What powers the feather dump solenoid valve?

The feather dump solenoid valve in the T-6A is powered by the PROP SYS circuit breaker on the battery bus. This is crucial for understanding how the feathering system works, especially during engine malfunctions or when transitioning from flight configurations. The PROP SYS circuit breaker is specifically designed to supply power to systems associated with the propeller, allowing the solenoid valve to operate effectively.

By being on the battery bus, the circuit breaker ensures there is an immediate and reliable power source for this critical component, particularly when the aircraft may not be generating electrical power from the generators due to various conditions like engine failure. The other options, while related to the electrical systems of the aircraft, do not provide the right power source specific to the operation of the feather dump solenoid valve.