The film utilized actual North American B-25s Mitchell bomber planes which were flown over to England from the United States of America especially for the production of this movie. The B-25s flight to the UK was filmed and made into the documentary called B-25 Mitchells Do Fly IMC.
Most of the aerial flying scenes were filmed at the disused RAF airfield at Bovingdon, Hertfordshire.
Lesley-Anne Down replaced Sarah Miles who withdrew from the lead role of Margaret Sellinger. Geneviève Bujold was also cast as Margaret Sellinger before Down, but Bujold left the film when Kris Kristofferson withdrew from the movie.
This movie has become a favorite amongst aviation aficionados despite the fact that upon initial release, it bombed at the box office and was generally disliked by critics.