What is the primary function of the ground power unit (GPU) in aviation?

The primary function of a ground power unit (GPU) in aviation is to provide power to an aircraft while it is on the ground, particularly when the engines are not running. This power allows for the operation of various onboard systems, including lights, avionics, and climate control, without relying on the aircraft’s own power sources. This functionality is especially crucial in remote locations where other power sources might not be available, providing necessary operational support without the need for the aircraft's engines to be started.

While ground power units can be used to support multiple systems, they do not provide power while the aircraft is in motion, nor are they specifically designed to assist with in-flight entertainment or power the landing gear, as those components rely on different systems and power management. The GPU is a vital piece of ground support equipment that enhances the efficiency and safety of ground operations.