How far is far enough
 

Just curious, we all know one shouldn't fly too close to overhead power lines. Ten feet is way too close, 5 miles is obviously more than enough distance... How far away is "safe enough?"

I guess my rule of thumb is 3 times the length of the lines...Interested in what others use as a guideline or if there is an "official" number.

best regards and Merry Christmas to all!

Tom

RE: How far is far enough
 

I like to stay about 1000 feet away with metal lines. Maybe 500 with dacron. The model circulating through the air dragging those lines makes a lot of static electricity and the power lines can provide a means for a static discharge. It's like lightning. Very powerful and not very good for you!
Chris...

RE: How far is far enough
 

By the same token, just because there is no visible lightening in the area, don't think you are safe. I got a nice "bite" one slightly gray day in Texas. (read that as "thrown to the ground") I guess 60' of braided steel lines work pretty well as a lightening rod when your FlightStreak is dead overhead in a wingover.

RE: How far is far enough
 

Interestingly part of the AMA site has high power lines passing thru. Makes me uncomfortable just to see them.... but they seem far enough from the CL area.
Bob

RE: How far is far enough
 

AMA Safety Code, both 2006-present, and 2010 state:

"2. I will ensure that my flying area is clear of all utility wires or poles and I will not fly a model aircraft closer than 50 feet to any above-ground electric utility lines."

Personally that is not far enough for me. I like to at least be enough to have some run-back room if lines go slack for some reason, like 200 Ft. or so.

When using any handle where you may touch any part of a metal line or connection, you can well get static shocks while flying especially when you are griping fairly tight, like overheads, etc. Sunny days and rainy days. When Thunderstorms are in the area, that enhances the shock potential, even if you are out of range of hearing thunder. BTDT to actually having a BURN on the palm of my right hand.

I loved that short version of the EZ Just handle. The cable was on the back. Always getting pings regardless of wx except when fairly cold. I like the small pylon handle as there is no touch to metal. I have a couple home-made that adjust easily but have no metal-touch. I have not experienced any significant pings using these handles.

RE: How far is far enough
 

Short EZ is my handle of choice as well.. that's the one that gave the "closer my God to thee" experience.

RE: How far is far enough
 

For a short time in the 1970's we had a flying field on one end of park property where there were cross country high tension lines. The circle was maybe 150' from the nearest line but EVERY time you passed on that side of the circle you would get shocked. I suspect that the model flying through the surrounding magnetic field made the pilot the ground in a huge glow powered generator. We now fly in a much nicer park here in Omaha....
Bob

RE: How far is far enough
 

Omaha...That's where my wife gets those nice steaks from. ;)

George

RE: How far is far enough
 

I flew into power lines. Blew out a transformer and burned my lines in two. No damage to the airplane other than a broken prop, and no shock to me. I don't know if having a wood bellcrank in the airplane had anything to do with it. I do not intend to repeat the experiment.

RE: How far is far enough
 

Jim...buddy...am I named in your will?

RE: How far is far enough
 

Back in about 1961 I was learning to do wingovers flying on a parade ground at an air force base. What I didn't realise was that every time I did a wingover I was taking a pace or two backwards. Next thing I knew there was the model skidding along these power lines with sparks flying everywhere from the exposed leadouts under the wing. A sudden thought went through my mind that I was holding a metal handle so I threw it away. Of course, if I was going to get zapped it would have been too late by then anyway :). The model finally fell off the power lines and had a bit of a crash. The worst part was that I blacked out most of the base :). Strangely though I never felt even a tickle from the handle and I've always put it down to the fact I was wearing heavy air force working boots.

RE: How far is far enough
 

Seems to me you should examine the height of the lines above the ground. Ever notice that really high power lines are up really high while the neighborhood lines are lower. Ever seen power lines under a golf course fairway or seen construction crews working with metal equipment under lines? How can golfers be safe holding a metal golf club under the lines? How can a construction worker be safe working with hand tools and power equipment under power lines?

I think there is a relationship between the height of the lines and the potential for danger. Perhaps someone with actual knowledge can enlighten us on this relationship.

I tend to believe that if your plane never travels closer to the power lines than their height then you SHOULD be OK. However, you should allow for taking a step or two in the event the lines get slack or increased static electricity from the lines moving through the air. I would say that if the center of the circle allows for the plane to travel no closer than twice the distance of the height of the lines then you should be OK.

Just my opinion.

RE: How far is far enough
 

Electric field strength is an inverse square relationship to distance which means moving back a little more provides a lot more safety. Under the right atmospheric conditions, an arc off a 40KV+ line could jump quite a ways.

RE: How far is far enough
 

I went to a contest in Rockport, IL. The sky was absolutely clear, but I got shocked so bad that I aborted my first stunt flight, packed up and went home. I've flown at that site several times with no problem, before and since.

RE: How far is far enough
 

Thanks for all the great info, i am surprised AMA says 50 feet is enough. Interestingly, apparently 50 feet from a 500 Kv High tension line is ok for AMA, which sort of scares the heck out of me. Maybe 50 feet from a 120 volt line going to a lamp post, but apparently the rule is one size fits all, coupled with a strong dose of common sense. Anyway very interesting replies and I appreciate all the input thus far.

best,

Tom

RE: How far is far enough
 

I think if the engineers who design high tension power lines feel that the distance from the ground up to the lines is far enough to offer a good safety factor for discharge, this distance from the model to the lines should also be enough. If you look at hi-lines you will see that the distance across the insulators that suspend the lines below the cross arms is no more than 6 feet at best and the lines don't short out to the tower. The AMA's 50 feet should be safe as long as it is always maintained while flying.
But saying that, what do the engineers know! I would double the distance from the ground to the line just to be safe.

Orv.

RE: How far is far enough
 

I just looked it up in the Electrical Engineers Handbook, 500 Kv will jump approx. 6 (six) inches in dry air at standard temp. and pressure.

Orv.

RE: How far is far enough
 

Here in Omaha steak is easy to come by... but good seafood is only at a few high end places that have it flown in.
Bob

RE: How far is far enough
 

So the problem isn't the electricity leaping out to get us, it's our control lines reaching the power lines.

Consider this plan:

We usually fly in a circle that has a relatively clear boundary. We almost always have a runway all the way around the circle. Stunters and sports planes with wheels land there, right. And pit crews, other flyers, and family members know that boundary well. OK, use it and the length of our lines to come up with our safe distance. How?

How often have you wandered while flying? Maiden flight and the new sucker doesn't pull worth spit and every pass upwind has you backing up etc etc. Or you're flying combat with a buddy and he hasn't learned about the center and the rules about flying from there. Lots of things cause us to wander sometimes. But with a little experience you learn how to come back to center and why it's a good idea. OK, every one of us has (or is developing) the return-to-center in the back of our minds. It's usually based on the idea to not move out of the circle, right.

OK, add the length of your lines to where the runway is on the side of the circle toward the power lines. Now, double the length of the lines and you have the answer. How far from power lines should you fly? Twice your line length from the side of the circle toward the side where death awaits.

You know, the real possibility of death does await. This ain't no laughing matter.

RE: How far is far enough
 

Actually, as someone mentioned above, in addition to direct contact and an arc because of close proximity we also have magnetic induction where the control lines act like a transformer. This in essence draws current just because of the magnetic field around the transmission lines building up and collapsing.

George

RE: How far is far enough
 

All good stuff, da Rock.

However just to illustrate how some folks are misled and how others can be misled I offer this tidbit:

I had recently moved into a suburban area of a large city. A few miles away was a fair sized hobby shop, mostly slot cars back in early '70s but a fair amount of airplane stuff. The owner was a relatively young person around the 30ish age. CL was still very popular in the area.
One day I was there and the owner was flying a CL model, regular metal lines, about 52' or so, (flying a .19 powered profile) UNDER a large group of the heavy power lines that transfer power to other areas, NOT just regular home delivery lines. I couldn't believe it!
He was obviously helping what looked like an early teen youngster with the model. I went in and asked the clerk about that situation and he replied that the owner did that often to teach CL flying to customers. Hard to believe!
Later I had the opportunity to try to discuss the danger with the owner. He stated that he kept the model well below the lines and nothing ever happened. He could see no danger. :eek:

Incidentally the HS Owner was a strong motorcycle person. He never wore a helmet, and mocked those that did. Too bad as a couple years later he met an untimely death in which a helmet would probably have saved his life. [&o]

RE: How far is far enough
 

The further from the lines, the better. Don't think that you're OK if using Dacron lines. Any moisture, even from the moisture absorbed from the air on a humid day can make them conductive. My father lost a childhood freing flying a kite with cotton string too close to 220 KV lines.

There are guidlines about how far a given Voltage will jump on a dry, windless day. For example from my own experience, 460 Volts should only jump something like 2.5 inches. After an experience, my version is 18 inches. I had the bruises on my back for a while from being thrown against a piece of equipment when the Voltage jumped that kind of gap through an empty fuse box and open contactor.

I'd say that the closest the runway for a CL plane should be to the plane of the lines on the ground should be at least twice the length of the lines you're using. An add any fudge factor you feel comfortable with.

I've only been zapped once while flying CL, and that was on a hot, dry but overcast day in North Africa. Cost me a plane and engine.

RE: How far is far enough
 

Thanks to all for the replies. I am buying a property that is 350 feet wide by a little over 800 feet long with power lines on two sides. Based on all the great input I believe I will be fine with as long as I stay on the Southwest side away from the lines. If I get zapped and killed I will log on and complain about the advice!!! Best to all and have a great Christmas and New Year!

Tom

RE: How far is far enough
 

Tom, Ijust noticed where you live in Vancouver WA. Iused to live in Bremerton as a Trident Sub sailor and Ithink you'll need nav lights on your plane more than worry about electrical lines if your weather is anything like mine was.
http://www.rcuniverse.com/forum/js/f...wink_smile.gif

RE: How far is far enough
 

Nav lights, or pontoons?