What is SWTG on Airbus A320? (Switching)

Switching on Airbus A320, often abbreviated as SWTG, refers to the process of activating various systems and functions on the aircraft. It involves turning on different switches to control and monitor essential components, such as the engines, electrical systems, and flight instruments. Understanding the concept of switching is crucial for pilots and maintenance crew members to ensure the safe and efficient operation of the aircraft.

Switching for Power-Up

When a pilot or maintenance personnel prepares an Airbus A320 for a flight, one of the initial steps is to perform the power-up procedure. This includes switching on various systems to enable the aircraft to function properly. Let’s take a look at some of the key switching activities involved in the power-up process:

1. Electrical Power

The first step in the power-up process is to establish electrical power. This involves activating the aircraft’s main electrical bus and connecting it to the external power source or the Auxiliary Power Unit (APU). The APU is a small turbine engine located in the tail section of the aircraft that provides electrical power and compressed air. By switching on the APU, the aircraft becomes self-sufficient in terms of power supply, allowing for the activation of other systems.

Once the electrical power is established, pilots proceed with additional switching activities.

2. Avionics System

The avionics system on the Airbus A320 consists of a wide range of electronic devices and instruments used for navigation, communication, and flight control. To power up the avionics, the pilots switch on the relevant systems, such as the Flight Management System (FMS), Flight Control Unit (FCU), and Autopilot. These systems allow for precise control of the aircraft’s flight path and enable the crew to navigate safely and efficiently.

Once the avionics system is activated, the pilots move on to the next switching activity.

3. Engine Start

Switching on the engines is a critical step in the power-up process. It involves starting up the aircraft’s turbine engines, which provide the necessary thrust for takeoff and flight. The engine start procedure typically includes the following steps:

1. Activating the fuel system by switching on the fuel pumps and opening the fuel valves.

2. Initiating the ignition sequence by switching on the igniters.

3. Engaging the engine starters to rotate the engine shaft and initiate combustion.

Once the engines are started and stabilized, the pilots can continue with other pre-flight preparations.

The Importance of Proper Switching

Proper switching procedures are essential for the safe and efficient operation of an Airbus A320 aircraft. By following the correct switching sequence and ensuring that all systems are activated as required, pilots and maintenance personnel can minimize the risk of malfunctions and ensure that the aircraft functions as intended. Here are some reasons why proper switching is crucial:

1. System Integration

An Airbus A320 is a complex machine that relies on system integration for its optimal performance. By activating the different systems through switching, pilots and maintenance personnel ensure that the various components work together seamlessly. For example, switching on the electrical system allows power to be distributed to essential components, such as the flight instruments, radios, and lighting systems.

Additionally, proper switching ensures that all necessary safety checks and self-tests are carried out before the aircraft takes off.

2. Emergency Response

In case of an emergency situation during flight, proper switching procedures become even more critical. Pilots rely on the aircraft’s systems to provide accurate information and assist in resolving the situation. By switching on the appropriate systems, pilots can access vital data, such as engine parameters, fuel levels, and flight controls, which are crucial for making informed decisions and taking appropriate actions.

Furthermore, emergency systems, such as the Emergency Locator Transmitter (ELT) and emergency lighting, can be activated through proper switching, ensuring that they are ready to be utilized in case of an emergency landing or evacuation.

3. Fuel Efficiency

Proper switching can also contribute to fuel efficiency, one of the key considerations in aviation. By activating systems like the Autopilot and Flight Management System, pilots can optimize the flight path and use the most efficient routes and altitudes. Proper switching of the engine control systems ensures that the engines operate at the optimal parameters, leading to reduced fuel consumption and lower environmental impact.

Furthermore, by following proper switching procedures, pilots can avoid unnecessary power consumption and wastage, ensuring that the aircraft uses only the required electrical resources.

The Role of Crew Training

Given the importance of proper switching, crew training plays a crucial role in ensuring that pilots and maintenance personnel are proficient in the procedures. Airbus A320 operators and airlines invest significant time and resources in training their crews to understand and follow the correct switching sequences. Crew members undergo comprehensive training programs that include practical hands-on exercises and simulations to reinforce their knowledge and skills.

Regular recurrent training is also conducted to keep the crews up-to-date with any changes in the aircraft systems or procedures related to switching. This ensures that pilots and maintenance personnel remain competent and capable of safely operating and maintaining the Airbus A320 aircraft.


Switching on Airbus A320 is a critical process that enables the activation of various systems and functions necessary for the safe and efficient operation of the aircraft. Proper switching procedures are crucial for system integration, emergency response, and fuel efficiency. Crew training plays a vital role in ensuring that pilots and maintenance personnel follow the correct switching sequences and are proficient in handling the aircraft’s systems. By understanding and adhering to the importance of switching, aviation professionals contribute to the overall safety and reliability of the Airbus A320 aircraft.


[1] Aviation Stack Exchange. (2016, November 5). What is the Airbus A320’s APU used for? [https://aviation.stackexchange.com/questions/33480/what-is-the-airbus-a320s-apu-used-for]

For More: What is MCDU on Airbus A320? (Multipurpose Control And Display Unit)