Not sure it needs a PM of details
At any given point on the approach path the aircraft on a 3.2 degree slope will be about 6% higher than the 3 degree slope
Sound attenuates with distance squared, measured as 20 log (r2/r1) decibels, where r2/r1 is the ratio of the distances, in this case half a decibel
That will apply to below the flight path; for places a bit off to the sides then the proportionate change in distance will be less.
Last edited by aox; 20th Sep 2015 at 00:46.