http://www.youtube.com/watch?v=Xp_RD3Xufdo
A "high tension" job, for sure ;D
i guess thats the line from the power station to las vegas. they cant turn it off for even a short duration so this is the only way to perform maintainance operations. since there is no connection to ground its safe actually. the only problem is that the heli has to be hooked to the power line to maintain equal potential so the pilot must be a one hell of an expert :)