...mmmm.. AFCAD I the ONLY way (FS9) to make basic airports....With it you get your runways......Parking...Start Points....runway textures lighting and markings..taxiways...apron textures...ATC recognition........ILS ....working AI... etc etc etc?. The rest is really just eye candy.........
....... This "eye candy" can be placed into your new airport using freeware RWY12 as CaptX has suggested , though a better bet is the payware EZ-Scenery.........much easier to use and can use the RWY12 objects and all the FS9 generic stuff too......plus many objects made by other guys and made available...........
Flattenbgl will do just that (flatten your site)and Excludebgl will be also needed to sort out the trees etc where you want to place your new airport........both these are freeware. Another utility you might need for those hard to move things like roads and pylons etc which could interfere with your plans is..Defarea.....a neat little program which is a blessing at times.......just a few suggestions

Good luck with the project..........commoner


"In theory, there is no difference between theory and practice. But, in practice, there is."