Design and Structural Analysis for Certification of an External Basket for an AS350 Helicopter

The following master's thesis was developed in collaboration with T.P.S. Group S.P.A.'s Airworthiness department. Based in Torino, this company specialises in the design and production of aeronautical parts and modifications. This work in particular focuses on the certification process of an external basket in both a short and a long version to be installed on an AS350 helicopter, with the objective of accommodating and transporting payload. Considering the maximum take-off weight of the subject aircraft, the project was carried out under Part 27 of the Federal Aviation Regulations with specific items being replaced with paragraphs from EASA's Certification Specifications 27 airworthiness standards and it encompasses virtually every area involved in a process of this kind. The first part consisted in developing the 3D model of the modification with CAD software, as well as the creation of technical drawings for each of the components. The second part concerns the execution of structural analyses of the basket through the use of Finite Element Method software in order to verify compliance with the mandatory requirements, which included an analysis simulating the most critical in-flight conditions considering manoeuvring and aerodynamic loads as well as modal analyses of the modification. In addition, a fundamental part of this work was the simultaneous writing of the necessary official documents to be presented to EASA. The work developed in this thesis involved several optimisation instances of both the model and the design in order to render the modification structurally sound and compliant with EASA regulations, specifically with respect to the development stage which serves as a preliminary step before the subsequent verification stages, in particular concerning flight testing activities, in order to conclude the certification process.