A reckless jet pilot goes to work for a demanding aviation tycoon.

In 1943, pilot Matt Brennan flies the large, cumbersome B-17 fighter planes, known as "Flying Fortresses," from a base in England. After one dangerous mission, Matt tells airplane designer Carl Troxell about the problems he faces with the planes and later takes Troxell on a mission over Germany so he can witness these problems for himself. Later, when Matt learns that his squadron is being sent home, he unsuccessfully tries to get permission to marry his girl friend, nurse Jo Holloway, and is forced to leave without explaining matters. Once back in the States, Matt opens a flying school, but after his one plane is destroyed, he is forced to close it. At loose ends, Matt willingly accepts an invitation from an old Air Force friend to a dinner party at airplane manufacturer Leland Willis' house. To his surprise, Jo, who is now Willis' private secretary, is there with Troxell. Another guest, General Hewitt, Matt's former commanding officer, begs Matt to rejoin the Air Force. Matt, who has not seen Jo since the day he left England, tries to explain that his life would not allow him to support a wife, but Jo is too hurt to listen to him. The following day, Troxell convinces Willis to hire Matt as a test pilot. The two men work together to refine a new style of jet plane, the JA-3. Although Matt is convinced that the plane is ready to sell, Troxell is worried that the pilot would not be able to bale out if something went wrong. He has developed a mechanism to eject the entire cockpit, but Matt opposes the idea and refuses to recommend that Willis postpone an approaching demonstration for Air Force officials so that he can refine or test the addition. Instead, Matt suggests that he make an unprecedented publicity flight over the North Pole. He designs a pressure suit that will enable him to fly at a high altitude and demands $30,000 from Troxell if he succeeds. Jo, who believes that Matt will die, begs him not to make the flight. Troxell accuses Matt of grandstanding and promises to have the JA-4 model with an ejection seat ready before Matt lands in Washington, D.C. Matt rejects both their arguments, focused only on the money that he hopes to earn. While Matt waits in Alaska for favorable weather, Troxell and his men work around the clock to finish the new plane. Matt finally takes off but runs out of fuel after he is caught in a storm, and as he coasts the plane to a landing in Washington, Troxell takes the JA-4 for a test flight in California. Matt lands safely, and tells Jo he risked his life so that he could earn enough money to marry her. Later, they learn that Troxell died when the pod failed, but that the tape he made during the test reveals the solution to the problem. Bostwick, Troxell's mechanic, tries to persuade Matt to fly the JA-4 during his demonstration for the Air Force, but Matt is unresponsive both to Bostwick's pleas and Jo's tears. On Saturday, however, as the test gets under way, Willis becomes enraged when he learns that Matt is flying the JA-4, and that, with the secret knowledge of General Hewitt, he plans to use the ejection pod. Matt shuts off his radio after Willis orders him to land and successfully completes the test, using the information gleaned from Troxell's tape. Jo is there to welcome him when he lands.