Keeble entered the
Royal Naval Air Service as a probationary flight sub-lieutenant, and on 2 August 1915 was confirmed in his rank of flight sub-lieutenant for temporary service. He was assigned to a squadron in No. 1 Wing, based at
Saint-Pol-sur-Mer, Dunkirk, and gained his first victory while flying a
Nieuport. On 25 January 1916 he forced down a German seaplane off
Nieuwpoort. His second victory did not come until 23 October when, flying a
Sopwith Pup, he destroyed another seaplane off Nieuwpoort. On 1 October 1916 he was promoted to flight lieutenant, and on 31 December 1917 appointed a
flight commander. On 1 April 1918, the Royal Naval Air Service was merged with the Army's
Royal Flying Corps to form the Royal Air Force, and Keeble became part of
No. 202 Squadron RAF, flying the
DH.4 two-seater day bomber. With Captain
Eric Betts as his
observer/gunner he went on to gain four more aerial victories; firstly destroying a
Pfalz D.III north of
Essen on 5 June, then driving down out of control a
Fokker D.VII over
Bruges on 10 August. Finally, on 16 September, he destroyed a Pfalz D.III over
Lissewege and a Fokker D.VII over
Dudzele. ==Inter-war career==