yon191

Hi there
Well recently at my Dad's local flying club he goes to there has been a lot of interference with the planes causing them to crash and loose control of them in mid air. Today I went with my Dad to his local club and we had 3 notable instances. All this interference seems to be taking place at around 2:30pm onwards on a Sundar afternoon and the club has been in touch with BT etc asking them is it the pylons nearby and they have said no its not and those companies aren't sending out any signals that should cause interference. They have also contacted the BMFA about the matter and they told the club to get hold of one of those scanners that scans the all the radio frequencies but when they do this it doesn't appear on the scanner. Today my Dad's plane cut out in mid air and he lost all control over it when trying to land it, a guy there's plane cut out and plummeted down smashing it and another guy's plane was on the floor and the engine powered up and ailerons started moving by themselves because his control was on the floor in a box with no one touching it. We don't know what this interference could actually be because the signal is not showing up on the scanner and it's not any of the pylons. We thought it could be someone in a house nearby with binoculars trying to purposely crash the planes. Could anyone shed any light on this situation please because it would be a great help.
Thanks in advance.

Rcpilot

My Feedback: (78)

Welcome to RCU.

How far away is the plane and how far off the ground when it gets hit?

I'm assuming you are operating on 72mhz band?

yon191

Over here in the UK the frequency for radio controlled aircraft is 35Mhz and the planes just stop in mid-air. The engine stops and then you have no control over the plane to try and fly it in to the ground. Like they are controlling the plane. The guy I said who's plane was on the floor no one was controlling it but at one point the ailerons became stuck and had no control over it. I definitely think it's someone causing the interference to be honest.

Rcpilot

My Feedback: (78)

Please answer the question so we can help you:

How far away was the airplane and how high was it?

Have you paid close attention to WHERE and WHEN the crashes take place?

There is actually a dead spot on all 72mhz radios. I know your using 35mhz, but it could be happening to your radios too.

If you want to find the dead spot on a 72mhz radio:
Point the radio antenna exactly 90 degrees away from the plane and set it down on the runway. Prop it up at about 45 degree angle so the antenna is not just lying on the ground. Don't touch it.

Walk off with the plane exactly straight down the runway. Take a tape measure with you. When you get somewhere between 400-500 feet away, you'll find the dead spot. It will be exactly perpendicular to the direction your radio antenna is pointing.

Now go back and move the radio antenna just a couple degrees.


Now go try and find the dead spot. Not there is it?

Move off in the direction you moved the radio antenna. When you move the right amount of degrees--you'll find it again.

Thats for 72mhz systems.

But, you could very well have the same problem with your 35mhz system. The distances will likely be different. Your dead spot might be 200' away, or it could be 800' away.

You need to experiment and try to replicate the problem under somewhat controlled circumstances.

Tape a receiver to a stick with a coiuple servos and a battery. Set the radio down on the runway as I instructed earlier. Prop it up a bit. Walk off and monitor your "radio" system. See if you can get it to react in the same manner as the planes. Take a scanner with you and check the SIGNAL STRENGTH. Don't check your signal to see if there is anyone else on it. Check the STRENGTH of the signal. It might be there, but so weak that your receiver can't "hear" it.

Experiment. Do it scientifically. Not just willy nilly. WRITE IT DOWN!! Get the whole club involved. Figure it out first. Thats the first thing you gotta do--FIGURE IT OUT. Only when you know WHAT is causing your problem can you even begin to come up with a solution.

yon191

Flying during the week though seems to be fine with no problems. The problem seems to be occuring at 1:30pm until 2:30pm on a Sunday afternoon only. The ones we definitely know about cought interference to the right of the airfield and we loose complete control of the plane. Some of the club think it is malicious and we have a club scanner which doesn't seem to show and any bands operating although we left a plane on the floor switched on and the radio switched on next to it and the control surfaces started operating. Three members of the club landed immediately due to the fear of interference.
Thanks for the help.

sowega flyer

RCpilet,
I for one thank you for that info. It sheds some light onto two mysterious crashes that resulted in the total loss of two of my planes. I never knew about the dead spot on 72 mhz, but looking back the situations for both crashes were roughly the same. The altitude of my plane and distance (from me) plus the direction my radio antenna was pointing. Good info- Thanks!
Jason

bfd04

sowega,

One thing that no one has mentioned is it could be amateur radio opperators in the area. They don't have to be on 35mhz but if they are close and running a couple hundred watts that may interfere also. I lost a heli to that very thing. You might want to ask the neighbors around the field to see if there are any living close.

John

Rcpilot

My Feedback: (78)

99% of fliers on 72mhz don't know about the deadspot. Thats because hardly anyone flies out at 400-500' down 20' off the deck.

We discovered it completely by accident. We built a 750' runway. We stand in the middle. That puts you 375' from the end of the runway. It's only natural to set your plane up and land at the end of the runway. We were coming in low and slow about 500' out from the centerline of the runway and we were dumping planes left and right. It took a lot of brains, experimentation and a lot of studying to figure it out.

We just modified our approach to land the planes closer. You can't see it when it's 300' away anyway. No point in trying to land so far away when you got a 750' runway. Now we fly a short approach and avoid the lown n slow deadspot out there. Even if you land it 100' away -- you still gor 500' to roll out and shut down. That brings your apporach angle way inside the deadspot. No problem.

Spektrum 2.4ghz is not bothered by it. We've flown planes all over out there--TRYING to get a hit or smash a plane using Spektrum. Can't find a dead spot.

dicknadine

Suggest that you contact your local FCC, or whatever it is over there and ask for HELP from them. they have the quiptment and should be glad to help. dick

Flying freak

I would for the price of our models...

Charlie P.

Is it happening on just specific frequencies/channels?

If it is hitting all equally it could be something like an arc from hgh power equipment (which basically transmits on all frequencies simultaneously). A cracked insulator on one of those "pylons" (if that is what you call high tension transmission poles) could do it.

Farm machinery with point-gap ignition?

Another club/group of flyers on the next road over (we had that problem big-time at the last club I belonged to).