How long can the C-5 APU operate continuously under normal conditions?

The C-5 APU is designed to operate continuously for a duration of 2 to 3 hours under normal conditions. This timing allows the APU to provide adequate power for essential systems and support ground operations without overheating or experiencing mechanical issues. The operational limits are set based on the APU's cooling capabilities and engine design, ensuring reliability while keeping systems functioning efficiently. Continuous operation beyond this specified time could risk overheating and lead to premature wear or failure of components. Understanding these operational limits helps maintain the APU's reliability and safety during its use.