This idea makes no sense. How well do drones fly in rain? They don't. How well do drones fly in heavy wind? They don't. How well do drone batteries do in the cold? Terribly. So you are only going to "log" when it is nice weather. How are you going to charge these drone in the middle of nowhere? Gas generators? Do you know how expensive a drone is? Especially one that could theoretically carry hundred-pound logs around? The technology to pull something like this off, regardless of cost is decades off. Add cost into the equation and this technology may never be useful when comparing it to human labor. Also, it would be very inefficient to cut each tree into individual, project-specific lumber dimensions. Imagine a contractor needing lumber for a house, and he has to wait for your company to go cut down his trees, fly them around, AIR DRY them, which takes months at best in a perfect climate. Then ship them to him. Only to find out you are a few boards short... Now what? He waits for the entire process to start over again? Imagine all the waste you would create by cutting trees up like that too. You'd be essentially trying to play jenga with each tree. Seeing how many different odd sized lumber pieces you could get out of it. Instead of just milling it effectively using the entire tree. Focus on practical solutions that can be implemented in the near future. Day dreaming in make belive land isn't going to help anyone.