Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Jeppesen Powerplant > Powerplant > Flashcards

Powerplant Flashcards

1
Q

What is the purpose of dynamic dampeners on crankshafts?

A

Reduce vibration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of bearings are found in recip engines?

A

-Plain bearings
-Ball bearings
-Roller bearings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Are the connecting rods in each cylinder of radial engine the same?

A

No, radial engines use master and articulating rods.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name different piston rings:

A

-Oil control
-Compression
-Scraper rings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where should piston ring gaps be installed relative to each other, and why?

A

Installed staggered to each other so that they do not align which prevents excessive blow-by

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What could result from incorrectly installed piston rings?

A

Excessive oil consumption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do oil control rings do?

A

Regulate the thickness of the oil film on the cylinder wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is used to help prevent valve surge or floating in an aircraft?

A

Two or more springs are used on each valve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

On engines equipped with hydraulic valve lifters, what should the running valve clearance be?

A

Zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the purpose of valve overlap?

A

-Better Volumetric efficiency
-Lowers cylinder operating temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What indications are given in the event of a leaking or open primer while the engine is running?

A

The engine will not idle properly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

A cold cylinder is found when troubleshooting a running engine. What does this indicate?

A

No combustion in that cylinder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When pulling a prop through, a hissing sound is heard indicating valve blow-by. What procedure should be performed next?

A

Compression check.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the purpose of performing a compression check?

A

Determine if the valves, pistons and rings are sealing properly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When an engine is overhauled, how is the total time affected? When an engine is rebuilt, how is its operating history affected?

A

The total time of the engine must be continued and the time since major overhaul is entered into the engine log. If the manufacture rebuilds the engine it can be granted ZERO time and is considered to have no previous operating history.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What inspections should be performed after a prop strike without sudden stoppage?

A

-Inspect engine mounts, the crankcase, the nose section for damage
-Inspect the oil , oil filters screens for metal particles
-Inspect the crank or drive shaft for cracks and miss alignment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name some of the precautions that should be performed prior to engine removal:

A
  • Disconnect battery
  • Turn off fuel valves
  • Chock the wheels
  • If necessary install a tail stand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When inspecting a piston, where are cracks most likely to be found?

A

-Base of the piston bosses
-Inside at the junction of the bore and the walls
-The ring lands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does it mean if an engine part is within “serviceable limits”

A

It means that the part is within the manufacturers limits

[DOES NOT REQUIRE REPLACEMENT]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What tools or instruments are used to inspect a cylinder barrel for out-of-roundness?

A

A dial indicator or outside micrometer is usually used to measure the top of the cylinder at the skirt. A telescopic gauge can be used as well.

  • 2 measurements must be taken 90* from each other.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How can a loose stud in an engine crankcase be repaired?

A

Remove the stud and inspect the hole for size and thread condition. It may be necessary to use an oversize stud or heli-coil insert.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What publication is used to check an engine for normal operation?

A

Manufacturers maintenance manual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

A weak cylinder is found during a compression check. What must be inspected?

A

The inside of the cylinder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What purpose does an oil analysis serve?

A

Metal particles in the oil show normal and abnormal wear of the engine. This helps in EVAL the engine’s internal condition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What inspection should be performed on an engine that has been in storage?

A

Perform an inspection to determine if there is any corrosion damage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Where would a carb air temp bulb be located?

A

In the RAM air intake duct.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the fuel pressure range on float-type carburetors?

A

3-5 PSI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Name the basic components of a fuel indicator system

A

The transmitter and the indicator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What unit of measure is generally used to indicate fuel flow?

A

Pounds or gallons per hour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why is fuel flow monitored?

A

To determine fuel consumption and engine performance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does the manifold gauge indicate and how is it calibrated?

A

It measures absolute pressure in the engine and is calibrated in inches of mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What directly controls manifold pressure?

A

Throttle opening and engine rpm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

During engine operation, where should the prop control be set when checking manifold pressure?

A

-Low Pitch
-High RPM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Is the aircraft electrical system required to power a cylinder head temperature gauge?

A

No, a thermocouple is used as the electrical source.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the possible indications of an oil pressure transmitter or indicator malfunction?

A

A severe or sudden drop in oil pressure while temp and supply remain normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What does a tachometer indicate on a recip engine?

A

Engine RPM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Where should the thermocouple be installed on a recip engine using a single probe cylinder head temperature system?

A

On the hottest cylinder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Explain the main difference and advantage a turbofan over turbojet engines.

A

A turbofan uses a fan to bypass air around the engine core and provide thrust. The advantage is additional thrust at no extra fuel consumption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Name the major components in a gas turbine engine.

A

-Air inlet
-Compressor section
-Combustion section
-Turbine section
-Exhaust section
-Gearbox and
-Accessory section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What determines the amount of airflow through a turbine engine?

A

-Forward speed of the aircraft
-Compressor speed
-Air density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Name the two types of compressors commonly used in turbine engines?

A

-Axial
-Centrifugal flow
compressors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Name two different methods for attaching turbine engine rotor blades to the rotor disks?

A

-Dovetail type root
-Bulb type root
-Fir tree type root

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is a split compressor system?

A

Also called dual or twin spool compressors, these are connected to the turbine section with two rotor shafts, one inside the other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are the different types of combustion chambers used in turbine engines?

A

-Can
-Annular
-Can-annular
-Reverse flow annular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What prevents the combustion chambers from burning?

A

Cooling air along the inside of the liner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the purpose of interconnecting tubes attached between can-type combustion chambers?

A

For flame propagation during start

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What functions do axial flow turbine nozzles perform?

A

They direct the mass airflow to drive the turbine rotor at a specific angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

How is thermal stress relieved on a turbine disc?

A

By directing bleed air onto the face of the disk, or by grooves being cut in the disk.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are carbon seals used for in turbine engines?

A

They are used as oil seals for the rotor shaft bearings.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is shaft horsepower?

A

It is an indication of the torque developed by a turboprop or turboshaft engine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Name the main components of a typical APU?

A

-Power section
-Compressor load section
-Gearbox

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is the greatest demand placed on an APU?

A

When supplying bleed air.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

How is an APU generally started?

A

With its own electrical starter and battery power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Where does the APU get its fuel supply?

A

From one of the aircrafts main fuel tanks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

At what speed does a gas turbine APU operate and how is this speed maintained?

A

At or near its rated speed regardless and is maintained by its fuel flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is used to prevent a heavily loaded APU from exceeding its maximum EGT?

A

A LOAD CONTROL VALVE modulates the pneumatic load to maintain EGT’s within limits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How is an APU shut down and why is the procedure used?

A

-Unload APU by closing the bleed air valve,
-It is run for a specified amount of time to allow the EGT to cool and stabilize.

If a heavily loaded APU is abruptly shut down without any cool down period, damage could occur as a result of thermal shock.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What powers the variable inlet guide vanes used on some APUs to regulate compressor intake airflow?

A

Fuel pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is fan blade slinging?

A

Overlapping of the midspan shrouds of the fan blade.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

When a turbofan or turbojet engine is shut down, what should a mechanic listen for during coastdown?

A

Any rubbing or other unusual sounds from the engine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Why are compressor washes performed and what methods are commonly used?

A

To remove any contaminants from the compressor section and improve engine performance.
-Fluid wash
-Abrasive grit wash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

How can you tell if a turbofan or turbojet engine is out of trim?

A

High EGT at target EPR for takeoff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Name the different types of compressor blade damage that may be found during inspection.

A

Dents, cracks, galling, pitting, scratches, burrs, burns, gouges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What kind of markers can be used to mark the parts in hot and cold sections during repair?

A

-Layout dye
-Felt tip marker
-Chalk.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

How does relative humidity affect turbine engine?

A

Negligible effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What criteria determines the replacement life limited turbine engine components?

A

-Cycles
-Hours
-Calendar time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

If turbine blades are removed from a turbine disc, why should they be re-installed in the same location?

A

To maintain balance of the turbine wheel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

How are gas turbine engine tachometers calibrated?

A

Percentage of RPM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

On a turbine engine, what is the engine pressure ratio and what does it indicate?

A

EPR = ratio of intake pressure to turbine exhaust pressure
Indicates thrust developed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

On a turbine engine, what does exhaust gas temperature indicate and how is it obtained?

A

EGT is the average temp of the turbine discharge gasses
[Obtained by thermocouples near the turbine exit.]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Can the EGT system of a turbine engine be checked without running the engine?

A

Yes by checking the resistance of the thermocouples and circuits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Name three components on the induction system of a recip engine:

A

-Air scoop,
-Carburetor
-Intake manifold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What could happen if the induction system becomes obstructed?

A

The engine may not be able to produce its rated power or it may not run at all.
[BAD FILTER]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

How does induction icing affect engine performance?

A

It causes a reduction in power and possible erratic operation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

How is induction icing categorized?

A

-Impact ice
-Fuel evaporation ice
-Throttle ice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What is common method used to prevent induction system ice in recip engine?

A

Preheating the induction air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What causes fuel evaporation ice?

A

When fuel evaporates into the airstream it decreases air temperature resulting in fuel evap ice.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Is carburetor ice more likely to occur at a higher or lower power setting and why?

A

At lower power setting because the throttle is partly closed, offering a larger surface area for the ice to accumulate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What may be the indication of leaking intake pipes?

A

The engine runs rough at low RPM.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What happens to engine power when the carb heat is applied?

A

Noticeable drop in power.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What could happen if carb heat is applied at high power settings?

A

Detonation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What are two types of supercharged induction systems?

A

-Internally driven
-Externally driven

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

How and at what point does an internally driven supercharger boost air pressure?

A

An engine driven impeller compresses the fuel air mixture after it leaves the carburetor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What is used to power a turbocharger?

A

Exhaust gas directed onto the turbocharger turbine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What could result if the wastegate on a turbocharger system does not fully close?

A

-Can’t produce its rated power at certain altitudes
-Aircraft struggles to or can’t reach critical altitude.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What function does a turbocharger waste gate perform?

A

It controls the amount of exhaust gas either into or around the turbocharger thus controlling boost pressure of the turbocharger.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What could cause a turbocharged engine to surge?

A

Waste gate or controller malfunction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What are the most common ways to control a waste gate?

A

-Either mechanically with linkages to the throttle or a separate control
-Actuator that is driven by oil pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

In a pressurized recip aircraft, what component in the turbocharger system is used to limit the amount of turbocharger airflow used for cabin pressurization?

A

The sonic venturi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is the function of a divergent shaped jet inlet during subsonic flight?

A

It causes the air velocity to decrease with a subsequent increase in air pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Where are bellmouth inlet ducts typically found?

A

Helicopter engines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

How do venturi type particle separators found on turbine powered helicopters function?

A

The intake is curved and the debris gains too much inertia to allow it to follow the curved intake toward the engine and is channeled away from the compressor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What are the most common methods used for anti-icing of turbine engine inlet ducts?

A

-Bleed air
-Electric heating elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What is the purpose of the exhaust system?

A

To remove high temp noxious gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Name two types of recip engine exhaust systems?

A

-Short stack
-Collector system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What drawback is using collector type exhaust systems is more than offset when used on turbocharged engines?

A

The loss of horsepower due to exhaust system back pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What could result if the internal baffles or diffusers in an exhaust system fail?

A

Restricted flow of exhaust gases resulting in a loss of engine power.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What type of exhaust system is used on turbocharged engines?

A

The collector system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What kind of material is normally used to make the muffler shrouds found in the exhaust system?

A

Stainless steel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

How do you inspect the internal baffles and diffusers of an exhaust system?

A

By disassembling the exhaust system as necessary and visually inspecting the components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Why is an exhaust system failure considered a severe hazard?

A

-Carbon monoxide poisoning
-Loss of engine power
-Fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

What could happen if lead, zinc, or galvanized marks are made on an exhaust system?

A

Change molecular structure,
result in cracks when heated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

What happens if the heat exchanger leaks exhaust gasses into the induction system?

A

Loss of engine power.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

What is an indication of an exhaust leak?

A

Sooty black deposit in the area of the leak.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Where are the most common places to find cracks in the exhaust system?

A

-Welded areas
-Clamped areas
-At the flanges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

What is a common cause of turbocharger waste gate sticking?

A

-Coke deposits [Excessive carbon build up]
-Carbon build up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Why are turbocharged exhaust system leaks very damaging at high altitudes?

A

Pressure differential will cause the leak to escape with torch like intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

What are exhaust system coke deposits?

A

Excessive carbon buildup.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

What is the result of changing the exhaust nozzle area of a turbine engine?

A

-Engine performance change
-EGT changes

110
Q

Name the components of a typical turbine exhaust nozzle?

A

-Tail cone
-Exhaust ducts
-Support struts

111
Q

What is the purpose of thrust reversers?

A

Assist deceleration of aircraft on landing

112
Q

How does a noise suppressor found on older turbojet engines work?

A

It converts low frequency into high frequency thus reducing the sound footprint.

113
Q

What are the two most commonly used types of thrust reverses?

A

-Aerodynamic blockage
-Mechanical blockage

114
Q

How much thrust do thrust reverses compared to the engines full forward thrust produce?

A

Substantially less

115
Q

What are the hazards of operating some thrust reverses at low ground speeds?

A

-Ingest foreign objects stirred up by the exhaust gasses
-Re-ingest hot exhaust gasses.

116
Q

What are some of the sources used to heat the fuel in a turbine engine fuel system?

A

-Bleed air
-Engine oil

117
Q

What are the most common types of fuel metering systems used on small recip engines?

A

-Float type carb
-Pressure injection
-Direct injection

118
Q

What function does the mixture control perform?

A

Controls the fuel/air to air mixture ratio

119
Q

What generally causes spark plug fouling?

A

Running the engine excessively rich at idle

120
Q

What is the purpose of an accelerating system?

A

It provides an immediate but brief increase in fuel flow in the venturi to enrich the mixture.

121
Q

What is the carb economizer system?

A

Power enrichment system provides richer mixture at higher power settings,
the extra fuel aids in engine cooling.

122
Q

When the mixture is placed in the idle-cutoff position, a slight rise rpm is noted prior to the engine decelerating. What does this indicate?

A

The idle mixture is not set correctly.

123
Q

Why should engine rpm be accelerated periodically when making carburetor adjustments?

A

Clear the engine

124
Q

What happens if the manual mixture control of a pressure injection carb is moved to the idle cutoff position?

A

The engine stops.

125
Q

What maintains the fuel pressure in a pressure injection carb?

A

Engine driven fuel pump

126
Q

How does an automatic mixture control function?

A

Sealed brass bellows expand and contract w/ changes in pressure & temperature to adjust the mixture accordingly.

127
Q

What are some of the advantages of fuel injection systems over carb systems?

A

-Less danger of induction icing
-Better acceleration
-Better fuel distribution
-Better fuel economy
-Reduced overheating of individual cylinders.

128
Q

What purpose do turbine engine fuel control units serve?

A

Automatically meter fuel to the engine.

129
Q

What are the two basic types of turbine engine fuel control units?

A

-Hydromechanical
-Electrical

130
Q

What are the engine variables detected by the fuel control?

A

-Power lever position
-Engine rpm
-Compressor inlet temp
-Compressor inlet pressure
-Compressor discharge pressure
-Burner pressure.

131
Q

What are the two major components of a supervisory electronics engine control?

A

The ECU and the hydromechanical fuel control.

132
Q

What are some of the advantages of a full authority digital engine control [FADEC] over a hydromechanical fuel control?

A

-Better fuel economy
-Improved starts
-No engine trimming
-Engine limit protection
-Provides constant idle speeds regardless of atmospheric conditions or bleed air requirements
-Fully modulates the active clearance control and allows more repeatable engine transients.

133
Q

What do turbine engine fuel spray nozzles do?

A

Inject fuel into the combustion area.

134
Q

What are the different engine indications used for trimming a turbine engine?

A

EPR or RPM is used depending on the engine.

135
Q

What maintenance adjustments are normally allowed on an installed hydromechanical fuel controller?

A

-Specific gravity for fuel
-Idle RPM
-Max RPM.

136
Q

What type of pump can vary the amount of fuel discharged regardless of speed?

A

A variable displacement pump

137
Q

What is used to keep water, sediment, and foreign matter out of the carburetor?

A

Main fuel strainer.

138
Q

What is the purpose of a pressure relief valve in a constant displacement pump?

A

It returns excess fuel that is not required to the inlet side of the pump.

139
Q

What type of engine driven fuel pump is widely used other than gear or piston pumps?

A

A rotary vane type.

140
Q

What function do fuel boost pumps perform?

A

They supply pressurized fuel to the fuel pump, which helps prevent vapor lock and cavitation.

141
Q

What is a commonly used type of fuel boost pump?

A

The centrifugal type.

142
Q

What causes vapor lock and why is it a concern?

A

Insufficient fuel pressure, high fuel temperature and excessive fuel turbulence and it can block fuel flow to the engine resulting in failure.

143
Q

What function does an engine driven pump on a turbine engine perform?

A

Continuous supply of fuel at the proper pressure while the engine is running.

144
Q

Name the two categories of turbine engine pumps.

A

-Constant displacement
-Variable displacement

145
Q

What category is a gear type pump classified in?

A

Constant displacement.

146
Q

When performing an external inspection of an engine driven fuel pump, what should you look for?

A

Leaks and security of mounting.

147
Q

What is the purpose of a shear section of the driveshaft in a dual element constant displacement pump?

A

Even if one element seizes the other still operates

148
Q

Where in a turbine engine fuel system is ice formation likely to occur and how is it prevented?

A

At the fuel filter, and it is prevented by fuel heater or fuel additive.

149
Q

What is the purpose of a bypass valve in an engine fuel system micron filter?

A

It is a safety feature that allows fuel to flow to the engine if the filter becomes blocked.

150
Q

What is the purpose of duplex nozzle?

A

Duplex nozzle discharges two different spray patterns, one wider during startup and acceleration and narrows when engine speed increases above idle.

151
Q

What are the functions of the pressurizing and dump portions of pressurizing and dump valve?

A

-Pressurizing portion provides primary and secondary fuel flow to duplex nozzles

-Dump portion allows fuel to drain from the manifolds after engine shutdown.

152
Q

What is the purpose do fuel selector valves serve?

A

They allow tank and engine selection and provide a means for shutting off fuel flow.

153
Q

How can the remaining service life of starter-generator brushes be determined?

A

By visually inspecting the amount of wear groove remaining on the brushes.

154
Q

What components of the starter-generator require periodic inspection?

A

Both commutator and brushes

155
Q

Between field and armature windings in starter-generators, which ordinarily receive current for operation in the start mode?

A

BOTH field and armature

156
Q

What are possible sources of low pressure compressed air used for starting jet transport aircraft equipped with air turbine starters?

A

-Ground power unit
-On board APU
-Compressed bleed air form an already running engine.

157
Q

When should ignition ideally occur?

A

Specific number of degrees before the piston reaches TDC on the compression stroke.

158
Q

Why are dual mags used in the engine ignition system?

A

Improve combustion efficiency and provide redundancy for safety.

159
Q

Why is mag timing so important?

A

For the engine to run properly, the spark plug in a cylinder has to fire at a specific time to produce the required energy for the spark at the required time or engine wont run or will run rough

160
Q

What function does a magneto perform?

A

It produces a high voltage that forces a spark to arc across a spark plug gap.

161
Q

Name the components of a high tension mag system

A

-Permanent rotating magnet
-Soft iron core
-Pole shoes.

162
Q

Name the three main circuits of a high tension mag system.

A

-Magnetic
-Primary
-Secondary

163
Q

What is an E-gap angle?

A

Where maximum magnetic field stress exists and is few degrees beyond the neutral position of a rotating magnet

164
Q

What reduces arcing in the points and also aids the collapsing of the magnetic field in a magneto?

A

A capacitor.

165
Q

How does a magneto produce the high voltage spark required to fire a spark plug?

A

In the rotation cycle, when the magnetic rotor is in e gap the primary points open which interrupts the current flow in the primary circuit causing a high rate of flux change in the core and inducing a pulse of high voltage in the secondary coil.

166
Q

What is the P-lead and how does it function?

A

The P-lead connects the ignition switch to the primary circuit of the magneto.
OFF = both grounded
BOTH = both on
LEFT = Right grounded
Right = left grounded

167
Q

What is the magneto timing light used for and what does it indicate?

A

Used for mag timing and indicates exact instant the mag points open.

168
Q

Why are turbine engine igniters generally not susceptible to carbon fouling?

A

Because the high energy sparks they produce clean off any deposits on the firing end.

169
Q

What is the function of a duty cycle in relation to a turbine engine ignition system?

A

Allows operation of the ignition system for a X amount of time, then followed by a minimum specified cooling down period.

170
Q

What are the three main components of a turbine engine ignition system?

A

-Ignition exciters
-High tension leads
-Igniters

171
Q

When the engine is operating, what does an ammeter / loadmeter indicate when connected to: 1. Battery positive lead, 2. Generator output lead?

A
  1. Ammeter indicates whether the battery is charging or discharging,
  2. indicates the current produced by the generator or electrical system load.
172
Q

What is done to ensure each generator shares the same load?

A

The generators are paralleled

173
Q

Where would you find generator rating and performance data?

A

On the data plate attached to the generator.

174
Q

How is the voltage of a DC generator controlled?

A

By carrying the field current strength.

175
Q

What is the most common type of alternator used in most aircraft AC systems?

A

Three phase alternator.

176
Q

How does a voltage regulator control the voltage of an alternator?

A

By regulating the voltage output of the DC exciter.

177
Q

What does the speed of rotation and number of poles of an alternator determine?

A

The frequency of the alternator output

178
Q

What are some of the methods used to maintain 400 Hz alternator output frequency on large turbojet turbofan engines?

A

Constant speed drives
integrated drive generators
variable speed constant frequency power systems.

179
Q

Name the major parts of a DC motor?

A

-The armature
-Field
-Brushes
-Frame assembly

180
Q

Name the components of a direct cranking electric starter system:

A

-Electric motor -Reduction gears
-Automatic engaging/disengaging mechanism.

181
Q

Name three types of DC motors:

A

-Series
-Shunt
-Compound

182
Q

What type of DC motor is commonly used for a reciprocating engine starter and why?

A

A series wound motor because it has high starting torque under heavy load conditions.

183
Q

What are the operating modes of a turbine engine starter motor?

A

It operates first as the starter, then as the generator when the engine is running.

184
Q

What is possible indication when a starter drags?

A

A dirty or worn starter commutator.

185
Q

Where would wire with high temp insulation be used?

A

When they run close to high temp areas such as exhaust stacks or heating ducts.

186
Q

What is the size standard for electrical wire used in US manufactured aircraft?

A

AWG American wire gauge

187
Q

How are wire sizes represented?

A

By a numbered gauge size. The smaller wires are represented by larger numbers. big wires are small numbers.

188
Q

What is the maximum slack allowed between the supports of a single wire or bundle instillation?

A

Not over 1/2 inch

189
Q

Why are wires bonded on powerplant installations?

A

To provide a current return path for electrical accessories, and to prevent static discharge.

190
Q

A recip engine is found to have excessive oil consumption without evidence of any leaks. What is the likely cause?

A

Piston rings are worn or broken

191
Q

What are the functions of lubing oil in recip engines?

A

Reduce the friction between moving parts and remove heat.

192
Q

Name two important characteristics of aircraft engine oil:

A

Oil must be light enough to circulate
heavy enough to provide proper oil film at operating temps.

193
Q

What could happen to an oil that is too low in viscosity at normal engine operating temperatures?

A

It may become too thin that the oil film between moving parts is easily broken, resulting in premature wear.

194
Q

What are some of the factors that must be considered by an engine manufacturer in determining the proper grade of oil for a particular engine?

A

-Operating load
-Operating temp
-Rotational speed

195
Q

Why do aircraft recip engines use a relatively high viscosity oil?

A

Because they have large operating clearances and operate at high temps and pressures.

196
Q

Name some oil contaminants:

A

-Dirt
-Metal particles
-Carbon
-Moisture
-Acids.

197
Q

What is a possible indication of low oil pressure together with high oil temperature?

A

A low supply of oil.

198
Q

In ashless dispersant oils, what function does the dispersant perform?

A

Keeps the oil rings good by dispersant causes sludge forming materials to repel each other until trapped at filter

199
Q

Why do oil reservoirs have expansion space?

A

-Oil foaming
-Thermal expansion
-Air in the return oil.

200
Q

What could cause oil foaming?

A

-Diluted oil
-Contaminated oil
-Oil level being too high.

201
Q

What controls oil pressure in a gear type oil pressure pump?

A

Oil pressure relief valve

202
Q

What function does an oil cooler bypass valve perform?

A

It directs the oil through a cooler or around it in order to maintain proper operating temps.

203
Q

Where is the oil temp bulb usually located?

A

At the engine oil inlet.

204
Q

What does the presence of metal particles in an engine oil filter indicate?

A

Depending on the size of the particles this usually indicates abnormal wear and possible engine internal failure.

205
Q

What should be done if metal particles are found in an engine oil filter?

A

Follow engine manufacturers instruction

206
Q

Where is the most critical point of lube in a gas turbine engine?

A

At the turbine bearing.

207
Q

What type of oil is used in a turbine engine oil system?

A

Synthetic oil.

208
Q

Where are oil screens or filters most likely located in a turbine engine oil system?

A

-Main filter
-Scavenge system
-At or just before the oil jet

209
Q

Name two types of turbine engine oil coolers?

A

-Air cooled
-Fuel cooled

210
Q

What could happen to an oil that is too low viscosity at normal engine op temperatures?

A

It may become so thin that the oil between moving parts is easily broken resulting in premature wear.

211
Q

What effect does excessive heat have on recip engines?

A

It shortens the life of engine parts, changes the behavior of combustion, and impairs lubrication.

212
Q

What is the purpose of cooling fins?

A

Provide a larger cooling surface area for removing heat from the cylinder heads of air cooled recip engines.

213
Q

What are the reasons for using engine cowlings, baffles and cowl air seals?

A

-Streamline the engine area to reduce drag
-Direct airflow for cooling.

214
Q

How does an augmented cooling system work?

A

Outer tube placed over the exiting exhaust gas creates a venturi effect that draws more airflow over the engine for cooling.

215
Q

Where should cowl flaps be positioned for ground operations?

A

Fully open

216
Q

What type of power is used to operate cowl flaps?

A

-Manual
-Hydraulic
-Electrical

217
Q

What should be done when cooling fin damage is discovered?

A

Sometimes they can be repaired subject to manufacturers repair and overhaul manual, if too much fin is broken off then the cylinder must be replaced.

218
Q

Why is cowl flap adjustment important?

A

The movement must be within tolerance to keep cylinder head temperatures within allowable limits.

219
Q

How are turbine engines cooled?

A

They are cooled by air passing through the engine. About 75% of the air passing through the engine is used for cooling which leaves only about 25% for combustion. This air is used to cool the combustion chamber and turbine.

220
Q

In a turbine engine, where does bleed air come from that is used to cool bearings and other parts?

A

The engine compressor

221
Q

What is the relationship between turbine engine temperature limits and power produced?

A

The higher the combustion temp that the engine can withstand without damage, the more power it can make.

222
Q

What is the approx percentage of air passing through a turbine that is used for cooling rather than combustion?

A

75%

223
Q

What can be done to effectively allow higher gas temperatures in the turbine section of some engines?

A

Compressor bleed air ducted through hollow sections in turbine inlet guide vanes and first stage rotor blades can lower temps enough to prevent heat damage.

224
Q

What types of fire detector systems are used for engine fire detection?

A

-Overheat
-Rate of rise,
-Flame detectors.

225
Q

How does a thermal switch fire protection system operate?

A

When heated past a predetermined temperature, the switch closes causing a warning device in the cockpit to activate.

226
Q

How many thermal switches are needed in a thermal switch fire protection system?

A

At least one

227
Q

What kind of fire detection system allows more complete coverage than a spot type system?

A

Continuous loop system

228
Q

What happens if an engine equipped with a thermocouple fire warning system overheats slowly?

A

Nothing because fast temp rise is required for this type of system to operate

229
Q

What is likely to cause a false fire warning?

A

The engine fire sensing loop is bent or kinked excessively.

230
Q

What are fire extinguishing systems designed to do?

A

They are designed to dilute the O2 levels around the engine to a point that does not allow combustion or to reduce temperatures below the ignition point.

231
Q

Describe how a kidde and fenwal continuous loop fire detection system functions?

A

-When a fire occurs in kidde system the resistance of the thermistor material drops allowing current to flow between the two wires and activate an alarm.

-With the fenwal system, the core resistance of the beads drop allowing current to flow between the electrode and ground energizing the alarm system.

232
Q

What elements must be present for a fire to occur?

A

-Ignition source such as heat or a spark
-Fuel
-Oxygen.

233
Q

What group of fire extinguishing agents are no longer manufactured because of environmental concerns?

A

Halons were no longer manufactured after 1995 however existing stocks of CFG may still be used and are subject to strict handling and disposal regulations.

234
Q

How are fire extinguishing agents distributed?

A

Through perforated tubing and discharge nozzles.

235
Q

What is the purpose of the discharge cartridge and how is it activated?

A

Electrically ignited, fires a projectile into the frangible disk, thereby releasing fire extinguishing agents.

236
Q

How is a fire extinguisher system with a high rate of discharge classified?

A

Spray nozzles and perforated tubing
As a HRD fire extinguisher system.

237
Q

What do the red and yellow discs in a fire extinguishing system indicate?

A

A yellow disc means it was discharged normally, a red disc indicates thermal discharge.

238
Q

How is the fire extinguishing agent in an HRD system distributed, and how long does it take to discharge?

A

Through a series of high pressure tubes and takes one to two seconds to discharge.

239
Q

What is the purpose of a pressure gauge in a fire extinguishing system?

A

Indicates the pressure within the container, to check if the pressure is within limits. A pressure-temp chart is used.

240
Q

What is the function of a propeller?

A

Create thrust to pull or push airplane through the air.

241
Q

What is the difference between a fixed pitch prop and a controllable pitch prop?

A

Fixed pitch propellers blade angle cannot be changed by the pilot where as controllable pitch props blade angles may be changed by the pilot.

242
Q

How are some wooden prop blades protected from wear?

A

By metal tipping fastened to the leading edge and tip.

243
Q

What happens to the blade angle of a constant speed prop during a constant power dive?

A

The angle increases to prevent an overspeed.

244
Q

What are the functions of a constant speed prop prop governor?

A

-Boosts oil pressure before it enters the hub
-Senses prop rotation speed
-Adjusts the oil flow to the prop to change pitch and prop speed

245
Q

What is the purpose for prop counterweights?

A

Centrifugal force acting on the counterweights causes the blade angle to increase.

246
Q

What is meant when a propeller governor is in an on-speed condition?

A

-Governor doesn’t have to accelerate or decelerate speeder ring
-Flyweight forces are in balance

247
Q

How is a constant speed feathering propeller feathered?

A

When the governor releases oil pressure the counterweights and feathering spring move the prop into feather position.

248
Q

What is an unfeathering accumulator?

A

Oil accumulator used to provide oil pressure to unfeather a prop.

249
Q

What is alpha range and beta range and where are they found?

A

Alpha is for operation in standard constant speed mode which is usually in flight, and beta is for ground operation when the prop is in zero or min thrust range and negative thrust or reverse thrust mode.

250
Q

What systems are commonly used for prop ice control?

A

Fluid [ALCOHOL] and electrical heat applied to the prop blade root.

251
Q

What prop repairs can be performed by a certified mechanic with a Powerplant rating?

A

Only minor repairs and alterations

252
Q

How are wooden props cleaned?

A

With a brush or cloth and warm water and mild soap.

253
Q

Where would you find the correct method and technique for cleaning an aluminum prop and hub?

A

In the prop manufacturers maintenance instructions.

254
Q

What type of nondestructive testing should be accomplished to a prop after blending?

A

Whichever procedure recommended by the manufacturer.

255
Q

What are the two criteria used by many manufacturers to determine the amount of bend damage that can be repaired by cold bending of aluminum propellers?

A

The extent of the bend and its blade station location.

256
Q

How can repair file marks be removed from an aluminum prop?

A

With very fine sand paper

257
Q

When performing a static balance on a two bladed prop what positions must the prop be placed in when measurements are taken?

A

Vertical and horizontal positions

258
Q

What is a prop protractor used for?

A

To measure prop blade angle

259
Q

What blade conditions can cause engine vibration?

A

-Prop out of track
-Prop out of balance
-Incorrect blade angle setting.

260
Q

What is blade tracking?

A

Comparing the position of the prop blade tips relative to each other.

261
Q

What controls both manifold pressure and RPM of an engine with a fixed pitch prop?

A

The throttle

262
Q

What publications can be used as a guide for 100 hour inspections on aircraft engines?

A

-Manufacturers maintenance manual -FAR part 43 appendix D

263
Q

How do you identify the engine serial number?

A

On the data plate

264
Q

Prior to returning a recip engine to service after a 100 hour inspection what operational checks must be performed?

A

-Check the power output
-Magnetos
-Fuel pressure
-Oil pressure
-Cylinder temp
-Oil temp

265
Q

Where are life limits parts of an engine listed?

A

In the maintenance manual, TCDS and the airworthiness limitation section of the instructions for continued airworthiness.

266
Q

Where can engine limitations be found?

A

In the engine manual, TCDS, and aircraft maintenance manual.

267
Q

Why are hot section inspections performed on turbine engines?

A

To determine the integrity and wear of the hot section components.

268
Q

What inspections can be performed following a turbine engine overspeed?

A

Refer to the engine manufacturer maintenance manual for the required procedures.

269
Q

What inspection must be performed on a turbine engine if the exhaust gas temp exceeds limitation?

A

Hot section inspection

270
Q

What FAA approvals are required when installing an engine that is not on the TCDS

A

An STC

271
Q

Under what conditions is compliance with an engine service bulletin mandatory?

A

When the airworthiness directive references the SB or when the compliance part of the approved operating specs for a commercial or air carrier operator. Or when the overhaul procedure require compliance at the time of overhaul.

272
Q

What are the possible causes for a turbojet or fan engine having high EGT lor RPM and high fuel flow at all engine pressure ratios?

A

Turbine damage or loss of efficiency due to wear.

Jeppesen Powerplant (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions