"This picture is respectfully dedicated to the Royal Canadian Air Force....With sincere appreciation of their cooperation and admiration for their abilities and courage...To those student pilots in this picture who are now in actual combat overseas....And most particularly is dedicated to the many in the Service who have trailed the shadows of their wings over the vastness of Canada from the forty-ninth parallel to the Arctic Circle....The Bush Pilots" Brian MacLean irritates fellow bush pilots Johnny Dutton, Tiny Murphy, Blimp Lebec, and British expatriate Scrounger Harris by outcompeting them for business in rugged Northern Ontario, Canada.

Later, after hearing Winston Churchill's "We shall fight on the beaches" speech on the radio, MacLean and the other bush pilots enlist in the Royal Canadian Air Force, only to discover that they are considered too old for combat.

MacLean, with his brash and fiercely independent nature, clashes with the military way of doing things, and he is court-martialed and dismissed from the service for flying too low, resulting in a cadet being severely injured.

For revenge, he and "Tiny" buzz the airfield when renowned Canadian First World War ace Air Marshal William "Billy" Bishop (playing himself) is speaking during the group's graduation ceremony.

During pre-production, Joseph W. G. Clark, the public relations director of the British Commonwealth Air Training Plan, was heavily involved in promoting a film project that was initially identified as "Bush Pilots" based on a script submitted by Canadian screenwriters.

After considering Raymond Massey, Errol Flynn, and Clark Gable, the decision was made to cast George Brent, but Warner Bros. was unsure whether he could carry the film.

The only holdup was casting, which was resolved when Warner persuaded its resident "cocky guy" (as producer Jerry Wald had dubbed him), 42-year-old James Cagney, to take on the lead male role.

The Warner Bros. principal cast and production crew of over 80 technicians, along with "half a million dollars of colour cinematography equipment," came from Hollywood, crossing into Canada on July 12, 1941.

[9] The aerial sequences were under the direction of Paul Mantz, a long-time Hollywood stunt pilot, who used a Stinson Model A trimotor camera ship.

MacLean's aircraft, CF-HGO on-screen, was a Noorduyn Norseman flown by veteran stunt pilot Frank Clarke (who doubled for James Cagney in flying scenes),[10] Johnny Dutton's silver CF-NBP was an actual Fairchild 71C bush plane, [N 1] while Laurentian Air Service's Waco EGC-7 and AGC-8 cabin aircraft provided the other float planes.

[12] In addition, there was a Waco CJC, registered as CF-AVW (transformed into CF-JPY in the movie), which belonged to Albert Racicot, a Montreal-based plane dealer and aviation mechanics who, at the time, was also one of the several instructors hired by the Canadian government to train military pilots involved in World War II.

At first things proceeded smoothly, but when it came time for him to fall into the lake, he overdid it and suffered a real concussion, putting the 10-day shoot at North Bay, Ontario farther behind schedule.

Weather was a constant challenge, and with the need to ensure continuity, small scenes became unnecessarily complex; as a result, a typical shooting day lasted almost into the night.

[12] One 30-second scene with all the principals running along the dock took an entire day to complete, with Cagney, Hale, and Tobias barely able to stand at the end of filming.

[13] With a Hollywood production in their midst, North Bay residents became such a persistent nuisance that the crew reverted to sending messages out of the location site by homing pigeons.

[9] The climactic ferry mission was staged out over the Atlantic from RCAF Station Dartmouth using the base's operational Lockheed Hudson bombers, along with a repainted Hawker Hurricane that posed as the German Bf 109.

[N 3] Due to the prominent Luftwaffe markings on the RCAF fighter, special alerts had to be posted in order to prevent "trigger-happy" home defence gunners from firing at it.

[22] The music score is by Max Steiner, and Harold Arlen wrote the title song (lyrics by Johnny Mercer), which is used as a march in the film.

[24] Three of the aircraft used in the flying sequences survive: the wreckage of the Noorduyn Norseman is on display in the Canadian Bushplane Heritage Centre, Sault Ste.