[_grilled_cheese]

The company that I work for builds power line detectors for helicopters. They sense the electromagnetic fields generated by the lines and alert the pilot when the field strength exceeds a threshold. I would imagine this tech could be easily adapted for a drone.

Obviously that wouldn't work for a crane though...

[heavyset_go]

What happens when they aren't live or is that just a thing that doesn't happen? I know nothing about this topic.