The Integrated State Assessment And Usage Time Forecast Of On-Wing Engines

By using advanced condition monitoring way, reliable assessment measure and integrated operation data, engine integrated state assessment system judges actual healthy condition of engine and implements scientific fault diagnosis and isolation, then finds fault position, severity degree and develop tendency which can identify early symptom of the fault. Usage time forecast of on-wing engines which apply scientific forecast and know integrated operation condition of engine fleet, then establish reasonable engine change and maintenance plan which can reduce usage and maintenance cost, improve reliability of engine.Combining with"engine all life management system"research project of CAAC, a new engine integrated state assessment and on-wing usage time forecast system is developed. On the basis of analyzing the disadvantage of several current state assessment and time forecast methods of aero-engine, the assessment and forecast system is constructed with system engineering theory, AHP theory and Fuzzy Math knowledge. Through analyzing every criterion and assessment index, this system deals with the normalization problem of qualitative index and quantitative index, analyzes and deals with lots of engine actual data which come from monitoring software, flight route, workshop and test cell, then extract a measurable evaluating value (MEV) based on variable weighting that stands for engine health state. By using this MEV, the engine on-wing usage time is forecasted. The result of queuing engine fleet respectively according to MEV and on-wing usage time will be helpful for engineers, related section and leaders to observe and assess operation status of engine fleet. By using ACCESS database, the system can store, extract, calculate and inquiry engine data easily. The engine data will be refreshed and shared immediately, which can carry out effective and real-time fleet management. The engineers can analyze and manage fleet operation status visually and conveniently through corresponding tendency chart. At last this system is successfully applied to PW4077D engines, which proves this way is not only valid for engine state assessment and usage time forecast but also helpful for establishing maintenance plan of airline and engine maintenance company.