G - Engine Lubrication Systems (Powerplant)

Name one type of oil filter used on aircraft engines

The oil filter used on aircraft engine is usually one of the four types: screen, cuno, canister or spin on

What is straight mineral oil

A type of natural lubricating oil that has no additives for foaming, cleaning or viscosity

What is ashless dispersant (AD) oil

A type of mineral oil with additives that evenly spread contaminants throughout the oil. The additives that are used do not form ashes

What is synthetic oil

Oil that is man made through the process of chemically altering the molecular structure of petroleum oil to achieve the desired characteristics

What is meant by multi viscosity oil

Type of oil that has varying viscosity

What are the purposes of reciprocating engine oil

Cleans, cools, cushions, seals and lubricates parts.

what is the most important property that aircraft reciprocating engine oil must possesses

viscosity

what factors must be considered in determining the proper grade of oil to use in a specific engine

operating load, rotational speeds, operating temp

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 air cooler. when the oil is warm it will be directed through the oil cooler

what are some oil contaminants

gasoline, moisture, acid, dirt, carbon, and metallic particles

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

diluted oil, contaminated oil, or oil level is too high

what would be an indication of blocked oiler passages

high oil temp

what would be an indication of inadequate oil supply

low oil pressure and high oil temp

what type of oil is used in turbine engine lubrication systems

specially developed synthetic oils

where can you find the specific grade of oil for a particular aircraft

oil grade can be found in the airplane flight manual (AFM), or the pilots operating handbook (POH)

what are two types of oil coolers used in a turbine engine lubrication systems

air-cooled oil cooler and fuel cooled oil cooler

what is the meaning of oil flash point

flash point is the temp at which the oil will begin to give off ignitable vapors.

fire point

temp at which there are sufficient vapors to support a continuous flame

what is the weight of the aircraft engine oil

7.5 pounds per us gallon

what is purpose of oil dilution system

thins oil by introducing fuel into the lubrication system which makes cold weather starting easier. fuel is used because it evaporates out of oil and leaves through crankcase breather

what is primary purpose of engine oil lubricant

reduce friction

what is the S.O.A.P analysis

(Spectrometric oil analysis program) oil analysis system that establishes a trend to measure engine health. one test doesn’t do much unless something is wrong

where are carbon seals used in turbine engines

carbon seals are used in aircraft gearboxes, air turbine motor starters, and main shaft seals

what is the key purpose of lubrication in a turbine engine

for lubrication of the main shaft bearings

where are engine oil filters located

between oil pump output and engine bearings

why do reciprocating engines require oil with a high viscosity index

allow for easier starting in cold temps and prevents the oil from becoming too thin at operating temps to protect bearings under operating loads

why do reciprocating engines require high viscosity oil

performs better in recip engines bc they have larger clearance, high operating temps, and high bearing pressures

what two factors impact fluid viscosity

temp and pressure

what is purpose of ashless dispersant oil

to prevent sludge build up and oil filters from clogging

what is most critical lubrication point in a gas turbine engine

turbine bearing

why is the oil tank required to have expansion space

provide for 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, at or just before oil jets

why do dry sump reciprocating engines have similar sump

to prevent a large accumulation of oil in the engine crankcase