On 1 July 1918, Gilmour capped his career with a performance that earned him a Distinguished Service Order (DSO). On that evening, within 45 minutes, he burned two Fokker D.VIIs and knocked another down out of control, set an Albatros D.V afire, and drove a Pfalz D.III out of the air. The times on his combat reports make it clear these were five separate engagements; many times, aces reporting multiple victories scored in a single engagement.
