What indicates that the PMU needs maintenance after landing?

The PMU STATUS annunciator illuminating is a key indicator that the Power Management Unit (PMU) requires maintenance after landing. This annunciator serves as a warning to the pilot that the PMU has detected a fault or an anomaly that needs to be addressed. The PMU is responsible for managing engine power settings, and any issues could significantly affect engine performance or safety.

When this indicator lights up, it prompts the necessary inspections or troubleshooting measures in accordance with maintenance protocols to ensure the aircraft remains safe and operational. This response is crucial for maintaining the aircraft's performance and operational readiness.

In contrast, the other indicators relate to different systems or conditions. An engine shutdown, while critical, does not specifically indicate PMU maintenance; it could happen for several reasons. A blinking battery indicator usually pertains to electrical issues and not directly to PMU status, while drops in oil pressure signal potential mechanical issues with the engine but not specifically with the PMU. Thus, only the illumination of the PMU STATUS annunciator directly correlates with the need for maintenance in the PMU system.