[NSRCA-discussion] Noise rules

Tue Jun 20 08:07:26 AKDT 2006

I think I'm agreeing with you, Gray.  I know that in my experience with 
noise testing YS 140DZ pattern planes, 92db on grass is much harder to 
meet than 94db on hard.
-Adam

Gray E Fowler wrote:
>
> Grass can kill 3 db....on a pattern plane where the exhaust exits down 
> 2 inches above the turf. Not so much on higher exhaust sport planes.
> Pattern planes are all about prop noise...especially on grass.
>
> It is easier to pass NATS noise requirements on grass than hard 
> surface even though there is a lower allowance for grass.
>
>
>
> Gray Fowler
> Senior Principal Chemical Engineer
> Radome and Composites Engineering
> Raytheon
>
>
> *"Michael Wickizer" <mwickizer at msn.com>*
> Sent by: nsrca-discussion-bounces at lists.nsrca.org
>
> 06/20/2006 10:37 AM
> Please respond to
> NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
>
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> Subject
> 	Re: [NSRCA-discussion] Noise rules
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>
>
> Lance / Gray:
>
> How does the 103 db at 10 feet over hard surface translate to a grass 
> field
> / strip?
>
> Thanks
> Mike
>
>
> >From: Gray E Fowler <gfowler at raytheon.com>
> >Reply-To: NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
> >To: NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
> >Subject: Re: [NSRCA-discussion] Noise rules
> >Date: Tue, 20 Jun 2006 08:20:26 -0500
> >
> >John
> >
> >To add to Lance's experience (he and I authored that specific noise rule)
> >most of the loud boys start out having no idea how loud they really are.
> >103dB is real easy to obtain , almost all of our planes are under 
> 100. 3dB
> >= 2X loud. The "A" weighting discards any sound below 500mhz. This is
> >important as "bass" does not irritate but can easily place you over the
> >limit. 1000 to 4000 is the most irritating to Mr Bob Complainer. This
> >brings up problem #2 which is large supersonic prop tips. Guess what
> >frequency they pop at??? right at 1000-2000 and now matter how quiet on
> >the ground the plane is, a supersonic prop in a dive will not only piss
> >off the neighbors but club members too. We dealt with this by limiting
> >prop size...that is making the IMAC type planes go to 3 blades. You 
> cannot
> >believe the grief I got by putting this in place....a guy spends over
> >$5000 on his plane and then bitches about having to buy a $150 prop. He
> >ended up selling his whole rig...plane, 5th wheel to haul it and all. The
> >prop issue is much more contrversial, and harder to regulate. Our rules
> >state "no supersonic props" so if at the field and you hear it any club
> >member can ask that person to stop flying. How to enforce that I do not
> >know but luckily the rules alone got rid of all the problems...that is,
> >nearly all those people quit, which was not the intention, but 
> hey......we
> >still have our field and only one psychotic lady to deal with-and the
> >County/Judges on our side.
> >
> >We never have to check now. Like Lance mentioned if someone brings out a
> >plane above 103dB you will know it immediately. By the way the IMAC 
> planes
> >4 years ago were 107-108 dB at 10 feet WITH supersonic props while 
> flying.
> >  That is about 3.4 times louder than a pattern plane plus prop noise.
> >
> >A wise Vulcan once told me "The needs of the many outweigh the needs of
> >the few", or something like that.....
> >
> >
> >
> >Gray Fowler
> >Senior Principal Chemical Engineer
> >Radome and Composites Engineering
> >Raytheon
> >
> >
> >
> >"Lance Van Nostrand" <patterndude at comcast.net>
> >Sent by: nsrca-discussion-bounces at lists.nsrca.org
> >06/19/2006 10:30 PM
> >Please respond to
> >NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
> >
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> >To
> >"NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
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> >
> >Subject
> >Re: [NSRCA-discussion] Noise rules
> >
> >
> >
> >
> >
> >
> >John,
> >I've been part of setting noise limit in 2 clubs.  One because I was an
> >officer and we put them in place just in time because when the complaint
> >came in the town saw that we were being proactive.  In the second, I got
> >roped in because I had "experience".  I've got the same sound meter that
> >they use at nats.  First rule is to get a great meter and spend the 
> money.
> >  You don't want to make a rule that limits a persons flying if, when you
> >go to enforce it, the defensive pilot points out the uncertainty of your
> >equipment.  McMaster Carr has a +- 1Db meter, which is as good as you can
> >get.  Its self calibrating too, which is important since it will probably
> >be stored at your field in the cold and hot.
> >
> >Second: I 've measured tons of planes from close and far, upwind and down
> >and talked to observers.  You must not succumb to claims that you can
> >measure from 25 feet (or more) and get reliable results.  Way too many
> >variables.  Measer from 10 feet at a consistent location.  use A
> >weighting, slow response to average the results.
> >
> >Third: after doing this twice with different observers 103dB limit (10
> >feet over hard surface) is reasonable.  Thisis where both clubs ended up.
> >It is a lenient threshold that few planes will exceed, but when they do
> >you and everyone will know it.  If the law still complains you can lower
> >it, but no one will say you are being too restrictive with this. 
>  Even the
> >loud boys will agree, but they'll probably violently oppose the 
> concept of
> >a noise rule.
> >
> >--Lance
> >
> >----- Original Message -----
> >From: John Ferrell
> >To: NSRCA Mailing List
> >Sent: Monday, June 19, 2006 8:08 PM
> >Subject: [NSRCA-discussion] Noise rules
> >
> >If someone out there has a set of noise rules for a general purpose RC
> >club? Especially a set that works.
> >
> >I cannot expect the masses to conform to pattern numbers, but I need
> >something to start with. "Reasonable" does not seem to mean the same 
> thing
> >to every one.
> >
> >
> >John Ferrell    W8CCW
> >"My Competition is not my enemy"
> >http://DixieNC.US
> >
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