Honestly I trust the NZDF, RNZAF, and MoD to do a through examination of the options and purchase the appropriate option. If anything between the KC-390, C-2, and C-130J they're almost spoilt for choice.
To me the likely requirements will be carrying an LAV in a combat configuration or close to. Antarctica range with no point of no return. And carrying a good payload to austere airstrips in the rest of the Pacific Islands.
I’m not convinced LAV transport is necessary. NZ essentially ruled out transporting a LAV via the C-130H given the LAV weight. Since the LAV was acquired only eleven have been deployed overseas and the primary method of transport was leased commercial air or sea transport.
In 2001 the NZ Government published a report that spoke about LAV transport via sea and air. The report recommended upgrade and eventual replacement of the C-130. Given we are now 17 years later and approaching the half life of the LAV fleet nothing has changed and large fleets of LAVs have not been deployed around the world I don’t consider that an essential requirement. It probably ends up being a nice to have feature for future military transport but not a need to have. https://www.oag.govt.nz/2001/lav-lov/docs/lav-lov.pdf
Quoting a ferry range is a useless metric as there is no payload attached to that config.
Going by this, without refueling only the A400M and the C-2 can fly there, find out that the weather is too bad, and return home safely, with the C-2 having a lot more margin and presumably more payload as well. The KC-390 could do it but not with much/any payload and only with additional fuel. Not sure about the C-130J.
I already stated the above including finding a reference that indicated the C-130J was capable of having no point of no return (although as stated with no indication of payload).
The A400M has better short and rough field characteristics, whereas the C-2 has greater speed and range. Obviously, the C-130 beats both when it comes to price, STOL and overall flexibility, and the KC-390 does everything the C-130 does but in a modern, faster package. So I guess it depends a lot on which capabilities NZ thinks they absolutely need and which they would like to have on top of that (and the price of course).
Personally, I'd go with the C-2 for the heavy long-range stuff & some C-295 for smaller tasks. Or just the A400M, which could do both a little bit.
I don’t think we will see a dual fleet, it will be winner take all. It will likely come down to budget given as already stated further up the thread NZ will look for a minimum of four aircraft in their fleet and likely prefer a one for one replacement for what they already have.
A KC-390 aircraft costs something like 1/3 of the A400, so it is natural that they are bought in larger quantities.
NZ doesn’t have an infinite budget. They have five C-130H and two B757s in their transport fleet. It is likely the B757s will be replaced by another commercial jet so that leaves a likely one for one replacement of the C-130H. You AAR plan then ties two of those aircraft down for every Antarctic flight.
As for the difficulty of AAR, it should be remembered that the KC-390 is a full FBY aircraft and since this task is present from the beginning of the project, makes this procedure much simpler.
The F-18 is a FBW aircraft as well, so are many others that refuel by hose and drogue. It doesn’t mean there haven’t been accidents or that the operation is risk free.
"...At that point, Menini selected the flight controls to air refuelling mode. Like many aircraft, the KC-390’s default FCL are not optimum for air refuelling. In AAR mode, pitch and roll axis FCL were tweaked for the fine tracking task of air refuelling. As we again advanced toward the basket I did not perceive any differences in the pitch axis, but it was an almost opposite feeling for lateral tracking.
While I was certainly no “Ace of the Base”, with AAR mode engaged I could approach and make controlled stabs at the basket. After a few solo attempts Menini joined me on the controls. While DUAL INPUT sounded intermittently, I could feel his stick inputs as we closed and made several solid contacts. Having been an instructor pilot, Menini’s ability to feel my control inputs greatly enhanced his ability to teach me how to air refuel the KC-390. With the air refuelling exercise complete, we rounded out the simulator session with visual approaches to normal landings."
You know that was a simulator right?