Bradley Farrell, an ace test pilot for McMasters Aviation Corp., breaks his leg when a new airplane crashes because it is too heavy to get off the ground. When Brad's younger brother Douglas, who just graduated with a degree in aeronautical engineering, flies in, Brad argues that flying is too dangerous for his brother. Brad arranges for Doug to be hired as a design engineer for McMasters. One afternoon, Doug runs into Carol Blake, who is looking for Brad to interest him in her father's design for a plastic plane. Doug pretends to be Brad because he is attracted to the pretty Carol, but his ruse is revealed later at The Flyers' Roost, a nightclub hangout for local pilots. Brad takes Carol out flying to impress her, but her only interest is in getting him to meet her father. Finally, she brings her blind father, Professor Blake, to The Flyers' Roost, and Brad becomes immersed in Blake's plane designs. That same evening, Brad's friend, Johnny Coles, loses his life test flying his own design for a plastic plane and leaves behind his wife and child. Despite Johnny's death, Brad convinces McMasters to build Blake's plane, and Doug is put in charge of the project. Trouble mounts between the brothers when Doug, just returning from a business trip, sees Carol kiss Brad before he takes off for a cross-country flight and does not realize the kiss was only a setup for a newspaper photograph. Brad sets a new cross-country speed record, and when he returns, he proposes to Carol. Carol gently rejects him because she is in love with Doug. Unaware of Carol's decision, Doug picks a fight with Brad and in a rage quits his job, but a talk with Professor Blake changes his mind. The construction on the plastic "geodetic" plane is completed, and Army officials, interested in the plane as a trainer, arrive for the test flight. An arrogant Brad balks at all the test equipment Doug has installed in the plane and also protests having his inexperienced brother fly with him as a test pilot. Once in the air, Doug orders Brad to execute a 9-G power dive, which causes Doug to pass out. His equipment breaks off and slides under the rudder, and Brad is unable to maneuver the plane. He forces Doug to parachute to safety, and then cuts the rudder wires and wraps them around his hands. Although his hands bleed profusely, Brad manually lands the plane safely. Relations between the brothers heal, Doug and Carol marry, and Brad finally gives up the hazards of being a test pilot to take a desk job as vice-president of McMasters Aviation.