Mmm... perhaps things have changed since I played in the certification sandpit.
However, I suggest that the registration dictates the principal line of Regulatory control. The only modifier I have seen (in Oz) is where a basically civil aircraft used as a State aircraft is subject to additional DGTA tech airworthiness requirements.
If an aircraft doesn’t satisfy the definition of state aircraft, a consequence is that a whole bunch of civvy rules apply. If an aircraft does satisfy the definition of state aircraft, a consequence is that a whole bunch of civvy rules don’t apply.
I'd go along with that for operational airworthiness but not tech airworthiness. (For those who have no familiarity with the ADF, the MIL folk tend to separate the civil airworthiness and flying ops sides of things somewhat more clearly than one sees in the civil world).
Perhaps you can cite some documentary support for your position ? Wouldn't be the first time I have been (or last time I will be) wrong but, for my own reasons, I am interested in this discussion and, if I am an outdated dinosaur, then it would be appropriate for me to bring my knowledge base up to date.
the definition determines whether and by whom an aircraft must or may be registered (and regulated generally).
Now, that doesn't sit well with my reading of the rulebook tealeaves. Again, can you cite the relevant bits for my benefit ?
despite being on the VH register, and CASA has no regulatory responsibility for it
Now that is an adventurous statement. I will undertake to discuss that with my civil regulatory colleagues in Canberra as that doesn't fit with my understanding of how things appear to work these days.
Conversely, if an aircraft happens to be entered on the ADF register but then doesn’t satisfy the definition of state aircraft
.. likewise. I shall have to make a couple of calls to Williams to clarify my now confused state of mind. Specifically, can you cite a circumstance where this might apply ? I have no success in endeavouring to do so myself.
Again, can you cite something a bit more concrete in respect of your last two referenced comments ?