Electromagnetic Environmental Effects on Aural Warning Systems in Aircraft

Aural warning systems play a critical role for the safety of commercial and military airplanes. Due to their potential susceptibility to electromagnetic interferences (EMI) and indirect lightning effects in the flight deck, regulatory agencies impose stringent electromagnetic requirements for the aural warning systems. Because the EMI and lightning risks on Aural systems are of safety concern, governmental agencies require aircraft manufacturers to evaluate and mitigate the hazardous effects of EMI and lightning occurrences in aircraft. In order to have commercial transportation aircraft be qualified and certified, airplane manufacturers must prove that the design and performance of aural warning systems meet the safety and regulatory specifications. Typical regulatory EMI and lightning requirements include RTCA DO-160 and MIL-STD-461. Aural warning systems present unique features to researchers since both audio and radio frequencies are utilized for their functionality. This means the pass and fail criteria for aural warning systems are far more complex than those of systems that utilize only the radio frequency. The purpose of this paper is to present and discuss the unique issues and test methods related to the aural warning system evaluation to achieve the necessary high quality and meet the regulatory requirements. In Section 1, we introduce the nature and function of aural warning systems. In Section 2, we discuss the standard risk modeling of evaluation parameters. Then we present the radiated and conducted susceptibility of the aural warning systems in Section 3. In Section 4 we present the lightning susceptibility for the aural warning systems. We conclude, in Section 5, with a summary and suggestions for the future work of EMI and lightning protection for aural warning systems.