International Civil Aviation Organization Committee on Aviation Environmental Protection: Helicopter Noise Measurement Repeatability Program

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International Civil Aviation Organization Committee on Aviation Environmental Protection: Helicopter Noise Measurement Repeatability Program

J. S. Newman / M. Locke

The participating ICAO CAEP WG II nations set out to investigate the degree of variability in test results of the existent helicopter noise certification rule by conducting a multinational noise measurement flight test program using a single, widely available helicopter, the Bell 206L-1 (or the acoustically equivalent 206L-3). The HNMRP has provided a large number of certificating authorities and industry participants the opportunity to acquire experience in helicopter noise certification and the opportunity to thoroughly test and review the requirements of Chapter 8 and Appendix 4 of ICAO Annex 16 through implementation experience. As a result of this experience, recommendations for improvements and refinements to Annex 16 were developed, and subsequently adopted as proposed amendments at the CAEP/1 meeting in Montreal in June 1986. The HNMRP also provided ICAO WG II the chance to review the inherent repeatability of noise levels for a single helicopter model tested by different teams at different locations. This report contains: a history of the HNMRP, a summary of the multi-nation comparison data, and discussion of the results of the program, including the refinements proposed for the international helicopter noise certification standard. Future analytical opportunities using HNMRP data are also discussed at the end of the report.