What is the frequency of the UH-60M's main AC generators?

What is the frequency of the UH-60M's main AC generators?

• A. 50 Hz
• B. 60 Hz
• C. 400 Hz
• D. 800 Hz

Answer: (C)

Aircraft electrical systems use a higher frequency to keep transformers, motors, and other power avionics lighter and smaller. The UH-60M’s main AC generators provide three-phase power at 400 Hz, and they’re driven through a constant-speed drive to keep the frequency stable as engine speed varies. This 400 Hz standard allows compact, lighter hardware while delivering reliable power for avionics and mission systems. Using 50 Hz or 60 Hz would require bulkier components, and 800 Hz isn’t a standard for this helicopter, so 400 Hz is the designed frequency.

Aircraft electrical systems use a higher frequency to keep transformers, motors, and other power avionics lighter and smaller. The UH-60M’s main AC generators provide three-phase power at 400 Hz, and they’re driven through a constant-speed drive to keep the frequency stable as engine speed varies. This 400 Hz standard allows compact, lighter hardware while delivering reliable power for avionics and mission systems. Using 50 Hz or 60 Hz would require bulkier components, and 800 Hz isn’t a standard for this helicopter, so 400 Hz is the designed frequency.