Also the PC9's don't have a GPS of any description (except iPad, which they're using without approval because it's safer to break the rules and come back alive). Single pilot IFR, no autopilot, no GPS
It would cost 355 million dollars to fit them too. You need the 5 year project set up with 25 people. Engineering approvals, operational approvals, project meetings, stakeholder meetings, then a tender and 4 year selection process. Nothing would happen during any election year or minority government, so another 6 years passes until finally a minister announces they're buying the second lowest tender (Bowen's law - everything the ADF operates is second lowest tender).
It gets blocked by contractor maintenance because servicing the new equipment is not in the contract. The RAAF eventually folds to contractor demands because they need their aircraft serviced, costing a further $3m. Training/operational demands blow out operational test flight/evaluation schedule.
The aircraft is retired before fitment of the new box.