<br><font size=2 face="sans-serif">Adam</font>
<br>
<br><font size=2 face="sans-serif">You are talking FAI I do believe. For
AMA it is 96 dB on hard and 94 on grass (right?) Grass in this case
is easier as it kills much of the exhaust noise, but in your case, at 92
and 94, prop noise is the main driver and the grass has less effect, so
you are probably right that it is better to have the 94dB on hard.</font>
<br>
<br><font size=2 face="sans-serif">At the NATS where I am a terminal Advanced
flyer, my noise reading are always lower on the grass (site 4) than what
I measure at home on the asphalt.</font>
<br><font size=2 face="sans-serif"><br>
<br>
<br>
Gray Fowler<br>
Senior Principal Chemical Engineer<br>
Radome and Composites Engineering<br>
Raytheon</font>
<br>
<br>
<br>
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<td width=40%><font size=1 face="sans-serif"><b>Adam Glatt <adam.g@sasktel.net></b>
</font>
<br><font size=1 face="sans-serif">Sent by: nsrca-discussion-bounces@lists.nsrca.org</font>
<p><font size=1 face="sans-serif">06/20/2006 11:08 AM</font>
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<div align=center><font size=1 face="sans-serif">Please respond to<br>
NSRCA Mailing List <nsrca-discussion@lists.nsrca.org></font></div></table>
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<div align=right><font size=1 face="sans-serif">To</font></div>
<td><font size=1 face="sans-serif">NSRCA Mailing List <nsrca-discussion@lists.nsrca.org></font>
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<td>
<div align=right><font size=1 face="sans-serif">cc</font></div>
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<div align=right><font size=1 face="sans-serif">Subject</font></div>
<td><font size=1 face="sans-serif">Re: [NSRCA-discussion] Noise rules</font></table>
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<br>
<br>
<br><font size=2><tt>I think I'm agreeing with you, Gray. I know
that in my experience with <br>
noise testing YS 140DZ pattern planes, 92db on grass is much harder to
<br>
meet than 94db on hard.<br>
-Adam<br>
<br>
Gray E Fowler wrote:<br>
><br>
> Grass can kill 3 db....on a pattern plane where the exhaust exits
down <br>
> 2 inches above the turf. Not so much on higher exhaust sport planes.<br>
> Pattern planes are all about prop noise...especially on grass.<br>
><br>
> It is easier to pass NATS noise requirements on grass than hard <br>
> surface even though there is a lower allowance for grass.<br>
><br>
><br>
><br>
> Gray Fowler<br>
> Senior Principal Chemical Engineer<br>
> Radome and Composites Engineering<br>
> Raytheon<br>
><br>
><br>
> *"Michael Wickizer" <mwickizer@msn.com>*<br>
> Sent by: nsrca-discussion-bounces@lists.nsrca.org<br>
><br>
> 06/20/2006 10:37 AM<br>
> Please respond to<br>
> NSRCA Mailing List <nsrca-discussion@lists.nsrca.org><br>
><br>
><br>
> <br>
> To<br>
> nsrca-discussion@lists.nsrca.org<br>
> cc<br>
> <br>
> Subject<br>
> Re:
[NSRCA-discussion] Noise rules<br>
><br>
><br>
><br>
> <br>
><br>
><br>
><br>
><br>
><br>
> Lance / Gray:<br>
><br>
> How does the 103 db at 10 feet over hard surface translate to a grass
<br>
> field<br>
> / strip?<br>
><br>
> Thanks<br>
> Mike<br>
><br>
><br>
> >From: Gray E Fowler <gfowler@raytheon.com><br>
> >Reply-To: NSRCA Mailing List <nsrca-discussion@lists.nsrca.org><br>
> >To: NSRCA Mailing List <nsrca-discussion@lists.nsrca.org><br>
> >Subject: Re: [NSRCA-discussion] Noise rules<br>
> >Date: Tue, 20 Jun 2006 08:20:26 -0500<br>
> ><br>
> >John<br>
> ><br>
> >To add to Lance's experience (he and I authored that specific
noise rule)<br>
> >most of the loud boys start out having no idea how loud they really
are.<br>
> >103dB is real easy to obtain , almost all of our planes are under
<br>
> 100. 3dB<br>
> >= 2X loud. The "A" weighting discards any sound below
500mhz. This is<br>
> >important as "bass" does not irritate but can easily
place you over the<br>
> >limit. 1000 to 4000 is the most irritating to Mr Bob Complainer.
This<br>
> >brings up problem #2 which is large supersonic prop tips. Guess
what<br>
> >frequency they pop at??? right at 1000-2000 and now matter how
quiet on<br>
> >the ground the plane is, a supersonic prop in a dive will not
only piss<br>
> >off the neighbors but club members too. We dealt with this by
limiting<br>
> >prop size...that is making the IMAC type planes go to 3 blades.
You <br>
> cannot<br>
> >believe the grief I got by putting this in place....a guy spends
over<br>
> >$5000 on his plane and then bitches about having to buy a $150
prop. He<br>
> >ended up selling his whole rig...plane, 5th wheel to haul it and
all. The<br>
> >prop issue is much more contrversial, and harder to regulate.
Our rules<br>
> >state "no supersonic props" so if at the field and you
hear it any club<br>
> >member can ask that person to stop flying. How to enforce that
I do not<br>
> >know but luckily the rules alone got rid of all the problems...that
is,<br>
> >nearly all those people quit, which was not the intention, but
<br>
> hey......we<br>
> >still have our field and only one psychotic lady to deal with-and
the<br>
> >County/Judges on our side.<br>
> ><br>
> >We never have to check now. Like Lance mentioned if someone brings
out a<br>
> >plane above 103dB you will know it immediately. By the way the
IMAC <br>
> planes<br>
> >4 years ago were 107-108 dB at 10 feet WITH supersonic props while
<br>
> flying.<br>
> > That is about 3.4 times louder than a pattern plane plus
prop noise.<br>
> ><br>
> >A wise Vulcan once told me "The needs of the many outweigh
the needs of<br>
> >the few", or something like that.....<br>
> ><br>
> ><br>
> ><br>
> >Gray Fowler<br>
> >Senior Principal Chemical Engineer<br>
> >Radome and Composites Engineering<br>
> >Raytheon<br>
> ><br>
> ><br>
> ><br>
> >"Lance Van Nostrand" <patterndude@comcast.net><br>
> >Sent by: nsrca-discussion-bounces@lists.nsrca.org<br>
> >06/19/2006 10:30 PM<br>
> >Please respond to<br>
> >NSRCA Mailing List <nsrca-discussion@lists.nsrca.org><br>
> ><br>
> ><br>
> >To<br>
> >"NSRCA Mailing List" <nsrca-discussion@lists.nsrca.org><br>
> >cc<br>
> ><br>
> >Subject<br>
> >Re: [NSRCA-discussion] Noise rules<br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> >John,<br>
> >I've been part of setting noise limit in 2 clubs. One because
I was an<br>
> >officer and we put them in place just in time because when the
complaint<br>
> >came in the town saw that we were being proactive. In the
second, I got<br>
> >roped in because I had "experience". I've got
the same sound meter that<br>
> >they use at nats. First rule is to get a great meter and
spend the <br>
> money.<br>
> > You don't want to make a rule that limits a persons flying
if, when you<br>
> >go to enforce it, the defensive pilot points out the uncertainty
of your<br>
> >equipment. McMaster Carr has a +- 1Db meter, which is as
good as you can<br>
> >get. Its self calibrating too, which is important since
it will probably<br>
> >be stored at your field in the cold and hot.<br>
> ><br>
> >Second: I 've measured tons of planes from close and far, upwind
and down<br>
> >and talked to observers. You must not succumb to claims
that you can<br>
> >measure from 25 feet (or more) and get reliable results. Way
too many<br>
> >variables. Measer from 10 feet at a consistent location.
use A<br>
> >weighting, slow response to average the results.<br>
> ><br>
> >Third: after doing this twice with different observers 103dB limit
(10<br>
> >feet over hard surface) is reasonable. Thisis where both
clubs ended up.<br>
> >It is a lenient threshold that few planes will exceed, but when
they do<br>
> >you and everyone will know it. If the law still complains
you can lower<br>
> >it, but no one will say you are being too restrictive with this.
<br>
> Even the<br>
> >loud boys will agree, but they'll probably violently oppose the
<br>
> concept of<br>
> >a noise rule.<br>
> ><br>
> >--Lance<br>
> ><br>
> >----- Original Message -----<br>
> >From: John Ferrell<br>
> >To: NSRCA Mailing List<br>
> >Sent: Monday, June 19, 2006 8:08 PM<br>
> >Subject: [NSRCA-discussion] Noise rules<br>
> ><br>
> >If someone out there has a set of noise rules for a general purpose
RC<br>
> >club? Especially a set that works.<br>
> ><br>
> >I cannot expect the masses to conform to pattern numbers, but
I need<br>
> >something to start with. "Reasonable" does not seem
to mean the same <br>
> thing<br>
> >to every one.<br>
> ><br>
> ><br>
> >John Ferrell W8CCW<br>
> >"My Competition is not my enemy"<br>
> >http://DixieNC.US<br>
> ><br>
> >_______________________________________________<br>
> >NSRCA-discussion mailing list<br>
> >NSRCA-discussion@lists.nsrca.org<br>
> >http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<br>
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> >NSRCA-discussion@lists.nsrca.org<br>
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><br>
><br>
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