Originally Posted by
Stickshift3000
Outside of the 'CASA system', if you have a PPL you can get a FIR and instruct on RAAus machines towards a RPC, all without a CPL.
Technically that's true, although I haven't encountered it. It seems more common for experienced commercial pilots to go and instruct in RAA - I guess they don't want to deal with the CASA system, or don't want to work under instructors still working their way towards airline jobs.
Having learnt in both RAA and GA systems, the RAA instructors tended to have more real world commercial flying experience.