In our previous field, the RS readings would have stood up in the local municipal court during a situation with a neighbor, according to several diffferent lawyers, including the law director. Situation was rectified by working together to achieve a mutually agreeable solution, although we had a couple hot heads who could have screwed the situation up.

Using the pamphlet that came with my employer's B&K, we even were able to calculate the effective sound level since the engine sound level at the neighbor's property was less than 8 dbA above the local ambient noise. With the original field layout, we were boarderline by the local statute, and by rotating the flightline 12 degrees, we lowered the sound level at the neighbor's property line to below the limits on a calm day. This actually meant that on a windy day, the local wind through the trees was illegal. Raising our starting time by an hour eliminated the complaints. In fact, he used to bring his kids to the field to watch us fly, although he stayed pretty much out of sight because he realized there were some who held a grudge against him. In fact, our handling of noise issues got us a couple local neighbors joining our club.

The big gas engined guys did continue to be a problem, because of few effective mufflers at the time, and a "Perception" that the big engines were not as loud because of their lower tone. We had a couple people who used what could best be described as deflector manifolds. Relatively quiet with the plane on the ground at idle, but when the plane banked and pointed the outlets at you at as much as 100 feet away, your whole body hurt. What is the threshold of pain anyway, 120, 130 dbA?

When we had a IMAA meet at our new field a couple years ago, the improvements in mufflers on these engines was impressive. Hope they keep improving.