Philip Stuart Ball Jr., 64, a member of the staff of the Johns Hopkins Applied Physics Laboratory since 1960, died of cancer Saturday in the Howard General Hospital in Columbia, Md.

Mr. Ball was an authority in the field of operations research. His work included studies on the effectiveness of air defense weapons systems and on biomedical analysis.

Prior to joining the laboratory, he had worked for two years as chief of the Air Traffic Control Aviation Agency.

Mr. Ball was a native of Baltimore. He earned an engineering degree at the University of Virginia and attended Johns Hopkins University.

During the 1940s and early 1950s, he was an aerodynamicist with the University of Chicago and the Grumman Aircraft Corp., and an engineer with Glenn Martin.

From 1954 to 1958, he was operations analysis civilian branch chief of the Air Force Air Defense Command at Colorado Springs, Colo.

Mr. Ball served as a Navy fighter pilot aboard carriers during World War II. He retired from the reserves with the rank of commander in 1963.

He was a member of St. Louis Catholic Church in Clarksville, Md., and was president of the parish council in 1972.

Mr. Ball served on the Howard County Zoning Commission from 1963 to 1972.

Survivors include his wife, Madeleine, of the home in Clarksville; two daughters, Susie T., of Oyster Bay, N.Y., and Catherine McAuliffe of Clarksville; three sons, Philip S. III, of Ellicott City, and James D. and Michael M., both of Columbia; a brother, James, of Reistertown, Md. and two sisters, Alice Newman of Baltimore, and Martha Harlan of Auburn, Ala. CAPTION: Picture, PHILIP STUART BALL JR.