Made this collection of all the big and quality airports I could find on Planet Minecraft, I'll be looking for some more that might be hidden away in city projects and such, but this represents the bulk of most airports. A trend I noticed with some of them is they are under a 75% completion threshold. Meaning they get abandoned anywhere from a quarter to half way. I hope this provides some reference and inspiration to other people hoping to make there own and hopefully fully completed airport in the future.