What is the main purpose of the oil pump in the CSU?

The primary function of the oil pump in the Constant Speed Unit (CSU) is to increase the engine oil pressure sufficiently to operate the propeller pitch change mechanism. The CSU uses engine oil under pressure to adjust the angle of the propeller blades, allowing for changes in pitch as necessary for efficient engine performance at various speeds and conditions.

By providing the required hydraulic pressure, the oil pump ensures that the pitch change mechanism can effectively respond to control inputs, allowing the propeller to maintain a constant rotational speed regardless of the variations in engine power. This is essential for optimizing performance, fuel efficiency, and overall flight safety.

While the oil pump does indeed play a role in lubrication, which is important for maintaining the health of engine components, its primary function in the context of the CSU is the regulation of oil pressure to enable the pitch mechanism's operation. Additionally, feathering and unfeathering the propeller are actions that rely on this pressure as well, but they are specific tasks rather than the fundamental purpose of the oil pump itself.