Electromagnetic susceptibility of installed avionics

This paper reports on research and experimental results of commercial aircraft avionics and control systems exposed to conducted and radiated electromagnetic interference (EMI). Several experiments were conducted on modern avionics certified to High Intensity Radiated Fields (HIRF) standards while installed in the Federal Aviation Administration's (FAAs) CV-580 research aircraft. This research used radio frequency (RF) sources and probes onboard the aircraft to evaluate installed avionics susceptibility thresholds. The effects of this on-board RF interference to primary systems operations was examined under various operational scenarios during several different experiments under two FAA Research Grants. One experiment was performed during Phase I of the Grant in August 1996, the second during Phase II of the Grant in April and May 1997. Mode stirring of the aircraft's cavity was used during Phase I to allow accurate estimation of the upper bounds of system susceptibility. Experiments in both Phases determined how susceptible installed avionics are to different low power RF sources located in passenger cabin and baggage compartments, and avionics and cargo bay areas.