A study of occurrence rates of EMI to aircraft with a focus on HIRF

Advanced aircraft avionics systems are sensitive to electromagnetic interference (EMI) from a wide variety of sources: external EMI from high power transmitters, radar, etc. (HIRF), natural phenomena (lightning), internal EMI from onboard systems or passenger electronic devices (PED). This paper summarizes the results of a study conducted for NASA Langley Research Center concerning the occurrence rates of HIRF. The methodology used was to send an anonymous questionnaire to a group of pilots and EMI engineers and analyze the responses concerning types, frequencies, and severity of EMI. As a byproduct, some information on other sources of EMI, e.g., FED was collected