Automated Health Management for Gas Turbine Engine Accessory System Components

Traditional engine health management development has focused on major gas turbine engine turbomachinery components, such as disks, blades, and main bearings, because these components are expensive to maintain and their failures frequently have safety implications. However, the majority of the events that compromise mission success and equipment availability in military aircraft arise from the degradation or failures of engine accessory system components, such as valves, pumps, and actuators. Failure or statistical-based maintenance of these components fails to account for unanticipated and extreme operating scenarios, which are a major cause of unscheduled maintenance events. U.S. military systems are thus moving toward condition-based maintenance (CBM), wherein maintenance is performed as and when required, thus improving asset availability and contributing significantly to mission success. The authors have developed low-overhead diagnostics and prognostics techniques, which would enable a shift toward CBM of engine accessory components. The current work focused on aircraft fuel and lubrication systems. Model- based and data-driven techniques were developed to provide reliable health assessments of hydraulic pumps and valves, which are essential components on these systems.