Edward C. "Ned" Prettyman, 64, who since 1960 had worked at the Johns Hopkins University Applied Physics Laboratory, died of pneumonia Dec. 16 at Shady Grove Adventist Hospital. He lived in Rockville.

At the time of his death, he was the associate head of operations in the power projection systems department at the lab. In the mid-1990s, he taught classes at the Johns Hopkins graduate school of engineering.

Mr. Prettyman was born in Olney and graduated from Richard Montgomery High School. In 1957, he received a bachelor's degree in electrical engineering from the University of South Carolina. After that, he served three years in the Navy and retired from the Naval Reserve as a lieutenant in 1967.

He served on the board of the Montgomery County Coalition for the Homeless, Rockville Academy and Montgomery County Cotillion. He was a member of Christ Episcopal Church in Rockville, serving on many of its committees; Peerless Rockville Historic Preservation Ltd.; and the Special Olympics.

He also was a member of the American Society of Naval Engineers.

Mr. Prettyman volunteered at Sophia House for women and Chase Shelter for men, both in Rockville.

His hobbies included canoeing, tennis and playing the violin.

Survivors include his wife of 38 years, Maureen Frances Black Prettyman of Rockville; two daughters, Elizabeth Barrett Prettyman Guay of Gaithersburg and Mary Cecilia Prettyman of Rockville; a son, Charles Philip Prettyman of Hasbrouck Heights, N.J.; and three grandsons.

A daughter, Mary Alice Prettyman, died in the early 1960s.