Noise Limitations
Craig, we are in the same boat at our field. We have a rule that all planes must have working mufflers and have banned gassers. Recently though we have noticed some planes with mufflers are quite loud. We have begun some testing with information provided by the AMA. We have set a Max sound level of 98dbs measured at 9 feet from the side of the plane the muffler is on. The meter is placed down wind of the plane. we set the plane in a stand thats about 3 feet off the ground and set the meter level with the muffler. We make sure no one is standing close to the plane and the meter so as not to reflect sound. Also the AMA shows the meter to be turned 70 degrees away from the plane. So far a magnum 46 with a Pitts muffler has failed and a Zenoah G38 and a US41 have passed. So we may lift the ban on gassers. Hope this helps