Why is bonding to the airframe important, and what could happen if bonding is inadequate?

• A. Bonding reduces stray currents and corrosion and improves electrical performance; inadequate bonding can cause arcing, erratic instrument operation, or corrosion
• B. Bonding increases fuel efficiency
• C. Bonding has no effect on electrical systems
• D. Bonding only affects radio reception

Answer: (A)

Bonding provides a low-impedance return path and keeps all metal parts of the aircraft at the same electrical potential. This minimizes stray currents, helps prevent galvanic corrosion at joints and fasteners, and stabilizes voltages so electrical systems operate reliably. When bonding is inadequate, voltage differences can build up across surfaces or between conductors and the airframe, leading to arcing, especially if a fault or static charge is present. Arcing can damage equipment and wiring, cause erratic instrument readings or interference with avionics, and accelerate corrosion at connection points. Bonding also helps control EMI, aiding radios and other sensitive systems to function consistently.