I agree with your intuition, There are lots of corner cases, but there are also a fucktonne of checklists: https://www.aviationhunt.com/boeing-737-normal-checklists/ (this is just a small "normal" one) but for loads of situations there are check lists, thats something the LLM can probably do very well.

However its as far as I know the check list volume scales with how "airline-y" the plane is. so for a one seater, the checklist is small and only handles a few things. For a 777 its a binder.