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<DIV><FONT face=Arial size=2>Well I'll just add that the amount of rain you've
had has the most effect. 2-3 db over arable soil, 0 db reduction over the
dried out concrete soil in Texas in the middle of a drought. You might get
some amplification if you put your pipe over one of the bottomless cracks in the
ground.</FONT></DIV>
<DIV><FONT face=Arial size=2>--Lance</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=gfowler@raytheon.com href="mailto:gfowler@raytheon.com">Gray E
Fowler</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, June 20, 2006 11:01
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Noise
rules</DIV>
<DIV><BR></DIV><BR><FONT face=sans-serif size=2>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.</FONT> <BR><FONT face=sans-serif
size=2>Pattern planes are all about prop noise...especially on grass.</FONT>
<BR><BR><FONT face=sans-serif size=2>It is easier to pass NATS noise
requirements on grass than hard surface even though there is a lower allowance
for grass.</FONT> <BR><FONT face=sans-serif size=2><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 face=sans-serif size=1><B>"Michael Wickizer"
<mwickizer@msn.com></B> </FONT><BR><FONT face=sans-serif
size=1>Sent by: nsrca-discussion-bounces@lists.nsrca.org</FONT>
<P><FONT face=sans-serif size=1>06/20/2006 10:37 AM</FONT>
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<DIV align=center><FONT face=sans-serif size=1>Please respond
to<BR>NSRCA Mailing List
<nsrca-discussion@lists.nsrca.org></FONT></DIV></TR></TBODY></TABLE><BR></P>
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<DIV align=right><FONT face=sans-serif size=1>To</FONT></DIV>
<TD><FONT face=sans-serif
size=1>nsrca-discussion@lists.nsrca.org</FONT>
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<DIV align=right><FONT face=sans-serif size=1>cc</FONT></DIV>
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<DIV align=right><FONT face=sans-serif size=1>Subject</FONT></DIV>
<TD><FONT face=sans-serif size=1>Re: [NSRCA-discussion] Noise
rules</FONT></TR></TBODY></TABLE><BR>
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<TD></TR></TBODY></TABLE><BR></TR></TBODY></TABLE><BR><BR><BR><FONT
size=2><TT>Lance / Gray:<BR><BR>How does the 103 db at 10 feet over hard
surface translate to a grass 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 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
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 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
planes<BR>>4 years ago were 107-108 dB at 10 feet WITH supersonic props
while 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 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. Even the<BR>>loud boys will
agree, but they'll probably violently oppose the 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 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>>_______________________________________________<BR>>NSRCA-discussion
mailing
list<BR>>NSRCA-discussion@lists.nsrca.org<BR>>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR><BR><BR>>_______________________________________________<BR>>NSRCA-discussion
mailing
list<BR>>NSRCA-discussion@lists.nsrca.org<BR>>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR><BR><BR>_______________________________________________<BR>NSRCA-discussion
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list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR></TT></FONT><BR>
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