What must be connected immediately upon every arrival at the aircraft?

The requirement to connect the Ground Power Unit (GPU) immediately upon every arrival at the aircraft is crucial for the operational efficiency and safety of the turnaround process. The GPU provides electrical power to the aircraft while it is on the ground, which is essential for maintaining systems that require power when the engines are not running. This includes lighting, avionics, and other critical onboard systems.

By ensuring the GPU is connected right away, ground personnel can perform aircraft checks and prepare for the next flight without delay. This practice also prevents battery depletion, which can cause operational issues and delays if the aircraft needs to start its auxiliary power unit or main engines to restore power. Having a reliable power source helps streamline the boarding process and the proper functioning of equipment, thus contributing to a smooth and efficient operation.