Shooting overlapped somewhat with the tail end of production on Universal Pictures' Tremblement de terre (1974), forcing Charlton Heston, George Kennedy, cinematographer Philip H. Lathrop, and producer Jennings Lang to juggle their schedules between the two films. This film was released first.
In his book journal "The Actor's Life", Charlton Heston relates that he had begun working on this movie only 15 hours after he had finished the final shot on Tremblement de terre (1974).
Gloria Swanson wrote all her own dialogue. She also delivered the last line of the film. This was her first movie in 22 years. She explained, "I was holding out for a picture I could take my grandchildren to see, something exciting and contemporary without senseless violence."
Charlton Heston was somewhat reluctant to do this film so soon after doing Alerte à la bombe (1972), another movie where he played an airline pilot.