Focus on Competition
Technically Speaking ...
Greg Hahn Technical Director [email protected]
SOUND ISSUES: The greatest cause of losing existing flying fields in the past 20 years has been, of course, the noise — or the volume of that noise — we generate when flying our model aircraft. The second greatest cause is the proliferation of soccer, but we'll deal with that later.
Dealing with clubs' sound problems is easily 25% of my job. I'm either talking with club officers directly or discussing with their neighbors ways to control, eliminate, or soften the impact of the noise.
I've often been chastised for not having a set of rules or regulations pertaining to sound, as has the AMA. The fact is, sound is regulated throughout the U.S. by local municipalities, cities, and towns through zoning ordinances.
Towns and cities are able to set the sound limits to their own levels, which leads to a huge inconsistency in the number they put on the limit and the way it is enforced. If we (AMA) were to put a number out there as a guideline or rule, you can imagine the problems that would arise. Clubs would think that our guideline were the legal limit and act accordingly, only to find that the local limit is different, and so on.
The other problem with setting guidelines is the almost impossible task of putting a number on a perception. What a model sounds like in the air is completely different from what it sounds like on the ground. There are also many factors that actually create the sound you hear in a model, for example:
- the propeller
- the engine (and its carburetor)
- the muffler
- the airframe
- environmental conditions
To do as much as I can to help, I always steer clubs to the local authorities to first find out the decibel level that is allowed to cross your property line. That level can be found in the zoning ordinances for your area.
Then locate the boundaries of the property you fly from and, as a reference, set up a simple RadioShack decibel meter at the property line and take some readings.
Recommended steps:
- Check local zoning ordinances to learn the allowed decibel level at the property line.
- Mark your flying field's property boundaries.
- Place a decibel meter at the property line.
- Take readings with several models and under different atmospheric conditions (sound varies with humidity, cloud cover, sun, etc.).
- Repeat measurements multiple times to get reliable data.
Knowing whether or not you're "legal" can give you a leg up on a dispute. But do realize that when it comes to politics, residents will almost always win out over modelers, so schmoozing can come in handy when the going gets tough.
If you do the testing and find you have a problem, don't wait until the authorities contact you; take it upon yourselves to address the issues and get them under control now. Often by the time the law shows up, it's too late.
I'll follow this up next month with another piece on ways to control the noise your model puts out. MA
Transcribed from original scans by AI. Minor OCR errors may remain.
