Upgraded Growlers?
I think it's clear that the Growler fleet will be kept in lock step with the USN fleet (as others here have mentioned), the Growlers would appear, at this stage, to have a full RAAF service life ahead of them (30+? years), including NJG and whatever Blk III mods the USN performs to their Growler fleet.
As to a possible replacement for the crispy Growler, well that's something that we probably won't know about for a while (year or so?), no doubt there will eventually be recommendations to Govt by the RAAF to replace or not, and again we don't know if the initial buy of 12 airframes included attrition.
Upgraded Super Hornets?
Well that's where the crystal ball is very cloudy and murky too! Firstly I wouldn't expect a decision on the replacement of the Super Hornet fleet until around the mid 2020s, lets not forget the RAAF will have it's hands full with the conversion of the Classic Hornet fleet to F-35A between now and late 2023 (when the last F-35A is due), I think the last thing the RAAF would want to do is 'tinker' with a relatively small fleet of aircraft that will be 'the main game' at least until the F-35A fleet reaches FOC.
I would imagine that the Super Hornet fleet will still have the various 'incremental' Blk II upgrades that happen (if I remember correctly the RAAFs Super Hornet fleet has recently gone through an upgrade to keep in lock step with the USN).
But even 'if' the Government does decide to retain the 24 Super Hornets in operations for a full service life, the path from Blk II to Blk III is going to be long and slow regardless.
The USN currently has between 650-700 Super Hornets and Growlers, all Blk II except the first 130 or so Super Hornets which are Blk I.
Things are going to get pretty messy for a decade or so, the USN will have Bk I, II and III all in service at the same time, existing build and new build to Blk III standard, and also on top of that is the Service Life Modification (SLM) program that is just starting to, which will extend the lives of the oldest (most used) airframes from 6000hrs to 9000hrs.
Long Live the Super Hornet!
Here's a couple of other links to read:
Block III Super Hornet upgrades to begin this spring
And this:
http://australianaviation.com.au/20...-to-extend-us-navy-super-hornet-service-life/
And this too:
http://www.thedrive.com/the-war-zon...r-plan-for-the-f-a-18e-f-super-hornets-future
As I said, things are going to get pretty messy for a while to come until all the various life extension and Blk upgrade programs settle down, which will be well into the mid 2020s in my opinion.
I imagine that the Government/RAAF keeps performing the incremental Blk II upgrades to the fleet (to at least keep in step with USN Blk II airframes), but beyond that, if they do decide to keep the Super Hornet fleet, it also has to look at the SLM program and Blk III upgrades that could see a substantial number of the fleet 'out of service' while those programs are being performed, is it worth it??
Personally, I hope the decision is made in the mid 2020s to proceed with the 4th Sqn of F-35A (18 airframes plus the 10 attrition airframes, total 28), and retire the Super Hornet fleet without wasting all that money on SLM and Blk III.
And at the very least keep the 12 pre wired Super Hornets as both a possible expansion of the Growler fleet and future attrition replacement airframes, as to the 12 standard Super Hornet airframes, sell them back to the USN or break them down for spares.
Anyway, just my opinion of course too!
Cheers,