Air Force Col. Alex Turner Jr., 50, a pilot and Vietnam war veteran on duty with the directorate of command control and communications at the Pentagon, died Sunday following a heart attack. He was stricken in his car at the Naval Observatory.

Col. Turner had been chief of the tactical command control and communication division of the directorate since June 1978. Before that, he had served for six years at Travis Air Force Base in California.

He was with the 834th Air Division in Vietnam in 1967 and then spent four years at Air Force headquarters here as air operations officer in the office of the deputy chief of staff for programs and resources.

Col. Turner was born in Medina, Tenn. After high school graduation, he served in the Army Air Corps and the Air Force from 1946 to 1949. He earned a degree from Texas A&I University and reentered the Air Force as an officer in 1953. Later he received a master's degree from Central Michigan University.

At the time of his death, Col. Turner was chairman of deacons at Fort Washington Baptist Church in Maryland where he taught Sunday school and Men's Bible Class. He was on the executive board of the D.C. Baptist Convention.

He is survived by his wife, Jean C., and four children, Deborah, Alex, Dolores and Anthony, of the home in Oxon Hill, and his parents, Mr. and Mrs. Alex Turner Sr., a brother, Hubert, and a sister, Martha Newsom, all of Chicago.