Active Drogue In-Flight Refuelling

There's basically two versions of in-flight refueling, probe and drogue and flying boom. The probe and drogue trails a fuel hose from a tanker aircraft with a small "drogue" on the end. This provides some drag for stability. Where the drogue ends up is determined by aerodynamics, and the pilot of the receiving aircraft is responsible for flying their aircraft in such a way as to plug their probe into the drogue to take on fuel. The flying boom method has a movable arm on the tanker, that is inserted into the receiving aircraft by a professional boom operator. This method was developed for Strategic Air Command, and makes sense in that context, larger fuel flow, much less maneuverable aircraft and the advantage of a specialist in the back of the tanker. The probe and drogue method however, has a number of advantages. It's the dominant technology, you can deploy it from diverse aircraft - using a pylon mounted pod, you can refuel multiple aircraft and it's cheaper.

How about a bit of both? Add an electrical power supply and control lines running down the hose, then add a nifty quadcopter on the end. This will have to be a high performance unit with powerful electric ducted fans enabling it to fully maneuver itself and the weight of the hose around a relatively large volume behind the aircraft, including above the usual plane of operation, thus avoiding vortices and jet/prop wash. A selection of reference signals from the tips of the wings and vertical stabilizer should allow very precise station keeping and maneuvers. Additionally, the operator inside the tanker can have camera feeds from the Drogue-copter as well as the usual windows etc. Now the operator can invite an aircraft into a specific zone, then do the detailed maneuvers necessary to connect up the fuel before leaving the drone to station keep while the go connect another plane behind and above the other wing. The quadcopter should be equipped to service both probe AND boom type aircraft, and include a screen. Because fighting a war is no reason to miss the boat race.