<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt">From the AMA Competition Regulations for RC Aerobatics (I removed the text on motor type and scoring penalties)<br><br>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><br><br>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.<br><div> </div>Bob Kane<br>getterflash@yahoo.com<div><br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font size="2" face="Tahoma"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Scott Pavlock <f3aflyer7@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> NSRCA Discussion List <nsrca-discussion@lists.nsrca.org><br><b><span style="font-weight: bold;">Sent:</span></b> Wednesday, May 20, 2009 7:28:05 AM<br><b><span style="font-weight: bold;">Subject:</span></b>
[NSRCA-discussion] db Rules<br></font><br>
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 ?<br>
<br>Regards <br>Mike<br>
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