New manufactureing methods - blow molded foam/fiber/polymer material to produce CompARF like quality giant 1/3 scale plane and jet for under $100.  (10 years)
Ready to fly with motor / servos / receiver for under $500 ( vs $ 4,000 today)
Better integrated training and crash-saver technologies built into RC system. Voice Commands  such as Oh! No... Save my plane...landing...
Optical / audio aid devices to help pilot see greater distance. Projection views that able to zoom -in rear view of the plane and flight datas.

Electric motor / batteries become better choice. Audio system become available that will simulates turbine, 4-stroke ...etc.

Full scale car, boat, plane racing and sports today will be replaced by full scale or scale down RC models for even more extreme actions (in 50 years)

License and registration will be needed for some RC operations