Helicopter noise measurements data report. volume I. helicopter models: Hughes 300-C. Hughes 500-C, Bell 47-G. Bell 206L

PDFTech ReportFAA-RD-77-57, 1HelicoptersAircraft noiseDatabasesGround effectApproachGlide path systemsAcoustic measuring instrumentsSound levelEffective sound pressureVirginiaUnited States. Federal Aviation AdministrationTrue, H.C.Rickley, E. J.Letty, R.M.United States. Federal Aviation AdministrationJohn A. Volpe National Transportation Systems Center (U.S.)AGR-IMPACTS-EnvironmentNTL-AVIATION-Aviation Energy and EnvironmentNTL-ENERGY AND ENVIRONMENT-Aviation Energy and EnvironmentVolpe National Transportation Systems Center, Technical Reference CenterThis data report contains the measured noise levels obtained from an FAA Helicopter Noise Test Program. The purpose of this test program was to provide a data base for a possible helicopter noise certification rule. The noise data presented in this two volume report is primarily intended as a means to disseminate the available information. Only the measured data is presented in this report. All FAA/DOT data analysis and comparisons will be presented in a later report which is scheduled for distribution in July, 1977. 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. Volume I contains the measured noise levels obtained from the first four helicopters while Volume II contains the data from the remaining four. The test procedure for each helicopter consisted of obtaining noise data during hover, level flyover, and approach conditions. The data presented in this report consists of time histories, 1/3-octave band spectra, EPNL, PNL, dBA, dBD and OASPL noise levels