Lubrication Sys-Powerplant
17 (8427) - What advantage do mineral base lubricants have over vegetable oil base lubricants when used in aircraft engines?
B- Chemical stability.
43 (8452) - What is the primary purpose of the oil-to-fuel heat exchanger?
B- Cool the oil.
89 (8498) - An oil tank having a capacity of 5 gallons must have an expansion space of
A- 2 quarts
51 (8460) - How are the teeth of the gears in the accessory section of an engine normally lubricated?
A- By splashed or sprayed oil.
13 (8423) - What type of oil system is usually found on turbine engines?
A- Dry sump, pressure, and spray.
24 (8434) - 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.
66 (8475) - Where are sludge chambers, when used in aircraft engine lubrication systems, usually located?
A- In the crankshaft throws.
53 (8462) - From the following, identify the factor that has the least effect on the oil consumption of a specific engine.
A- Mechanical efficiency.
80 (8489) - Where is the oil of a dry sump reciprocating engine exposed to the temperature control valve sensing unit?
A- Oil cooler inlet.
58 (8467) - Where is the oil temperature bulb located on a dry sump reciprocating engine?
A- Oil inlet line.
44 (8453) - What unit in an aircraft engine lubrication system is adjusted to maintain the desired system pressure?
A- Oil pressure relief valve.
16 (8426) - Which of the following has the greatest effect on the viscosity of lubricating oil?
A- Temperature.
9 (8419) - 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 place and maintain a reasonable film strength.
40 (8449) - Why are fixed orifice nozzles used in the lubrication system of gas turbine engines?
A- To provide a relatively constant oil flow to the main bearings at all engine speeds.
64 (8473) - What is the primary purpose of the hopper located in the oil supply tank of some dry sump engine installations?
A- To reduce the time required to warm the oil to operating temperatures.
19 (8429) - High tooth pressures and high rubbing velocities, such as occur with spur-type gears, require the use of
A- an EP lubricant.
29 (8439) - 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.
65 (8474) - The purpose of the flow control valve in a reciprocating engine oil system is to
A- direct oil through or around the oil cooler.
6 (8416) - Lubricating oils with high viscosity index ratings are oils
A- in which the viscosity does not vary much with temperature change.
90 (8499) - As a general rule, a small amount of small fuzzy particles or gray metallic paste on a turbine engine magnetic chip detector
A- is considered to be the result of normal wear.
70 (8479) - The pumping capacity of the scavenger pump in a dry sump aircraft engine's lubrication system
A- is greater than the capacity of the oil supply pump.
39 (8448) - After making a welded repair to a pressurized-type turbine engine oil tank, the tank should be pressure checked to
A- not less than 5 PSI plus the maximum operating pressure of the tank.
2 (8412) - (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
23 (8433) - The type of oil pumps most commonly used on turbine engines are classified as
A- positive displacement.
82 (8491) - The purpose of a relief valve installed in the tank venting system of a turbine engine oil tank is to
A- prevent oil pump cavitation by maintaining a constant pressure on the oil pump inlet.
20 (8430) - Manufacturers normally require turbine engine oil servicing within a short time after engine shutdown primarily to
A- prevent overservicing.
48 (8457) - Some larger reciprocating engines use a compensating oil pressure relief valve to
A- provide a high engine oil pressure when the oil is cold and automatically lower the oil pressure when the oil warms up.
47 (8456) - The purpose of directing bleed air to the outer turbine case on some engines is to
A- provide optimum turbine blade tip clearance by controlling thermal expansion.
12 (8422) - The viscosity of a liquid is a measure of its
A- resistance to flow.
45 (8454) - Low oil pressure can be detrimental to the internal engine components. However, high oil pressure
A- should be limited to the engine manufacturer's recommendations.
59 (8468) - Cylinder walls are usually lubricated by
A- splashed or sprayed oil.
10 (8420) - In addition to lubricating (reducing friction between moving parts), engine oil performs what functions?1. Cools.2. Seals.3. Cleans.4. Prevents corrosion.5. Cushions impact (shock) loads.
B- 1, 2, 3, 4, 5.
22 (8432) - What type of oil do most engine manufacturers recommend after new reciprocating engine break-in?
B- Ashless-dispersant oil.
77 (8486) - How are the piston pins of most aircraft engines lubricated?
B- By oil which is sprayed or thrown by the master or connecting rods.
71 (8480) - In which of the following situations will the oil cooler automatic bypass valve be open the greatest amount?
B- Engine oil below normal operating temperature.
3 (8413) - An oil separator is generally associated with which of the following?
B- Engine-driven vacuum pump.
91 (8500) - Why is expansion space required in an engine oil supply tank?
B- For oil enlargement and collection of foam.
55 (8464) - Which of the following lubrication system components is never located between the pressure pump and the engine pressure system?
B- Fuel line for oil dilution system.
11 (8421) - Which of these characteristics is desirable in turbine engine oil?
B- High flash point.
5 (8415) - Upon what quality or characteristic of a lubricating oil is its viscosity index based?
B- Its rate of change in viscosity with temperature change.
21 (8431) - What type of oil do most engine manufacturers recommend for new reciprocating engine break-in?
B- Straight mineral oil.
62 (8471) - What is the primary purpose of changing aircraft engine lubricating oils at predetermined periods?
B- The oil becomes contaminated with moisture, acids, and finely divided suspended solid particles.
26 (8436) - What will happen to the return oil if the oil line between the scavenger pump and the oil cooler separates?
B- The return oil will be pumped overboard.
25 (8435) - The engine oil temperature regulator is usually located between which of the following on a dry sump reciprocating engine?
B- The scavenger pump outlet and the oil storage tank.
63 (8472) - What determines the minimum particle size which will be excluded or filtered by a cuno-type (stacked disc, edge filtration) filter?
B- The spacer thickness.
54 (8463) - How is the oil collected by the piston oil ring returned to the crankcase?
B- Through holes drilled in the piston oil ring groove
31 (8441) - What is the purpose of the last chance oil filters?
B- To filter the oil immediately before it enters the main bearings.
41 (8450) - Possible failure related ferrous-metal particles in turbine engine oil cause an (electrical) indicating-type magnetic chip detector to indicate their presence by
B- To filter the oil immediately before it enters the main bearings.`
52 (8461) - What is the purpose of the check valve generally used in a dry sump lubrication system?
B- To prevent the oil from the supply tank from seeping into the crankcase during inoperative periods.
81 (8490) - Under which of the following conditions is the oil cooler flow control valve open on a reciprocating engine?
B- When the temperature of the oil returning from the engine is too low.
75 (8484) - A turbine engine dry sump lubrication system of the self-contained, high-pressure design
B- consists of pressure, breather, and scavenge subsystems.
15 (8425) - Specific gravity is a comparison of the weight of a substance to the weight of an equal volume of
B- distilled water at a specific temperature.
27 (8437) - 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
B- lower than the pressure pump capabilities.
18 (8428) - The recommended aircraft engine lubricants are
B- mineral or synthetic based.
69 (8478) - (1) Wet sump oil systems are most commonly used in gas turbine engines.(2) In most turbine engine oil tanks, a slight pressurization of the tank is desired to ensure a positive flow of oil.Regarding the above statements,
B- only No. 2 is true.
30 (8440) - The oil dampened main bearing utilized in some turbine engines is used to
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.
72 (8481) - In order to maintain a constant oil pressure as the clearances between the moving parts of an engine increase through normal wear, the supply pump output
B- remains relatively constant (at a given RPM) with less oil being returned to the pump inlet by the relief valve.
38 (8447.2) - Oil tank fillers on reciprocating engines are marked with the word
C- "oil," in accordance with 14 CFR part 23.
37 (8447) - According to Federal Aviation Regulations, oil tank fillers on turbine engines must be marked with the word
C- 'oil.'
88 (8497) - Which type valve prevents oil from entering the main accessory case when the engine is not running?
C- Check.
36 (8446) - Which of the following is a function of the fuel-oil heat exchanger on a turbojet engine?
C- Increases fuel temperature.
42 (8451) - What would be the probable result if the oil system pressure relief valve should stick in the open position on a turbine engine?
C- Insufficient lubrication.
87 (8496) - The main oil filters strain the oil at which point in the system?
C- Just as it leaves the pressure pump.
33 (8443) - What prevents pressure within the lubricating oil tank from rising above or falling below ambient pressure (reciprocating engine)?
C- Oil tank vent.
74 (8483) - What will result if an oil filter becomes completely blocked?
C- Oil will flow at the normal rate through the system.
14 (8424) - Which of the following factors helps determine the proper grade of oil to use in a particular engine?
C- Operating speeds of bearings.
50 (8459) - What is the source of most of the heat that is absorbed by the lubricating oil in a reciprocating engine?
C- Pistons and cylinder walls.
93 (8502) - Which of the following bearing types must be continuously lubricated by pressure oil?
C- Plain.
46 (8455) - What is the primary purpose of the oil breather pressurization system that is used on turbine engines?
C- Provides a proper oil spray pattern from the main bearing oil jets.
84 (8493) - If the oil in the oil cooler core and annular jacket becomes congealed, what unit prevents damage to the cooler?
C- Surge protection valve.
1 (8411) - 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?
C- The oil pressure will be lower than normal.
67 (8476) - Why is an aircraft reciprocating engine oil tank on a dry sump lubrication system equipped with a vent line?
C- To prevent pressure buildup in the oil tank.
35 (8445) - Oil picks up the most heat from which of the following turbine engine components?
C- Turbine bearing.
28 (8438) - (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,
C- both No. 1 and No. 2 are true
60 (8469) - If a full-flow oil filter is used on an aircraft engine, and the filter becomes completely clogged, the
C- bypass valve will open and the oil pump will supply unfiltered oil to the engine.
85 (8494) - The primary source of oil contamination in a normally operating reciprocating engine is
C- combustion deposits due to combustion chamber blow-by and oil migration on the cylinder walls.
76 (8485) - Lube system last chance filters in turbine engines are usually cleaned
C- during overhaul.
61 (8470) - Oil accumulation in the cylinders of an inverted in-line engine and in the lower cylinders of a radial engine is normally reduced or prevented by
C- extended cylinder skirts.
86 (8495) - A drop in oil pressure may be caused by
C- foreign material under the relief valve.
56 (8465) - As an aid to cold-weather starting, the oil dilution system thins the oil with
C- gasoline.
7 (8417) - Compared to reciprocating engine oils, the types of oils used in turbine engines
C- have less tendency to produce lacquer or coke.
57 (8466) - The basic oil pressure relief valve setting for a newly overhauled engine is made
C- in the overhaul shop.
8 (8418) - The oil used in reciprocating engines has a relatively high viscosity due to
C- large clearances and high operating temperatures.
68 (8477) - Excessive oil is prevented from accumulating on the cylinder walls of a reciprocating engine by
C- oil control rings on the pistons.
32 (8442) - 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
C- oil through the heat exchanger.
83 (8492) - In a reciprocating engine, oil is directed from the pressure relief valve to the inlet side of the
C- pressure pump.
73 (8482) - The valve assemblies of opposed reciprocating engines are lubricated by means of a
C- pressure system.
79 (8488) - An engine lubrication system pressure relief valve is usually located between the
C- pump and the internal oil system.
49 (8458) - In order to relieve excessive pump pressure in an engine's internal oil system, most engines are equipped with a
C- relief valve.
92 (8501) - The purpose of a dwell chamber in a turbine engine oil tank is to provide
C- separation of entrained air from scavenged oil.
78 (8487) - The vent line connecting the oil supply tank and the engine in some dry sump engine installations permits
C- the oil tank to be vented through the normal engine vent.
34 (8444) - In an axial-flow turbine engine, compressor bleed air is sometimes used to aid in cooling the
C- turbine, vanes, blades, and bearings.
4 (8414) - 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
C- viscosity.