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.
Just before World War I's end, Courtney was promoted to acting brigadier-general and sent to France to command the 11th Brigade, which was being formed as a subordinate unit of the RAF's Independent Air Force. However, after the armistice was declared, the commander of the Independent Air Force, Major-General Sir Hugh Trenchard, returned home, and Courtney took over his position as commander.