FAA Powerplant Written Practice Test

On a Pratt and Whitney PT-6 turboprop engine, where does the oil for the propeller governor come from?

1. The auxiliary oil tank

2. The engine oil supply

3. The dedicated propeller oil reservoir

4. The external oil pump

The correct answer is: The engine oil supply

The correct answer is that the oil for the propeller governor on a Pratt and Whitney PT-6 turboprop engine comes from the engine oil supply. In turboprop engines like the PT-6, the propeller governor requires a continuous flow of oil to operate effectively, and this oil typically comes directly from the engine's oil system. The engine oil supply is pressurized and routed to the governor, which allows for the regulation of propeller pitch and control of RPM (revolutions per minute) based on power requirements. Using oil from the engine's oil system ensures that the governor receives an adequate supply of oil that is kept at proper temperature and pressure, which is crucial for efficient operation. The other options, while potentially viable sources in different contexts, do not apply specifically to the PT-6 engine's design. For example, the auxiliary oil tank is not used by the governor but may serve other systems within the engine. A dedicated propeller oil reservoir is typically found in engines where the propeller and engine oil systems are separate, which is not the case with the PT-6. Lastly, the external oil pump is not a standard feature associated with the oil supply to the propeller governor in this engine type.