The movie is based on a short student film directed by Kevin Reynolds when he was in USC film school. The student film is basically just the skydiving sequence, based on a true story. Steven Spielberg, having seen the student film Proof (1980), recruited Reynolds to direct a full-length movie based on it.
Kevin Costner auditioned for and lost a part in the student film on which Fandango is based, the same part he later played in the feature film.
Actor Chuck Bush (Dorman), the large, mild-mannered schoolmate, was "discovered" in a '7-Eleven' convenient store. He had no prior experience or connection with the movie industry, prior to being "seen" and asked to "read" for the part.
Dorman manages to get quite a bit of reading done over the course of the film. He's seen reading Steppenwolf by Herman Hesse, Being and Nothingness by Jean Paul Sartre, The Prophet by Kahlil Gibran and The Incredible Hulk #128.
Actress Suzy Amis was simply billed as "The Girl" in the credits, but her character's name was actually Debbie. Actors Judd Nelson and Sam Robards both say her name in the film.