What is the voltage requirement for external ground power?

The requirement for external ground power in the T-6A is set at a voltage range of 28 to 28.5 VDC. This voltage specification is critical for ensuring that the aircraft's electrical systems function properly while on the ground and is compatible with the internal systems of the aircraft, which are designed to operate effectively on this particular voltage. Choosing a voltage that falls within this specified range ensures adequate power to start the engines and run various systems without causing damage or operational issues. This standard aligns with the aircraft's design and operational guidelines, ensuring reliability and safety during ground operations.