Development of a Multi-Faceted Integrated Health Management System for Rotorcraft Engines

The goals of maturing and embedding diagnostics and prognostics functionality are fundamental to the desire of the US Army to reduce rotorcraft operational support and sustainment costs and to transition the Aviation fleet towards Condition Based Maintenance (CBM). Only an embedded, and truly integrated, set of technologies will be capable of comprehensively assessing the health state of aircraft components and projecting their failure horizons based on actual usage in operational environments. The propulsion system is a critical member of the rotorcraft health assessment and an area where diagnostics and prognostic technologies have seen some success. Nonetheless the development of an integrated set of technologies for a rotorcraft engine is a challenging and active area of research. Here we will describe our efforts to design and demonstration multiple technologies for achieving the CBM objective of reducing inspections, extending the time between overhaul, and predicting component failure with sufficient foresight to allow proactive maintenance scheduling on a rotorcraft engine. Six propulsion health management (HM) technologies: continuous power assurance, erosion, remaining useful life, bearing health, model based torque and power management have been integrated into a comprehensive propulsion HM solution. The initial design concept was to provide a single on-board executable. This code was to be hosted on an enhanced health and usage monitoring system (HUMS) driven with engine and flight operational data. Ultimately, as we further considered the HM requirements we adopted a different design architecture. The HM requirements and design trade-offs will be discussed to illustrate the advantages of our partitioned architecture that contains both on-board and off-board processing and data management components. Data flow, as well as examples of subsystem and system level condition (CI), health (HI) and prognostics indicators (PI) will be presented. In addition to the software development activities, engine test cell and bearing rig data has been collected using a set of seeded faults. The value of these indicators will be discussed using the results of the seeded fault data to show how they address critical operation and sustainment questions. Three separate regimes: on-board, flight line and depot maintenance, and mission planning will be illustrated with situational operation and support scenarios.