Here is the preliminary report for the Coffs Harbour Mooney accident.
https://www.atsb.gov.au/publications/investigation_reports/2019/aair/ao-2019-052/
The report verifies Bindook’s old statement where he called Class C airspace “road block airspace”. To prevent it being “road block airspace” with unnecessary accidents occurring, the Minister John Anderson issued a directive with the following words on 1 August 2004 – yes, 15 years ago. Note this refers to Class C over D.
“AA must … provide an operating ATC control tower at the airport and an approach radar control service at the earliest time one can be supplied and installed.”
This would mean that ATCs could operate Class C airspace and successfully keep VFR and IFR aircraft apart, but not with ridiculous procedural standards. For some reason, Airservices decided not to comply with this Minister’s directive, and CASA once again remained mute, saying nothing.
What is not discussed in the report is what the cloud tops were. Is there a chance that the aircraft was above cloud at 6,500’ and in good visual flight conditions?
Also, do I read it correctly? Is it clear that the aircraft was not reported missing until it did not arrive at Taree? That is, the local ATC controllers at Coffs, or in the Centre, did not notice that it had disappeared? I would imagine the aircraft was at least fitted with a Mode C transponder, and that surely would mean it would be visible from the local secondary surveillance radar unit.