What happens if a prop on the T-54 goes overspeed beyond 2120 RPM and is feathered?

When a propeller on the T-54 goes overspeed beyond 2120 RPM and is feathered, the appropriate response is to shut down the engine immediately. In this situation, the propeller is designed to be feathered to minimize drag, but if it exceeds the RPM limit, it indicates a critical situation that could lead to engine failure or significant damage. Maintaining engine integrity and ensuring safety requires an immediate shutdown to prevent further complications.

Other options, while they might seem plausible under different circumstances, do not align with the urgency that this specific scenario presents. For example, resetting the propeller or automatically adjusting conditions are not viable solutions when faced with an overspeed, as they do not address the potential danger posed by the overspeed condition. Immediate landing may be necessary, but this is a secondary action resulting from the engine shutdown rather than a direct response to the overspeed event itself. Therefore, shutting down the engine is the correct course of action to ensure safety and prevent any catastrophic failure.