How does the propeller react when there is a loss of engine power?

When there is a loss of engine power, the propeller feathers as a response to reduce drag on the aircraft. Feathering refers to the adjustment of the propeller blades to a nearly flat position relative to the oncoming airflow, which minimizes the resistance the propeller creates. This is an important aerodynamic feature designed to enhance the aircraft's performance and safety, particularly in multi-engine aircraft where one engine may fail.

The process of feathering effectively turns the propeller blades into a position that helps stabilize the aircraft and maintain control, allowing the pilot to manage the situation better during the engine-out condition. Feathering is a vital system in ensuring that the aircraft can glide without excessive drag, which is crucial for maintaining altitude and planning a safe landing.

In contrast, if the propeller were to speed up, remain in high pitch, or idle, it could create significant drag and complicate the handling of the aircraft after losing engine power. Such responses would not help mitigate the effects of the power loss and could jeopardize the safety and control of the aircraft.