While you are esentially correct every field I have been at measures sound at 9 - 10 feet to one side of the aircraft on the runway surface so in my eyes this thread has some definite merits. I fly at 3 of those types of fields so I am always looking for someone who has these measurements.
I feel it will help those who are concerned about sound at their field but that's just my opinion.
I totally agree with you this subject needs to see the light of day. The field I fly at has the same rule 98DB's at 3 meters (9ft.) and it was a hassle in the beginnig when I wanted to fly gaint scale.
Soon as I bought a large gas Engine the noise police came out of the woodwork, not knowing much at that time I thought they were picking on my type of flying, now I sure they are. i would grade myself a "5" out of ten for skills but I try to fly 3D and that's where the problem is.
3D is not something that my field likes or promotes, so you come under a different microscope than some body else without a muffler and waking up the dead flying a cub. [sm=punching.gif]
These are tests that I was a part of and can verify.
3w 100 (old style) with pitts type muffler it was about 3 years ago but I remember it being 104 or 105 db's[sm=thumbdown.gif]
ZDZ-80 my first one, with a pitts style muffler 104DB's[sm=thumbdown.gif]
Same Engine with a KS header and KS-89VS4 canister externlly mounted on a hanger 9 sukhoi 99 to 100 db's[sm=confused.gif]
ZDZ-80 blue head mounted on a hanger 9 Edge with KS header and KS-90VS4 mounted internally 97 to 98 DB's[sm=thumbup.gif]
Soon will be testing BME 105 with MTW 75 cans and in a couple months my new DA 100 with cans will post data on my web site.
Hope this helps
Thanks