I was practising this over the weekend for hours and eventually got a full load of fuel over the course of some 10 or so contacts, only being able to stay connected for a maximum of 10 seconds.
My problem seems to be pitch instability as even with a good trim my A-10 needs pitch input to try and keep it in position under the tanker, eventually leading to too much pitch at some point and the inevitable disconnect.
Some tips would be appreciated.