Which pair of materials is acceptable conductors for aircraft wiring according to FAA?

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

Answer: (A)

The important idea is which metals FAA approves for aircraft wiring conductors. Copper is the standard conductor because it has excellent electrical conductivity, ductility, and proven reliability in aviation environments. Aluminum is also acceptable in some wiring to save weight, but it requires proper attention to connections and anti-oxidation measures since aluminum can form oxide and is more prone to galvanic effects if not used with compatible hardware. The other metals listed—steel, brass, and bronze—either conduct electricity far less efficiently or bring corrosion and compatibility issues that make them unsuitable as primary wiring conductors. So the pair that matches FAA guidance is aluminum and copper.