The story follows Hal Dane, a resourceful, air-minded youth who supports his family by driving an old truck while cultivating a passion for flying. After witnessing an airplane crash, he races to the scene, helps free the injured aviator, and strives to preserve a crucial mail packet; that incident propels him into a life of practical experiments, mechanical problem-solving, aerial contests, emergencies, and rescues that shape his progress and eventual success in aeronautics.