OCU
Graduating from the OCU was not a foregone conclusion; my course of 8 on the F4 OCU had one pilot and one nav chopped. The hawk was a reasonable prep, but working as a crew and with a radar was different. At this stage of training you are moving away from learning to fly to becoming operators of a weapon system.
It then took 6 months to become QRA qualified and another 6 months to become combat ready (and again you could be chopped at any stage).