 Fairclough gained his first aerial victory in a SPAD on 6 December 1917, scoring steadily throughout the month, and had nine victories to his credit by the end of the year.His squadron converted to the Sopwith Dolphin in January 1918, and he scored five more victories between 17 March and 2 May, by which time the Army's Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS) had been merged to form the Royal Air Force.He was awarded the Military Cross, which was gazetted on 10 May 1918.