Noise Measurement Flight Test: Data/Analyses, Sikorsky S-76A Helicopter

Abstract : This report documents the results of a FAA noise measurement flight test program with the Sikorsky S-76 helicopter. It contains documentary sections describing the acoustical characteristics of the subject helicopter and provides analyses and discussions addressing topics ranging from acoustic propagation to environmental impact of helicopter noise. This report is the sixth in a series of seven documenting the FAA helicopter noise measurement program conducted at Dulles International Airport during the summer of 1983. The S-76 test program involved the acquisition of detailed acoustic, position and meteorological data. This test program was designed to address a series of objectives including: (1) acquisition of acoustic data for use in assessing heliport environmental impact; (2) documentation of directivity characteristics for static operation of helicopters; (3) establishment of ground-to-ground and air-to-ground acoustic propagation relationships for helicopters; (4) determination of noise event duration influences on energy dose acoustical metrics; (5) examination of the differences between noise measured by a surface-mounted microphone and a microphone mounted at a height of four feet; and (6) documentation of noise levels acquired using international helicopter noise certification test procedures.