What is the advantage of using AC current to power large aircraft?

• A. Easier maintenance
• B. Less wire weight
• C. Higher efficiency
• D. Better reliability

Answer: (B)

High-voltage AC distribution lets you move large amounts of power with less current by using transformers to step voltage up for the run and down where needed. Since power equals voltage times current, increasing voltage reduces current for the same power. Fewer amps in the wires means you can use thinner conductors, lighter wiring, and less copper, which is a big weight saving on a large aircraft. That weight reduction is the main advantage of using AC for powering large aircraft systems. The other points can be true in some designs, but they don’t deliver the same weight savings as reducing the current through high-voltage distribution.