Bonding jumpers should not exceed what resistance?

• A. 0.01 ohm
• B. 0.0003 ohm
• C. 0.003 ohm
• D. 0.03 ohm

Answer: (C)

Equipotential bonding keeps all metal parts at the same electrical potential, so bonding jumpers must provide a very low resistance path. That tiny resistance ensures fault currents and static charges don’t create meaningful voltage differences across connected parts. Using a limit of 0.003 ohm means, even with substantial fault current, the voltage drop across the jumper stays very small (for example, 100 A would yield about 0.3 V), minimizing risk of arcing, heating, or EMI at joints. Values higher than this would permit larger voltage differences and potential problems, while such an extremely low figure (like 0.0003 ohm) is typically impractical to meet with standard aircraft hardware. Therefore, 0.003 ohm is the specified practical target for bonding jumpers.