RE: NH90 self-deploying.
At the time of their purchase (around 2006) this was something that was noted in the (then) Govt's Q&A's for the purchase.
From Hansard 1 Aug 2006 then Defmin Goff stated "
The other advantage is that this aircraft can self-deploy to the Pacific. It does not need a C130 to carry it, or, for that matter, a multi-role vessel."
Hansard Volume:633 Page:4542
(The rest of that Hansard report on Question Time quickly degenerates into a scene similar to a toddlers kindergarten bust up - looks like that was the time (now Defmin) Ron Mark was infamously photographed "flipping the bird" with a cheesy smirk).
Anyway the NH90's are yet to self-deploy overseas. I'm pretty sure I saw a comment on the WONZ forum once explaining that self-deploying would require alot of associated maintenance upon arrival at the final destination (but I haven't been able to locate the comment and the commentator to verify the veracity of that statement). Then with the recent (single) engine failure a year or two ago and the resulting need to quickly land, whether a self-deployment over vasts tracts of ocean is worth the risk?
I did however locate this comment (which was from a former senior Air Force officer when the NH90 was initially transitioning into service). I think from his answer it is clear that a self-deployment requires additional support resourcing (so not necessarily the most efficient method), which would arrive a couple of days beforehand (unless the support departs later)! Presumably the NH90 aircrew would need to rest at the various stopovers as well etc. (FW = fixed wing).
"With internal and external aux fuel tanks fitted, the NH90 can fly in excess of 580nm, which is the greatest single leg required to deploy to Australia or the South Pacific Islands. A transit to Australia would probably (subject to winds) require stops in Norfolk Island and Lord Howe Island. Such 'self'deployment' would only provide an aircraft and four crew - support equipment and technicians would need to be deployed by FW or by sea."
Presumably a South Pacific self-deployment would follow an initial similar route eg Norfolk Island, New Caledonia, Fiji, then onto whereever etc. But at the end of the day (and at this point of time) I would hazard a guess self-deployments would be very unlikely (also due to NZ's isolation and its "tyranny of distance" issue). If so then other options could come into play ...