What mode is indicated when both the PMU FAIL and PMU STATUS annunciators illuminate?

The illumination of both the PMU FAIL and PMU STATUS annunciators indicates a failure in the Power Management Unit (PMU). This situation occurs when the PMU is not functioning properly, which necessitates the pilot to take manual control over the engine operation and associated systems.

Manual Mode is designed for scenarios where automated systems are compromised or provide erroneous information. In Manual Mode, pilots must override the automated settings and handle the engine parameters directly, ensuring that they maintain control over performance despite the loss of automated assistance.

The other modes do not fit this scenario. Auto Mode would suggest normal operations managed by the PMU, while Standby Mode typically indicates a backup system is engaged but does not indicate a failure in the primary system. Diagnostic Mode is generally used for maintenance checks rather than operational control during anomalies like this. Thus, Manual Mode is the proper response when both annunciators are illuminated, signaling that the PMU has failed and that the pilot needs to take direct action.