ATC, in my recent experience, solves that confusion by saying ...
There should be no confusion. I am not confused. If ATC are saying things like that then I suggest they are encouraging confusion. Is that non-standard phraseology from ATC for that situation? I hope to get round to checking that out.
It should not be so grey
It is perfectly black and white, provided you take the view that "ATS surveillance service" really means "radar vectored". This makes perfect sense, after all, and I will now give the evidence (circumstantial) for why this new term, in this context, means "being radar vectored":
1. We saw, from the old AIP book, that the words "being radar vectored" were in the place that is today occupied by the words "receiving ATS surveillance service". A small wording change, but a BIG change to procedures if it now means what you think it means. Do you think CASA would have made such a change without telling anybody?
There have been no NOTAMS, AIRACS or articles in the monthly magazine. There have not even been any published incident reports arising from pilots not correctly following this supposedly new procedure.
And,
2. Why make such a big change to this procedure? There was nothing wrong or unsafe about the procedure when it used the words "being radar vectored".
But the strongest evidence can be seen in everyday (night) flying:
3. I routinely fly into Darwin at night, on a track not aligned with the runway, and do visual approaches. At the point where I'm cleared for the visual approach, the last assigned altitude has often been A080.
Of course, I continue the descent through that assigned altitude, as my limiting altitude is now the MSA.
Despite having been doing this for 4 years now I have never been queried by ATC or sent the more formal "please explain".
These occasions have all been where no radar vectoring was involved - I had been tracking to Darwin under my own navigation, in accordance with my clearance. I remember one occasion where radar vectoring did occur and one of the last instructions to me from approach was to "descend to 1,600" (the MSA).
Here are the typical radio exchanges:
ME:
Darwin approach, good evening, XYZ, on descent to FL140, received ALPHA, 3 POB.
APPR:
XYZ, Darwin approach, good evening, descend to A100, QNH 1012, landing runway 29.
A short time later:
APPR:
XYZ, descend to A080
A short time later:
ME:
XYZ, visual
APPR:
XYZ, cleared visual approach runway 29, contact tower 133.1 at 5 miles, good night.
Notice how short and sweet that all was. It can be even shorter than that. Sometimes, on the initial call to Approach, if I report "visual", the controller clears me for the visual approach as soon as I hit 30 DME!
This is another important point: controllers want, and need to have, short and simple procedures so as to minimise the radio exchanges.
Is there an air traffic controller following this thread that can finally settle this question? I will be continuing to conduct the visual approaches exactly as described above.