Well... The other day I was flying my Cessna 182, practicing landing. Take off, go into patern, set up approach, land smoothly (sometimes). I live/fly on a military base and appraently Igot a little too close to some power lines. My plane started to fly crazily. I'm a beginner but I'm not that bad. No matter what I did I could not regain control of my plane. All I could do was watch as my plane came tumbling down towards the road, which is pretty remarkable considreing there aren't many roads around as this place is in the middle of no where. Luckly, the first car that drove by stopped where my plane had crashed. By the time I got to the road this gem of a person had picked up my plane, saw me running toward her, and was making her way to the fence to hand over my pile of foam. Damage was not as bad as I thought it would be and repair won't be too bad but I just wanted to pass on a little info to the other newbies here. Power lines give off EMI (Electro Magnetic Interference). This EMIcan interfere with your transmitter's ability to sendinformation to your receiver, causing you to lose control of your plane. Always, at all times, keep far away from power lines. This pertains mainly to those (like me) who don't fly at a club but in thier back yard or local parks.

Brett

Sorry to hear about what happened.

I really never knew powerlines could interfere with your signal. We have a powerline running right through our field on the farm - have never had any problems regarding signal loss or similiar due to it. We had signal loss one time - but that was due to a non-charged battery pack in the plane. Also there is one club which I have been to which is right by huge powerline structures. Really is a first of me hearing about this. Good to know.

Brett: Ouch!! We have some power lines near our field, but near is relative. They are about, oh, a half mile or so away. We keep well clear of them.

There was a study back a few years ago about Broadband over Power Lines. The power companies were checking the feasibility of transmitting broadband internet data over the power lines as a means of transmission other than fiber or copper via phone lines or the cable company. I don't know where that stands out in California, you might ask that question of your local power company.

Broadband over Power Lines was looked at by the AMA as a source of interference for our systems, but 2.4 GHz was supposed to eliminate any possibility of this.

No matter, you learned something through this.. when I read your thread title, I thought you might have run into the power lines, which happens. Inteference!! Well, again, you learned something and that's to keep them well clear.

CGr.

Powerlines do not interfear. Our field is located next to powerlines and sometimes people even manage to fly through the lines (without touching them). Also once a plane was stuck on the powerlines, but the RC was still functioning.

I would search for another reason for this faillure.

Power lines do give off energy, called near-field radiation. And it is strong. It all depends on the frequency of operation of your radio as to whether or not you can or will get problems from them.

The best situation is to avoid flying around them. If you or your fellow club members have not had a problem with it, well, you're lucky. That's not the same situation over here. It can and will happen under the right circumstances.

It's called being prudent.

CGr.

One of my clubs moved to a field adjacent to power lines. This was a couple years ago, and part of the process involved getting our AMA AVP or frequency guru to visit with a spectrum analyzer.

Several visits showed power line generated signals of interference level on channel 56 only. One of our members was using #56, and he switched to a different channel.

Only one member has filtered his aircraft through the power lines...

Best wishes,
Dave Olson

Yeah, as I said, the AMA did a study on this a few years back based on this broadband issue and I beleive they found that there was nothing going on, but I also believe that the power companies, at least some of them, decided not to do it. That does not mean that all decided that way, but the potential is there none-the-less. And I seem to recall an issue on channel 56 also, but that was several years ago and I'll have to see if the AMA still has that up on their web site.

CGr.

I fly my glider across the street from where I live (on a farm) and I fly on ch. 57.

If I pass very close or underneath the high lines I get a little glitch. Doesn't last very long and it really happens more when I go under the lines getting ready to land.

There is a lot of energy in and around these power lines. And, not all power lines are created equal. Some are very high voltage, some are less. Those that are really high voltage will have a near field effect that can and will cause problems on any frequency. Drive under one with your car radio turned on and see what happens to the radio reception.

The signal levels we use with RC is very small and to think that these high power lines don't affect them is asking for problems. As I said, it's prudent to avoid the situation if at all possible.

CGr.

South Africa is running out of energy so I don't think we will have much powerlines with voltage going through them in the near future :P <- was a joke btw

Powerlines can have defective components and will generate RF interference. In Canada I have called BC hydro and they met me and aimed a "gun" at the poles and got a high reading. They replaced the bad component and the RF interference was gone. This was job related not RC planes. Industry Canada or FCC in the states regulate these things and take complaints quite seriously (espesially in regards to "private" radio channels). You could try a call to your power company - just try not to let on that it is for rc planes, just say that you have a rx that is getting "hit" and you suspect their power lines.

And, depending on the weather, if it's foggy, or high humidity for instance, there will be some corona forming around where the connectors are at each of the poles where the cable stand-off's are. This can cause inteference because it radiates as a radio signal would. If you go near a power line in high humidity or foggy conditions, you can hear it..sounds like a sizzle.

I was on a LORAN "C" transmitting station in the Pacific. We put out about 2.3 million watts of RF energy. In the morning, when the humidity was the highest, we could see a blue light or "corona ring" form at each of the 16 "TLE's" or Top Loaded Elements.

It's everywhere when high voltage is concerned.

CGr.

Yep. The lines that are high voltage can cause incredible RF interference. The higher the voltage, the more likelihood of a problem. I'm reminded of this every time I drive by the dynamometers at work and the radio signal completely cuts out on every channel when you're within 30 yards of one that is operating.

This also applies to other things. I fly at a farm my dad raises cattle. When I first started flying I noticed glitches over certain areas of the electric fence. It wasn't as bad as you decribed and it usually only lasted about two seconds and most of the time I could not recreate it. Because of this I stopped having my landing approach go over them and I don't fly anything over a 10 size plane by them at all. I haven't flown with the 2.4ghz by them yet so I don't know if it would still be a problem. But then again I aint gonna try it to find out.-BW

We have a "dead zone" at our field where, occasionally, we get glitches as we fly by or through this area. We try to avoid it, but, well, often we just forget it's there. What results is a bump or a small change in something, throttle perhaps... but we witness something strange in that area. We can't define why because it's at the other end of the field where the power lines are (which are about a half mile away) so we can't explain it, but it's there and occasionally, we see the results.

As I said, nothing catasthrophic, just a glitch in operation. Even the pattern folks have noticed it, so it's not in our minds.

CGr.

There is another possibility (even though I still think it was EMI from the power lines), and it could explain the interference even with a 2.4 GHz system. There could be cable TV RF running next to the power lines. Cable TV RF can boradcast into the upper portion of the UHF frequency band which is 300 MHz to 3 GHz. A degraded cable or connector could cause the RF to broadcast out through the damaged area. I have first hand experience with this. When I was a young technician back in Cape May, NJ we had a problem once where we were getting a strange static coming over on channel 23 and 83 on our VHF marine band radios. After checking the small boat station's comms station as well as all of the boats, myself and another technician came up with an idea to locate the where the interference was coming from. We installed a KDF-538 (CGr will know what this is ) direction finder in one of our vehicles. We then drove all around the base and were able to locate the source of the interference just outside the front gate, but we didn't know what cdould be out there causing the interference. The FCC sent out a representative and they confirmed the problem was where we thought it was. This resulted in a technician from Comcast Cable coming out, investigating and finding failing weatherproofing and a bad connector on one of there lines. Once the connector was replaced, the interference was gone on channel 23 and 83. Just food for thought and I felt like sharing a little sea story [8D].

Brett