McGoun originally enlisted in the
24th Battalion (Victoria Rifles), CEF of the
Canadian Expeditionary Force but transferred to the
Royal Flying Corps in October 1916. He was assigned to
No. 20 Squadron RFC as a pilot of a
Bristol F.2 Fighter. He scored his first victory on 27 October 1917; by 17 February 1918, he had run his total to five, becoming an ace. On 8 March 1918, while still a Temporary Second Lieutenant, he was appointed
Flight Commander and Temporary Captain in 22 Squadron. He scored four more triumphs with this squadron, with the last one occurring on 12 April 1918. His final tally was four enemy planes destroyed, five driven down out of control. His passage was paid by the British government. His height is given as five feet eight inches. His sister was named as his next of kin, and his home of record was given as 1 Cote Saint Antoine Road, Westmount, Quebec. And although others on the passenger manifest are noted as being in transit to Canada, he is not. McGoun was awarded a Military Cross on 26 July 1918. ==Postwar career==