He had gained a further three victories; driving down Albatros D.Vs on 17 July and 14 August, and a DFW Type C reconnaissance aircraft on 10 September,[1] before being promoted to flight lieutenant on 1 October 1917.
[16] His squadron was then re-equipped with the Sopwith Camel, and on 6 December he gained his fifth aerial victory, driving down an Albatros D.V north of Passchendaele, to become an "ace".
[1] On 10 July his aircraft suffered an engine failure over enemy lines, forcing him to land, and he was held as a prisoner of war until after the armistice in November 1918.
[18] Ridley was transferred to the Royal Air Force's unemployed list on 28 February 1919,[19] but was granted an RAF short service commission on 24 October, with the rank of flight lieutenant,[20] and posted to No.
On 17 May 1920 Ridley's Bristol Fighter aircraft (D8059) collided in mid-air with that of Flying Officer John Dartnell de Pencier (H1566) at Lindenthal, Cologne.