VOR jammed up: use VOR 2 receiver if you have one, or the trusty ADF. Ground station failure? Should be other beacons to divert to.
Electrical system failure: yep, you are up the proverbial creek (not a scenario in Old Akro's post, it was antenna failure). You may be lucky enough to have 2 independent GPS systems with separate antennae to cover an on-board failure if that is what you meant by 'electrical failure'.
Entire or part GPS constellation affected by jamming, solar flare or military activity: use the VOR or ADF...oh, wait...
I suppose that that radar vectors to one of Australia's few ILS somewhere might be an option.
We could always bring back the VDF approach!
Last edited by Captain Dart; 22nd Jul 2016 at 11:39.