John V. Hearn Jr., 58, a retired Air Force colonel and an official of the National Academy of Sciences, died at George Washington University Hospital Friday following a heart attack.

Col. Hearn was born in Cardinal, Va., graduated from Virginia Polytechnic Institute in 1940, and shortly thereafter joined the U. S. Army Air Corps. He served in the North African and Italian campaigns in World War II and in the Korean conflict. He also had serveral assignments in Washington before his retirement in 1966.

Col. Hearn, who had been engaged in research and development work in the Air Force, then joined the Bell Acrospace Co. in Niagara Falls, N. Y. in 1972, he returned to Washington and went to work for the National Academy of Sciences. At the time of his death, he was executive secretary of the academy's national materials advisory board.

He was a member of the Scientific Research Society of America, of the American Institute of Chemical Engineers, or the American Ordnance Association, and of the American Institute of Aeroncautics and Astronautics. He also was a member of the Military Order of the World Wars.

Surivors include his wife, Stephanie B. Hearn, of the home in Annandale; two sons, John V. Hearn III, of Brookfield, Ohio, and Bruce P. Hearn, of Stamford, Conn., and three grandchildren.