LUBRICATION SYSTEMS Flashcards
What is the primary purpose of lubricant in an aircraft engine?
To reduce friction between moving parts
What is the most important property that aircraft reciprocating engine oil must possess?
Viscosity
What factors must be considered in determining the proper grade of oil to use in a specific engine?
The operating load, rotational speeds, and operating temperatures are the most important
factors to be considered.
What is the purpose of the oil flow control valve?
The oil flow control valve, located on the oil cooler, regulates the flow of oil either into or around
the oil cooler.
What are the main oil contaminants?
They are gasoline, moisture, acid, dirt, carbon, and metallic particles
From what location on a reciprocating engine is the oil temperature usually taken?
In a dry sump lubrication system, the oil temperature bulb is located anywhere in the oil inlet
line between the oil tank and the engine. Wet sump systems have the temperature bulb located
where it senses the temperature after the oil passes through the oil cooler. In either system, the
bulb is located where it measures oil temperature before it enters the hot sections of the engine.
What do metallic particles on an oil screen indicate?
Metallic particles may be an indication of internal failure of the engine.
What could cause oil foaming?
Foaming can be caused by diluted oil, contaminated oil, or the oil level too high.
What would be an indication of blocked oil cooler passages?
High oil temperature
What would be an indication of an inadequate oil supply?
Low oil pressure and high oil temperature
What type of oil is used in turbine engine lubrication systems?
Specially developed synthetic oils
What are two types of oil coolers used in turbine engine lubrication systems?
The air-cooled oil cooler and the fuel-cooled oil cooler are the two basic types in general use.
What is the meaning of oil flash point? Fire point?
Oil flash point is that temperature at which the oil will begin to give off ignitable vapors. The fire
point is that temperature at which there are sufficient vapors to support a continuous flame.
What are the functions of engine oil in a reciprocating engine?
In addition to lubrication, oil cools various parts of the engine, helps to seal the combustion
chamber by providing a film between the cylinder walls and the rings, and aids in cleaning the
engine by carrying engine residues to the oil filter.
What is the weight of aircraft engine oil?
Approximately 7.5 pounds per US gallon
