Operator-Specific Engine Trending Using a Feature-Based Model

The operators and manufacturers of propulsion systems in the aerospace industry demand more powerful and reliable engines. In order to achieve this, a better understanding of engine aging over lifetime is required. Therefore, a performance model has been extended in order to perform feature-based performance deterioration calculations on the basis of differing operating conditions. In this paper, the main focus is brought on the influence of differing environmental and operational circumstances on the performance of a jet engine. Therefore, a detailed analysis of the aforementioned conditions was carried out for a number of regional airlines. Flight routes and destinations were evaluated in order to derive distributions for environmental parameters such as the ambient temperature and pressure altitude as well as the particle and sea salt concentration. By using details on the operational concept along with engine health monitoring data of the regarded airlines, derate distributions were set up. It could be concluded that environmental and operational conditions can be represented and characterized by statistical parameters (e.g. mean value, standard deviation) for engines that are used on regional jets. In order to connect the environmental parameters with performance parameters, a control system is necessary which transfers the environmental input to the performance program. Against this background the influence of the control system itself was analyzed. Hence, a kink point shift procedure was carried out followed by a study of the kink point shift effects. Based on previous work, the extended performance model is applied on feature-based deterioration calculations. As a result, trends of relevant performance parameters for a fleet of engines are derived. This extended calculation procedure demonstrates an approach for engine deterioration trending due to varying environmental and operational conditions.Copyright © 2010 by Rolls-Royce Deutschland Ltd. & Co KG