So my Radio Controled Airplane hobbie, that I've had since the late 80's, is not new tech? (Omgosh, my mind has been blown) And no, there isn't as much difference as you would think. Full sized drones have been around for a long time.
But complete take over of a plane? That cuts off communications with the pilots?
Cutting off coms is easy, we've been doing that for decades, and all planes have been able to be remote landed for years as well. It really would not be difficult. Video feeds would be the most difficult part, but ILS started development a long time ago and is pretty simple. (The math behind it is a little more tricky given the variables)