Leak detection in the lubrication system of an aircraft turbine engine

A model based system for leak detection in the lubrication circuit of an aircraft engine is presented. It achieves on-line detection of leaks during flight. The system is based on a model of oil level variation, including gulping and consumption. A procedure for systematic parameter estimation from data recorded during the previous flight is described. The residual generation is based on a time varying Kalman filter. The decision system consists of a multi-level CUSUM algorithm followed by a decision logic. The effectiveness of the systematic parameter estimation and the leak detection system is illustrated by processing flight data.