While, the RAN doesn't currently have any plans to purchase the F-35B. That hardly means it won't at some point. Especially, considering it will already operate F-35A's with the RAAF. So, you can't make a firm case either way at this stage.
Also, its worth noting that even if the RAN doesn't operate F-35B's from the LHD's. Its allies do and could do so in time of conflict or war. In short a nice option to have.........
That said, if I were a betting man. I would say the odds are very good that the F-35B will be a part of the RAN LHD's at some point.
Given the imposed savings on defence over the next 10 years, it is even more unlikely than EVER that we will acquire F-35B.
Whilst they share a lot with F-35A, the cost and capability difference and the increased support required for F-35B makes them different enough to impose a serious logistical headache on RAAF.
Furthermore, what would they actually offer ADF? Each Canberra Class LHD could only ever carry a handful of F-35B's due to the ships not carrying the bunkerage (ie: fuel storage) and armoured magazine for ordnance. The storage areas of the ships, designed to carry troops, vehicles and helos would have to make way for workshops to support the aircraft, lessening the ships capability in their primary role...
What would 6-10 F-35B's at sea actually provide Australia? Some local air defence and limited strike. What they can't provide is 24/7 combat air patrol/fleet defence and they can't provide ANY combat air patrol AND strike capability simultaneously. Such a small fleet could only do one or the other, for very short durations, again only to the detriment of the amphibious capability of the Canberra class.
Personally if the billions that would have to exist in addition to the AIR-6000 budget to acquire an F-35B capability, were actually available, I'd much prefer that money to go into REAL strike and air defence capability within ADF.
1. Every major surface combatant and submarine in RAN service in future years be equipped with Tomahawk Block IV launch capability.
2. Every major RAN surface combatant be equipped with high power 3D air defence radar systems, CEC capability and the ability to launch and/or control multiple ESSM and SM-2/SM-6 missile systems at "over the horizon" (OTH) ranges.
3. Every major RAN vessel, combatant and otherwise to carry a UAV/UCAV system that is capable of conducting OTH air to air and air to surface surveillance missions to maximise the capability of extended range SAM systems such as SM-2 and SM-6.
4. Additional Wedgetail AEW&C aircraft and CEC fitted to the Wedgetail fleet, (if it isn't programmed already, which I think it might be).
5. Priority acquisition of Global Hawk surveillance aircraft and modification to allow "surrogate extended range air surveillance" role in combination with Wedgetail.
Wedgetail would be linked to GH via Link 16/21 and the GH optimised for A2A and maritime surveillance to provide an extensive wide-area air surveillance and targetting coverage, just as the USN and USAF plan. With the aerial surveillance covered, the full envelope of SM-2/SM-6 could be employed, providing enormous air defence capability at extended ranges.
(As an insight into what this would achieve, imagine one of Dr Kopp's pretty pictures, with a 300k radius on each side of a single ship. Overlay that on ANY island in the Pacific and see what that does for deployed ADF air defence capabilities, even with just one ship... If 2 or more were deployed, we could have a deployed air defence system with a coverage "bubble" near 1200k's in diameter with only 2 ships and a deployed warshot inventory of greater than 80x long ranged anti-air missiles, more than 120x medium ranged anti-air missiles and up to 50x TLAM's, plus the amphibs providing full capability in their intended role. That would be a tough nut for anyone to try and crack...
5. Additional KC-30A refuelling aircraft.
6. Extended range standoff weapons for RAAF tactical fighter aircraft (JASSM-ER or JSOW-ER if JASSM falls over).
7. Extended range strike systems for Army offensive fires capability. (HIMARS and ATACMS surface to surface missile systems).
All of these systems are funded in some way (bar the HIMARS/ATACMS combo). The billions your handful of deployed F-35B's would soak up, would go a LONG way to covering the rest of these capabilities.
A purpose designed carrier would be nice, but there is SO much OTHER capability we could obtain for the price of a light carrier plus it's air group that would give us SO much more...
It is possible some "cross deck" operations may occur in future, with F-35B's from allies using our flattops for refuelling, emergency landings etc. I don't see even in the most "out there" crystal ball gazing, RAN employing their own F-35B's from these vessels.