addition to his work with Pepco, he served on the District's Steam Operating Engineers Board from 1960 to 1966, and was a member of the Maryland State Board of Engineering Examiners in the late 1950s and early 1960s.

He was a 32nd degree Mason and a member of York Masonic Lodge and the Scottish Rite. He also was a member of the Light and Kilowatt clubs. He was a member of the Kiwanis Club and an affiliate member of the Interfaith Chapel at Leisure World.

Mr. Evans was native of Edinburg, Va., and came to Washington when he was 12 years old. He was a member of the Maritime Service during World War II.

His wife of 51 years, Florence T. Evans, died in 1973.

Survivors include his wife, the former Estelle Leatherwood of Silver Spring; a daughter, Margaret E. Fanning of Hyattsville; a stepdaughter, Joan Norton of Mt. Vernon; two brothers, Olin and Robert Evans, both of Woodstock; two sisters, Mary Corbin of Edinburg, and Josephine Cahill of McLean, and two stepgrandchildren.