Where does the propeller governor control oil flow to and from?

Where does the propeller governor control oil flow to and from?

• A. to the engine oil pan
• B. to and from the pitch changing mechanism
• C. to the fuel system
• D. to the exhaust system

Answer: (B)

The key idea is that the propeller’s pitch is controlled hydraulically. The governor senses engine speed and modulates oil pressure to move the hydraulic piston inside the propeller hub, which changes the blade angle to hold a set rpm. The oil is directed to the pitch-changing mechanism and then returned from it, so the flow goes to and from the pitch-changing components. This is how the propeller pitch is adjusted. Oil to the engine oil pan, fuel system, or exhaust system isn’t involved in changing blade pitch.

The key idea is that the propeller’s pitch is controlled hydraulically. The governor senses engine speed and modulates oil pressure to move the hydraulic piston inside the propeller hub, which changes the blade angle to hold a set rpm. The oil is directed to the pitch-changing mechanism and then returned from it, so the flow goes to and from the pitch-changing components. This is how the propeller pitch is adjusted. Oil to the engine oil pan, fuel system, or exhaust system isn’t involved in changing blade pitch.