Navy Capt. Donald W. Knutson Sr., 49, on the staff of the Deputy Chief of Naval Operations for Logistics, died Saturday in Portsmouth, Va., after a heart attack. He was stricken while visiting there.

Capt. Knutson was assigned to the staff of the deputy chief in 1974 and was head of the ordnance materiel management branch of the material division at the time of his death.

His first assignment in Washington came in 1964 with the Bureau of Naval Weapons where he was a research and development officer for guided missiles and later executive assistant to the commander of the Naval Ordnance Systems Command.

From 1968 until 1970, Capt. Knutson was commanding officer of the destroyer, the USS Mullinix, and was awarded the Bronze Star for combat operations in Vietnam. He then was executive officer and commanding officer of the cruiser, USS Saint Paul, and received a second Bronze Star and Navy Commendation Medal for service in Vietnam.

Capt. Knutson returned to Washington in 1971, where he was assigned to the Naval Ordnance Systems Command as Talos weapons system manager. He subsequently was deputy Tartar weapons system manager and standard surface-to-surface missile manager.

Born in Dovray, Minn, Capt. Knutson enlisted in the Navy in 1945. He was appointed to the U.S. Naval Academy at Annapolis and graduated there in 1951.

He saw duty aboard the attack transport, the USS Cambria, the tank landing ship, the USS LST-603, and the destroyer, the USS The Sullivans.

He was on the staff of the commander, Cruiser Destroyer Force, Atlantic Fleet, studied at the Naval Post-graduate School in Monterey, Calif., and was commanding officer of the fleet tug, the USS Utina.

After studying at the Naval War College in Newport, R.I., Capt. Knutson was executive officer of the guided missile destroyer, the USS Semmes, until his first assignment in Washington.

He is survived by his wife, Anne F. Knutson of the home in Arlington; four children, Margaret, Susanna, Donald and Beth Knutson, and three stepchildren, DeWitt, Alys and Bernard Marsh.