Humm, I'm not quite sure how they were controlled, but while I was in Viet Nam, in 1968/69, I stumbled upon a bunker that had some really neat "DRONES" inside. Apparently self powered "target" drones. They were winged, with a single prop, and a gas engine, identical to what was used in a lot of the portable generators, of that time. Before I could really get into them, some guys from the First Air Calvary came and collected them.