RE: How far is far enough
 

One of the great things about C/L is that we can fly floats, navlights, (in my case should be skis tommorow) and there will be someone out there to help ya figure it out!

RE: How far is far enough
 

Small world. I rode diesel subs out of Groton, CT.

George

RE: How far is far enough
 

Reply to the basic question...

Served a few years in Omaha (Hi, Bob!) in the 1970's. Flew a lot with the Orbiting Eagles.

We did a flying show for a church group or orphanage (it's been years, some details fade. Others do not.) The location was many miles south of Omaha, along the Missouri River. We could see clouds stacking up out at horizon distance further south - vicinity St Joseph, MO? Lovely thunderheads; very picturesque. Bright daylight, so couldn't see - or hear - if there was any cloud or ground-strike lightning. We started getting zapped whenever we went up: loop, wingover, anything much above low level flight.

Not particularly unusual, in that part of the midwest anyway. So we stayed low, if we flew, and used a handy trick to bleed off handle shocks: contact with one of the flying lines, or the metal adjuster on the back of an EZ-Just. Idea: conduct away the charge before it builds enough to jump a gap. If it jumps a gap, it has plenty to give you a sharp sting...

Got so bad that that didn't work well. No shocks at the handle, but the charge grew enough to jump through our sneaks into the ground (in both senses of the word 'ground!') Nasty! War dance until the tank runs out? Been there, done that, NO thanks! We packed up the flying stuff and just discussed the hobby and the equipment with the kids...

Another incident turned out worse. None of us regulars involved, but a site we often used was. Below Bellevue, Nebraska, just south of what is/was? Offutt AFB, and nearer to river level was a cleared flat space, a flood shoulder in case of high water. Most of the town was atop a bluff further from the channel...

Someone none of us knew was flying alone there and apparently got too close (for the atmospheric conditions, anyway) to some high voltage, cross-country lines. A notice in the newspaper mentioned severe burns to the guy. I went out and took a look at the site. Sure enough, there was a sort human fetal position char mark in the grass, at least 200' fom the nearest ground under bare hi-voltage wires...

Jim, was that you at a Lincoln(?) NATS who put a combat model's lines across power lines and - as you said - blacked out quite a bit of area. Don't answer if statute of limitation hasn't expired :D .

I DON'T trust arbitrary definitions of how far is safe! In one example above, 30 miles from thunder clouds was noticeably affected. In the other, in Bellveue, closest approach couldn't have been less than about 140', not including the slant up to the actual lines...

RE: How far is far enough
 

No, I wasn't at the Lincoln Nats. I was flying in a churchyard where I often flew. There was a pile of trash by where I flew, and the guys were there burning the trash. I said no problem, I'll just move over, forgetting there were power lines there. The transformer blew sounding like a shotgun. Guys thought someone had shot down my airplane. We called the power company and reported a power outage of unknown origin. :eek:

RE: How far is far enough
 

Just a little comment. I used to live a block from so,e 220KV lines. When the weather was very humid, you could hear the lines humming. Posssibly the imagination was at work, but if you were walking under the lines, you could think there was something happening, like the Voltage was about to jump down to bite you.

RE: How far is far enough
 

50+,

Yeah, me too. Could swear that there were times my hair started to tingle. Audible line hum is usually there, but more evident in damp OR very dry conditions, IME...

Cross country lines are AC at some frequency to improve transmission of power, I think. Same as the very high voltage is used to reduce losses... (Or am I talking bosh? - I don't know much about these lines, and would welcome any corrections needed.)

HOWEVER, as has been mentioned, sweeping our metal lines in a repeating circle can become a very effective receiving antenna, in an alternating electromagnetic field. ...Even damp non-metal lines, apparently, can cause this effect...

WE have to show respect to the possibilities, THEY are simple, specific conditions, with no sense of civic responsibility, political correctness, or sympathy. They just do what they do, so don't get in the way.

RE: How far is far enough
 

In this country, most generated electricity is 60 Hertz AC. I think some hydroelectric plants, like the Tennessee Valley Authority, used a lower frequency, something like 25 Hz. A lot of other countries use 50 Hz. A lot of aircraft systems use 400 Hz. There at one time was intense competition between Edison and Tesla over which was better for power distribution, AC or DC. Edison won. If I recall my Industrial Electricity classes from the 1960s, DC can be transmitted over distances with a lower loss factor, but changes in Voltage are easier with AC. To change something like a 2200 Volt power line to 120 V for house distribution, DC would back then need some form of motor generator type system with attended mechanical wear, while AC needs just a simple transformer with no moving parts.

RE: How far is far enough
 

quote:

ORIGINAL: BtnFlyGuy
Tom, I just noticed where you live in Vancouver WA. I used to live in Bremerton as a Trident Sub sailor and I think you'll need nav lights on your plane more than worry about electrical lines if your weather is anything like mine was.

Not Nav lights so much down here. I am about 75 miles inland, South of Puget Sound by about 90 miles, so we dont get the fog and drizzle like Seattle, Tacoma, Bremerton etc.

I just need a healthy dose of ground repellent and maybe pontoons as was previously suggested. Although with running lights I coould fly at nite....hmmmmm

best

Tom

RE: How far is far enough
 

some frequency to improve transmission of power, I think. Same as the very high voltage is used to reduce losses...

I also think it is 60 Hz. The high voltage is used to reduce the IR losses.

Paul

RE: How far is far enough
 

Right. Higher Voltages mean lower curent for a given power level in transmission. The higher the current flow, the greater the heating effect in a conductor, and heat in the transmission cables is just wasted energy. And, while higher frequencies have some advantgages, like the 400 Hz in aircraft applications, there are other quirks with increasing frequency that require special equipment and even differences in cabling. Low frequency current will travel through a ire. As frequencies go up. a larger portion of the current will actually travel on the surface of the conductor, rather than through the wire. In fact, in most of the RFI test equipment I was using at work, much of the circuitry was hollow berylium copper and stainless steel tubing, rather than copper wire. A plumber would feel right at home.

RE: How far is far enough
 

uhhhhm....100' minimum distance at ground level from a High Voltage triphase transmission line at 380KV 1500A means that flying at ground level with 50' metal line, you are fishing into an mean electric field of 500V/m. In other words you are fishing with metal wires into an electric field at a potential of 7.5 KV more than the potential of pilot. And things should be worse if you fly above ground level....

RE: How far is far enough
 

I'm an engineer and I understand most of this high-falootin' stuff, but I go by the old addage in this instance. If it looks dangerous, it probably is.

RE: How far is far enough
 

And if you've gotten away with something before, you're like the cat who has used up 8 of his 9 lives running across traffic, about to do it again. I've gotten zapped by 480 VAC at what should have been several times a safe distance, which made me FAR more cautious even working on household 220 down to even 5.0 VDC (yes, back in my college days, I turned into a conductor for a hi-current 5 VDC power supply that definitely got my attention. My hand hurt for several hours after!) High Voltage electricity is a very unstable, unpredictable ally, not really a friend.