Ules,
I am pretty sure that unless you are in a position that you
require a CPL for, then all expenses relating to your CPL are your problem and the ATO aint interested, buddy!
HOWEVER
Once you have a CPL (and you have earnt a taxable income as a pilot, and you have a Group Certificate to prove it) you will also have:
*a technical library - which you can depreciate
*technical equipment (headset, nav 'puters, etc etc) - which you can depreciate
* any travel from your
FIRST JOB directly to your
SECOND JOB... but don't stop at the shop for any personal reason 'cos it won't count
*A medical certificate, the balance of which you can claim
In 2007 I earnt $12,000 as an instructor and a lot more in another field. I claimed $6,000 in deductions (validly), and every single dollar of those deductions was from my Aviation job.
Your expenses don't have to be proportional to your respective incomes.
There is a retrospective claim for your education expenses, somewhere.... I'll get back to you on that tomorrow