What is EXT PWR on Airbus A320? (External Power)

The Airbus A320 is a widely used commercial aircraft known for its efficiency, versatility, and advanced technology. One of the crucial components that ensure the smooth operations of this aircraft is external power, commonly referred to as EXT PWR. External power plays a significant role in powering the aircraft during various ground operations, reducing reliance on the internal power system. In this article, we will delve into the details of what external power on Airbus A320 is, its functions, and its importance in aircraft operations.

Understanding External Power

External power, as the name suggests, refers to the electrical power supply that is connected to the aircraft externally while it is on the ground. It is a vital source of power that helps in running various systems and equipment of the aircraft, ensuring smooth functioning during ground operations. The external power supply is typically provided by a Ground Power Unit (GPU) or an airport power source.

Functions of External Power on Airbus A320

The Airbus A320 relies on external power for several important functions during ground operations. Let’s explore its key functions:

1. Powering Aircraft Systems

External power is used to supply electrical energy to the aircraft, enabling the operation of various systems and equipment. These systems include the aircraft’s avionics, lighting, air conditioning, and other critical components. By connecting the external power source, the aircraft’s internal battery and on-board APU (Auxiliary Power Unit) can be preserved or turned off, reducing unnecessary fuel consumption and contributing to cost savings.

For example, during aircraft maintenance or pre-flight inspections, external power is crucial in running the avionics system, allowing technicians to perform system checks and diagnostics efficiently. Similarly, during pre-flight preparations, external power can be used to supply electricity to the cabin, ensuring passenger comfort and convenience.

2. Battery Charging

External power is also utilized for battery charging. The Airbus A320 is equipped with a battery that powers essential systems in case of an emergency or power loss. By connecting the aircraft to an external power source, the battery can be charged, ensuring it is fully operational and ready for use during flights. This helps to enhance the safety and reliability of the aircraft, as a fully charged battery provides a backup power supply in critical situations.

Moreover, by utilizing external power for battery charging, the reliance on the APU-generated power is reduced. This leads to fuel savings and mitigates noise and emissions produced by the APU, contributing to a greener and more sustainable aviation industry.

3. Ground Operations

External power is essential for various ground operations carried out on the Airbus A320. During boarding and deboarding, the aircraft requires a continuous supply of electricity for cabin lighting, ventilation, and other essential systems that ensure passenger comfort and safety. External power allows these operations to be carried out efficiently without draining the aircraft’s internal power sources.

Additionally, external power is crucial during engine start-up. The APU, while capable of providing electrical power for engine start-up, consumes fuel in the process. By utilizing external power instead, the APU can be kept off, reducing fuel consumption and emissions during ground operations.

Furthermore, during long ground delays or layovers, external power is connected to the aircraft to keep vital systems running, such as air conditioning and lighting, ensuring comfort for passengers and crew.

Importance of External Power

The importance of external power on the Airbus A320 cannot be understated. Here are some key reasons why external power is crucial for the aircraft’s operations:

1. Fuel Efficiency

By relying on external power during various ground operations, the Airbus A320 reduces the need to use its internal power sources, such as the APU. The APU consumes fuel when generating power, whereas external power eliminates this fuel consumption entirely. This significantly contributes to improving the aircraft’s fuel efficiency, resulting in cost savings for the airline and a reduced environmental impact.

According to Airbus, using external power instead of the APU during a gate turnaround can save approximately 200 kg (440 lbs) of fuel per flight. Over the course of a year, this saving can potentially add up to millions of dollars and significantly reduce carbon dioxide emissions.

2. Maintenance and Safety

During maintenance and safety inspections, external power is crucial for powering the avionics system and running necessary diagnostic tests. By providing a stable and reliable power source, external power ensures that technicians can efficiently perform their tasks, maximizing maintenance efficiency and aircraft safety.

Additionally, a fully charged aircraft battery, made possible through external power, serves as a backup power source that can be critical in case of power loss. This enhances the aircraft’s safety by reducing the risk of electrical failures and maintaining critical systems’ functionality.

3. Passenger Comfort

External power plays a crucial role in ensuring passenger comfort both during the boarding process and during layovers. By providing a continuous supply of electricity, external power enables the operation of cabin lighting, air conditioning, and other systems essential for passenger well-being. This helps to create a pleasant and comfortable travel experience for the passengers.

Moreover, utilizing external power instead of the APU during ground delays or layovers reduces noise and emissions, leading to a quieter and greener environment for passengers and nearby communities.


External power, or EXT PWR, is a critical component of the Airbus A320, providing electrical energy for various systems, battery charging, and powering critical operations during aircraft ground operations. By utilizing external power, the A320 enhances fuel efficiency, reduces emissions and noise, improves maintenance efficiency, and ensures passenger comfort and safety. The implementation of external power demonstrates the continuous efforts of the aviation industry towards greener and more sustainable operations. As the Airbus A320 continues to be a preferred choice for airlines worldwide, the significance of external power remains indispensable for its smooth and efficient operations.

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