May I suggest using AFCAD 2 by Lee Swordy it's
FREE and smiple.
"
52. Creating a New Airport From ScratchIn addition to modifying existing stock airports, AFCAD can create a new airport, one that doesn't currently exist in the game. This can be done at any location. You can create a visible airport with runways, taxiways, aprons, lights, communications, navaids and ATC. However, since the current version of AFCAD can't create taxiway signs or buildings and other structures, such an airport will be somewhat bare. These features will be available in subsequent releases."
reference cited: AF2 Readme
bill
p.s. add scenery using FREE
Rwy12