So how far does the RNZAF need to fly in one go and why? So we need to refuel, don't all aircraft eventually, no big deal unless we are in a hurry (can't see why) and even then if that was the case then could use one of those cheaper non-stop civilian flights you quote but either way still faster, comfier and twice the range of our other transport AC.
Yes we could charter someone elses airliner, just as easy as we can charter someone elses cargo plane or even someone elses cargo ship but the issue is exactly that, it's someone elses and therefore we are reliant on someone elses terms, conditions and timings to certain degrees, not overly ideal especially when the ship hits the fan. History has proven this reliance has not always been in our best interests, viable or even as financially beneficial as is made out in the overall scheme of things and having flown both mil and civ numerous times can attest to both pros and cons of each such as timelines, availability, flexibility, destination, opsec and changing situations to name but a few.
Yes we could get bigger aircraft to fly longer distances but then comes even bigger costs and for what, one less stop for fuel? Also the bigger we go the less runways we can use, especially pertinent in our pacific AO (remember not everything we do is at maximum distance from NZ) as even the 757 has restrictions as evidenced by the PM and delegates use of C130 on a recent trip which would have otherwise used the boeing. The 757 is able to move a coy sized group, same as our sealift ship for good reason as this is our most likely functional deployable group to be based around.
Even on commercial flights we generally stop in either Singapore, Hawaii or another Loc and sometimes even over night for connecting flights if not refuel anyway so no different. Airlines achieve those efficiencies in costings by flying set routes at set times ultimately with set pax numbers IOT acheive maximum profit and sad one if they don't suit our requirements, take it or leave it. The reason our boeings cost more p/fh is that we do not acheive this regularity and is more erratic in nature due to the varience of work. It could be the same for us as well if we ever decided to fly boeings full of service pers to say San Fran on a weekly basis but alas going on a planned holiday with a commercial airline vs a short notice deployment via your own assets involves a differing approach to planning and logistics, a price you pay for coveineance with any company. What exactly does a one way charter of that spare Air NZ plane into an Apod of NZDFs choosing C/W a multitude of DAC at short notice cost these days anyway?
It's no secret the boeings cost more (in fact same could be said for the majority of our AC in their designated roles dependant) then say a civilian counterpart but then their roles are not quite the same are they and we have learnt this the hard way in some instances of trying "civilianisation" IOT "save" with some disastrous results as savings are sometimes more than just financial when it comes to anything military just that financial seems the easiest to achieve.
From my perspective, the B757-200 is the wrong-sized aircraft to provide a strategic airlift capability to the RNZAF. Depending on what requirements are considered of primary importance, I believe either a larger or smaller aircraft is really what is required.
To move personnel/gov't officials between NZ and an overseas conference (not necessarily in a VIP configuration) where the number of NZ personnel/officials is likely 20 or less, using a 200+ passenger aircraft is overkill and very inefficient, especially if it needs to make more refueling stops than longer-ranged aircraft would require.
In terms of personnel moved that are not pre-planned and would require the movement of a significant number of people over a long distance, are the B757-200M's in RNZAF service really fit for purpose? I am specifically thinking of the possible desire or need to evacuate Kiwis or other foreign nationals from an area following a crisis like was contemplated after one of the recent Thai coups, or a natural disaster like 2004 tsunami. In both of these situations, the ~240 passenger seats would likely be insufficient, and again the need for additional refueling stops would delay the overall response.
With respect to the aircraft size being appropriate for the S. Pacific region, I have looked into a number of the airports on the various island nations and it seems that most of the airports which can handle civilian jetliners can handle those up to and past the A330 in size, Tahiti for instance can handle A380's. Of the airports which are unable to handle such large aircraft, they seem to be similarly unable to handle B757 or B737-sized aircraft for the most part as well. And of course if the airport has been damaged as the result of a natural disaster, then airlift based around civilian airliners would be inappropriate until repaired anyway.
In terms of range for strategic lift, at least for passengers, I would consider a non-stop flight between Singapore/Malaysia and New Zealand, or between New Zealand and Hawaii (with a safe fuel margin, 320 km/30 minutes fuel reserve is insufficient IMO for the distance traveled) or something similar, given that the RNZAF lacks an in-flight refueling capability. Forcing an aircraft to "island-hop" across the Pacific due to safety concerns imposed range limits is inefficient in terms of both time and operating costs.
Lastly, consider why Boeing stopped production of the B757 and has not introduced or started planning for a comparable replacement. It has been my understanding that it was due to airline aircraft purchases trending towards either smaller aircraft like the B737 and A320 family, or larger aircraft like the B767, B777, or A330, A340 or A350 families, depending on the routes and passenger capacities desired. Basically the B757 had basically become either too much aircraft, or not quite enough. At this point, the airliner which seems closest in terms of range and performance to that of a B757-200 would be an Airbus A321neo, which has about the same range and single seating type passenger capacity, but the aircraft is itself smaller, being 3 m short in overall length, a wingspan 2 m shorter, a height 2 m lower and perhaps most importantly MTOW and OEW weights which are ~18 tonnes and ~7 tonnes less respectively.
The trend in airliner development does seem to be towards either high capacity, long-haul intercontinental airliners, or lower capacity, short/medium-haul transcontinental airliners, and the B757 seems to have been a bit between the two.
