What is the distance you can safely travel near a power line or antenna.   Don't get me wrong, I'm looking to get anywhere near something that will take my bird away.   Am I safe a 1/4 mile?   Just curious what a safe distance is.

I  have been close to power lines above them and had no problems.

powerlines can mess up the compass, so this is not a good advice, you probably had just luck and it depends obviously which powerline you will "meet". I would not risk it, the same counts for cell phone towers, i knew a place in germany on a hill where many phantoms used to fly away because of such a tower

Daninho Posted at 2015-1-6 08:26
powerlines can mess up the compass, so this is not a good advice, you probably had just luck and it  ...

I have flown over those almost every time to get there I need to go.

How far away about is safe?    I have a field with a Water tower approx. 1/4 mile away.  The tower is loaded with cell equipment.    Should I be ok as long as I stay clear?

Daninho Posted at 2015-1-6 08:26
powerlines can mess up the compass, so this is not a good advice, you probably had just luck and it  ...

I don't fly under them.

Depends on the power lines, but generally powerlines are not a problem. I realize that that contravenes conventional internet wisdom, but there's nothing inherent in modern R/C radio transmitters and receivers that makes them particularly susceptible to power lines.

Why would power lines mess up a compass?

MacCool Posted at 2015-1-6 08:57
Depends on the power lines, but generally powerlines are not a problem. I realize that that contrave ...

Now that is interesting. You clearly have some wisdom on this MacCool, I have always been nervous about power lines not only on the compass but the GPS stability too.

I am in New Zealand and many power supplies to land and lifestyle blocks is via overhead rather than underground feeds down here.. I occasionally have to fly on such properties and have always kept clear of power lines, even the domestic supplies. I turned down a recent job because it meant getting within about 5 metres of an overhead domestic feed.  Am I being over cautious?
Cheers!
Rod

Power transmission is 60Hz in the U.S. and in my opinion they wouldn't be a likely threat.  Now, would I test that theory?  Heck no.  

1) If something goes wrong, whether it is or is not the fault of the power lines, I would hate to have to explain why my "toy" was tangled in those lines.
2) Power transmission lines (big, interstate types) are considered critical infrastructure in the U.S. and anyone doing anything questionable around them is just asking for a visit from the police or feds and possible confiscation of copter, possible prosecution, possibly being placed on lists you don't want to be placed on.  Call it Fascism, but is it something you want to test?

Things to stay away from, in general:
Airports and any place where aviation is active (such as a hospital with helo pad or an active wild fire)
Power plants, all, especially nuclear
Military facilities
Government facilities and monuments
Dams
Large bridges and overpasses
and...shooting ranges (you're just asking for it...)

Yes, many aren't technically illegal and you aren't likely to get caught, but unless you are intentionally poking Big Brother in order to get footage of them overstepping their authority, you are just asking for trouble and possible confiscation.  If you aren't up for a confrontation, read that list again.

Powerlines = electrical field = magnetic field

High-voltage power lines cause low frequency electric and magnetic fields around them. I guess it will depend on the fact how well the power cables are shielded. Every elecrical cable causes an magnetic field. The higher the voltage, the wider and stronger the magnetic field will be. The radius of  those magnetic fields is approx 100 meters.

Surely you wouldn't fly over a huge magnet? But  this is exactly what you are doing flying over/under and around high voltage power lines and towers!

Thanks for the responses.     The highest voltage transmission lines I've seen are 765KV.  These are unshielded and definitely create significant magnetism.         How about the recommended distance to stay away from large cell towers?

Marcus, Yes a good point. The recalibration of the compass does I believe involve drawing magnets over it .  Let the technical discussion begin and those who are about to get fluxed, we salute you.!

Gerry1124 Posted at 2015-1-6 08:23
I  have been close to power lines above them and had no problems.

Looking at your pictures I would say point proven.

rod@voxvideopro Posted at 2015-1-6 10:04
Marcus, Yes a good point. The recalibration of the compass does I believe involve drawing magnets ov ...

Magnetism is a set field, with molecules of the item, such as iron, aligned.  Something magnetized, which in not desired to be magnetized, is cleared of it by degaussing, which flips a magnetic field back and forth, leaving the molecules randomized, once again.  The process described in the manual is a very simple method.  Others use (gasp) an AC electromagnet.

Yes, AC electricity results in a magnetic field.  But it is flipping back and forth (N-S-N-S-) at 60Hz.  The compass may not be accurate, but it's not going to be drawn away, as if N is now solidly S.  Again, some have no trouble, others might.  It's an unknown and not something to test.

I wouldn't calibrate my compass within 200 feet of a powerline carrying greater than 100 KV or within 25 feet of a low-voltage transformer like in a neighborhood. Especially an older one that might be leaking RF. I would not be concerned flying around them. The only concern l would have flying underneath powerlines is the possibility that a sudden RTH might send the bird up in the wires. Same concern as flying underneath a tree canopy.

I am not a particular believer in the deleterious health effects of low-frequency EMF fields

MacCool Posted at 2015-1-6 11:53
I wouldn't calibrate my compass within 200 feet of a powerline carrying greater than 100 KV or withi ...

I'm the same way, I wouldn't want to have RTH triggered.  That's why I go above them or to the side of them.

I think the most accurate answer is "it depends". Those who are flying 100% in GPS mode and barely have a GPS fix might see a problem - whereas others in ATTI mode or with strong GPS fixes will see none.

Since basic residential power lines are almost everywhere (here), it's hard to avoid them and I've never has a problem with the relatively low voltage small neighborhood poles. But RFI can be additive - a bad GPS day, some big buildings, other wifi signals AND the power lines could add up.

But, yeah, so far I've never been affected by them.

great info and discussion, thanks for the comments, very useful.  you guys were silent on the cell tower (there is a park i fly in with a huge cell tower in it and on one of my first flights i realized that i was near it (higher than it was but still relatively close) and i wondered if it could affect the navigation in any negative way.  it didnt but would also like to hear others on this thread speak to that in addition to the power line info that has been shared.

gnixon@comporiu Posted at 2015-1-6 13:46
great info and discussion, thanks for the comments, very useful.  you guys were silent on the cell t ...

There's a cell tower about 1/2 mile from me.  One of these days, weather permitting and it warms up some, I'll go fly near it and see what happens.

haha, you're funny gerry.  dont go getting heathcliff or gertrude injured on my account.

gnixon@comporiu Posted at 2015-1-6 13:58
haha, you're funny gerry.  dont go getting heathcliff or gertrude injured on my account.

They would never leave each other.  Besides, my friend has a snow sled to chase it if it does wander away.  The weather has me grounded this week, snow high winds and cold cold temps.

I think the fact that these are going to be used for powerline and other such inspections does say something!
https://www.linkedin.com/pulse/s ... ba-med-gdm-scpm-pmp

I've got huge power lines in front of my window , I walk the dog under them every day. I can tell you I have seen and heard the most unbelievable things there. Especialls in the morning if dew covers the plants underneath the cables, you can sometimes see the plants vibrating and if you touch the plants, you'll get (a tiny) electrical shock. Also there is this weird humming noise in the air. This can not be good for sensitive equiptment. Luckily it does not affect me in any way. I will never fly my Phantom close to them!

markus@egide.de Posted at 2015-1-6 23:04
I've got huge power lines in front of my window , I walk the dog under them every day. I can  ...

That's why these things not allowed near human residence in DK.
They melt your brain over time.

emf is everywhere (the earth produces emf although it i believe is like DC current not AC current but it is still there).  ive seen/read many studies with little to no correlation between emf and 'danger' (speaking biologically not radio interference).  studies have been done on hundreds of thousands of power line workers in dozens of countries who are exposed to high emf on a daily basis and found zero effects.  VERY HIGH and prolonged exposure to emf has been performed on lab animals also with no effect.  id say you might see 'odd things' with stuff like emf and water particles moving leaves and such but i dont believe there is any real material danger (people should probably be more worried about UV exposure than EMF exposure).

now, i still wouldnt fly my phantom near those but i would think that your normal neighborhood power lines are completely benign when it comes to flight disruption.

Get a 4 foot florescent bulb an walk under it, too cool

b.w.j@joergense Posted at 2015-1-6 23:18
That's why these things not allowed near human residence in DK.
They melt your brain over time.

If I want to leave my development to the south I have to fly over these. Which I do more than I like to admit.

wow, i think id crap my pants.  ive only had 10 or so flights in total and i have been up to over 300 ft but for me it is the lateral distance that seems to worry me more and so i havent ventured out much 'away' from me yet.  i can say i would have never flown over that, pretty cool looking even if unwise for all those unknown unprovable reasons, nice pics.

I've been asked to come out and film this weekend at a motocross track that has powerlines running over the top of it. I have included a photo from their facebook and one from Google Earth where you can see the layout of the track with the lines through the center. Any advice? Should I not fly at all or stay a certain distance from the lines themselves?

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gnixon@comporiu Posted at 2015-1-6 01:46
great info and discussion, thanks for the comments, very useful.  you guys were silent on the cell t ...

Part of my job for my company is to maintain our microwave radio network for our two way radio towers. We also have some equipment that uses the same types of radios as cell phone towers, so they operate in the same frequency bands; 900 MHz. Our microwave links are all unlicensed and operate in the 2.4 GHz band; the same general area as our Phantoms.

I've flown near our towers (on my own and just for fun, not for work! I had to include that disclaimer in case the FAA is reading) and have been within 20 or 30 feet and have never had an issue. One thing I am very careful of is not to fly near the microwave dishes, especially directly in front of or behind them, that's where the energy from them is strongest. My concern is that the energy from the dish would overload "fry" the receiver on the Phantom's radio.

There are several companies that use UAV's for tower inspection and I will be honest, I don't know if they will inspect a tower with the equipment hot or not. They may require the the tower owner to turn everything off before they will get near it.

I can tell you with a high degree of confidence that getting within a quarter of mile of a cell tower is not going to cause any harm or erratic behavior in your Phantom.

markus@egide.de Posted at 2015-1-5 17:58
Powerlines = electrical field = magnetic field

High-voltage power lines cause low frequency electric and magnetic fields around them. I guess it will depend on the fact how well the power cables are shielded. Every elecrical cable causes an magnetic field. The higher the voltage, the wider and stronger the magnetic field will be. The radius of  those magnetic fields is approx 100 meters.