Notes
Aviation Noise and Emissions Symposium (ANES) Aviation Working Group (AWG) presentation on seven specific community requests to airlines to mitigate departure noise at John Wayne Airport (SNA/Orange County). Covers NADP-1 steep departure procedures (1.2 dB reduction), STAYY4 two-turn procedure approved by FAA, 1200-foot throttle cutback, further power reduction at 1200 feet altitude initiated April 2024 on Airbus equipment (estimated 3.3 dB reduction), auto-throttle delay until 4000 feet/shoreline, and fleet modernization with Boeing 737 MAX and Airbus NEO aircraft (4.5–7 dB quieter than 737-700/737-800). Includes SEL noise contour maps generated using FAA AEDT-3e tool from simulated departures comparing Boeing 737-800 current procedure (SIM run #1: STAYY3, NADP-1, 1200-foot cutback) versus alternative procedure (SIM run #5), and single-event noise level contour boundaries above 80 dB, 85 dB, and 90 dB overlaid on residential areas near SNA. Community ask focuses on single-event noise levels versus 24-hour DNL/65 CNEL contours.