HPM Tests Mark Advanced Flight Control Progress Published Dec. 13, 2010 By Holly Jordan Air Vehicles WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- A multidisciplinary team of Air Force Research Laboratory researchers recently completed a series of high-power microwave tests ultimately aimed at reducing the susceptibility of modern air vehicles to potentially damaging electromagnetic, or radio frequency, sources. Conducted at the US Army's HPM facility in White Sands, New Mexico (and in conjunction with the US Army Survivability, Vulnerability, and Assessment Directorate), the testing reflects AFRL's ongoing efforts to validate the use of optics--rather than conventional electronics or hydraulics--for the aircraft flight control systems of tomorrow. Air vehicle command and control typically relies on fiber-optic cables, the benefits of which include their capacity to transfer data at high speeds and their immunity to electromagnetic interference. In these systems, however, certain components remain susceptible to EMI and must be protected. The purpose of AFRL's recent test series was to gather data on various HPM sources with the potential to impact these vulnerable flight control components. Accordingly, the researchers subjected several materials both to narrowband RF sources and to wideband sources, an approach that effectively mimics high-risk conditions. Among the materials tested were two--the ultradense alignment-tolerant fiber-optic cable and the nickel nanostrand composite electronics enclosure--that demonstrated preliminary suitability as possible vehicle protection candidates, with both materials tolerating the RF exposure well. Specifically, the test results indicate that the UDAT cable exhibited no significant EMI leakage, while the NiNS enclosure provided shielding equal to--or, in some cases, better than--that provided by an aluminum enclosure of the same dimensions. Based on the test data recorded, AFRL plans to investigate further design considerations with respect to this technology.