The only way to get meaningful change out of CASA is to make the Minister very uncomfortable. I say this because CASA is doing an incredible job in its primary function of preventing any nastiness from falling in the Minister's lap. Its their secondary and lesser function that needs changing.
Now, as this shambles has been going on for 23 + years this is not going to come from the Opposition benches as they once sat on the Government benches and also made a total cluster **** of it.
As a suggestion, I understand that the FAA did an audit on the Australian system and found it wanting. A time period was put in place for certain changes to be made which was done but only just. I understand a lot was left to be desired. What would happen then if lobbying the FAA led to a "fix or get out of our airspace" edict? The brown stuff would fly in all directions very rapidly with a monstrous kick up the behind to CASA. It is not unfeasible.