TailTwister

My Feedback: (1)

My club is considering adding SPL (Sound Pressure Level) limits at our new field. As the Safety Chair, I'd have to add it to the Field Rules, and police it.

Anyone belong to a club with such rules? How did adopting such rules go? Any input on a dB number to go with?

We are pretty far from our neighbors, but leaves fall early, and come back late here, so we are concerned.

Any input is welcome.

bbbair

... Just what is SPL (Sound Pressure Level)?

I think that it's some kind of noise level... but I have never heard of it - can you explain it a bit more?? []

TailTwister

My Feedback: (1)

You measure SPL in decibels (dB). It's a measure of how loud something is.

MajorTomski

Why not just follow the sound guidelines followed in the AMA comp. manual?

http://www.modelaircraft.org/comp/07...aerobatics.pdf

If you're in the middle of no where and you don't have neighbors complaining, why bother with the headache of trying to limit noise?

I went through a three year 1:1 aircraft acquistion program, and the biggest fights occured over noise/sound levels. OSHA pulled a bigg sheet over our eyes, sound compliance is more black magic than science.

Who's going to pay for and maintain the calibration of the sound measuring unit? Are you going to certify the operators?

You going to work in dBA or dBspl?

Is your club going to a fixed testing station, including a weather station to determine atmospheric conditions?

Without all of this, measuring sound levels with an off the shelf, radio shack type uint will generate a bunch of numbers that have no relation to other numbers taken on any other day unless the wind, temperature and pressure are the same as the the other day the numbers were recorded.

Now if you're going to stop members from flying because of noise, how do you defend telling one person they can't fly and another that they can when you can't prove you've done any of the above variables with consistancy?

Unless you're defending against a complaining neighbor, it isn't worth the hassle.

TailTwister

My Feedback: (1)

Well, the concern is multi faceted, I guess...

First off, we want to know how many fields even do this. Is it even a reasonable endeavor, or a complete failure where those fields are? Is it s rule for the sake of making a rule?

If there is a limit, and I speak to a complaining neighbor saying, "We are within AMA contest guidelines.", does that help, or not? I'd guess not.

If we wait, for a complaint, and issue the restriction then, how will that effect the membership and neighbors at that time? What if we are already in the limits, and still get a complaint? What if the engine complained about was within limits the whole time?

What engines will fail, even with a stock exhaust?

Anyone have experiences with any of this?

MajorTomski

Most sound measuring uints have an accuracy of +/_ 1 dB. So something that may be at 95 dB has a measured range of 94 to 96 dB. A general rule of thumb is that 3 dB is a 100% increase in percieved noise level. so something at 97 dB is twice as loud as something at 94dB. And the meter already has 66% of that error built in.

The best you're going to be able to do at your field is a pass or fail fail number for that day depending on the conditons of the battery in the box at that time.

To be fair to anyone being measured, except at a contest at one site with measurements of all contestants taken over a short span of time, you cannot point and shoot, take a quickie measurement and judge pass or fail, if you do then that measurement is only valid for that day/those conditons. The same plane may come back the next day and pass by 2dB.

TailTwister

My Feedback: (1)

I thought I read 6 dB doubled?

I've got to do some more reading...

mscic-RCU

My Feedback: (6)

You might want to check with the county and/or township you live in to see if they have established sound limits already and comply with them. This might be a can of worms best not opened.

rc-sport

My Feedback: (12)

It's 3db doubles the sound level. I did alot of research on this very question for our field. We limit out planes to 98db measured at 9 ft. The planes are placed on a stand 3 ft off the ground and secured to the stand. The meter is on tripod level with the planes muffler. We measure planes with the meter down wind from the muffler. No one is aloud to stand near the plane or with 2 feet of the meter. We use A weighting because that is said to be closest to the human ear. So far it is working well.

Scar

My Feedback: (3)

This is a good procedure. I belong to one club that has a similar procedure.

We're a little closer to the neighbors, and if there's a question about a particular plane we like to get a reading from the neighbor's yard. If he's in his yard talking quietly, the sound level is around 50 dB. We'd like to keep the plane flying past from registering more than 55 dB, and we'll get complaints if it gets up around 80. That 98 dB at 9 feet away is the max that keeps us from getting complaints.

Luckily, the people we've had tell us about our louder planes were just concerned about other people being annoyed. A good policy is to keep the planes as far away from the neighbor as is practical.

I submit that a good neighbor will explain to you that your plane's noise is annoying him. Gives you a chance to adjust. I want to keep that neighbor happy.

Best wishes,
Dave Olson

Deadeye

Thank God I live in rural Montana. SPL? What a PITA! I'll never have to worry about noise. I feel bad for you RC brothers that do. [&o]

MajorTomski

Tail twister, aslo note that rc-sport's club process is much more restrictive than the AMA standard I linked to.

bbbair

This is a real problem for all of the above reasons and a few more.

Once we had a problem neighbour, we did the checks and all of our club planes met standards... the neighbour was still not happy. So we measured a lawnmower and chain saw - both made more noise closer to their house than we did - BUT WE WERE A PROBLEM!

Attitude is what it's all about... try to make friends with the neighbours, no flying before 8 AM Monday - Friday, not before 9 AM Weekends and holidays. End the flying at a reasonable time in the evening and DON'T fly over their house, Don't chase their Horses, dogs, sheep, ducks etc... be nice... it works.

donkey doctor

Hello; The noise debate rages on, what's too loud, what's annoying? We volunteered to fly our planes for the local gov'ts to sample. We set it up at a farmers field and invited everybody we could think of. First we flew some electric planes, kind of to check out the audiences level of acceptance. Then I flew my Taube with a Laser 100, the quietest plane I've ever heard. In the air, the Taube is actually queiter then the electric planes we flew. By this time the audience was talking among themselves about how it's some kind of artistic pursuit, that shouldn't be inhibited.

Then Steve fired up his big hots with a ST 3000. He was carefull about rolling the throttle down when he was near us, but he wrung it out big time. After he landed and taxied back, the group was having a little huddle. We walked over to them, one person said that they couldn't understand anyone condemning what we do for noise. We asked them all for their candid comments, so that we could comply with any existing noise regulations. They all said that we don't have to do anything, and that if anyone complains about excessive noise, they're being unreasonable.

Our field is far away form town, on a dairy farm. We quite often have people come by to watch us fly. If someone has a noisy plane, they keep it for a time when it won't annoy any visitors. But we are all sensitive to each others sensitivities, and no one deliberately would annoy another.

As long as things continue the way they have been, I don't forsee any problems.

TailTwister

My Feedback: (1)

You know, I think the can of worms analogy is dead on. I've recommended that we do not consider it a problem, until it is. We have no close by neighbors, so it's not likely to even come up. If it does, we may restrict the use of a tuned pipe, or tuned exhaust. With real mufflers, it might never come up. We also feel like there are less than 5 tuned pipes in our club, and along the lines of 3 tuned exhausts.

I also agree with being good neighbors from the start. At our last field (given up by us voluntarily) we hit a neighbor's shed. By thr end of the day, the pilot bought a few cans of paint, and we had a paint party. The neighbor was happy that we took responsibility, and fixed the damage. He never spoke ill of us, as far as I knew. He and our property owner were pretty tight, so if he wanted us gone, it would have happened.

Thanks for the thoughts. I figured there would be a more level set of experiences, but most seem like the effort was either not worth it, or just a hassle.

I'm going to go put the lid back on my can of worms now...

MajorTomski

Before you pound that lid closed... Don't always blame engine/muffler. Quite often the the prop tips going near super sonic are the source of annoying noises.

daven

My Feedback: (1)

The ama info is "recommended" it is not an AMA rule. I am struggling finding clubs in the area that will allow me to fly the planes that I prefer because they are "Too Loud" (over 105 db at 9 ft). Despite the fact that the planes I fly are legal for two AMA racing classes.

Twister, are you talking about the Hilbert field? Don't they host a race in May? I was hoping to make it.

tailskid

My Feedback: (34)

We do....but only if someone asks for a check. Last week a big 40% got a loud 104 dB, so he's out looking for a better muffler!

TailTwister

My Feedback: (1)

Nope, Valley Aero Modelers in Appleton.

MajorTomski

Umm you may ask the clubs to re evaluate their noise position. The only ama guidelines on noise are now found in the Pattern and Scale aerobatics RULES and they conflict with one another. IN pattern we're trying to emulate FAI so the sounds are to be measured at 3 METERS ( 9.84 feet ) and In Scale they just want a noise level but that is measured at 25 feet! Big diff in the results. So if they're actually following the rules/ guidlines it may make a difference.