Fox Rule joined the
Royal Flying Corps as a cadet in early 1917, was commissioned as temporary second lieutenant (on probation) on 5 July 1917. He was confirmed in his rank on 31 August, and joined No. 49 Squadron RFC on 26 November 1917. His squadron was initially equipped with the
Airco DH.4 light bomber, in which he gained his first two victories, driving down German reconnaissance aircraft in early March 1918. On 15 May 1918 Fox Rule was appointed a
flight commander with the acting rank of captain. In June he gained three more aerial victories, driving down two
Albatros D.Vs, and shooting another down in flames. In July he sent a
Fokker D.VII down out of control, and another in early August, bringing his total to seven. On 20 September 1918 his award of the Distinguished Flying Cross was
gazetted, his citation reading: :Lieutenant (Temporary Captain) Gordon Fox-Rule. ::"Whilst on a bombing raid this officer dived to and obtained a direct hit on a bridge, completely destroying it. Seeing a body of the enemy on the bank of the river he attacked them, causing them to disperse in disorder. He was then attacked by five biplanes; these he drove off, though his observer had been hit twice, and he landed safely at a French aerodrome. In all, he has taken part in thirty bomb raids and ten photographic reconnaissances, invariably displaying a marked offensive spirit." He also received the
Croix de guerre with palm from France in 1918.
List of aerial victories ==Post-war service==