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Noise Solutions: "Ninety at nine feet"

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Old 07-22-2002, 09:03 PM
  #1  
Cheech
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Default Noise Solutions: "Ninety at nine feet"

Our club is trying to hang onto its existance in the presence of a neighbor complaining about noise . For years this AMA'd club has leased privately from a farmer, but he has recently sold out to the county forest preserve district . There is the feeling that we over accomadate the complaining neighbor or lose the field forever. Guys from the club went to the complainers lawn and yes, you could really hear airplanes.

So we have agreed that all planes will meet a 90 db at nine feet noise limit . That sounds awful quiet to me. Is 90 DB at 9' unattainable? We have not started measuring .

We also are banning our gas burners. I guess we will find another place to run the gassers.

I have read some of the noise related stuff on this forum. Anyway, what IS 90 at 9'? I think we will all be relegated to gliders and electrics real soon. Help!

-Cheech
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Old 07-23-2002, 01:19 AM
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Mettler1
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Default Noise Solutions: "Ninety at nine feet"

Try this site for some ideas.http://www.flyingsites.co.uk/howto/noisechart.htm They get the db readings at 7 meters and prop they're motors to run under 10,000 rpm. Browse the whole site to get the most info. Hope this helps.
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Old 07-23-2002, 02:40 AM
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Default Noise Solutions: "Ninety at nine feet"

If I were you, then I would rethink banning the gassers. Yes, they might be a little louder, but the tone of sound is much different from the glow engines. The glow engines have a much higher pitch which can be much more annoying than the sound of a lower pitched gas engine. Just my thought on the subject.
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Old 07-23-2002, 06:01 AM
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Default Noise Solutions: "Ninety at nine feet"

Just a thought - how do those leaf blowers and weed wackers keep their noise so low. You can stand next to one and it only makes a humming cound and the muffler must be compact to fit inside those housings.

Agreed there is a LOT of prop noise compared to the fans inside the blowers, and I've heard electrics turning gas props that sounded like .40's when they were flying, but they WERE electric and seemed quieter overall.

We lost our field due to an inconsiderate flyer that refused to recognize that he was flying WAY to close to the neighbors with an unmuffled gas engine and scaring their horses to the point they were running around their corrals - took a total of 30 days to get kicked off a field that the club had used for 10 years - WITH the same neighbor AND we've crashed in the corrals.

Only thing I can suggest it that you prop for low speeds, put after-mufflers on the existing mufflers and hope for the best.
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Old 07-23-2002, 12:34 PM
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Default Noise Solutions: "Ninety at nine feet"

...Only thing I can suggest it that you prop for low speeds, put after-mufflers on the existing mufflers and hope for the best.
Looks like that really is the only solution. The UK flyers seem to have been facing this for a long time. They have their planes propped for RPM's under 10K and they're using after market mufflers that are bigger, more baffled, longer, etc...

That really kind of blows. I strongly prefer a good strong plane & engine setup over one that has been governed for sound. But at this field at least, it is what it is .

Thanks for the advice.
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Old 07-23-2002, 12:44 PM
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Default Noise Solutions: "Ninety at nine feet"

Cheech,
Your field sounds like ours. A few years ago we banned gassers and required all planes must have muffler. Recently we have begun noise testing on our planes because we found that some plane with mufflers were quite loud but some of the newer twins without mufflers were quite. I contacted the AMA and they sent me some info on noise levels and how to setup the test stand. They suggest 98db at 9'. What we found with our planes was quite interesting,most of the planes were in the 92db range a few higher a few lower. We tested 2 gassers, a G45 and a US41, both came in at 98db. We also found that props were the culprit to alot of noise. Another interesting thing we found that some of the planes own fuselage made alot of noise, so isolation mounts were installed and reduced the db output 2db, amazing. Good luck with your field, by the way were are you located. We are in Riverwoods, IL.
Robert
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Old 07-23-2002, 01:07 PM
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Default Noise Solutions: "Ninety at nine feet"

"Good luck with your field, by the way were are you located. We are in Riverwoods, IL. "

Thanks. The 98 db at nine feet sounds much more reasonable and attainable. I think our club was using some pattern airplane guidelines when they resolved the 90 at 9' .

Our club is in the little town of Gilberts, off of hwy 72 near Randall road way out on the northwest tollway. The club is the Elgin RC Flyers
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Old 07-23-2002, 04:17 PM
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Default Noise Solutions: "Ninety at nine feet"

I was in your neck of the woods last week for the Giant scale at St. Charles. Oh, I forgot to mention that we have a stand that all planes must be mounted on for sound testing.
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Old 07-23-2002, 04:31 PM
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Default Noise Solutions: "Ninety at nine feet"

I too was at the Festival of Giants on Saturday. Took my two sons and snagged some pit passes. We were with a friend demo'ing a turbine. Among other things, we met Mac Hodges and got great photos of my sons and his huge 94 lb B-29 ( http://www.rcwarbirds.com/stcharles.htm )

What sort of stand are you testing on? I understood the db measurements are best taken on a hard surface, like concrete or asphalt.
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Old 07-23-2002, 04:48 PM
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Default Noise Solutions: "Ninety at nine feet"

Years ago a club I belonged to began a 90 db at 9 ft rule !!!! You cannot believe the chaos that followed. Everybody tried. After mufflers, and larger propellers....iso mounts....ect.....ect.....ect...
It is an almost impossible task !!!! Get ready for fried engines !!! Dead sticks after dead sticks...that result in ruined airplanes. There was terrible infighting amongst the members. The slower crowd with thier Kadet seniors had no problem and were running around with db meters. Most of the members left to other clubs.
That same club still lost thier field....and still cont. to loose fields despite their attempts to maintain 90 db rule......If you have a neibhor who doesn't want you there no matter what you do he will cont. to try to get you out!!! The planes are now a bother to him. As long as he knows you are there he will "think he hears you" even if he doesn,t
Sorry if this sounds bleak....but I think the worst part back then was the fighting between club members. 98 db is a good start 90 is almost impossible. I had to leave myself, it was no longer fun to fly there
Oh and that club I mentioned went from 350 members back then to about 60 or 70 right now......and they are in the process of loosing their field AGIAN despite their db rules.
Goodluck
Brian
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Old 07-23-2002, 05:49 PM
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Default Noise Solutions: "Ninety at nine feet"

So I did not come right out and say it, but I believe you are RIGHT ON TARGET, bigbri . I see this new noise concession as step one towards losing the field. The neighbor will most likelt ALWAYS have a problem. And there are already differences between members with different types of planes.
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Old 07-23-2002, 06:19 PM
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Default Noise Solutions: "Ninety at nine feet"

I thought 90 at 9 was very hard to get but found out that it is not. I just started flying at the Traverse Area Pilots Society and they require 90 at 9.

The first time I made it! I had brought a plane from Florida with an old Enya .60-4C and 13-6 DynaThrust prop using the stock Enya muffler burning 10% Byron fuel__ 88db at 9 feet!
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Old 07-23-2002, 08:16 PM
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Default Noise Solutions: "Ninety at nine feet"

Cheech, our stand is just a simple wood structure that can be adjusted to different size planes and hold them securely which is important because no one can stand near the plane when it is being tested. I saw that turbine at St Charles it was amazing, to fast for me though. I was in the pit also with a friend. He was flying a Ryan STA and a Spacwalker, you may have seen the Ryan cartwheel and its landing attempt. That b-29 was absolutely incredible, I'll tell you one thing, Mac Hodges has some mighty big stones to be flying that thing inverted 3 feet off the runway. Lordy!
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Old 07-23-2002, 09:09 PM
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Default Noise Solutions: "Ninety at nine feet"

I understand bingo flyer......but remember there are different types of flyers. I am sure an older 60 4-stroke overproped with a 13-6 is very quiet...but....see ....... there are already differences here. To each his own.
Good luck to all
Brian
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Old 07-24-2002, 12:05 AM
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Default Noise Solutions: "Ninety at nine feet"

Brian,

My "Bingo" with an OS .91 Surpass with an ACP 14X6 has almost unlimited vertical and checked out at 92db at 9 feet, again with stock muffler, I am sure that it will be easy to meet the 90 db requirement.

After you lose a field or two you will be for noise abatement also.

By the way the TRAMPS just won a Township election by a substantial margin that allows them to fly for several years to come. Township officials actually want them.
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Old 07-24-2002, 01:02 AM
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Default Noise Solutions: "Ninety at nine feet"

Remember noise doubles every 4 db....it is NOT a lineir scale. That last 2 db is VERY difficult to eliminate. Trust me I have tried



BTW.....I know it is possible.....I know sometimes it needs to be done, I am just relating my experences..

Brian
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Old 07-24-2002, 01:07 PM
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Default Noise Solutions: "Ninety at nine feet"

Sound pressure doubles every three db, not four db. Remember that ambient conditions (humidity, windspeed, temperature, barometric pressure, etc) have just as much effect as ground conditions (surface, wet grass, pavement, concrete, wood table with drainage slots that can act as baffles, etc). A plane tested on a cold calm day will score differently on a hot windy day. As stated above, even a person can reflect or refract sound, hence the reasoning behind the "box" where sound pressure is measured. We do not have an official noise policy at our field, but have measured a couple of the realllllllly loud planes. After trying to politely encourage the owner/pilot that mufflers can be a good thing (was even given a stock ys 120 fourstroke muffler). His planes were well over 106 db, and he didnt take the hint. He no longer flies at our field, and has been subsiquently run off from the other fields within 50 miles, and has now given up the "sissy hobby" his quote, not mine (after sinking close to $6000.00 in planes, engines, radios, etc in the last 9 months). He cut his nose off to spite his face (which would have been an improvement), because he wanted to do things his way, or no way at all.

Watching one of the import car shows on ESPN2 a couple weeks ago, and they showed a car stereo contest. There were specifically designed vehicles, with 1 inch thick poly carbonate windows, windshield, etc, bolted to the vehicle and sealed. They were acheiving over 167- 172db within the passenger compartment. Now that is just absolutely ridiculous. I'm sure we all have the teenagers(and older peeps) who have to drive around with the stereo cranked wayyyy up, hearin them 4 blocks before they pass by, ( I will admit to being one of them about 10 years ago). Those would be harder to enforce because they are transient, most of our fields are static. Look at it from the homeowners side, and put yourself in their position. Imagine having 6 weedeaters/lawnmowers/screaming circular saws, leaf blowers, etc, going from sunup to sundown. Most fields tend to be away from highly congested areas, and chances are these people bought their property to get away from the above congestion. When you have what amounts to a fairly nonstop invasion of screaming two strokes, 4 strokes thumping, and gassers buzzing around, it would have to get annoying. The fact remains that even though we do not live at the field (well, there are a few of us that seemingly live there ), those homeowners are our neighbors. If we cant perform some sort of regulation on ourselves, it will be imposed on us by someone else, usually someone who is uninformed (city/county government, etc). Worst case, as Cheech has pointed out, is your field will be closed and lost.

I have found that a very effective way to cut down on exhaust noise on my enya 80 four stroke (that didnt come with a muffler), was to use blue silicone tubing over a soft aluminum sleeve that slipped over the exhaust header. That tubing dampened the resonation from the exhaust pulses without affecting power, and only cost a couple of bucks. It is one of the most powerful size/weight planes at our field, as well as one of the more quiet ones. I also used a piece of blue tubing as an exhaust extension on several motors that I used in my avistar, which worked twofold. I was able to take the baffle out of my stock os muffler, and it was still quieter than the stock setup, with more power. It also turned that plane into a two paper towel plane. We are now going to try something similar on a BME gasser to see if that helps it.

If you guys have any ideas that worked, or didnt work, post it. It will save time, effort and grief for the rest of us.

Steve
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Old 07-25-2002, 02:54 AM
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Default Banning?

Our club had a similar problem. It all started when some "well to do members" (not really active fliers) decided on their own behalf to go to an adjacent neiborhood and "poll" the owners to see if there was any problems.

It wasen't long before they were able to come up with several people who would love to see us stop flying all together. GREAT!

Long story short, these members had to be told to QUIT GOING OVER THERE OR ELSE. While they were in their mind premting a potential problem, they in fact created the perfect enviroment for it to happen. What a ridiculous thing for them to do.

Do you think the guys that drive by on Sunday moring with their loud ***** Harley Davidson motorcycles stop by the owners houses to have a cup of tea and discuss these issues? Do you think that the neighbors check with each other for the "best times to cut the lawns"? How about the local airport, do you think the controllers divert traffic for a neighbor with a headache? How about the frogs in the summertime, maybe they should "keep it down" so someone can get some sleep.

The point is this; we live in a world of cronic complainers. Given the choice we all would like to live in Utopia. Why do modelers always have to be so accomodating? We deserve to make noise as much as anyone.

Answer; BAN THE MEMBERS WHO TRY TO ACCOMODATE
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Old 07-25-2002, 12:08 PM
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Default Noise Solutions: "Ninety at nine feet"

Heavybird, I can see what they were trying to do, they just wanted to know if a problem was about to happen and stop it before it went to far. Sure there are going to be people that don't want the noise only because they're not the ones making it but it s OK for them to run a lawn mower or chain saw. Our field is in a quite residential neighborhood and we limit our flying time and engine size to appease the neighbors but its OK for them to bring in landscapers with their big lawn mowers, weed wackers and leaf blowers that make a whole lot more noise. Once we had a neighbor come over and start screaming that he was gonna shut us down because of all the noise we were making that morning, turns out it was his neighbor with a chain saw, think we got an apology out of him, yea right. What gets me is why do people see us as such athreat and source of noise when there are so many more things in the environment that make more noise. Near my house is a Skeet club and when the wind is out of the south it sounds like they're shooting in my front yard but no one says a damn word to them. Like you said you can't make everyone happy.
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Old 07-25-2002, 12:46 PM
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Default Noise Solutions: "Ninety at nine feet"

I have not yet had the experience of losing a field. But it seems to me that once a neighbor or group of neighbors start complaining, the end is probably near. Maybe we can appease this guy now, but there could be others later or he could change his mind. I see our particular nose abatement attemps as a near term compromise but NOT a long term solution.

Like I mentioned, we are on public ground now. We seem very evictable to me.

-Mark-
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Old 07-25-2002, 02:33 PM
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Default Noise Solutions: "Ninety at nine feet"

I wish more of the RC modelers would be more concerned about noise for our own safety, first and foremost. The noise levels many of us subject ourselves to will flunk OSHA safety requirements in a heartbeat. It pains me every time I see some old timer teaching a youngster how to tweak the needle valve by ear, with a screamin' .40 engine 3ft from their ears. Never mind the neighbors, save our own hearing!

Some of you may not mind wearing hearing aids and have your grandkids shout into your ears when you get old. I do. I own 3 sets of ears muffs and wear them any time I'm subjected to sustained loud noise, whether it is mowing the lawn, weedwacking or running an engine on a bench. I also bring disposable ear plugs to the field for protect myself against those inconsiderate RCers who insist on running their LOUD engines wide open on the table under the roof. When there is a concrete floor and a roof cover, the noise level could have as much as 6dB gain.

Just because there are plenty of inconsiderate jack*****'s out there who run loud pipes on their Harleys, or drive around with their 1200watt car stereo blaring doesn't mean we are excused from acting responsibly ourselves. I am a motorcyclist, a car audio enthusiast, and a RCer, and I always try to be considerate towards others while I enjoy these and many of my other ineterests. Because I know, when I go home and relax in my backyard with a tall glass of lemonade, I would want others to return the favor.

Is 90dB at 9ft doable? Absolutely! Can we motivate every RCer to abide by it? I'm afraid not likely. When we stop trying to wring every last ounce of power out of our engines and start thinking and acting responsibly toward noise safety, this hobby will be better for ourselves and our beighbors.
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Old 07-26-2002, 02:19 AM
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Default Noise Solutions: "Ninety at nine feet"

Cheech,

The 90 /9 rule can be met but from my experience, ain't
worth it. My advice is to start to look around for another field.

Once your forced into such a requirement because of the
neighborhood, the writing is on the wall. Bigbri and I have
seen this time and time again and the result is always the same.

One local club in our area had a noise problem , the nearest
house was about 3 miles away on the other side of a marsh.
A 90 db rule was put in place. No good ,still she complains about
the noise from the planes. Keep in mind she's 300ft from active
train tracks and a 2 lane highway and the planes are a problem !

Then it hits the fan, of all things, a well attended contest that starts very early in the morning and go's most of the day.
That put the final nail in the coffin . She complains very loudly
about the horrific continuous noise throughout the day. She
finally got her way and the field shut down. The board members
attempted to keep the field open but to no avail . Are you ready
for this THE CONTEST THAT FINISHED THIS FIELD WAS A GLIDER
EVENT . When this was pointed out it fell on deaf ears. They were
told that "it's easier to shut you down than listen to her"
The land fill was closed and that's that.

This is an extreme example I'll admit but this is what I've seen.

The club Bigbri and I are in now is on a New Hampshire farm
with tons of open space,but we're always looking around
just in case.....................and it will happen in time

Been there and done that
Good luck, happy hunting
Roby







through
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Old 07-26-2002, 06:36 PM
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Default Noise Solutions: "Ninety at nine feet"

I tend to agree with Roby, once you begin down the slope of apeasement the end of the game is near and this was my point. I just was watching a movie the other day and there was a line that went something like "give a mouse a cookie and he'll want a glass of milk".
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Old 07-27-2002, 12:12 AM
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Default Noise Solutions: "Ninety at nine feet"

Cheech, I'm sorry to hear about your field problems. Once the
complaints start it is usually a sign that it's time to look elsewhere

I've been flying with Bigbri for many years and watched what
happens with "noise rules" it ain't pretty and the end result
is usually the same. The field gets closed anyway,sometimes
it takes months,sometimes years,but they close just the same

Fly out of the place as long as you can then move on. In the meantime look around , you may actually find a better location.

Remember, for the most part we're land beggars and don't get
attached to ANY field. Always be prepared to pull up the stakes
and move on

good luck on your hunt

Roby
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Old 07-27-2002, 07:26 AM
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Default Noise Solutions: "Ninety at nine feet"

Cheech, something that has been left out is that a dB measurement on the ground at 9 ft does not depict how much sound is heard in flight.

Before the war starts here, I fly both Pattern and IMAC. As well as Ducted fans and Sport.

There are a number of variables involved. Do you point the dB meter at the fuse, prop or at a degree away from the plane. Then you have temp, humidity etc.

The pattern standard is 96dBs at 9 feet with the dB meter pointed 45degrees to the fuse to the front. Most people agree that pattern planes are extremely quiet in the air, and actually a flame out can't be detected with a 40 size sportplane in the air.

IMAC has worked hard to come up with an intelligent solution for measuring sound. Props, exhaust deflection, carb noise(air intake) and the fuse are the main culprits with the big gassers. I have cannisters and 3 blade prop on my 3W150 and again, a 40 size sport plane will be louder in the air than this set up. Imac measured at distances the noise generated while the plane was flying( the important part to complaints) with all sorts of props, engines etc while comparing it on the ground info. IMAC has come up with 24 ft away with the dB meter resting 24 inches off the ground and aimed directly at the prop arc with a standard of 98dB.

Turbines are very noisy on the ground, but get them in the air and again are barely audible.

Ducted fans are noisy on the ground, and noisy in the air.

My point is different standards on the ground should apply to different applications. A sound measurement is fopah if it doesn't correlate to the noise of the plane in the air. Again, in the air is when we get complaints.

none of this is perfect, and in urban areas noise is a problem. Certainly wish your club good luck

Ed
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