The way I undertsand the Cadetship is you have to pay the first $40K but Rex organises a deferred payment schedule with repayments increasing as your base increases. For that you have to give them 5yrs or pay it back immediately at market rates.
A scholarship for the next $40K means you have to give them a 6th year or pay it back in full with interest. If you don't get the scholarship awarded, you have to find the 2nd $40K yourself.
See
http://www.rex.com.au/cadetpilot/Default.aspx