Final answer:
The EMER PWR selector is a function found in aircraft's electrical systems, allowing the pilot to manually override automatic power source selection in emergencies or system failures.
Step-by-step explanation:
The EMER PWR selector is a function found in aircraft's electrical systems. It allows the pilot to manually override the automatic power source selection in case of an emergency or system failure. It is typically used to prioritize power sources and ensure vital electrical systems remain operational.
For example, in the event of an engine failure or an electrical system malfunction, the EMER PWR selector can be used to switch power sources to emergency or backup systems, such as the auxiliary power unit (APU) or battery, to maintain critical functions like flight instruments and communication systems.
Overall, the function of the EMER PWR selector is to provide a manual backup in case of emergencies or power system failures, ensuring the availability of essential electrical power to vital aircraft systems.