Opened the Shannon Airport in Fredericksburg Virginia in 1950. In 1976 Shannon opened the Shannon Air Museum, with one of the rarest collections of antique aircraft in the world that he had acquired. Upon his passing in 1981 the collection was donated to the Virginia Aeronautical Historical Society, and moved to Richmond international Airport.

began his association with Pitcairn aviation In May 1929, a company flying the U.S. mail out of Byrd Field in Richmond. His dedication to aviation never ceased. Shannon's capabilities as field manager…chief dispatcher…and reserve pilot were contributing factors to the growth of Pitcairn, which became Eastern Air Transport Inc. In 1933 the name was changed to Eastern Airlines Inc. Recognized for his outstanding expertise in aviation, he was promoted to VP of operations, became a member of the Board of Directors of Eastern Airlines in 1938, and after retirement as Senior VP of Eastern Airlines in 1959.

Flew the airmail routes for Virginia in the 1920s and 1930s. He learned to fly just after World War I, and amassed some 45,000 hours of flying time. He was best known in Virginia for his exploits flying the airmail for Pitcairn Aviation which later became Eastern Airlines. He was the personal pilot for President Dwight D Eisenhower, and set numerous flying records including earning the coveted Harmon Trophy, presented by President Franklin D Roosevelt, for the first commercial round-trip Atlantic flight in 1937, in a Vultee V1-A, named Lady Peace.