AUS "Descent CTA to OCTA" 26JUN17
 

I'm trying to tie up another loose end with my radio calls and hope I might be able to get some help with the following AIP ENR 1.1 paragraph:

7.7 Descent from Controlled Airspace
7.7.1 Before descending from controlled into Class G airspace and
before separation with any aircraft operating near the base of
controlled airspace can be compromised, the pilot in command
of an IFR flight must report position, level, intentions and
estimate for next position/destination to the ATS unit providing
services in Class G airspace.

The descriptor "report" isn't lost on me, but never the less is this radio call purely for ATS to be able to pass on my details to other relevant IFR traffic, or is this also meant for the benefit of unidentified VFR traffic listening on frequency?

If so should this strictly be a ATS report or a hybrid report-broadcast, such as:

"Speedbird 5776, six zero DME to the west of..."

vs

"ATR42, Speedbird 5776, six zero DME to the west of..."

Lastly, are we supposed to make this call the moment we start our descent, or prior to passing into Class G?

(We normally cruise in Class E at FL190 and enter Class G at FL180, so it makes sense wrapping the above report and the "leaving FL190" call into one, although I've heard some operators do the same at FL230 and above)

Yep, this is all very pedantic, but the intent is to learn and improve.

Many thanks to anyone who cares to give their time to reply.

TM

It's for both - providing an updated estimate for IFR traffic purposes and to alert VFR traffic to your impending entry into "G".

It doesn't really matter whether it's at top of descent or later - the idea is to do it before you get within 500ft of the highest level a VFR could be operating at. Ideally you'll transferred to the "G" frequency far enough before entering "G" to allow you to combine your report with the frequency transfer.

I'd suggest no later than 2 to 3 minutes before entering "G" would be good airmanship - gives other traffic a chance to assess and take action, and for the controller to reassess traffic.

AUS "Descent CTA to OCTA" 26JUN17
 

Excellent. Thank you! :ok:

TM

It may also alert you to the fact that you are leaving CAS and the service level you will be given; ie "leaving CAS passing FL75 Basic Service" or "leaving CAS at GIBSO, Deconfliction Service".

It should be given by controllers as a timely reminder to look at the window more, or whatever your SOPs are for operating outside CAS.