Utilizing Integrated Vehicle Health Management Systems for Airworthiness Credit: Statement of Concerns AIR8474

The statement of concerns within this document may be specific to commercial and/or military applications. They also discuss unique concerns between different regulators. They apply to the entire end-to-end health management function throughout the aircraft’s design and operational life, covering on-board and off-board elements. Regulatory approval has been provided to some engine and aircraft Original Equipment Manufacturers (OEMs), allowing the use of health management functionality to comply with Airworthiness Directives (AD), extend inspection intervals, comply with MSG guidance, or to more effectively utilize component lives to optimize “time on wing.” However, different variations and applications of IVHM systems could bring up new concerns which are not currently addressed in standards, especially when attempting to obtain approval to use higher criticality IVHM systems for airworthiness credit. This document addresses both existing and new designs, as well as current and planned MSG guidance. This document does not teach how to design an IVHM function, how to do a safety or risk analysis, prescribe hardware or software assurance levels, how to obtain approvals, or answer the question “how much mitigation and evidence are enough.” These will be determined between the applicant and the regulator, using existing guidance from SAE International and other sources. This document uses the term IVHM to refer to any health management function applied to an air vehicle. The SAE standards committees have been using this term for decades; however, other communities within this industry have used terms such as Aircraft Health Management or Monitoring (AHM), Integrated Aircraft Health Management (IAHM), Vehicle Health Management (VHM), and Rotorcraft Health and Usage Monitoring System (HUMS) to refer to the same concept. At the subsystem level, terms such as Structural Health Monitoring (SHM), Equipment Health Management (EHM), Engine Condition Monitoring (ECM), and Engine Health Management (EHM), are also commonly used. It should be understood that all these terms refer to the same function.