In which position must the battery switch be for a fire handle shutdown?

For a fire handle shutdown in the C-5 Auxiliary Power Unit system, the battery switch must be in the NORM or STBY position. This requirement is crucial because these settings ensure that the auxiliary power unit can still receive power to allow for proper functions during a fire emergency, such as activating fire suppression systems and ensuring that warning signals are operational.

When the battery switch is in the NORM or STBY position, the necessary electrical systems remain powered, which is vital for executing the shutdown procedures effectively. If the battery switch were turned OFF or locked, this would disable the APU and associated systems, potentially jeopardizing safety measures during a fire event since critical functions would not be available.

The AUTO setting typically refers to operational configurations where the APU operates automatically based on system demands, rather than specifically for actions related to fire emergencies, making it unsuitable for this context. Thus, the NORM or STBY positions support the critical actions required during a fire handle shutdown, emphasizing the importance of maintaining electrical power to systems responsible for safety and emergency response.