[NSRCA-discussion] Example noise ordinances that work

[Ed White]

Tom,

You are correct that 85 dBA is loud.  My reaction is that your 96 dB at 25 feet over grass is pretty loud too.  

After our complaints we instituted a limit of 98 dBA at 3 meters over a hard surface (the pattern plane requirement at the time).  We bought several noise level meters to enforce the rule.  Many club members did need to take action to meet the limit, though the actions were generally not too onerous for most airplanes.  At the time, early 90's, open mufflers were not unusual and adding baffles helped a lot.  Also going to smaller, higher pitched props.  Occasionally, better mufflers were needed.  Though we are mostly a sport flyers club and didn't have many high performance aircraft or 40% gas IMAC airplanes to deal with.  We had a couple ducted fans and they pretty much couldn't make the limit.

Ed

Tom Simes <simestd at netexpress.com> wrote: On Wed, 23 Jan 2008 09:59:51 -0800 (PST)
Ed White  wrote:

> We had somewhat of an issue with noise complaints at our old flying
> field.  The noise ordinance in the area at the time was that it can be
> no higher than 85 dBA measured at the property line of the source.  A
> rough calculation indicates that an airplane that passes the pattern
> rule for noise (96 dB at 3 meters) should be below 85 dBA at anything
> more than a distance of about 40 feet from the airplane.  Pretty easy
> to live with.

Thanks for the input Ed.  My first reaction is that 85 dBA at the field
boundary is really loud!  Many communities base their ordinances on a
model ordinance published by the EPA in the 70s which in
summary recommends levels at the border of the receiving property of 60
dBA during the day and 50 dBA at night.

> But the legal allowable level for noise, and what people will complain
> about are two very different things.  Just because the neighbors can't
> show you are exceeding legal limits on noise will probably not be the
> end of the issue.

You're right on the money there, and our recent experience is that a
few mad neighbors carry much more political weight than whether you are
actually violating any codes.  Our current self imposed standard is 96
dBA over grass at 25 feet.  Presuming we can keep the field, we
obviously need to adjust that number downward to be better neighbors.
 
Does anyone have an example of a lower number that has worked for your
club at a noise sensitive field?  Testing last summer showed that with
only a couple exceptions we could drop our standard to 92 dBA and the
mix of IMAC, pattern and sport planes tested would still meet it.

Thanks

Tom
 
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Tom Simes                                       simestd at netexpress.com 
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