FAA Powerplant Written Practice Test

Which turbine engine component does the oil primarily absorb heat from?

1. The exhaust turbine bearing

2. The fuel nozzle

3. The turbine casing

4. The oil cooler

The correct answer is: The exhaust turbine bearing

The oil in a turbine engine primarily absorbs heat from the exhaust turbine bearing. This is due to the high temperature and operational stresses that the bearings experience. As the engine operates, the bearings are subjected to significant friction and heat due to the rapid rotation of the turbine components. The oil circulates through the engine and moves past these bearings, absorbing excess heat to help maintain optimal operating temperatures and prevent overheating. This cooling process is vital for ensuring the longevity and reliability of the engine components, as overheating can lead to premature wear or failure of the bearings and associated parts. The effective transfer of heat from the bearings to the oil allows it to carry the heat away to the oil cooler, where it can be dissipated before returning to the bearings again. In contrast, while the fuel nozzle, turbine casing, and oil cooler play roles in the overall operation of the engine, they do not directly serve as primary sources of heat absorption for the oil in the same way the bearing components do. The oil cooler's function is specifically to chill the heated oil before it re-enters the system, rather than being a source of heat that the oil absorbs directly. Therefore, the exhaust turbine bearing is the correct answer, as it relates specifically to the component from which the