If the game was built with an airport at that location, it doesn’t matter if it’s handcrafted or part of the base game - it’s not really removable without some serious modding.
Since you’re having what you presume is a conflict between the base game and payware, your best option is to contact the Payware author/maker and let them know what you’re seeing. Maybe they can issue a fix. Most payware airports operate atop the base game’s object - overriding it.