1. Community Noise in Airplane Design FAA/ICAO have very specific requirements Numerous contributors Jet noise Flow Sep’n noise Clean airframe noise (Source: www.airliners.net)

2. 2 Noise Sources u Consider aircraft noise in the conceptual design phase u Design for low-airframe-noise transport aircraft using MDO u Quantify change in performance w.r.t. traditionally designed aircraft Ref: AIAA 2006-0230

3. 3 FAA Part 36 Noise Requirements Approach Noise (EPNdB) (Data from “Advisory Circular”, DOT, FAA, November 2001) EPNdB - frequency weighted metric TOGW - 1000lbs

4. 4 Aircraft Noise Certification u Aircraft must be certified by the FAA and ICAO in terms of noise levels u Certification noise is measured at flyover, sideline, and approach u Based on aircraft max TOGW and number of engines, the noise level is limited u Additionally, regulations limit the hours and the number of operations 2,000 m (1.24 miles) 6,500 m (4.04 miles) Approach Flyover Sideline 450 m (0.28 miles) Threshold Lift-Off Thrust Cutback Brake Release 120 m (394 ft)