[9] He went on to be secretary to the Air Committee in November 1912 and a staff officer in the Directorate of Military Aeronautics in May 1913[10] and was then transferred to the Reserve of the Royal Flying Corps on 17 December 1913.

[12] On 5 October 1914, he was sent, not to a flying post but to be the Deputy Assistant Quartermaster-General at the headquarters of the British Expeditionary Force in France.

[13] On 6 March 1915 he was granted a brevet promotion to lieutenant colonel[14] and posted as the assistant adjutant and quartermaster-general of the 2nd Cavalry Division.

[16] On 20 November 1917 he was made the deputy director-general of military aeronautics under Major General John Salmond at the War Office.

[17] Ellington succeeded John Salmond as director-general on 18 January 1918,[18] holding the post until it was disestablished with the creation of the Royal Air Force in April 1918.

He was promoted to the temporary rank of major general and appointed acting Controller-General of Equipment in April 1918,[12] becoming substantive in that post in August 1918.

[12] He went on to be Air Officer Commanding RAF India in November 1923[12] and put down a rebellion by Mahsuds on the North West Frontier in what became known as Pink's War.

[37] It was in his capacity as inspector-general that in 1938 Ellington visited Australia to investigate standards in the Royal Australian Air Force.