k Flashcards
what is the primary purpose of an aircraft reciprocating engine lubricant?
Reduce friction between moving parts
what are two important characteristics relating to viscosity that an engine oil must possess
Light enough to circulate freely, heavy enough to provide proper oil at engine operating temperatures
what is the most critical lubrication point in gas turbine engine?
Turban bearings
what may happen to an oil that is too low in viscosity at engine operating temperatures
Becomes thin that the oil film between moving parts is easily broken
what factors must an engine manufacturer consider in determining the proper grade of oil for an engine?
Operating load, rotational, speed, and operating temp
What is the function of dispersant additive as contained in ashes dispersing oil?
keeping the engine, interior clean, and suspend the oil until they can be trapped by the filter or till next oil change
Why must aircraft reciprocating engines use an oil with relatively high viscosity
Aircraft engines have large, operating clearances, high, operating temperatures and high, bearing pressure
Why is an oil tank required to have an expansion space
For thermal expansion and air in the return oil
What is the purpose of an oil cooler bypass valve?
Direct oil through or around the cooler to keep oil temperature in operating limits
Where does the oil temperature bulb usually since oil temperature?
The engine oil inlet
What does the presence of metal particles in an engine oil filter indicate
Possible engine internal failure
name at least two areas of a turban engine oil system where oil screen/filters may be located
Oil pressure system or scavenger system
what are some oil contaminants?
Moisture acid, dirt, carbon, and metal particles
What type of oil is used in turban engine oil systems?
Synthetic oil
What could be the cause of excessive oil consumption without evidence of oil lease in a reciprocating engine
broken piston rings
