1600vw
Pattern Altitude
You don't know about chemtrails ? If the exhaust pointed up, then we couldn't spread our chemicals with the accuracy needed. Think of a crop duster, how well would that work if the nozzles faced up?
I don't believe crop duster or those spraying chemtrails are the issue. Its the 172 and others who fly over all the time. I know if my airplane had up facing exhaust tips you would hear nothing on the ground from my airplane. It would be whisper in the air. Its not the prop you hear on my airplane. The prop makes music the engine makes noise. IMHO...Unless you have one of those war birds. Those sound awesome. But how often does a war bird fly over Joe Shmoes house. But to hear an engine and say that is music, I say that is noise. Unless you have open headers and heading down the drag strip. But who would want to live next to a drag strip? Maybe one or two bent folks who like loud engines, but not many.