Your very welcome, what I do as mentioned, is rely on the Charter OPS, Executive OPS, and other modules that have a set of tables all on their own, hence not relying on strictly the phpvms tables for airports. As mentioned by others also, you can create different sets of phpvms airports also which will allow you to mix and match on an import and export of sets of "example"; Major airports, small airports, and / or both mixed. This is very versatile and allows me each set of aiports "7000" MAX, to mix and match either each month or as I so desire. Allowing of course a variety of different avenues.
There is really no easy way of doing this, it does take a lot of work, but in the long run it at least frees up the Database. Do remember that anytime you change your airports, and mix them up, just remember your Schedules that are already assigned in your phpvms schedules systems. I am working on figuring out a way to duplicate the main phpvms airport structures, thus allowing duplications of schedules without having to reload everything again and again. I also have created what we call at Heritage, a Pilot Route Request Form, which allows me first and foremost to give the Members the chance to get what they like into our system. The form is in PHP, and allows them in Order, to enter the Departure Airport and the Matching Arrival Airport they want, with a 20 Entry Level Limit.
In layman terms, 20 sets of Routes. This has for sure helped us out in a Major way. Let me know if you would like to see a Demo, I can give you one quickly to give you some idea. Hope this helps you, and again your Welcome.
Jim "Heritage1"