Charles F. Kiefer, 67, a retired executive director of the Civil Aeronautics Board who had almost 40 years of government service, died Wednesday at his summer home in Bethany Beach, Del., following a stroke.

Mr. Kiefer was born in Hamilton, N.Y., grew up in Ilion, N.Y., and came to Washington in 1931. He began his government career that year as a messenger with the Department of Commerce.

He joined the Department of Agriculture in the mid-1930s and became a specialist in agricultural economics and commodities. He directed the department's office of management appraisal and systems development until 1966 when he transferred to the CAB as its executive director. He retired in 1970.

Mr. Kiefer earned a bachelor's degree from George Washington in 1940 by attending night classes. He later earned a master's degree at Harvard University.

In 1959, he received the Agricultural Department's Certificate of Merit.

After his retirement from the CAB, Mr. Kiefer was a Ford Foundation consultant to the governments of India, Nepal and Thailand. He also was a consultant for the World Bank in Kenya. In 1976, he was a senior fellow at the East-West Center in Hawaii.

Mr. Kiefer was a member of the American Society for Public Administration and belonged to the Harvard and International clubs of Washington.

He was a member of Rock Spring United Church of Christ in Arlington and was a former chief lay officer of the church.He was a member of the policy implementation committee of the Office of Church in Society of the United Church of Christ.

Survivors include his wife, Maxine, of the homes in Arlington and Bethany Beach; a son, Charles, of Lexington, Mass., and a brother, Paul, of Williamsville, N.Y.

The family suggests that expressions of sympathy be in the form of contributions to the Rock Spring Endowment Fund, Rock Spring United Church of Christ, 5010 Little Falls Rd., Arlington, 22207. CAPTION: Picture, CHARLES F. KIEFER