What is the primary function of a Ground Power Unit?

The primary function of a Ground Power Unit (GPU) is to supply power to the aircraft while it is on the ground at the terminal. This is essential for various critical operations, such as powering the aircraft's systems when the engines are not running, enabling the use of lights, avionics, and cabin heating or cooling. By providing electrical power, the GPU ensures that the aircraft can be prepared for departure without relying solely on its own onboard power sources, which might be needed for engine start-up and other essential functions.

While other ground support equipment and components related to charging aircraft batteries are important, the GPU's dedicated role in supplying temporary power directly to the aircraft makes it a crucial asset on the ramp. Monitoring engine performance does not fall under the GPU's functions, underscoring its specific and vital purpose in maintaining the operational efficiency of ground handling activities.