Based on

Movies like The Lone Eagle (1927)

During WWI to prove his mettle against a charge of cowardice to everyone including his girl Mimi, American pilot Lieutenant Billy Holmes accepts an assignment with the Royal Flying Corps. He downs a German aircraft piloted by the brother of squadron leader Lebrun. Out of bitterness Lebrun challenges him to a dogfight from which Billy emerges victorious restoring his lustre and reputation.