Lightweight Modular Infrared Radiation Suppression Systems For Aircraft

The need for a lightweight, low-cost, highquality, easily maintained, and highly effective infrared radiation (IR) suppression system has led to the development of a rectangular IR suppressor that uses a bolted assembly construction. The rectangular design offers economy of scale through clesign modularization. The size can be scaled to suit a wide range of applications, thus offering significant fabrication cost savings and military spare parts inventory costs. The rectangular IR suppressor has brazed cooling panels that are either straight or slightly curved in one direction. Fabrication costs thus are lower than for the axisymmetrical configurations, such as the AiResearch suppressor for the Bell AH-1S helicopter. Maintainability and repair are simplified because the bolted assembly concept allows the suppressor to be serviced in the field. Hover flight signature reduction below today's threat levels, and aircraft penalty requirements can be met by the low-cost modular suppressor design. Infrared radiation signature levels for the rectangular suppressor has been successfully demonstrated in hover flight tests performed on a UH-60 helicopter at Edwards Air Force Base in 1985. AiResearch's IR suppressor development since 1985 includes an advanced materials, lightweight, variable geometry, rectangular IR suppressor for the V-22 Osprey. This suppressor system has been in flight since 1988. Signature level predictions are qualified by test and are within specification requirements. This advanced technology was used in conjunction with the UH-60 rectangular suppressor design to develop a lightweight, low-cost, high-quality, and maintainable IR suppressor system for today's military needs. This paper discusses today's modular suppressor design, fabrication, and application versatility to meet engine flow ranges from 3 to 30 pps.