What is an IDG?

What is an IDG?

• A. Integrated Drive Generator that maintains a constant 12,000 rpm regardless of engine setting.
• B. Inertial Dynamic Generator that varies RPM with engine power.
• C. Internal Direct Generator that supplies only DC loads.
• D. Independent Drive Gear that reduces RPM as required.

Answer: (A)

An Integrated Drive Generator is a generator with a built-in constant-speed drive that keeps the generator running at a fixed speed so the electrical output stays at a constant frequency. It’s driven from the engine’s accessory gearbox and typically runs at about 12,000 rpm to produce 400 Hz power, regardless of engine RPM. This constant speed ensures stable electrical frequency for aircraft systems, which is essential for avionics and other equipment. The IDG combines the generator and the speed-control mechanism in one unit, rather than relying on a separate gear or a device that lets RPM vary with engine power.

An Integrated Drive Generator is a generator with a built-in constant-speed drive that keeps the generator running at a fixed speed so the electrical output stays at a constant frequency. It’s driven from the engine’s accessory gearbox and typically runs at about 12,000 rpm to produce 400 Hz power, regardless of engine RPM. This constant speed ensures stable electrical frequency for aircraft systems, which is essential for avionics and other equipment. The IDG combines the generator and the speed-control mechanism in one unit, rather than relying on a separate gear or a device that lets RPM vary with engine power.