Prior to the United States' entry into World War II, Major Chick Davis and Captain Buck Oliver of the United States Army Air Force argue about the most efficient bombing method. Buck, a pilot, advocates that pilots should dive bomb their own targets, while Chick argues for the high altitude precision bombing of the bombardier. In a contest between the two methods, the bombardiers win the challenge, and Chick is assigned to establish a school for bombardier training at Hughes Field in New Mexico. The field is run by Burton "Burt" Hughes, an attractive woman whose father was a respected general and with whom Buck is in love. Chick at first disapproves of Burt's presence at his school, but soon begins to rely on her efficiency. Although still convinced that bombardiers are inferior to pilots, Buck arrives at the base to fly the new trainees. Among the new cadets are Burt's brother Tom, Joe Connors, girl-crazed Ignacius "Chito" Rafferty, Paul Harris and Jim Carter, who develops a crush on Burt. While flying a mission one day, Buck disputes a bombardier's authority to decide a pilot's heading, prompting Chick to vow that when his trainees graduate, they will receive commissions that grant them equal rank with pilots. After passing their ground training, the cadets begin aerial training. While on a test flight, the controls on Buck's plane freeze, and Buck orders the cadets to parachute to safety. When Tom panics and refuses to jump, Carter knocks him unconscious and informs Buck that everyone has bailed out. After Buck jumps from the plane, Carter takes charge of the cockpit and saves Tom's life by unjamming the controls and landing the plane on its belly. Out of gratitude for saving her brother's life, Burt agrees to go out with Carter and they begin dating. Tom is considered for elimination from training because of his refusal to parachute, but Chick agrees to give him another chance. While piloting another flight, Buck's oxygen equipment fails and he passes out. When the plane suddenly plunges out of control, Tom falls out of the plane's escape hatch to his death. Although a board of inquiry finds Buck innocent of negligence, he requests a transfer and leaves without saying goodbye to Burt, who has taken a leave of absence. After the bombing of Pearl Harbor, the bombardiers win their commissions and are called into active service. Now a colonel, Chick asks Burt to marry him, but she refuses, telling him that he is too much like her father. At the airfield, as the bombardiers board their planes, Burt embraces Carter and asks Sergeant Dixon, Chick's assistant, to give Buck a letter telling him that he is forgiven. After crossing the Pacific and landing at an island base, Chick and Buck meet again. Chick tells Buck that his mission is to fly low over a Japanese base near Nagoya and light up the camp for a surprise bombing attack. That night, Buck and Dixon take off, but are shot down by the Japanese before completing their mission. After they are taken prisoner, Dixon remembers Burt's letter and is about to hand it to Buck when a Japanese soldier intercepts it. The Japanese then begin to torture the Americans to force them to divulge the location of their base. Just as a Japanese soldier begins to taunt them that their mission has been a failure, the hum of American bombers is heard overhead and the camp goes dark. In the ensuing chaos, Dixon is shot, but Buck escapes and drives a flaming truck through the camp, setting the base on fire and lighting it up for the bombardiers. In the air, the bombardiers drop their missiles on the target, knowing that a hit will mean Buck's death. As his comrades' bombs explode around him, Buck finds Burt's letter and dies a happy man.