What is a common cause of uncommanded power loss?

Uncommanded power loss in an aircraft, particularly in the T-6, can often be attributed to engine rollback due to PMU (Power Management Unit) scheduling. PMU plays a crucial role in managing engine power output based on various parameters such as speed, temperature, and power requirements. If it detects conditions that can lead to engine performance issues or if there are fluctuations in engine parameters beyond acceptable limits, the PMU can automatically adjust the engine's power output to protect the engine from potential damage. This is often perceived by the pilot as an uncommanded power loss since the engine’s power is reduced without a deliberate command from the pilot, resulting in an unexpected decrease in performance.

The other options, while they may relate to engine performance in different ways, do not directly explain the phenomenon of uncommanded power loss in the same manner. Thus, understanding PMU scheduling helps clarify how oversight in engine management can lead to these unexpected scenarios.