Would part of the reason for grounding the cadets be, because the ops manual states. All initial intake pilots require: 1500hr total time, 500hr on multi-engine aircraft & 250hr PIC.
However saying this, there is a clues that states: In some circumstances the Chief Pilot may determine that a pilot is sufficiently qualified and experienced for recruitment with less than the qualifications and experience.
So, if all of this is stated in their ops manual and no other internal company memos have been released which overrides the ops manual, are Jetstar operating illegally?
This is just my two cents worth, and I would hazard a guess that they have put in steps to side step the ops manual and legally(not safely) operate the cadets in Australia.
Now, I'm not going the man I am going the ball. Having seen and talked to the cadets I personally believe the Jetstar cadet system is rubbish, and if Jetstar do require and cadet system then it should be modelled off say that of Qantas. Where after gaining you CPL you go off and fly for a regional for two years, then you come back to Qantas and fly as an SO.
Safe flying.
Shnee.