According to the FAA, which conductors are acceptable?

• A. Aluminum and Copper
• B. Aluminum and Steel
• C. Copper and Brass
• D. Aluminum and Bronze

Answer: (A)

Copper and aluminum are acceptable conductors for aircraft wiring. Copper provides excellent conductivity and reliability, making it the standard choice. Aluminum offers a weight-saving alternative, which is why it’s also used in aviation wiring, though it requires proper connectors and practices to address differences in expansion and oxidation. Other metals like steel, brass, or bronze do not meet the conductivity and material performance needs for aircraft wiring, so they are not used as primary conductors.