The first thing to mention is that there are Cowboy operators out there and they will operate without any consideration for the below or the rules in general. They are operating illegally!!!.
There are two things to consider when it comes to airspace:
A. 3nm (5.5km) ‘No Fly Zone’ around Aerodromes such as Brisbane, Archerfield and the Gold Coast, and
B. Helicopter Landing Sites (HLS),