Calculation of Sideline Noise Levels During Takeoff Roll.

This report discusses an improved analytical approach for computing the sideline noise generated by aircraft during takeoff roll. The relationship accounts for the effects of acceleration on the typical shape of noise radiation pattern from a static full-power ground runup. This simplified model is suitable for hand calculations or direct implementation into NOISEMAP, the computerized procedure used by the Air Force to generate contours of equal noise exposure about airbases resulting from aircraft flight and ground runup operations. For the Boeing 707-300 aircraft, the new, simplified model yielded results within 0.5 dB of those obtained with more complex computational procedures involving the effects of forward speed on the jet noise output.