What would happen if a helicopter/chopper chops a power line, does the helicopter get electrocuted to death?
from cheese_greater@lemmy.world to nostupidquestions@lemmy.ca on 21 Mar 17:04
https://lemmy.world/post/44556959

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slazer2au@lemmy.world on 21 Mar 17:06 next collapse

Phone lines? Not likely, phones generally run at 12 or 48v

Power lines? Only if they complete a circuit to the other line or ground.

There are people whose job is to crawl out of a chopper onto high voltage power lines to repair them. www.youtube.com/watch?v=9YmFHAFYwmY

Pat_Riot@lemmy.today on 21 Mar 18:22 collapse

Hell, even if a rotor managed to go phase to phase long enough to draw the arc before it cut the lines it would probably just vaporise it between them and the helicopter would fall, but it wouldn’t electricity the whirlybird in any way that would directly effect the pilot.

Forester@pawb.social on 21 Mar 17:24 next collapse

If the helicopters rotors touch the line, then the helicopters rotors likely explode violently as the centrifugal force rips them apart. They are made of laminated synthetic materials like carbon fiber or vinyl and the crew falls to their deaths.

isVeryLoud@lemmy.ca on 21 Mar 17:31 next collapse

I like your question, but I can’t help but break it down:

  • A chopper is an informal name for a helicopter
  • Helicopters don’t (generally) fly near telephone or fiber optic lines
  • Telephone lines only carry around 90 volts AC at most at around 40 mA (give or take as more power draw sags voltage). You might feel it a bit on your tongue as it’s only roughly 3.6 watts at most. Volts tingle, amps kill.
  • The helicopter does not get electrocuted, the occupants would be the ones to be harmed
  • Electrocution implies death, “electrocuted to death” is redundant. It’s a portmanteau of the words “electric” and “execution”.

TL;DR unlikely scenario, in which case the phone line current will not be felt at all and the occupants are instead more likely to die in a fiery helicopter crash from the blades colliding with power lines and / or power poles.

Blue_Morpho@lemmy.world on 21 Mar 18:04 next collapse

Also the occupants wouldn’t be harmed by the electricity because of Gauss’s law. Electricity stays on the outside of a conductor.

OwOarchist@pawb.social on 21 Mar 18:25 collapse

Volts tingle, amps kill.

I prefer to state it as power (watts) kills. To be truly dangerous you need voltage to overcome the electrical resistance of the human body and amperage to cause damage and burns along the way. Either one alone is relatively safe.

(And then there’s a whole other discussion to be had about frequency. DC pretty much only causes damage by burning tissues along the current path. Low frequency AC is especially dangerous because it can interfere with and disrupt nerve signals, causing muscle convulsions that force you to grip tightly onto the source and potentially disrupting the heart’s timing if it passes through the heart’s separate little nervous system. But at a certain point (around radio frequencies), higher frequency AC stops being as dangerous because the frequency gets too high for nerve cells to react to, and it goes back to only causing damage through burns, like DC.)

Darkassassin07@lemmy.ca on 21 Mar 18:03 next collapse

The big hazard there would be the actual line tangling up in the rotors and causing physical damage.

Phone lines don’t carry enough power to be a real problem. They won’t actually electrocute you with enough current to cause damage.

High voltage powerline work is regularly done via helicopter, because it’s the easiest way to reach lines suspended above wilderness. The helicopter flys in close, an operator reaches out and touches the line with a metal rod to bring the aircraft to the same voltage potential as the line, then work can be performed on the line as needed, from the aircraft, without shock hazard because there’s no connection to ground or anywhere else for current to flow. Just don’t touch more than one line at a time nor the towers/pylons.

Kolanaki@pawb.social on 21 Mar 18:27 next collapse

A phone line doesn’t have much electricity running through it, so probably not.

cheese_greater@lemmy.world on 21 Mar 19:01 collapse

I meant power line, fixed

zout@fedia.io on 21 Mar 19:24 next collapse

This actually happened in the Netherlands in 2007, and again in 2017. Both times an Apache helicopter flew into a power line during a night flying excersize.

cheese_greater@lemmy.world on 21 Mar 19:33 collapse

And…did it survive [the electrocution]

zout@fedia.io on 21 Mar 19:37 collapse

The only thing in the news was that a lot of people had no electricity, I think the first time it even lasted for days. The choppers were damaged and had to do an emergency landing but the personnel was fine.

untorquer@quokk.au on 21 Mar 22:29 collapse

This is called a Wire Strike. While the helicopter can conduct electricity it’s much less of a concern than damage or loss of control for the helicopter. The aluminum skin is actually protective for the occupants against shock. Think if the helicopter snags the line then it it can tear itself apart or simply end up in an unrecoverable flight path.

Many helicopters are fitted with [Wire Strike Prevention Systems] (https://en.wikipedia.org/wiki/Wire_strike_protection_system) which just cut the wire.

Aussiemandeus@aussie.zone on 22 Mar 02:48 collapse

That’s cool as, I’m sightly confused too how it cuts it though. Just sharp?

untorquer@quokk.au on 22 Mar 12:38 collapse

Yeah, there’s a wedge shape that creates a shearing stress on the wire while pushing a blade against it. It uses the momentum of the helicopter. Like when you cut paper by holding scissors open and just pushing them through.