My pop was in the US military when he was in Taiwan and he used to catch the MAC flights to HK free of charge. He often went to HK that way.
MAC flights are a way of life for the US military personnel who are able to use them. The US military personnel in Okinawa would have the use of such flights as they would EXIST. They dont exist in Taiwan anymore.
But lets examine this scenario: (my two cents )
AIT person (also still a US State Dept career officer mind you) has a wife who has a premee and both of them need to be hospitalized. In many other postings where there may be a US military base there would also be a US military hospital. And US embassy personnel would be able to use those facilities with Uncle Sam picking up the tab.
This may have been problematic on the wan as being on paper normal US citizens working for the “private” AIT, they may be covered under the standard insurance your average foreign legal resident of Taiwan is covered by. And I understand babies are not covered until X months after birth.
This creates a logistical problem. Mom may be covered by the standard insurance while baby is not. Should the hospital just charge accordingly and Uncle Sam picks up the tab? A premee could run up quite a bill you know?
So they probably thought why not ship them off to a US military facility where Uncle Sam can pick up the tab ? There are US military flights all over the region all the time (just not landing in Taiwan). So they can schedule a diversion of a suitable aircraft.
This was probably done hours or even a day or two before the actual landing so they would know that the plane is coming and what type of aircraft with how many extra seatings?
Thus other AIT personnel could avail of this particular flight as well.
Maybe we had some Couriers on normal missions that diplomatic outposts incur (The AIT still has a lot of courier traffic one could presume). OR some personnel may be using this essentially MAC flight to get to Japan and jump on other US military flights there going back to the USA, etc etc.
Im sure a number of people normally travel on commercial transport would be told to make use of this flight.
So all in all, nothing unusual except that KC135 landing in Sungshan is probably a FIRST ever.
So its unusual but explanable.
OR? maybe its all part of a new Bond flick?? See any camera action goin on?