In an unusual alliance, the Southern California cities of Newport Beach and Laguna Beach, as well as Orange County, owner and operator of John Wayne Airport (“JWA”), joined with Culver City to challenge the adequacy of the Federal Aviation Administration’s (“FAA”) Environmental Assessment (“EA”) and Finding of No Significant Impact (“FONSI”) for the Southern California Metroplex OAPM (“Project”). The Project is a redesign of the approaches and departures to and from more than a dozen Southern California airports. Its stated purpose is to enhance “safety and efficiency” by consolidating the various flight paths to and from these airports by using area navigation (“RNAV”), instead of ground based radar, which requires the use of “waypoints” that, in turn, require dispersion of the aircraft over large areas, and, consequently, the consumption of more fuel.
First is FAA’s conclusion of the insignificance of the Project’s noise impacts on populations surrounding airports. To reach that conclusion, FAA used the day-night average sound level (“LDN”) noise metric. LDN is in general use throughout the country except in California where FAA’s regulations require the use of the Cumulative Noise Equivalency Level (“CNEL”) metric. See, e.g., FAA Order 5050.4B, Chapter 1, § 9.n., p. 8. This is a critical difference because CNEL weights noise created between 7:00 p.m. and 10:00 p.m. by an additional 5 decibels, thus resulting in higher, and often more significant, noise levels than those resulting from the use of the LDN metric.