At the weekend, two of the Young DocHs are travelling CNS to SYD on QF31 arriving at 09:45, before leaving SYD for LHR at 16.55 (BA/QF operated codeshare).

They would like to use the 7 hour stopover to go into the centre of Sydney, but are concerned this may not be possible as immigration authorities will have already embarked them from Australia, when boarding at Cairns.

(They think this , because on our arrival the flight up from Sydney was classified as International and immigration was handled at CNS, rather than at SYD where we arrived in Australia).

Is it possible to get out of SYD airport? If so, do they need to go through immigration again (very slow). Is there a way around this?

Apologies if this have been covered many times before, I have tried searching but cant find the answer. Any help appreciated.