Hi Jimbo,
to IIS!
If nothing is planned for the Airfield, it is best not to intrude. There is no parking area there outside the Airfield.
There are times when the Airfield is not available to us. On these occasions, there are a couple of fall-back sites we have, but the are open public places. One is Hargraves Lookout, the other Mt Blackheath Lookout. Both are accessed via Blackheath, and it is literally a fork in the road that leads to one of the other!
Hargraves Lookout has a more expansive sky, but it is much more exposed. In the depths of winter it can be most bloody cold. In summer, the worst that can happen is wind. You will need to lug your gear across from the parking lot to the observation area.
Mt Blackheath Lookout is more protect, but the sky is more restricted. There is also a launch pad for hang gliders and paragliders there. Finding a suitable flat spot to set up is more tricky.
While both sites are very remote, the occasional lost tourist does show up in the middle of the night. And local twits can too. So always go with a mate.
Be careful driving along the road leading from Blackheath between dusk and dawn. There are kangaroos around then, and the dopey buggers have no road sense. I came very close to crashing into two one time. Much of this road is unsealed too, so don't drive too fast either - if a roo or a car appears suddenly from around a corner, you're stuffed.
If it's summer, head to Hargraves. If winter, Mt Blackheath is a warmer option. But always take warm clothing, even in summer. It does still get cold up there at night.
Mental.
