Small Engine Inlet Air Particle Separator Technology

The initial deployment of gas turbine engine powered Army helicopters was accomplished with no consideration of inlet protection. Early operational experience did not reveal any serious problems associated with sand and dust erosion. During the formulation and operational testing of the airmobile concept, engine deterioration and damage due to sand and dust erosion became a serious operational problem and subsequently a series of major research and development (R&D) programs were initiated to solve the problem. These R&D programs included numerous approaches: (1) investigation of materials/coatings, (2) definition and control of environment, (3) definition of engine susceptibility, (4) development of separator kits, and (5) development of integral particle separators. This paper summarizes 15 years of US Army R&D activities pertaining to sand and dust erosion of helicopter gas turbine engines which have led to the current requirement for integral inlet particle separators.