Gas Engine Interferance
 

Hello everybody,
Am going to trow something in to your direction see if you guys can help us figure out the possible reasons of our crashes. I own(ed) a brillelli 26 which i had in my CMP giles 202. I have flow my new plane about 9 to 10 times, flawlessly. My friend, own(ed) a dl-50 which he had in his stinger. This plane also flew about 8 times flawlessly. However last Sunday we both lost both our planes and our engines due to fatal crashes.
The strange thing is that we both lost them within half hour from eachother and in simmilar manner. Note, we were the only two gas engines on the field. Both planes did the same "maneuvers" and kissed the ground. I was going downwind in a level flight, I had the plane quite high. All the sudden I felt like I lost radio contact and the plane spiraled straight down. After about half a second I regained controll over the plane and put it in a left bank heading towards the strip for a landing. However about one secon later, it did the same thing but all the way towards the ground. I had no controll over it whatsoever. Well, about half hour later, it happened EXACTLY the same, with my friend. The same sequence and the same spiral dive.
We still cannot figure out what might have caused this. We had each at least 1ft seperation betwee radio and engine (by the book). Needles to say we are a bit hesitant and (scared) to reinvest in the same type of combination, here gas engine seeming to be the common issue since my radio system is futaba and his is JR. The only thing a bit out of the normal was the weather. Uncommon for Aruba, we had overcast and here and there a bit of rain, or mist, cannot really call it rain.
Needless to say we want some input as to what we might have overlooked or what might have happened.

Guys Please shed some light upon our darkness

Thanks

P.S. My engine used the fly-wheel and my friend's had an electronic ignition.

RE: Gas Engine Interferance
 

I'm no expert but that doesn't sound like engine interferance to me. Sounds more like some sort of phantom radio hit. I've flown at a place that if you fly infront or to the right of the runway you're fine but it you wander off to the left of the runway you're going to have problems. To the left of the runway puts you between the path of two communication towers that bleed over into the 72mhz freq

RE: Gas Engine Interferance
 

the only two gasser at the field? how do the other club members feel about gasers? sounds kind of like you may have an enemy somewhere in the neighborhood.

RE: Gas Engine Interferance
 

That is quite the coincidence, two similarly powered planes, 30 min apart, same description of events during loss of control...etc, when both setups passed several uneventful flights prior. It begs a lot of questions....

RE: Gas Engine Interferance
 

I'm gonna go off in a different direction, and wonder about something...

OP mentioned a mist in the air...could moisture have worked its way into the transmitters via the antenna mast, and caused temporary glitching?

RE: Gas Engine Interferance
 

Did you check the batteries right after the crash ? Could be something pretty simple, like due to the mist, the moisture has cased you intensive current leakage and battery failure inside of your radio, most likely receiver, and associated circuits toward the servos, but could be the transmitter as well, depending how much time they have been exposed to that weather in OFF position prior switching them on. What you wrote that you regained control for short while seems like onboard battery attempt to recover ... Well there could be many more reasons, but it does not seems to be gas-engine related at first.

RE: Gas Engine Interferance
 

Thanks for your replies so far guys, wel maybe I should not have used the term mist, since we do not have real mist here. It was just water from the rainy day. And yes we did check the bateries, they were both in excellent condition. we do not have any power nor radio towers in a radius of about 3 miles. If it was some communication interference there would not be any reason for the other planes not to get it. We are a small but very close nit club so it fell like it was everybody's plane that crashed, since everybody was trying to figure out what happened.
Anyway if anyone else has any ideas, please lets discuss them since we reeeaaaaaly realy are trying to figure this one out. Also we have to other friends who bought new gassers, like mines and are now very hesitant to put them in a plane. Eventhough, as I said b-4. People have been flying gassers for a while now. But the happenings seemed to have been too coincidential.
Hoping to hear frm you all. Regards

RE: Gas Engine Interferance
 

Well, at least here are two ways to investigate:

1. Ask the local EMC (electro-magnetic-compatibility) Company, the one who takes case for all kind of intereferences checkings, and it is part of the Goverment, and maybe of the Police, to come with their
equipment and measure the field. You are paying Taxes I believe in the country, so you are then well
covered by their Services, as wtitten on some of their cars, "To Serve and to Protect". They might do
that if you find appropriate way to ask and a bit friendly challenge them with such "parasitic" emission
which has gone "out of control", maybe ... well I am not in USA, so you should know better what you
can or cannot ask them for. Well, make sure that they do not close the Airfield as a "Public Danger".

2. Put on Air hellium filled in baloon like those which are sold on the public events, your receiver
with all servos and connect the servos to some flaps and ask you friend to walk there where the
crashes happened. I.e. the baloon will be the "flying RC" and then you and he watch if those
flaps refuse to follow your Transmitter ... This way you can go to up to even 50 high and see
what is there, if "anything" is there... At least this might be fun for you and your friends. If
you make it, please post some photos on RCU so we can have fun here too and spread the
Experiment arround. At the end this is lot more easy than to build and ... crash another plane.

Well, at the end, those new 2.4GHz systems which are coming might solve this problem or even
make it lot worse ... Anyway, fail-safe/save options in any king of Radio are good thing.
Especially for Gas-engines, 2.4GHz systems are inherently lot better shielded against most of
the intereferneces but the problems with them beside the wave-propagations one is that they
are in "baby-age" and suffer from "baby-ilnesses" and it might take 1-2 years more to get
them well in place and maybe replace the current FM radios.

RE: Gas Engine Interferance
 

Sounds like someone turned a radio on with the same channel. Could be someone at home close to the field working on a plane, not knowing he well crash a plane at the field. Turned on the radio to check something turned it off then back on. 1/2 hr lator the someone at home did the same. I'd talk to the club memebers with the same channel as you and see if they live close to the airfield to cause this. Not that it's his falt but would be something to bring up at the next club meeting.

RE: Gas Engine Interferance
 

I bad. I should have asked if you boys were on the same channel. I can see one bird and someone at home but two on different channels long shot.

RE: Gas Engine Interferance
 

well it may sound stupid and I kinda dont even want to say this but at my field we had A guy with his own radio like cb call station , well every half hr that there on "line" they have to call in there #'s or radio call sign. Well we noticed the same thing and lost 1 plane before noticing that he was the problem. Long story short he felt like A moron and paid for the repairs to the rig and now everything is fine he keeps it off! Anyway longshot but that was our problem. good luck and keep us posted.

RE: Gas Engine Interferance
 

Hi,

Among many possibilities for intereference there could be broken Transmitter of someone, or a Radio-amatheur radio which is with pretty high output power and "blocks" i.e. makes "blind" the Receivers of the RC. It is not bad idea in any club to have frequency monitoring unit at the field, like those sold on Tower Hobbies for example.

RE: Gas Engine Interferance
 

-----------------


Were there any military vessels in the ocean nearby? They do not always abide by the same radio rules as the rest of us.

With a gas engine operating normally, there is still a bit of "RF noise" being generated, even though it is not usually enough to affect your control. Add to this any extraneous RF noise, such as a passing military vessel, an official vehicle with HF/VHF radio equipment onboard, etc., and you have an opportunity for the noise floor (radio talk for background noise) to be higher than normal. More noise floor, but same Tx signal, can often lead to loss of control. Even weather phenomenon (called ducting) can cause competing signals to be received from normally out-of-range sources. Couple the higher background noise with the noise that all ignition systems generate and you could have an explanation to your problem. This is why I harp on folks to keep their system as "RF clean" as possible. You never know when something is going to happen that will add to the noise floor and rob your receiver of a coherent Tx signal.

As others have suggested, check your batteries, chargers (many a model has been lost due to a lying/defective charger) and other support gear.

I'm sorry to learn of you and your buddy's loss, but, as we all know, it is normal to lose a model now and then, even when our thumbs didn't cause the loss directly.

I wouldn't give up on gas engines. Normally they work just fine when set up carefully, as it sounds yours and your friend's were. Good flying.


Ed Cregger

RE: Gas Engine Interferance
 

Good point about naval vessels. Some aircraft as well. In that area anything's possible. The electronic warfare ships or an EA6B Prowler can easily wipe out anything that's broadcasting for miles around. I've seen this happen on a practice range where we were we flying some stuff. Suddenly the controls on 4 planes went absolutely nuts from an E6B "playing music". On 1.3 and 2.4 gigs using hop tables no less!

If those two planes were on the same frequency then they were probably shot down from an outside source.

RE: Gas Engine Interferance
 

Still the good point is that nobody caused a jam to the EA6B Prowler's controls ... meaning that in such
environment of "Musicians" arround the only thing one can do is to take it easy and fly ... control line
non-RC plane.

It is maybe good to check the local Radio-Amateur Club, they might have good records what was the day for them,
they for sure have notived such "music" from EA6B Prowler arround, or they might have played some "music"
themselves... for example on SW-band MHz with 1-5 kW in the Antena - that would be more than enough to
"blind" many RC receivers of all kinds, like your neighbour would puts his 100 Watts stereo to full power
when you just talk to someone ...

RE: Gas Engine Interferance
 

There is absolutely no way to jam an EA6B Prowler when it's "playing music" The term refers to the fact that the prowler is jamming all or specific frequencies, and can do it directionally with full control of the beam width. You just ain't gonna interfere with what they do. Ain't possible. Those babies RADIATE!!

RE: Gas Engine Interferance
 

I hope then Prowlers do not try litle target practice at that partilar RC Field ... I fact the two birds "shot down" might be good reason for
the RC guys to ask the Navy for compensation of any kind, can the to that ? (I guess yes, if they find good proves and good Lawyer
for that, is it ?)

RE: Gas Engine Interferance
 

Not likely. First they have to find the actual cause, and even then yiu would have to prove it. Good luck there. Right now everything noted in this thread is speculation in any case.

RE: Gas Engine Interferance
 

Just curiuos because both planes were relativly new --8 to 9 flights, assuming that max RPM were still being achieved based on newness of engines , how was your on-board receiver battery /ignition battery/ insulated and how far was your receiver from the ignition ?
I am just getting into gas , told 12 "min from ignition for the receiver and throttle servoe

RE: Gas Engine Interferance
 

Any roads nearby that are traveled much? I had a airplane shot down by some kind of TX...just as a fire truck and other fire related trucks passed by where I was flying. As soon as I heard sirens...airplane went down. All raido gear worked again in next aircraft with no problems. Capt,n[:-]

RE: Gas Engine Interferance
 

As these two planes were the only two affected, and they both went down in similar fasion, I am also leaning in the direction of a deliberate act. My brother and I lost a scale Hawker hurricane to a deliberate act from a police car. The two officers denied any involvment at the field, but where overheard to admitt it after a few drinks at a local watering hole. They "just wanted to see what would happen", as they said. Serve and 'protect'?

This was years ago, but I still can't rule out this senerio.

RE: Gas Engine Interferance
 

This sounds like one of those old wives tales! I work with police and fire communications and can think of no radio equipment that would be carried in any of these vehicles anywhere in the country that would interfere directly with our RC equipment. Maybe the officers were keying their mics in a joking manner to see if they had any effect but I suspect your crash wasn't related to that. When your plane crashed when they did whatever they did, perhaps they thought they were the cause and got vocal about that when they were well "watered".

The incident in this thread sounds like some kind of a deliberate act but I seriously doubt it came from emergency vehicles. Speculation about military and other causes could be possible but I suspect someone with a synthesized transmitter module to be a more probable cause.

RE: Gas Engine Interferance
 

Sorry all. Did not mean to imply that emergency vehicals could be or were involved in this latest incident.

In regards to the incident I related, as I stated, it was quite a few years back. We were using AM eguipment at the time. It was discovered that the officers keyed up as they were leaving. At that time, I had just turned onto final and this put them closer to my plane than I was. I do believe this interfered with my signal and resulted in the throttle going wide open and the dive to the deck.

My relating this was simply to remind folks that there are people that have little or no regard for our safety or property and given the means, will do this sort of thing. Even warped public servants. We can scan for frequencies in use, so can others. One reason I really like the new 24G systems and I will be converting as soon as I have the money.

RE: Gas Engine Interferance
 

were both of you on the same channel.was it humid like just after a rainstorm.what was the air like at the feild,raining,misting,or just stopped.i have dish tv(satellite),when it starts to rain there goes my signal and the tv stations flicker and then i get the onscreen menu that says trying to locate signal.cloud cover does this also,not that you where flying in the clouds.where ther any puddles of water on the ground that you flew over.at one time i was flying and all of a sudden my plane was doing loops,rolls,spins,evrything and i wasnt moving my sticks.got the plane down,couldnt find anything wrong so kept flying.about a half hour later a guy drives into our feild and gets out and goes(hello guys,didnt know there was a flying feild here,i was just flying by the side of the road over there).no s--t sherlock,i know now.there was another time when a plane went down and noone new why.next day a fellow returned and said hed caught his kid playing with the tx in his car but didnt realize it untill he got home and the kid admitted it.is there any place around your feild like bushes or cover where kids could hide,(maybe even a pissed off adult).thats just to strange to not be diliberate or its the weather.low clouds will bounce signals.

RE: Gas Engine Interferance
 

2.4 GHz ? - well, hold on for couple more years/months prior jumping there. Beside the fact that EA6B Prowler's can
"oversing" any of those, the baby-age of the 2.4GHz systems is not over yet.

I just wander after all, USA is such a big counry and why you guys shoud get so stacked to that "guilty field"...
as is that song: "... guilty field ... got no river ..."