Zenreverend
In the case that the employee pays, as long as the costs are for 'furthering a career in which you already derive an income' those costs are tax deductible.
Only if such a qualification can be used by your current employer. If you currently fly for a company that say, only operates Dash 8’s for instance and you went and did a B737 or A320 endorsement that you paid for, then it “IS NOT” tax deductible.
FROM THE ATO
WORK-RELATED SELF-EDUCATION EXPENSES
You can only claim self-education expenses that related to your work as an employee at the time you were studying. If your self-education was to help you get a new job or commence a new income-earning activity, you cannot claim your expenses.
Self-education expenses are expenses related to a course of education provided by a school, college, university or other place of education. You must have undertaken the course to gain a formal qualification for use in carrying on a profession, business or trade, or in the course of employment.
OTHER WORK-RELATED EXPENSES
Other expenses include union fees; overtime meals; attending formal education courses provided by
professional associations; seminars, conferences or education workshops; books, journals and trade
magazines; tools and equipment; protective items such as sunscreens and sunglasses; computers and software; telephone and home office expenses.
You cannot claim the cost of entertainment, fines or penalties. You cannot claim private expenses such as child care expenses or fees paid to social clubs.
An endorsement would be classed as a Work-Related Self-Education Expense, not a work-related expense.