Well I already seen this film before and it is still quite good, personally I prefer the 2nd one (i also seen these films in the wrong order, first the 2nd then the first). Although its quite dated its still watchable and still quite rude by todays standards, it uses features which were commonly used in filmography such as a blue screen behind a car set with a rolling film. The creators/directors work with this to make it obvious to what it is and they add elements to it making it funnier for the audience.
Another feature is the dialogue, common phrases which we have all heard are mistranslated in the film in a funny way;
A good example is the scene where the doctor tells the stewardess that he has to get a patient to a hospital where the woman replies "What is it?" referring to what the medical problem is but through direct listening its as if she is asking what a Hospital is where then the doctor replies "it's a big building with patients, but that's not important right now." Typing it down doesn't give it justice but the idea was good.
Yeah its a comedy film at the end of the day full of jokes based around a serious subject of a plane crash. Its better when you see these sort of films the first time around since you don't expect them to happen the way they do but they are still good. As I said i prefer the 2nd one to the first one which sometimes doesn't work with sequels, there was more going on in it and I believe it was a bit longer in feature length.
Anyway Airplane! is a worthwhile film to watch, i'd recommend to anyone.