Clearance ambiguity

[Cougar]

G'day all,
Got this clearance today (in Australia) and am a little confused. Was passing FL130 on descent and had traffic 10 miles away co-level, which we had sighted. We were descending OCTA and ATC told us to "leave control area on descent, visual".
Does this mean you must remain visual on descent, ie clear of cloud etc, or does it mean you are responsible for your own visual terrain clearance. Why would he give us this clearance?

Look forward to someone clearing this up for me.

Cheers

[2daddies]

If you can recall the other details of the conversation it might be a little easier to work out, but on face value the ATCO could have meant for you either to keep the traffic in sight, or to maintain 8km VIZ, 1500m lateral and 1000ft vertical seperation from cloud AND clear of terrain.

Visual when appended to an instruction in CTA is straight-forward, but confusing when OCTA.

[Blue Heeler]

"Visual" assigns terrain clearance to the pilot.

[Binoculars]

Unless the lowest safe altitude was above the base of control area the "Visual" comment, which does transfer responsibility for terrain clearance to the pilot, seems superfluous. Sounds a little to me as though the controller was covering his ass re the traffic. Covering of arses is, unfortunately, becoming the first and overriding criterion of air traffic control these days. :(

[Cougar]

Thanks Binos, no the lowest safe was lower than the CTA steps. This was what caused the confusion. I was quite confused as to what the term visual meant in this regard and thought i might be missing something. Thanks for the input. Good to see ATCO's helping us out when needed :)

[Bellthorpe]

I'm puzzled as to why you didn't ask the controller. After all, you're required to read back clearances. This implies that you have copied and understood the clearance. How could you have done that if you didn't fully understand it?

[weasil]

Very Good question BT!