Easily Retrofitted, Active Noise Cancellation System

Foster-Miller proposes to develop an easily retrofitted, Active Noise Cancellation System (ANCS) for reducing the external noise of large transport and multifunction aircraft during takeoff and landing. Billions of dollars have been spent relocating peoplefrom around airports in which the average noise level is 65dB or greater (1). Therefore any easily retrofitted improvements that can be made to reduce the external noise footprint during take-off and landing of aircraft, without harming the aircraftperformance, will result in large cost savings for the U.S. Navy. Aircraft structural modifications or hushkitted aircraft have been tried with mixed noise abatement results. The Navy has a need to develop a noise reduction system that is cost-effective,easily retrofitted onto the current turboprop and turbofan aircraft, and that is low in weight and power consumption. Foster-Miller proposes to use an active treatment in the shroud of the engine inlet to control the reflected sound emanating from thevanes of the inlet fan. Phase II will focus on conducting a limited field demonstration of prototype. Our team includes experts in acoustic modeling and will include an aircraft engine manufacturer. (P-030132) Successful development of easily retrofitted acoustic noise reduction technology would have broad application to commercial aviation. The implementation of this technology would save billions of dollars that would have been spent relocating people awayfrom the airport's >65dB zone. The development of this technology would also result in greater breadth in determining takeoff and landing profiles. The reduction of noise complaints would improve the public relations between the airport and thesurrounding community.