PMAs Toy,
I made the jump last year from UK Brown Jobs to Down-Under Brown Jobs. I know its not strictly Air Force, but the process is very similar. If you are interested in the RAAF I would contact the Mil Attache in Australia House first. They are well practised in the area of lateral recruiting for all three services and will be able to answer 90% of your questions. Bearing in mind what Captain Sand Dune said, if you were to put in an application now, you could expect it to take not less than a year before you actually touched down in the worlds largest Sgt's Mess
(the paperwork is extraordinarily lengthy), so by then the RAAF may be accepting laterals again. Maybe a RAAF pilot will have more to add to this.
A word of warning though
However crap things are at home remember that if you transfer you are only transferring to another Air Force that is undermanned, overstretched, underfunded and has equipment procured by self-serving, ill-informed and generally witless politicians ensuring that you will never achieve the mission quite as well as you could have done without the aforementioned handicaps. That said, Australia is a fine country, the lifestyle is awesome and you will not come across a society that has such a large proportion of f**king good blokes/ladies outside of dear old Blighty
If things are not doing it for you at home and the RAAF is recruiting and you're not doing it just because you think the grass is greener, then go for it. I doubt you will regret it.
EO
[Edited for bid granma]