THE CERTIFICATION PROCESS FOR HEALTH AND USAGE MONITORING SYSTEMS

Health and usage monitoring systems (HUMS) are being developed to provide valuable benefits to the helicopter operator. The benefits include reduced operating costs, increased availability, and enhanced safety. Some of these benefits require aviation authority approval. In these instances, a “credit” is sought to allow the HUMS to “intervene” or provide an “alternate means” of maintaining the continued airworthiness of the aircraft. The certification of health and usage monitoring systems is unique in the fact that the continued airworthiness of the helicopter is improved and/or credits are received based primarily on indications from ground-based equipment. Historically, ground-based equipment has been approved as part of a manufacturer’s recommended maintenance procedures, and airworthiness limitations have been approved as part of an aircraft’s maintenance manual. The installation of airborne equipment has been typically approved as part of the aircraft Type Certification or Supplemental Type Certification by the appropriate certification office. Since factors that affect the integrity of HUMS processing are now often distributed and include ground-based commercial-off-the-shelf (COTS) equipment and software, both the airborne and ground-based equipment must be certified. Because of this, the selection of a specific system architecture and determination of hardware and software qualification levels are very important. This paper will provide the reader with a suggested procedure for the HUMS certification process and some focus on key issues which will need to be addressed during certification.