dook, you are correct. The mystery aerodrome is in Queensland, otherwise known as the Deep North.
Concerning the Black Stump, when you drive beyond it, you are in the GAFA!
I remember an Aussie TV ad in the 80s for a Ford Falcon (or possibly a petrol or oil ad), where the video ended with a car driving down a bush track and passing a black stump. Nicely done.