FDAS Flutter Data Acquisition System: a new data acquisiton system for flutter monitoring aiming to continued airworthiness in small aircrafts flight test certification

• Grant number: 15/22719-2
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: August 01, 2016
• End date: April 30, 2017
• Field of knowledge: Engineering - Electrical Engineering - Electrical, Magnetic and Electronic Measurements, Instrumentation
• Principal Investigator: Fernando de Souza Cabral da Fonseca
• Grantee: Fernando de Souza Cabral da Fonseca
• Company: Aeroteste Soluções em Aviação Ltda
• City: São José dos Campos
• Associated scholarship(s): 16/18208-5 - FDAS Flutter Data Acquisition System: a new data acquisiton system for flutter monitoring aiming to continued airworthiness in small aircrafts flight test certification, BP.PIPE

Abstract

Recently, the National Civil Aviation Agency (Agência Nacional de Aviação Civil - ANAC) promoted the "Small Size Aircraft Project Certification (iBR2020), whose goal is to improve the national aviation industry ability to develop small aircraft designs in order to succeed when submited to a type certification". The aircraft design is based on multidisciplinary requirements. Among these, the structural integrity stands out and especially the flutter is one of most worrisome. Because it is an aeroelastic phenomena, i.e. the one associated with the interaction of aerodynamic forces and structural body response, it is necessary the in-depth knowledge of geometric features, materials and structural anatomy and vehicle mass distributions. Thus, the mathematical representation of these characteristics allows the estimation of the vehicle behavior given its aeroelastic integrity. In this context, many light aircrafts were designed and built without carrying out appropriate engineering analysis and the proper certification tests, as required by a type certification. A semi-empirical method accepted by the certifying agencies is the methodology presented in the report of the Federal Aviation Administration - FAA, the Report45 - "Simplified Flutter Prevention Criteria". However, even such criteria minimally depend on information obtained typically from numerical structural analysis, or ground vibration tests to characterize the vehicle structural dynamic behavior. Such information usually does not exist, thus extra experiments are necessary to characterize the aircraft dynamic structural response. Aiming the flight safety and the continuing airworthiness, concepts now necessarily extended to small aircrafts, the PIPE 1 goals are to develop a new real-time flutter analysis and monitoring algorithm and to study the technical feasibility of the Flutter Data Acquisition System - FDAS hardware prototyped. Measured signals can be acquired in practice by acceleration transducers, strategically positioned into the wing stringers for instance. It is intended that the new FDAS equipment offers a new alternative to the FAA Report45 to know the flutter boundaries in light aircrafts, with real-time tests on the same flight. The alternative can meet the certification requirements set out in paragraph 23.629 of RBAC and can meet the iBR2020 strategic national program. (AU)