On 1 March 1917 appointed flying officer while still temporary second lieutenant. He was then assigned to No. [20 Squadron RAF|No. 20 Squadron RFC] to pilot a Royal Aircraft Factory FE.2d. He scored his first victory on 8 June 1917, with Edward Sayers manning the observer's guns. Durrand scored three more wins while flying a FE.2, with number four coming on 21 September. He then upgraded to another two-seater fighter, the Bristol F.2, and scored again almost immediately, on the 27th, with observer William Benger as his gunner. His next victory came on the first day he flew as Temporary Captain and Flight Commander on 17 October 1917. Durrand scored twice more with the Bristol, ending his victory string on 8 November 1917. His final tally was two enemy planes driven down out of control, and six destroyed.