Originally Posted by
MarkerInbound
The autofeather system is armed by raising the guard and then the switch under it found at the center of the pedestal aft of the prop controls. There is one green light to the left of the switch that indicates the system is armed. When the throttles are advanced to a point that equates to ~45 inches MAP and the BMEP drops below ~70 for more than one second a solenoid pulls the feather button in and the prop feathers as if the feather button was pushed. The system also then disarms to prevent autofeathering the other prop.
Sounds like it's likely the identical system which was installed on the DC-6.