A lengthy, comprehensive and interesting article in Flight Global
Snippet regarding AAR performance (in the Sim):-
The advantages offered by the active SS became clear during our simulated air-to-air refuelling (AAR) exercise.
After rendezvousing with another KC-390, I tried to stabilise just behind the refuelling drogue extended from the left-hand Cobham refuelling pod. I could easily remain stable fore and aft, but lateral stability proved challenging. We slid from side to side, almost wingtip to wingtip, as I tried to stabilise behind the basket. After working up a sweat, I backed out of the approach and stabilised about 100m (328ft) behind the tanker.
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.
The article then continues with a description of aircraft performance for real, albeit no AAR.