Is a TCAS alert generated when a HCRPT aircraft comes into close proximity to an aircraft without a transponder?
The oh-so-Australian irony is that a well-publicised and ATSB-investigated incident at Mildura a few years ago arose from a near miss alerted by TCAS, which investigation focussed on the aircraft that wasn’t the one that came closest to the HCRPT aircraft at the time. The aircraft that came closest didn’t need to be and wasn’t fitted with a transponder, thus didn’t generate a TCAS alert.
Only in the weird and whacky world that is Australian aviation...