Certification of Engine Health Management Systems: Guidelines for Selecting Software Assurance Levels (2011-01-2704)

The use of Engine Health Management (EHM) systems has been growing steadily in both the civilian and the military aerospace sectors. Barring a few notable exceptions (such as certain temperature and thrust margin monitoring) regulatory authorities around the world have not required these systems to be certified in any way. This is changing rapidly. New airframes and engines are increasingly being designed with the assumption that EHM will be an integral part of the way customers will operate these assets. This leads to a need for better guidelines on how such systems should be certified. The SAE E-32 committee on Propulsion System Health Monitoring is leading an industry-wide effort to develop a set of guidelines for certifying EHM systems. Since software plays a critical role in these systems, and since the hardware and the system-level aspects of certification have been covered thoroughly by other standards such as ARP 4754A, the emphasis of this initial effort is EHM software, and will result in an Aerospace Recommended Practice (ARP 5987) titled, “Guidelines for Engine Health Management System Software Assurance Levels.” In this paper, we summarize ARP 5987, which is due to be published toward the end of 2011, and walk the reader through a real-life example (related to managing life limited parts) to illustrate clearly how these guidelines can be applied. The authors are presenting this paper on behalf of the E-32 working group that is responsible for writing the ARP.