FAA Powerplant Written Practice Test

What type of engine oil lubricating system is commonly used in aircraft reciprocating engines?

1. Gravity feed system

2. Pressure type or a combination of pressure and splash type

3. Splash type only

4. Vacuum system

The correct answer is: Pressure type or a combination of pressure and splash type

The correct answer is based on the common lubrication systems employed in aircraft reciprocating engines. In these engines, a pressure type lubricating system or a combination of pressure and splash type is typically used to ensure proper oil distribution and minimize wear on engine components. A pressure type system delivers oil under pressure from the oil pump through oil galleries to various components, ensuring that critical parts receive consistent lubrication. This method is effective at maintaining adequate oil flow, especially during high-demand conditions such as takeoff or climb. In addition, some engines utilize a combination of pressure and splash lubrication, where the pressure system actively delivers oil while also allowing some components to receive oil through splash, relying on the movement of the engine parts to fling oil onto surfaces that require lubrication. This hybrid approach can help enhance oil coverage, particularly in areas that might not receive sufficient oil solely from a pressure system. Other systems such as gravity feed, splash type only, and vacuum systems are generally not suitable for modern aircraft reciprocating engines. Gravity feed systems can lead to insufficient lubrication when the aircraft is in various flight attitudes, while splash type alone may not provide adequate lubrication at all times, especially in high-stress areas. Vacuum systems are not utilized for oil lubrication in these engines; they are more relevant