Assessment of Noise Levels in and Around the Sikorsky S-7OA-9 Black HawkHelicopter

摘要

This document reports the results of a comprehensive noise survey of the SikorskyS-7OA-9 Black Hawk helicopter environment and provides an assessment of the hearing protection devices worn by personnel exposed to this environment. Ambient noise levels were measured in the cabin of the Black Hawk at four positions under various flight conditions and at thirteen positions outside the Black Hawk under various ground running conditions. The attenuation properties of the ALPHA helmet, the Roanwell MX-25O7 Communications Headset and the EAR earplug were also assessed. Results show that these devices do not always provide enough hearing protection to meet current conservation regulations (DIG PERS 19-4), even when worn in combination. Recommendations relating to the use of these hearing protection devices and the maximum Permissible Daily Exposure Duration (PDED) for personnel exposed to the Black Hawk environment are made.