Alfred J. Bell, 57, an aeronautical design engineer on the principal professional staff of the Johns Hopkins University Applied Physics Laboratory, died of cancer Tuesday at his home in Silver Spring.

A pioneer in the development of guided missiles to protect Navy ships, he had supervised the research engineering group that contributed to the early structural and mechanical design of the Terrier, Tartar and Talos missiles.

Mr. Bell later was chairman of the guided missile correlated task group appointed by the Defense Department, which helped determine that the Standard missile would replace the Navy's "3 Ts."

He had joined the Johns Hopkins laboratory in 1946. In recent years, he was involved in the design of new transportation and solar and geothermal energy systems.

Mr. bell was born in Williamsport, Pa. He graduated from Catholic University in 1943 and was a junior aeronautical design engineer at the Chance-Vought Aircraft Co. in Stratford, Conn., until 1946.

He was a member of science and engineering panels of the National Academy of Sciences, the Department of Defense and the Applied Physics Laboratory. He held patents on guided missile designs, including one powered by a ramjet airbreathing engine.

He is survived by his wife, Lorraine Margaret, of the home; a daughter, Beverly Anne Assaf, and a son, Robert A., both of Silver Spring; another son, Alfred J. Jr., of Laurel; a brother, Robert Emmitt, of Harpers Ferry, W. Va.; a sister, Mary Young, of District Heights, and four grandchildren.