After leaving school he worked for the Union Bank of Scotland, before joining the Royal Flying Corps as a cadet in 1917,[1] and being commissioned as a temporary second lieutenant (on probation) on 21 June.
He was reported as being wounded in action in early November 1917,[4] but gained his first aerial victory on the 15th of that month, flying an Airco DH.5 single-seat fighter, driving down out of control an Albatros D.III over Diksmuide.
24 Squadron was then re-equipped with S.E.5 fighters, and on 19 February 1918, MacDougall and Lieutenants Andrew Cowper, Ronald T. Mark, and Reuben Hammersley shared in the downing of a Rumpler C over Servais and a DFW C over Bernot.
Two days later, on 21 February, he drove down an Albatros D.V south of Honnecourt, and on the 26th he destroyed a Fokker Dr.I east of Laon.
His citation read: MacDougall was eventually transferred to the RAF's unemployed list on 29 April 1919.