What is IDG in Aviation? (Integrated Drive Generator)

In the world of aviation, there are countless technological components and systems that work together to ensure the safe and efficient operation of an aircraft. One such component is the Integrated Drive Generator, commonly known as the IDG. The IDG is a critical part of an aircraft’s electrical power system, providing power to a variety of vital systems and equipment on board.

The IDG serves as both a generator and a drive unit, combining these functions into a single device. It is typically found on larger aircraft, such as commercial airliners, where a high electrical power output is required. The IDG is responsible for converting mechanical energy from the aircraft’s engines into electrical energy, which is then distributed throughout the aircraft.

How Does an Integrated Drive Generator Work?

The IDG operates through a series of components and mechanisms that work together seamlessly to generate and distribute electrical power. Let us take a closer look at the key elements of an IDG and how they contribute to its overall functionality:

1. Generator

The generator within the IDG is responsible for converting mechanical energy into electrical energy. This is achieved through the use of a rotating magnetic field, which induces a current in the stator windings of the generator. The mechanical energy is transferred to the generator through the accessory drive gearbox, which is connected to the aircraft’s engines.

The electrical energy generated by the generator is typically three-phase, which means it consists of three alternating currents that are out of phase with each other. This three-phase power is ideal for powering the various electrical systems and equipment on board the aircraft, as it is highly efficient and capable of handling large electrical loads.

2. Drive Unit

The drive unit of an IDG is responsible for maintaining a consistent rotational speed of the generator and transmitting the mechanical energy from the engines to the generator. It consists of a combination of gears and bearings that ensure the smooth and reliable operation of the IDG.

The drive unit is often designed to accommodate different engine speeds and loads, allowing it to adapt to the varying conditions experienced during flight. This flexibility ensures that the IDG can continue to generate electrical power even if the engines are operating at different speeds or if there are fluctuations in the demand for power.

3. Control System

The control system of an IDG is responsible for monitoring and regulating the operation of the generator and drive unit. It ensures that the generator is operating within safe limits and that the electrical power being produced is at the desired levels.

The control system also includes safety features, such as over-speed protection and fault detection, which help prevent damage to the IDG and ensure the overall safety of the aircraft. It continuously monitors various parameters, such as temperature, voltage, and frequency, to ensure the optimal performance of the IDG.

The Importance of Integrated Drive Generators in Aviation

The Integrated Drive Generator plays a crucial role in the safe and efficient operation of an aircraft. Here are some key reasons why it is an essential component in aviation:

Reliable Power Generation

The IDG provides a reliable source of electrical power to the various systems and equipment on board the aircraft. This includes powering critical components such as the flight control system, lighting systems, communication systems, and navigation equipment. Without a consistent and robust power supply, the operation of these systems could be compromised, potentially leading to safety issues and operational disruptions.

Furthermore, the IDG is designed to withstand the harsh conditions typically encountered during flight, including high temperatures, vibrations, and extreme altitudes. This ensures that it can continue to generate power reliably, even in challenging environments.

Redundancy and Backup Power

In aviation, redundancy is crucial to ensure the safety and reliability of systems. Many aircraft are equipped with multiple IDGs to provide redundancy in case of a failure in one unit. If one IDG were to experience a fault or malfunction, the other units can seamlessly take over the power generation, reducing the risk of power loss and maintaining the crucial systems’ operation.

In addition to redundancy, the IDG also serves as a backup power source. In the event of an engine failure or loss of main electrical power, the IDG can function as an integrated auxiliary power unit, providing emergency electrical power to essential systems and instruments. This capability is crucial during critical phases of flight, such as takeoff and landing, where the reliable operation of systems is paramount.

Efficiency and Weight Savings

The integration of the generator and drive unit into a single device, as seen in the IDG, offers significant efficiency benefits. By reducing the number of separate components and eliminating the need for additional power transmission systems, the IDG minimizes energy losses and increases overall system efficiency.

Additionally, the integration of the IDG contributes to weight savings, as it eliminates the need for bulky and heavy transmission components. In the aerospace industry, every kilogram matters, as reducing weight can lead to improved fuel efficiency and increased payload capacity.

Overall, the combination of reliability, redundancy, backup power capability, and efficiency makes the Integrated Drive Generator an indispensable component in the aviation industry.


The Integrated Drive Generator (IDG) is a vital electrical power system component in aviation. It seamlessly combines the functions of a generator and a drive unit to convert mechanical energy into electrical energy, ensuring reliable and efficient power generation for the various systems and equipment on board an aircraft.

External Links

If you are interested in delving deeper into the technical aspects of Integrated Drive Generators, you can refer to this detailed article on the principles of operation.

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