Ace of Aces was based on Bird of Prey by John Monk Saunders, an acknowledged master of aviation epics. Richard Dix stars as Rex Thorne, a pacifistic sculptor who registers as a conscientious objector when WWI breaks out. Thorne's unwillingness to fight in a war he believes to be unnecessary is misread as cowardice by his socialite sweetheart Nancy Adams (Elizabeth Allen). In "four feathers" fashion, Thorne signs up with the air corps to prove his courage. Before long, he has established a reputation as a reckless, ruthless flying ace, with little concern for anyone's safety, including his own. This fails to satisfy Nancy -- now also serving her country as a Red Cross nurse -- who feels that Thorne has become too bloodthirsty for his own good (What does this woman want?) The supporting cast includes radio singer Art Jarrett and James Cagney's look-alike brother Bill. Some of the aerial scenes in Ace of Aces were "borrowed" from Howard Hughes's Hell's Angels.