Lubrication Systems Flashcards
- What will be the result of operating an engine in extremely high temperatures using a lubricant recommended by the manufacturer for a much lower temperature?
a. the oil pressure will be higher than normal
b. the oil temperature and oil pressure will be higher than normal
c. the oil pressure will be lower than normal
c.
- (1) Gas turbine and reciprocating engine oils can be mixed or used interchangeably.
(2) Most gas turbine engine oils are synthetic.
Regarding the above statements,
a. only No. 2 is true
b. both No. 1 and No. 2 are true
c. neither No. 1 nor No. 2 is true
a.
- An oil separator is generally associated with which of the following?
a. engine-driven oil pressure pump
b. engine-driven vacuum pump
c. cuno oil filter
b.
- The time in seconds required for exactly 60 cubic centimeters of oil to flow through an accurately calibrated orifice at a specific temperature is recorded as a measurement of the oil’s
a. flash point
b. specific gravity
c. viscosity
c.
- Upon what quality or characteristic of a lubricating oil is its viscosity index based?
a. its resistance to flow at a standard temperature as compared to high grade paraffin-base oil at the same temperature
b. its rate of change in viscosity with temperature change
c. its rate of flow through an orifice at a standard temperature
b.
- Lubricating oils with high viscosity index ratings are oils
a. in which the viscosity does not vary much with temperature change
b. in which the viscosity varies considerably with temperature change
c. which have high SAE numbers
a.
- Compared to reciprocating engine oils, the types of oils used in turbine engines
a. are required to carry and disperse a higher level of combustion by-products
b. may permit a somewhat higher level of carbon formation in the engine
c. have less tendency to produce lacquer or coke
c.
- The oil used in reciprocating engines has a relatively high viscosity due to
a. the reduced ability of thin oils to maintain adequate film strength at altitude (reduced atmospheric pressure)
b. relatively high rotational speeds
c. large clearances and high operating temperatures
c.
- If all other requirements can be met, what type of oil should be used to achieve theoretically perfect engine lubrication?
a. the thinnest oil that will stay in one place and maintain a reasonable film strength
b. an oil that combines high viscosity and low demulsibility
c. an oil that combines a low viscosity index and a high neutralization number
a.
- In addition to lubricating (reducing friction between moving parts), engine oil performs what functions?
- Cools.
- Seals.
- Cleans.
- Prevents corrosion.
- Cushions impact (shock) loads.
a. 1, 2, 3, 4
b. 1, 2, 3, 4, 5
c. 1, 3, 4
b.
- Which of these characteristics is desirable in turbine engine oil?
a. low flash point
b. high flash point
c. high volatility
b.
- The viscosity of a liquid is a measure of its
a. resistance to flow
b. rate of change of internal friction with change in temperature
c. weight, or density
a.
- What type of oil system is usually found on turbine engines?
a. dry sump, pressure, and spray
b. dry sump, dip, and splash
c. wet sump, spray, and splash
a.
- Which of the following factors helps determine the proper grade of oil to use in a particular engine?
a. adequate lubrication in various attitudes of flight
b. positive introduction of oil to the bearings
c. operating speeds of bearings
c.
- Specific gravity is a comparison of the weight of a substance to the weight of an equal volume of
a. oil at a specific temperature
b. distilled water at a specific temperature
c. mercury at a specific temperature
b.
- Which of the following has the greatest effect on the viscosity of lubricating oil?
a. temperature
b. pressure
c. volatility
a.
- What advantage do mineral base lubricants have over vegetable oil base lubricants when used in aircraft engines?
a. cooling ability
b. chemical stability
c. friction resistance
b.
- The recommended aircraft engine lubricants are
a. animal, mineral, or synthetic based
b. mineral or synthetic based
c. vegetable, mineral, or synthetic based
b.
- High tooth pressures and high rubbing velocities, such as occur with spur-type gears, require the use of
a. an EP lubricant
b. straight mineral oil
c. metallic ash detergent oil
a.
- Manufacturers normally require turbine engine oil servicing within a short time after engine shutdown primarily to
a. prevent overservicing
b. help dilute and neutralize any contaminants that may already be present in the engine’s oil system
c. provide a better indication of any oil leaks in the system
a.
- What type of oil do most engine manufacturers recommend for new reciprocating engine break-in?
a. ashless-dispersant oil
b. straight mineral oil
c. semi-synthetic oil
b.
- What type of oil do most engine manufacturers recommend after new reciprocating engine break-in?
a. metallic-ash detergent oil
b. ashless-dispersant oil
c. straight mineral oil
b.
- The type of oil pumps most commonly used on turbine engines are classified as
a. positive displacement
b. variable displacement
c. constant speed
a.
- As a general rule, the mixture setting on a reciprocating engine operating at or near takeoff power that provides the best cooling is
a. FULL RICH
b. LEAN
c. FULL LEAN
a.
- The engine oil temperature regulator is usually located between which of the following on a dry sump reciprocating engine?
a. the engine oil supply pump and the internal lubrication system
b. the scavenger pump outlet and the oil storage tank
c. the oil storage tank and the engine oil supply pump
b.
- What will happen to the return oil if the oil line between the scavenger pump and the oil cooler separates?
a. oil will accumulate in the engine
b. the return oil will be pumped overboard
c. the scavenger return line check valve will close and force the oil to bypass directly to the intake side of the pressure pump
b.
- At cruise RPM, some oil will flow through the relief valve of a gear-type engine oil pump. This is normal as the relief valve is set at a pressure which is
a. lower than the pump inlet pressure
b. lower than the pressure pump capabilities
c. higher than the pressure pump capabilities
b.
- (1) Fuel may be used to cool oil in gas turbine engines.
(2) Ram air may be used to cool oil in gas turbine engines.
Regarding the above statements,
a. only No.1 is true
b. only No. 2 is true
c. both No. 1 and No. 2 are true
c.
- In a reciprocating engine oil system, the temperature bulb senses oil temperature
a. at a point after the oil has passed through the oil cooler
b. while the oil is in the hottest area of the engine
c. immediately before the oil enters the oil cooler
a.
- The oil dampened main bearing utilized in some turbine engines is used to
a. provide lubrication of bearings from the beginning of starting rotation until normal oil pressure is established
b. provide an oil film between the outer race and the bearing housing in order to reduce vibration tendencies in the rotor system, and to allow for slight misalignment
c. dampen surges in oil pressure to the bearings
b.
- What is the purpose of the last chance oil filters?
a. to prevent damage to the oil spray nozzle
b. to filter the oil immediately before it enters the main bearings
c. to assure a clean supply of oil to the lubrication system
b.
- In a jet engine which uses a fuel-oil heat exchanger, the oil temperature is controlled by a thermostatic valve that regulates the flow of
a. fuel through the heat exchanger
b. both fuel and oil through the heat exchanger
c. oil through the heat exchanger
c.
- What prevents pressure within the lubricating oil tank from rising above or falling below ambient pressure (reciprocating engine)?
a. oil tank check valve
b. oil pressure relief valve
c. oil tank vent
c.
- In an axial-flow turbine engine, compressor bleed air is sometimes used to aid in cooling the
a. fuel
b. inlet guide vanes
c. turbine, vanes, blades, and bearings
c.
- Oil picks up the most heat from which of the following turbine engine components?
a. rotor coupling
b. compressor bearing
c. turbine bearing
c.
- Which of the following is a function of the fuel-oil heat exchanger on a turbojet engine?
a. aerates the fuel
b. emulsifies the oil
c. increases fuel temperature
c.
- According to Federal Aviation Regulations, oil tank fillers on turbine engines must be marked with the word
a. ‘oil’ and the type and grade of oil specified by the manufacturer
b. ‘oil’ and tank capacity
c. ‘oil’
c.