Updated Software for Predicting Noise From Aircraft

The FOOTPR and RADIUS computer programs implement state-of-the-art mathematical models for predicting levels of noise generated by existing or proposed aircraft. These programs can be used to calculate Federal Aviation Administration (FAA) noise-certification levels, airport-vicinity noise footprints, and levels of noise generated during climb and en route. FOOTPR and RADIUS originated in research at Lewis (now John H. Glenn) Research Center in the year 1981. Since that time, seven jet-noise models, four fan-noise models, a fan-noise-suppression model, and second core and turbine-noise models have been added to these codes, and a ground-reflection model already in the codes has been enhanced.