Retired Air Force Brig. Gen. William J. Flood, 81, a pioneer aviator and balloonist, died Sunday at the Bethesda Naval Hospital after a long illness.

He was commanding officer of Wheeler Field in Hawaii and was wounded during the Pearl Harbor attack.

Gen. Flood then was chief of staff of the Seventh Army Air Force with headquarters at Saipan for the duration of World War II. He retired from that command on June 1, 1946, and returned to Washington, where he had lived since.

Born in Peoria, Ill., Gen. Flood came to Washington with his family as a boy and graduated from Central High School.

He attended George Washington University law school but left to join the Army Air Service in 1917. He was commanding officer of an aero squadron with the American Expeditionary Forces in France in World War I.

Gen. Flood later graduated from the Army Balloon School, the Army Airship School, the Air Corps Engineering School, the Advanced Flying School as special observer and the heavier-than-air course of the Air Corps Training Center.

He held four flying ratings, those of airplane pilot, airplane observer, airship pilot and balloon observer.

During the 1920s, he was the first pilot to pick up mail from the top of a building while in flight. This was done at Newport News, Va.

Gen. Flood also was the first pilot to pick up mail from a steamer at sea while in flight. This was accomplished at Hampton Roads on Feb. 4, 1929.

Also in the 1920s, Gen. Flood participated in three National Elimination Balloon Races. He came in second in one and consequently took part in the International Balloon Race held in Belgium in 1925 in which he also placed second.

He was sent to Hickam Field in Hawaii in 1940, where he later became commanding officer. He was transferred to Wheeler Field just prior to the Japanese attack.

Gen. Flood held the Legion of Merit, the Bronze Star, the Air Medal and the Purple Heart.

After his retirement, he was active in a number of organizations in Washington. He was a past president of the Arthritis and Rheumatism Association, former national commander of the Military Order of the Caraboa and a former officer of the Ancient Order of Hiberians. He belonged to the Elks Club and the Army and Navy Club.

He is survived by two sisters, Geneieve F. Bryan and Dolores Flood, both of the home in Washington.

The family suggests that expression of sympathy be in the form of contributions to the Arthritis and Rheumatism Association.