Stage 2 Noise Certification of the Sikorsky S-76A and S-76C Helicopters

Stage 2 noise certification tests have been performed by Sikorsky Aircraft for the S-76A and S-76C helicopters. The S-76A test was the first to be conducted under the Noise Standards for Helicopters in the Normal, Transport, and Restricted Categories; Final Rule (14 CFR Parts 21 and 36) issued by the Federal Aviation Administration (FAA) in the Federal Register (Vol. 53, No. 24) on February 5, 1988. The present paper summarizes the methods used to conduct the noise certification flight tests, the analyses performed to determine take off, approach, and flyover Effective Perceived Noise Levels (EPNL) in accordance with Federal Aviation Regulation (FAR) Part 36, and some of the lessons learned during the S-76A and S-76C noise certification test programs.