FABRICATION AND FIELD EVALUATION OF A HIGH-CAPACITY, HIGH-EFFICIENCY CHARGE AIR FILTER SYSTEM FOR ARMY AIRCRAFT. PHASE 2. EVALUATION OF H-23C ENGINE AIR AND LUBE OIL FILTER SYSTEM BY RADIOACTIVE TRACER TECHNIQUES
This report covers the design, development, and field testing of a high-capacity, high-efficiency air filter for application on light aircraft engines. Radioactive tracer techniques were employed and a mobile gamma radiation scintillation spectrometer circuit utilized for rapid wear analyses in flight tests. The top piston ring of one cylinder of a H-23C helicopter engine was irradiated by neutron bombardment, and its wear measured when the engine was protected with various filters and also with no filter in the induction system. A reduction in piston ring wear by a factor of three was noted when the engine was protected with a high-capacity, high-efficiency air filter to one that had no filters.