Engine Lubrication Systems Flashcards
Name one type of oil filter used on aircraft engines.
Canister
What is straight mineral oil?
Natural lubricating oil that has no additives for foaming, cleaning, or viscosity
What is ashless dispersant (AD) oil?
Mineral oil with additives that evenly spread contaminates throughout the oil
What is synthetic oil?
Chemically altered petroleum oil manufactured to achieve the desired characteristics
What is meant by multi-viscosity oil?
When the oil is cold it will have low viscosity but when it warms up the viscosity will increase for better lubrication
What are the purposes of reciprocating engine oil?
It cleans, cools, cushions, seals, and lubricates 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?
Operating load, rotational speeds, and operating temperatures
What is the purpose of the oil flow control valve “oil cooler bypass valve”?
When the oil is cool the valve will direct it around the oil cooler, when it warms it will direct it through the oil cooler
What are some oil contaminants?
Carbon, Acid, Dirt, Moisture, Gasoline, Metallic particles
From what location on a reciprocating engine is the oil temperature usually taken?
Before it enters into the hot section
What do metallic particles on an oil screen indicate?
Internal failure of the engine
What could cause oil foaming?
Diluted Oil, Contaminated Oil, Oil level is 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
Where can you find the specified grade of oil for a particular aircraft?
In the Airplane Flight Manual (AFM) or the Pilot’s Operating Handbook (POH)
What are two types of oil coolers used in turbine engine lubrication systems?
Air and Fuel cooled
What is the meaning of oil flash point? Fire point?
Oil flash point is the temperature at which the oil will begin to give off ignitable vapors. The fire point is the temperature at which there are sufficient vapors to support a continuous flame.
What is the weight of aircraft engine oil?
Approximately 7.5 pounds per US gallon
What is the purpose of an oil dilution system?
Thins the oil by introducing fuel into the lubrication system which makes cold weather starting easier
What is the primary purpose of engine oil lubricant?
Reduce friction
What is the S.O.A.P. analysis?
Spectrometric Oil Analysis Program that establishes a trend to measure engine health
Where are carbon seals used in a turbine engine?
Gearboxes, air-turbine motor starters, and main shaft seals
What is the key purpose of lubrication in a turbine engine?
Lubrication of the main shaft bearings
Where are engine oil filters located?
Between the oil pump output and the engine bearings
Why do reciprocating engines require oil with a high viscosity index? (Small changes in viscosity over a wide temperature range)
Allow for easier starting in cold temperatures and prevents the oil from becoming too thin at operating temperatures
Why do reciprocating engines require high viscosity oil? (Oil flows slowly)
They have large clearances, high operating temperatures, and high bearing pressures
What two factors impact fluid viscosity?
Temperature and pressure
What is the purpose of ashless dispersant oil?
To prevent sludge build up and oil filters from clogging
What is the most critical lubrication point in a gas turbine engine?
Turbine Bearing
Why is an oil tank required to have expansion space?
Thermal expansion and air in the return oil
Name some areas of a turbine engine oil system where oil screens/filters may be located.
Oil pressure system, Scavenge system, before the oil jets
Why do dry sump reciprocating engines have a smaller sump?
To prevent a large accumulation of oil in the engine crankcase.
