Air Vehicle Sound Suppression Technology

Unmanned surveillance aircraft, particularly rotorcraft, radiate noise that significantly impacts their detection range. The Phase I research project will identify and quantify noise radiation and propagation factors that affect detection range, andsuggest strategies for improving this range. The primary focus of the research will toward determining the feasibility of applying active noise control technologies to reducing the detectability of unmanned rotorcraft, either by suppressing radiated noiseor by rendering the noise and its source direction less recognizable. A successful research result would make possible unmanned surveillance at closer range, improving the accuracy and reliability of information. It would also reduce the probability ofequipment loss in hostility situations. The technology could also be studied for migration to larger scale manned aircraft or even land vehicles.