Budget restrictions precluded location shooting, and all the flying scenes were staged at the MGM Studios. For an air of authenticity, footage shot at various United States Army Air Forces (USAAF) bases throughout the United States was incorporated via an exterior backdrop process. Authentic aircraft were used, although they remained firmly on the ground. The pivotal scene with Irene Dunne flying a Lockheed P-38 Lightning was recreated at Drew Field, Florida, utilizing a surplus P-38E which had been acquired from the USAAF, where it had been used as an instructional aircraft. Electric motors drove the propellers and allowed for an authentic run-up sequence. The miniature work was the product of the same MGM special effects team of A. Arnold Gillespie, Donald Jahrus and Warren Newcombe that would later be responsible for "Thirty Seconds Over Tokyo" (1944).