As Spaceballs to sci-fi, so Airplane! to disaster movies.Airplane is a satire of all the disaster movies around the time.
As Spaceballs to Star Wars so Airplane! to Zero Hour!
Surely you can't be seriousI disagree. If a movie is just making most of its jokes unrelated to the source material then its not a very good parody. You can't run an entire movie based only on satire jokes yes, but there is a limit to at which point its just unrelated.
If you are, I think you are missing the deeper point, in that its almost irrelevant whether the jokes are actually about the source material. While there's certainly nothing wrong with it, but parody is also more structural then that.
Airplane! and its source material... well Airplane! pretty much plagarized the source (because Paramount owned both) and added jokes or made "straight" lines into ones nobody could ever take seriously again. But unless I've missed something (possible) there's nothing overly particular to disaster movies about Kareem Abdul-Jabbar leaning on the fourth wall to admit he is Kareem Abdul-Jabbar in disguise when the kid disses his games.