Helicopter noise measurements data report. Volume 1: Helicopter models: Hughes 300-C, Hughes 500-C, Bell 47-G, Bell 206-L

The purpose of this test program was to provide a data base for a possible helicopter noise certification rule. Only the measured data is presented. The eight helicopters tested during this Helicopter Noise Test Program constituted a wide range of gross weights and included participation from several helicopter manufacturers. The helicopter models used in this test program were the Hughes 300C, Hughes 500C, Bell 47-G, Bell 206-L, Bell 212 (UH-1N), Sikorsky S-61 (SH-3A), Sikorsky S-64 Skycrane (CH-54B), and Boeing Vertol Chinook CH-47C. The test procedure for each helicopter consisted of obtaining noise data during hover, level flyover, and approach conditions. The data consist of time histories, 1/3-octave band spectra, EPNL, PNL, dBA, dBD and OASPL noise levels.