Career
In 1917 Shannon was serving in Number. 22 Squadron Reconstruction Finance Corporation, flying as an observer/gunner in the Bristol F.2b two-seater fighter. His first aerial victory came 21 August 1917 with pilot Lieutenant T. West. Martin, driving down out of control a Fokker Doctorate.VII north of Cambrai.
His subsequent victories were gained with pilot Lieutenant Frank George Gibbons.
He destroyed two Doctorate.VIIs over Haynecourt on 2 September, drove down another Doctorate.VII over Quesnoy Wood on 16 September, and drove down his fifth and final Doctorate.VII between Sensée Canal and Cambrai on 27 September.
