CIVIL TILTROTOR NOISE IMPACT PREDICTION METHODOLOGY

This paper describes the early development of a methodology to predict the noise impact of tiltrotor aircraft. Existing XV-15 and V-22 tiltrotor noise data are used, in conjunction with the FAA’s Heliport Noise Model (HNM), to predict noise contours and the effects of operating modes on approach noise. Results of these predictions illustrate the tiltrotor’s effectiveness in minimizing noise impact through proper selection of airspeed and nacelle angle. In addition to noise contour predictions of the two tiltrotor aircraft, the paper demonstrates the capability to make predictions for new designs, showing the effects of gross weight and tip speed on noise.