All it takes is a new interpretation of "major modification" to include software or firmware upgrades and you are back getting re-approved sweetheart.
Folks,
This one already has a history. Some time back, now, CASA decided that the monthly updates to your WizzBank Avionix GPS ( the ARAC updates every 28 days) for IFR could only be installed by an avionics LAME at CAR30 (before Part 145) approved avionics shop. Depending on your equipment, these are the ones you can download to a PCMCIA, USB stick card or whatever, from Jeppesen or whoever for your equipment.
There was a big stink at the time, the idea that a large % of IFR aircraft would have to visit an avionics shop somewhere around Australia once a month was just too silly for words.
Fortunately, this was during the all too brief period at CASA of Byron and Vaughan, and a sensible outcome was arranged, but the "attitude" of several avionics outfits, who saw the opportunity for yet more regulatory induced guaranteed cash flow, was not pretty.
Your transponder setup must be approved as well.
That applies even in the US, spurious/corrupted transponder returns could have all sorts of potential outcome if let loose inside CNS/ATM computers.
there are no firm foundations that guarante our existence
That is not entirely true, although there are enough in CASA who think it is true, and many more who wish it was true.
Part 21 aircraft categories are there
by right of law, not CASA indulgence, and it took a lot of effort to ensure the phrase
"----- and CASA is satisfied" was not part of the then new certification standards.
You build and fly your Part 21.189, 21.191 etc. aircraft by right of law.
If that is to change, to put CASA back in the driving seat, that will (only) happen if the aviation community let it happen, and sadly, among us are a few who hanker for the "good old days" when there was no such thing as "Experimental", and the old Australian amateur built category was subject to damned near as many restrictions as building a certified design under a production certificate --- with all the related charges being a very significant cost of building.
--- but only in the interests of safety, as I am certain you understand, after all, you can't be allowed to make your own decisions as to what risks you find acceptable.
That all went in 1998. Blood, sweat and (almost) tears, but it went!!
The government policy at the time was clear, where you voluntarily assume a risk, CASA's ONLY interest is the safety of those on the ground under the flightpath of the aircraft, and other airspace users.
It disgusts me that any in the aviation community want to see even a partial return to pre-1998, but far too many Australians seen unable to function "without regulations".
RAOz is a bit of a different animal, in 30 or so years, CASA and its predecessors have failed to present draft regulations to eliminate all the CAR 95 etc. exemptions.
To everybody's cost, and just look at the not so little empire being built in the CASA Sports Aviation office.
Tootle pip!!