Shielding, Grounding, and Bonding
Section 10: Environmental Qualification (DO-160)
Definition
Interconnected design practices that form the foundation of electromagnetic compatibility (EMC) in aircraft installations. Shielding uses conductive enclosures and cable shields to contain or exclude electromagnetic fields. Grounding provides a low-impedance return path for electrical currents and a reference potential. Bonding provides low-impedance electrical connections between metallic structural elements, equipment chassis, and cable shields to equalize potentials and facilitate current flow for EMC, lightning protection, and static charge dissipation.
Where This Shows Up
Effective shielding, grounding, and bonding are essential for meeting DO-160 EMI/EMC requirements and lightning/HIRF protection requirements. Equipment-level design must be coordinated with the aircraft installation design to ensure that shielding effectiveness, ground impedances, and bond resistances are maintained throughout the installation. Common issues include high-impedance bonds caused by surface contamination or incompatible materials, broken shield continuity at connectors, and ground loops that create common-mode noise. Bonding resistance requirements (typically less than 2.5 milliohms for primary structure bonds) are defined in aircraft installation standards.
Primary Sources
Multiple sections reference shielding, grounding, and bonding as factors in the electromagnetic environment and test setup.
Aircraft Lightning Environment and Related Test Waveforms — references bonding and shielding requirements for lightning protection.
Related Terms
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