Wasp-class - ships 50% larger than the BPE, that operate 6-8 Harriers. Hmmm.
Swerve, my point has all along been not about size, but about the mission!
The USN LHDs are configured for a mission.
The fact that they are 50% larger then the Canberra class designs is an issue of design specifications based on USMC/USN operational needs. However this provides only a marginal increase in personnel payload, and does not change the mission drastically. I need only mention the AAV-7A1 that the US Marines use that account for a large segment of the vehicle deck. They are also built to operate the Ospreys that have been in development for two decades, and will take up quite a bit of aircraft deck space. Take those two platforms out, and you end up with the 'small' European carriers (yes, carriers because they carry; like coal carriers and dry cargo carriers,etc.)
I have wargamed different configurations of ships, as well as task forces, using Soviet, British, French, Spanish and of course USMC models. I'm sure the professionals at ADF did also. In the end it comes out as a battalion-sized battlegroup unless one wants a very much larger commitment. The further one stretches the naval logistic tether, the larger the force has to be.
Only in the most 'soft', close-to-port of missions does the battlegroup do well without fixed-wing support. And this is not for reasons of air-to-air capability of a fast jet. I really do not get turned on by 'big shiny things'. Its whatever it takes to get the job done.
However I assumed a "hardened and networked" battlegroup operating against an opponent with at least a minimal anti-ship capability, and one with minimal surface-to-air and tactical missile capabilities. My other assumptions are that the opposition will not be professional, or well organised. The opposition will have warning time of Australian TF approach of at least 1-7 days.
I have assumed SF going ashore first by whatever means (subs tend to ensure greater survivability).
What happens in the end is that slowly the helicopter component starts to take losses (combat or non-combat), and the whole progress of the mission grinds to a logistic halt a the end of a tenuous tether from the naval TF that has to manoeuvre to avoid ASM threat. This is post 2015.
Then I consider the end-of-life service of the various systems involved C.2025. Logistics become even more crucial. The region is awash with tactical missiles that are far more advanced because most states can't afford to run ships due to cost of fuel. Most navies are retrograding through history, with only the economically strong having few very heavily armed and protected ships. The rest have large shore-defence artillery forces with UAVs providing over-the-horizon surveillance. Most countries can't afford to operate large numbers of fast jets either. The typical airforce is maybe a squadron or two of manned jets, with the rest being swarms of unmanned craft. These are armed with long range missiles equally usable against aircraft and naval ships.
The Australian TF would have to approach through a veritable swarm of missile fire. Average anti-ship missile range is beyond territorial waters limits,and most countries now claim the maximum 250nm if they can in competition for scarce marine resources. Almost every 'amphibious' operation is opposed to some degree, and that opposition starts 250nm away from shore, never mind objective.
Can the ARHs take out the missile batteries to allow the TF to approach the last 250nm to shore to launch its surface landing elements? I really doubt it. They fly too low and too slow to do the job. What about if a countermeasures helo is also used to jam missiles? Sounds good, but not much use against optical guidance on the cheap UAVs. So first the UAVs have to be removed from the equation. AWD will no doubt help, but for how long? Right now they are configured to protect against fixed wing threats. Will they do as well against large numbers of UAVs?
So I'm not here to promote JSF, or trumpet 'carriers'. All I'm saying is that if someone can show me how the TF can achieve its mission goals without fixed wing aircraft support 20-30 years from now, I will happy say sorry and go away with head hung in shame.
Right now I just don't see it, and the above is just half the story of getting to the AO.