Gigantic RC Blackbird SR-71 Stealth Turbine Model Jet Müllheim Jetcat Meeting 

I'm with you, that would be spectacular. Its probable that the only way you could fly that precisely from the ground is with on board cameras and a simulator-like display for the pilot. Then most of these planes only have about 5-7 minutes of on board fuel to begin with so you would have to make sure the KC could not only keep itself up that long but have enough extra fuel payload to transfer some. Also, you typically see these types of flights circle within a short range of their take-off/landing site. This just may be due to the visual range of the pilot, but could also be radio transmitter range limited. All that would make it near impossible for two RC planes to dock and remain coupled for more than a few seconds of straight and level flight thereby limiting the amount of actual fuel that could transfer. Lets not even mention building the fuel delivery system and the micro valves and the servos needed to open and close them. Okay, gotta stop thinking about it or my head will explode.

@Dupree Porter correct, original one has two ramjet engines. In this model jet turbine is hidden in center boom. It's very clever solution in my opinion. :)