FAA Powerplant Written Practice Test

What type of oil pump is predominantly utilized on turbine powered engines?

1. Positive displacement

2. Variable displacement

3. Gear pump

4. Rotary pump

The correct answer is: Positive displacement

The type of oil pump predominantly utilized on turbine powered engines is a positive displacement pump. This is due to its ability to maintain a consistent flow of oil under varying pressure conditions, which is critical for the lubrication system in turbine engines. Positive displacement pumps work by capturing a fixed amount of fluid in a chamber and then forcing it out, ensuring that oil flow remains reliable and adequate for the engine's operational demands. In turbine engines, the lubrication system must supply oil under high pressures to adequately lubricate and cool various components, particularly the bearings. A positive displacement design excels in this environment by providing a steady and predictable flow, which is essential for preventing catastrophic engine failures due to insufficient lubrication. Other types of pumps, such as gear or rotary pumps, might be used in different applications, but they do not provide the same level of pressure stability and flow consistency as positive displacement pumps do in the context of turbine engines. Variable displacement pumps, while useful in applications where flow needs can change significantly, are less common in turbine engines because the operational environment typically requires a reliable, constant flow rather than variable output.