superfrozo
Just a clarification for our Kiwi friend. If he takes an Aus base he will be paid Au$ into a HK bank account which he can transfer straight to NZ. Assuming he does four Aus – HK – Aus trips a month he will spend at most 12 days in Aus a month, well under the 180 days. Since his family also lives in NZ and he has no ties with Aus except that he operates flights out of there, he will not have to pay Aus tax. I wouldn’t ask for a ruling in Aus but if I was him/her I would get some professional advice from an accountant in NZ regarding his standing there.
Regarding the issue of HK based guys that commute to Aus being asked to pay Aus tax? I have not heard of any cases myself and I keep my ear very close to the wall on these types of issues. I do know of quite a few Aus based guys that have received letters from the ATO advising that they owe back taxes. This may be before your time at CX but it relates to a ruling by the ATO on the use of 23AG by CX pilots based in Aus and goes back quite a few years.