[NSRCA-discussion] db Rules

[Ron Van Putte]

That's highly unlikely.  Very few, if any, internal combustion  
engines and even few electric-powered airplanes could meet a noise  
standard of 78 dB at three meters.  The sound pressure level doubles  
every six dB, so 78 dB is 1/8 the sound pressure level of 96 dB.   
That's about the level of a mouse burp.

Ron

On May 20, 2009, at 10:20 AM, Duane Beck wrote:

> I hit send too quickly.   I meant to suggest that perhaps they're  
> using the same distance.
>
>
> Duane
>
>
> ----- Original Message -----
> From: "Duane Beck" <duane.e.beck at comcast.net>
> To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
> Sent: Wednesday, May 20, 2009 11:12:23 AM GMT -05:00 US/Canada Eastern
> Subject: Re: [NSRCA-discussion] db Rules
>
>
> p { margin: 0; }
> "...shall be 96 decibels measured at three (3) meters from the  
> center line of the model..."
>
>
> ----- Original Message -----
> From: "Bob Kane" <getterflash at yahoo.com>
> To: "General pattern discussion" <nsrca-discussion at lists.nsrca.org>
> Sent: Wednesday, May 20, 2009 10:10:38 AM GMT -05:00 US/Canada Eastern
> Subject: Re: [NSRCA-discussion] db Rules
>
>
> <!-- DIV {margin:0px;} -->
> Do they have a distance parameter defined?  The dB number by itself  
> is meaningless.
>
> Bob Kane
> getterflash at yahoo.com
>
>
> From: Scott Pavlock <f3aflyer7 at gmail.com>
> To: General pattern discussion <nsrca-discussion at lists.nsrca.org>
> Sent: Wednesday, May 20, 2009 8:19:03 AM
> Subject: Re: [NSRCA-discussion] db Rules
>
> Bob
>
> The club has set 78db as the standard for quiet flyers. Thanks for  
> the info.
>
> Mike
>
> On Wed, May 20, 2009 at 7:09 AM, Bob Kane <getterflash at yahoo.com>  
> wrote:
> From the AMA Competition Regulations for RC Aerobatics (I removed  
> the text on motor type and scoring penalties)
>
> 4.2: Noise Limit. <snip> The maximum noise level for all classes  
> shall be 96 decibels measured at three (3) meters from the center  
> line of the model with the model standing on concrete or macadam,  
> and 94 dB if an earth or short grass surface must be used All  
> measurements will be taken perpendicular to the fuselage centerline  
> on the right hand side of the model, with the nose of the model  
> aircraft pointed into the wind, with motor running at full power;  
> the microphone to be placed on a stand 30 centimeters above the  
> ground and in line with the motor. No noise reflecting objects  
> shall be nearer than three (3) meters to model or microphone. <snip>
>
> What actual dB number you use is up to the club. 94 dB would be too  
> loud for a park flyer. You might want to measure an acceptable  
> plane to see what the number is and use that as the standard. You  
> could also measure a plane considered too loud and see what it  
> measures. The tough thing is "loud" and "unpleasant" are not easily  
> related.
>
> Bob Kane
> getterflash at yahoo.com
>
>
> From: Scott Pavlock <f3aflyer7 at gmail.com>
> To: NSRCA Discussion List <nsrca-discussion at lists.nsrca.org>
> Sent: Wednesday, May 20, 2009 7:28:05 AM
>
> Subject: [NSRCA-discussion] db Rules
>
> Our club has recently added more flying times for quiet flyers. But  
> we need to have our planes db'ed before we can fly in these new  
> very early hours.  Where can I find a set of guidelines on how a  
> plane should be properly db'ed ?
>
> Regards
> Mike
>
>
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>
>
>
> _______________________________________________ NSRCA-discussion  
> mailing list NSRCA-discussion at lists.nsrca.org http:// 
> lists.nsrca.org/mailman/listinfo/nsrca-discussion
>
> _______________________________________________ NSRCA-discussion  
> mailing list NSRCA-discussion at lists.nsrca.org http:// 
> lists.nsrca.org/mailman/listinfo/nsrca-discussion
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion