ENVIRONMENTAL NOISE MODELLING FOR UK MILITARY HELICOPTER TRAINING OPERATIONS

This paper describes the techniques that have been developed to predict the noise contours and assess the impact of military helicopter training activities in the UK. The QinetiQ HAMSTER (Helicopter Acoustic Measurement System for Trials and Experimental Reduction) technique for measuring the free-space acoustic directivity characteristics of helicopters is described. These source characteristics are applied in the QinetiQ HELIACT (Helicopter Acoustic Contouring Tool) to establish the helicopter noise contours for flight over varied terrain and under the influence of atmospheric refraction, due to meteorological effects. The acoustic characteristics of WAH64 and Lynx Helicopters have been measured using HAMSTER for ten different flight conditions. Noise contours are predicted, under the influence of varying meteorology, for the Higher Level Environmental Assessment of the noise from Attack Helicopter military training in the UK.