On the East Coast of the US, electric demand is so high that utility companies can't take major transmission lines out of commission for maintenance and repair. Instead, workers fly up to the affected cable in a helicopter and work on the line while it's live — coursing with electricity. The helicopter hovers next to the line and the lineman leans out of a little bucket on the side and does his or her job, protected from electrocution by the same loophole that allows birds to safely land on those lines. As long as the entire contraption — lineman and helicopter — don't create a pathway from an area of high energy (the powerline) to an area of lower energy (the ground, for instance, or another power line that operates at a lower voltage) they're good to go. In order to do that, they have to energize the helicopter to the same voltage as the line.
Also check out this longer video with GoPro-style footage of helicopter-assisted transmission line repair and a British documentary following some of the men who do this job. Around six minutes in, the documentary has a nice explanation of how the workers energize the helicopter without killing themselves. Also, according to one of the linemen, "chicks dig it". Read the rest