EMI from sources in the cargo bay

Abstract

The possibility of interference to avionics from sources in baggage in aircraft cargo bays has recently been investigated. This could apply to sources such as electronic baggage tags, inadvertent or intentional transmissions from baggage. EMI sources in the cargo bays represent a possible threat source to the avionics in adjacent bays, avionics in the cargo bays themselves and to the CNI (communication, navigation, and identification) antennas mounted on the aircraft surface. Path loss calculations and measurements can be used to determine the coupling of these sources to the avionics and susceptibility assessments can be made on that basis. The FAA Technical Center has been conducting a series of experiments to gain information concerning both path loss/coupling questions and avionics upset effects caused by close-in sources. These experiments were conducted on both a CV-580 and B727 aircraft. Recent inspection of a wide range of commercial jets indicate there are many similarities in the physical relationship of the source locations and avionics and CNI antennas. This presentation includes the procedural and physical aspects of baggage handling as it effects assessment of the EMI risk.