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.
Prior to World War I's conclusion, Courtney received a promotion to acting brigadier-general and was dispatched to France to command the 11th Brigade, which was being established as part of the RAF's Independent Air Force. Following the armistice, Major-General Sir Hugh Trenchard, the commander of the Independent Air Force, returned home, and Courtney assumed his position as commander.