I have seen it maybe twice over the last 12 years where either ATC was busy/ distracted/ mis calculated/ whatever and I began a turn for final without having had the instruction. I think I had a strong tailwind and groundspeed high ( I should have configured earlier) both times. I have read a report where pilots relied 100% on automation to begin the turn and it hasn’t done a good job ( probably tailwind again).
My thoughts are that you stay aware of your groundspeed on base ( during the brief it’ll be obvious if there is a likely tailwind based on the ATIS) and configure to ensure you are not smoking along at 250kts groundspeed ( 220 is ok) and turn on unless told not to.
I was a slow learner on this and do see new pilots making the same mistakes I did quite regularly. Good topic because when you first start flying jets to Sydney it can take a while to pick up these things if it isn’t specifically covered during training.
This from the ATSB website;
A review of the ATSB database indicated that about 30 per cent of all reported TCAS RA occurrences in Australia, or involving Australian aircraft overseas, occurred at Sydney Airport. Data provided by Airservices indicated that about 62 per cent of all RAs in the Sydney terminal area occurred during IVA procedures. The other 38 per cent included other approaches, departures and overflying aircraft.
In certain situations, two aircraft can be flown on IVAs at Sydney in a manner consistent with the required procedures, yet both aircraft’s TCAS can generate an RA. For example, of the
277 reported RA occurrences during IVAs at Sydney during 2008–2013, 30 involved one of the aircraft passing through the extended centre-line. For many of the other occurrences there was insufficient information to determine whether a deviation occurred.