The outdoor set used for the 747 crash site was so convincing that pilots landing at Toronto Airport were radioing in what they thought was a recent airplane crash.
John Varley originally wrote the short story "Air Raid" in 1977. At the time, it was optioned as a project for FX director Douglas Trumbull, director of Silent Running (1972) and Brainstorm (1983). The plan was to make it a vehicle for Paul Newman and Jane Fonda. Trumbull's production fell through, only for it to be inherited first by Randal Kleiser and then Richard Rush. With all the comings and goings over the years, Varley was able to first turn it into a novel in 1983 and then a screenplay.
To create the time-travel effects of the Gate, cinematographer Rene Ohashi produced the ghostly shimmering lights by spinning metal wheels covered in Mylar.
The film takes place in 1989, 2989 and 1963.
In Kids in the Hall s1e20, Scott Thompson performs a monologue in which he talks about his involvement in this film.