SYSTEM FOR AIRCRAFT

THE "WEEPING WING" CONCEPT, IN WHICH A DEICING FLUID IS SLOWLY PUMPED THROUGH PORES IN A LEADING EDGE SURFACE TO REMOVE ACCUMULATED ICE AND PREVENT ADDITIONAL ICE FORMATION,HAS PROVEN VERY EFFECTIVE. COMMERCIAL AND DEVELOPMENTAL VERSIONS EMPLOY SINTERED STAINLESS STEEL OR LASER DRILLED TITANIUM AS THE LEADING EDGE MATERIAL. A LIGHTER, MORE COST-EFFECTIVE SYSTEM COMPATIBLE WITH COMPOSITE SUBSTRATE STRUCTURES IS NEEDED TO FULLY REALIZE THE POTENTIAL OF THIS CONCEPT FOR MODERN AIRCRAFT. THIS PHASE I PROGRAM PROPOSES THE DEVELOPMENT OF A POROUS PBT (POLY-P-PHENYLENE BENZOBISTHIOZOLE) FILM FOR APPLICATIONTO POROUS LEADING EDGE DEICING SYSTEMS. PBT IS AN EXTREMELYSTRONG, STIFF, STABLE AND RELATIVELY INERT POLYMER WITH PROMISE FOR USE IN THE POROUS LEADING EDGE STRUCTURE. THE PHASE I WORK PLAN INCLUDES DEVELOPING A PBT FILM WITH CONTROLLED POROSITY AND MEASURING ITS MECHANICAL PROPERTIES AND PRESSURE-FLOW CHARACTERISTICS. THE FEASIBILITY OF USINGIT AS A LEADING EDGE FOR THE "WEEPING WING" WILL BE ASSESSEDUSING AS A COMPARISON THE POROUS SINTERED STAINLESS STEEL LEADING EDGE MADE BY TKS LIMITED OF HALFWHISTLE, ENGLAND. IF PHASE I IS SUCCESSFUL, PHASE II WILL INVOLVE THE DESIGN, FABRICATION AND TESTING OF LAMINATES, SANDWICH PANEL CONSTRUCTION AND FINALLY LEADING EDGE PANELS FOR TESTING AT THE NASA LEWIS ICING RESEARCH TUNNEL.