There's two different arguments here. One is what to do in a surge - all hands to the pumps - and the second is how to sustain the core capabilities - what has been done in the RAAF for at least the last 36 years. In the first case it is reasonable that a current B737 guy (ex-RAAF) could undertake a differences course and get on with it. The trouble at the moment is the second argument - the supply of the guys who would run all the aspects of the differences course - FLTCDRs, QFIs, COs. The right people don't want to run the show.