I think what made that script work was they just threw everything at the wall and if it stuck it stuck and, if not, they moved along. There’s like three spoken jokes and two sight gags per every five minutes of film; some of it hit, some of it didn’t. Some of it was topical, especially concerning the films they were lampooning, the dramatic “Airport” series. Like the PA announcements in the airport scenes about abortion, that was in “Airplane” because there was a whole subplot about abortion in “Airport.” In the dramatic film, it was as if the writers wanted to beat you over the head about abortion, so that specific joke in Airplane lands differently if you’ve seen and are a fan of the Airport series. Still… it’s a real testiment to the skill of the screen writers that modern audiences, many who have never even heard of “Airport” still find “Airplane” hilarious.