How does the Airbus A320 IDG work in a simulator?

On the Airbus A320, each Integrated Drive Generator (IDG) converts variable-speed mechanical power from an engine into constant-frequency AC electricity. In a flight simulator, a well-modelled IDG automatically powers its associated AC bus after engine start; generator switching, faults and the irreversible-in-flight mechanical disconnect depend on the aircraft add-on’s systems depth.

What does an Airbus A320 IDG do?

The IDG combines a constant-speed drive and an electrical generator in one engine-driven unit. Each engine has an IDG connected to its accessory gearbox, so the unit turns whenever that engine is running and the drive remains connected.

Within its normal operating range, the drive keeps the generator at the speed needed to produce three-phase, 400 Hz AC power despite changes in engine RPM. A typical A320 generator supplies 115/200 V AC and is rated at 90 kVA, although exact details can vary with aircraft standard.

The Generator Control Unit regulates and protects the output. Once voltage and frequency are acceptable, the generator line contactor connects the source to its associated AC bus. With both engines running normally, IDG 1 supplies AC BUS 1 and IDG 2 supplies AC BUS 2. Our explanation of the A320 AC/DC buses and source-priority logic covers the wider network, including APU, external and emergency power.

What does the IDG DISC pushbutton actually do?

The guarded IDG DISC pushbutton mechanically separates the IDG from the engine gearbox. This is fundamentally different from switching an engine generator off electrically.

An IDG may need disconnecting after a serious oil-pressure or overtemperature fault. In real operation, crews follow the ECAM and approved checklist rather than disconnecting it merely because its generator has tripped. A mistake we see in simulators is pressing IDG DISC when the pilot only meant to switch GEN 1 or GEN 2 off.

How do flight simulators model the A320 IDG?

IDG behaviour is determined mainly by the aircraft package, not by whether the host platform is Microsoft Flight Simulator, X-Plane or Prepar3D. The visual switch may be present even when the underlying constant-speed drive, oil system and protection logic are simplified.

• Basic aircraft: the engine generator becomes available above a defined engine-speed threshold, and the GEN pushbutton acts as a simple power toggle. IDG temperature, oil pressure and permanent disconnection may not be simulated.
• Intermediate aircraft: bus contactors, source transfer and generator failures work, but IDG DISC may behave like another generator switch or reset when the flight reloads.
• High-fidelity aircraft: the simulation may distinguish generator faults from drive faults, show voltage, frequency and load on the ECAM ELEC page, shed selected loads and preserve the mechanical disconnect until a maintenance reset.

If electrical failures matter to your flying, assess the aircraft’s systems depth rather than assuming every A320 behaves alike. Our comparison of A320neo add-on fidelity in Microsoft Flight Simulator explains what separates simplified and systems-focused versions.

How can I test the IDG in an A320 simulator?

The safest useful test is to compare a recoverable generator switch-off with an intentionally latched IDG disconnect while parked and prepared to reset the aircraft.

1. Establish another power source. Keep the APU generator or external power available, then run the engine being tested at stable idle.
2. Open the ECAM ELEC page. Confirm that the engine generator shows plausible voltage, frequency and load, and that its AC bus is powered. Our guide to interpreting A320 ECAM indications explains the system-page symbols and warning workflow.
3. Test the GEN pushbutton first. Switch the relevant generator off and observe its contactor open. The remaining engine generator, APU generator or external source should supply the affected bus according to the aircraft’s automatic logic.
4. Restore the generator. Select the GEN pushbutton on again. A healthy generator should reconnect once its output is within limits.
5. Use IDG DISC only for a deliberate failure exercise. In a realistic simulation it will remove that IDG for the rest of the flight. Use the add-on’s failure or maintenance controls to restore it afterwards; some aircraft require the flight or aircraft state to be reloaded.

What happens if one A320 IDG fails?

After one IDG fails, the remaining engine generator can normally supply both main AC buses through the automatic bus-tie logic. The APU generator can also serve as a replacement source when available and permitted by the checklist.

Depending on aircraft configuration and simulated load, commercial or galley loads may be shed. This is not the same as losing both main AC sources, which can lead to the emergency electrical configuration and RAT-driven emergency generation.

Why will the simulated IDG not work or reset?

Most apparent IDG problems come from add-on limitations, an active failure or an unintended control binding rather than incorrect engine RPM.

• No generator output after engine start: verify that the engine is stable, the corresponding GEN pushbutton is on and no failure remains active.
• The generator repeatedly switches off: check for duplicated hardware bindings that continuously send a generator toggle command, then inspect the failure settings.
• IDG DISC has no effect: the aircraft may not model mechanical disconnection, or its logic may require the engine to be running.
• The IDG will not reconnect: this is expected in a high-fidelity simulation. Use its maintenance reset, clear the failure or reload the aircraft rather than repeatedly pressing the guarded button.