What is the typical AC frequency used in most aircraft applications?

What is the typical AC frequency used in most aircraft applications?

• A. 60 Hz
• B. 50 Hz
• C. 100 Hz
• D. 400 Hz

Answer: (D)

Using a higher AC frequency in aircrafts is chosen to save weight and space in the electrical system. The magnetic components that handle power, like transformers and inductors, scale with the volt-second product. By increasing frequency, you can achieve the same voltage with far fewer turns and a smaller, lighter core. Less copper and iron mean a lighter, more compact power distribution system—crucial when every kilogram matters on an airplane. That’s why aircraft electrical systems standardize on 400 Hz: it allows compact, robust power conversion equipment while still delivering the needed power to avionics and other systems over relatively short, shielded aircraft wiring. This approach differs from land-based grids, where 50/60 Hz is used because long-distance transmission would be inefficient at higher frequencies.

Using a higher AC frequency in aircrafts is chosen to save weight and space in the electrical system. The magnetic components that handle power, like transformers and inductors, scale with the volt-second product. By increasing frequency, you can achieve the same voltage with far fewer turns and a smaller, lighter core. Less copper and iron mean a lighter, more compact power distribution system—crucial when every kilogram matters on an airplane. That’s why aircraft electrical systems standardize on 400 Hz: it allows compact, robust power conversion equipment while still delivering the needed power to avionics and other systems over relatively short, shielded aircraft wiring. This approach differs from land-based grids, where 50/60 Hz is used because long-distance transmission would be inefficient at higher frequencies.