 Just before the end of World War I, Courtney was promoted to acting brigadier-general and sent France to command the 11th Brigade which was being established as a subordinate formation of the RAF's Independent Air Force.However, once the armistice was declared, the Independent Air Force's commander, Major-General Sir Hugh Trenchard, returned home and Courtney succeeded him as commander.After the war he served as Officer Commanding, No 2 (Indian) Wing and then after a tour on the Directing Staff at the RAF Staff College, Andover, he was appointed Deputy Director of Operations and Intelligence at the Air Ministry.