Gap Analysis between EASA and FAA Noise Regulations for Rotorcraft designed within the EU

The following thesis was written within Leonardo S.p.A - Helicopter Division in Cascina Costa, Samarate (VA), Italy. It delineates the basic principles behind the internal procedures implemented by a generic European Design Organization within the aviation sector under the latest amendment of the Commission Regulation (EU) No 748/2012 - Annex I (Part 21) and actively engaged in the helicopter market. Each procedure described should be understood as not specifically attributable to Leonardo S.p.A - Helicopter Division, but intended as the outcome of what the competent Authority requires from a DO located in the EU, in order to show compliance with the current Airworthiness standards and Environmental Protection requirements. The discussion outlined in this thesis primarily delves into Noise Certification, which is one of the items falling under the regulatory umbrella of Environmental Protection, alongside the topics of Engine Emission and Fuel Venting. Starting with this premise, the presented work reports a preliminary technical discussion concerning the most important and relevant concepts for understanding the phenomenon leading to helicopter noise generation. It then proceeds with a high-level description of the major international players active in the Airworthiness world and current regulations, with a specific focus on applicable Noise Standards. Finally, following an overview of the three main activities (Type-Certificate, Change to Type-Certificate, and Foreign Authority Type Validation processes) managed by the designated DO Airworthiness Office regarding Noise Certificates, this thesis proposes a gap analysis between the noise regulations adopted by two of the major international Authorities, EASA (EU) and FAA (USA), supported by the study of a case analysis of interest. The aim is to identify potential standard differences that may hinder validation activities conducted by Europe towards the U.S. or any other Country aligned with FAA regulations.