Life prediction of helicopter engines fitted with dust filters

Abstract

Engine erosion in environments such as those that may be encountered by helicopters during hover, nap-ofthe-Earth flight, dust storms, and generally dusty atmospheres can have significant effects on engine performance and life, resulting from the degradation of the first-stage compressor. Ingestion of dust into a turbine engine may be limited by means of dust filters fitted to the engine intakes. Efficient filtration of the dust results in a sparse dust concentration entering the engine that is comprised essentially of particles that have a diameter of less than 100 /urn, and indicated negligible particle-on-particle interactions. The dependence of engine performance on the erosion of the first-stage compressor by sparse dust concentrations may be extended to enable the life of an engine to be predicted for a typical flight in a specific dust environment. The methodology for predicting engine life is presented.