Challenges in Meeting the Framework for SHM System Certification and Compliance

Abstract

Monitoring the continued health of aircraft subsystems and identifying problems before they affect airworthiness has been a long-term goal of the aviation industry. Towards this end, Structural Health Monitoring (SHM) systems that could be used for the in-service monitoring of the health of new and existing aircraft structures are being matured. This paper will go step-by-step into the various challenges associated with meeting preliminary certification compliance requirements. A 5-year program completed under funding from the Federal Aviation Administration will be used as a guide to lead the reader through the various certification compliance steps The objectives of this program were to (1) develop, validate, and demonstrate Smart Patch System (SPS) technologies including advanced software, algorithms, and methodologies for structures and dynamic components to (a) detect fatigue cracks and damages before exceeding critical threshold or incipient failure and (b) characterize fatigue cracks and damages, and (2) develop preliminary certification compliance requirements and a framework for certification of an SPS that would be integrated into a Health and Usage Monitoring System (HUMS) for the fatigue crack monitoring of commercial rotorcraft structures per the guidelines provided in FAA Advisory Circular AC 29-2C, Section MG-15. This paper will use this program as a guide to discuss certification compliance challenges and recent work done to meet them. It presents the details on the tasks that were conducted towards the development, validation, and potential certification of the SPS and other similar SHM systems for specific structural applications.