Electric Power Line Cleaning Helicopter

[DrClapeyron]

We are in the midst of a drought here in Houston and the other day a utility helicopter flew by our office building. The helicopter had a rod located on the helicopter's nose or close to the nose which sticks out about 10 feet or so, and the crew were leaning out the door and spraying down the electric power lines (to clean them). Someone mentioned they clean the lines because they have built up too much resistance because of the lack of rain. So my question is what is this rod on the front of the helicopter?

I know V=iR, so does the rod act as a ground or neatralizer for the helicopter because of the higher voltage, or perhaps it acts like a conductor/capacitor/lightening rod to channel current elsewhere because the capacitance also goes down, C=Q/V?

 

[anorlunda]

The rod equalizes the potential of the helicopter with that of the line. That's confusing because the power is AC so voltage swings plus and minus. Nevertheless, the rod can match the instantaneous voltage of line and helicopter. After that, a wire is clamped on to maintain them at the same potential.

You can think of the helicopter as also having an AC potential relative to ground, but since it has no connection to ground, that is irrelevant.