ABSTRACT
Over the past five years, the Air Operations Division (AOD) of the Aeronautical and Maritime Research Laboratory (AMRL) has conducted acoustic analyses of various helicopters. These analyses have revealed that aircrew are subject to extremely high noise levels during operational flying. There are two possible impacts that high noise levels have on the use of an aircraft. They may restrict the exposure times of aircrew, effectively resulting in the aircraft flying for shorter durations than required operationally. Conversely, the aircraft may be flown for operationally required flight times increasing the risk of noise induced hearing loss (NIHL).
