Lubrication Systems (Jepp/Prep/Crane) Questions and Answers Already Passed

Lubrication Systems (Jepp/Prep/Crane) Questions and Answers Already Passed If a reciprocating engine is consuming an excessive amount of oil without any visible leaks, what is the likely issue? Worn or damaged piston rings. What are the roles of lubricating oil in a reciprocating engine? It minimizes friction between moving components and helps dissipate heat. What are two key properties of engine oil used in aircraft? The oil needs to be light enough for easy circulation but sufficiently thick to maintain an adequate oil film at the engine’s operating temperature. What might occur if the oil’s viscosity is too low for the engine’s normal operating temperature? The oil could become too thin, leading to a breakdown of the oil film and increased wear on engine parts. 2 What considerations must engine manufacturers account for when selecting the appropriate oil grade for an engine? They must consider the engine’s operating load, temperature, and rotational speed. Why do aircraft reciprocating engines require oil with relatively high viscosity? Because these engines typically have larger clearances and operate under high temperatures and pressures. What are common contaminants found in engine oil? Metal shavings, dirt, carbon deposits, moisture, and acids. What could be a sign of low oil pressure combined with high oil temperature? It could indicate an insufficient or low oil supply. In ashless dispersant (AD) oils, what role does the dispersant play? The dispersant keeps sludge-forming substances from clumping together by suspending them in the oil until they can be filtered out, preventing deposits and keeping the engine clean. 3 Why do oil reservoirs need an expansion space? To accommodate oil foaming, thermal expansion, and trapped air in the return oil. What factors can lead to oil foaming? Oil that is diluted, contaminated, or at an excessively high level can cause foaming. How is oil pressure regulated in a gear-type oil pump? Through an oil pressure relief valve. What does an oil cooler bypass valve do? It allows oil to either pass through the cooler or bypass it to regulate the engine’s oil temperature. What could be a sign of an obstruction