Hi Lebla312,
This is an example of what you will find in the config/earth/base folder if you open one of those files. So you can make a new file named Dallas and put in the right coordinates and texture.
Good luck.
BASE-V2.0
Name = Inyokern
Location = -117.83 +35.66
Size = 2000
BEGIN_OBJECTLIST
LPAD2
POS 0 0 0
SCALE 1 1 1
TEX Lpad02
NAV 132.80
END
END_OBJECTLIST