What is an inverter in aviation electrical systems?

• A. A solid-state electronic device that converts AC to DC for gyro instruments
• B. Lines connecting points of equal pressure
• C. A solid-state electronic device that converts DC into AC current of the proper voltage and frequency to operate A.C. gyro instruments.
• D. A high-altitude Jet Route

Answer: (C)

The essential idea is how an inverter functions in aircraft electrical systems: it turns DC power into AC at the proper voltage and frequency to run AC gyro instruments. In flight, DC power from generators or batteries is converted by the inverter to the alternating current those AC gyros require, typically providing a standard like 115 V AC at 400 Hz. This specific frequency allows the gyro motors to run smoothly and with stable performance, which is crucial for accurate attitude and heading indications. If the system used DC directly or produced AC at the wrong frequency, the gyro readings could become unreliable. The inverter is a solid‑state device, designed to deliver clean, reliable AC power as needed. The other choices describe lines of equal pressure or a navigation route, which are unrelated to electrical power. A device that converts AC to DC would be a rectifier, not an inverter, and would power DC instruments instead of AC gyros.