Community Noise Impact from Military Helicopter Operations

Abstract

Helicopter deployment and operations throughout the United States have mandated concern by the Army for studies of the environmental impact resulting from military helicopter operations. Federal and Department of Army guidelines for evaluation of helicopter noise were employed. Noise measurement stations were located throughout residential areas adjacent to bases having helicopter operations. Composite Noise Ratings (CNR) establishing zones of noise sensitivity were used complying with HUD guidelines. Although discretionary and unacceptable CNR zones were confined to the installations investigated or adjacent nonresidential tracts of land, operational recommendations were made to minimize possible community annoyance due to noise. It was concluded that the areas impacted from helicopters are not as widespread as those from jet aircraft due to the lower magnitude of noise levels. Community response is expected if pilots deviate from established noise-abatement flight patterns and procedures. There is a definite need to establish minimum altitudes for helicopter overflight. Runways utilized should be selected carefully to minimize noise levels intruding into residential areas. These conclusions are in agreement with other helicopter impact investigations. Special problem areas with respect to psychoacoustic response, blade slap, spectral content, meteorological effects, and multiple flights were encountered.