San Diego International Airport Part 150 Update Noise Exposure Maps

14 CFR Part 150 Update August 2009
San Diego International Airport Page 33
5 EXISTING AND FORECAST NOISE EXPOSURE MAPS
The development of NEMs requires the use of an FAA approved methodology or computer program,
which for this project is Version 7.0a of the Integrated Noise Model (INM). Measurements are used
for comparison purposes and not to determine the noise exposure contours.
The fundamental noise elements of NEMs are CNEL contours for existing and five-year forecast
conditions: i.e., 2009 and 2014 in this update.
Figure 2 and Figure 3 present the contours for existing conditions (2009) and forecast conditions
(2014), respectively. Figure 4 compares the existing and forecast conditions contours.
The aircraft operations assumptions used in developing these two sets of contours are presented in
Section 5.2.2. They differ only in terms of the level and mix of aircraft activity. The modeling
assumptions related to airport layout, runway use, and flight track assumptions are unchanged from
2009 to 2014. The comparison shows that the contours are very similar with a slight increase to the
east and a slight reduction to the west. These minute changes are likely due to the anticipated
replacement of the fuselage-mounted-engine aircraft (MD-80) with wing-mounted-engine aircraft
(Boeing 737). MD-80 aircraft have older technology engines that increase the noise on departure,
but the fuselage mounting of the engines make them quieter than wing-mounted-engine aircraft on
arrival. The forecast increase in overall airport activity of 1.6% produces a negligible difference to
the noise environment.
5.1 Comparison to Measured Noise Exposure
As with many major air carrier airports in the U.S., the Airport Authority operates and maintains a
noise and operations monitoring system “ANOMS” that produces daily CNEL values at 24
distinct locations dispersed throughout the communities to the east and west of SAN. ANOMS
determines the aircraft contribution to CNEL at each of the 24 RMTs by correlating the noise events
captured to an aircraft operation in the area of the RMT at the time of the event. The Airport
Authority has verified that the ANOMS, in general, separates aircraft from non-aircraft events
quite well at most sites. The Airport Authority determined the annual aircraft CNEL at each RMT
by combining the daily aircraft CNEL values using ANOMS. The INM provided CNEL values at
each of the RMTs from the 2009 NEM for comparison to the measured values. The results of the
comparison are provided in Table 4.
SAN DIEGO COUNTY REGIONAL AIRPORT AUTHORITY