Updated: May 29
Not being a member of the CAC is something of a disadvantage, but it only puts me slightly more in the dark than the committee members. There is very little opportunity for the public, even those with some background in the airport noise issue, to assess the validity of the results and or confirm what appears to be a result by a reviewer. But, I spent some time yesterday working with a neighbor from LJ going over the charts in more detail.
There seem to be two major conclusions that can be drawn from the charts:
The wider the dispersion, the lower the number of people within the 65 dB CNEL.
Moving the post 10 pm aircraft from the 275 to the 290 degree vector decades ago had little or no effect on the 65 dB CNEL.
The results from number 1 could be used in a lawsuit to explain to the jury why there has been such an increase in the number of noise complaints from South Mission Beach residents, when PADRZ was implemented.
The picture below shows the dispersion for the northbound flights pre-FAA RNAV satellite navigation implementation, i.e., PADRZ. We now have a dispersion that is far less, and as I said above, has resulted in far more noise complaints to the airport. Perhaps we need to spread the departures out again, or better yet move them south.
On Alternative 4, the consultants concluded that moving the post 10 departures back to the 275 degree heading made little or no difference to the 65 dB CNEL, so why did they move the departures to the 290 in the first place decades ago??? The answer is that the 65 dB CNEL is a very poor measure of the disruption of peoples lives from airport noise.