Powerplant Master Multiple Choice Exam


1. A cool-off period prior to shutdown of a turbine engine is accomplished in order to:

a) prevent seizure of the engine bearings.
b) allow the turbine wheel to cool before the case contracts around it.
c) prevent vapor lock in the fuel control and/or fuel lines.
2. The primary concern in establishing the firing order for an opposed engine is to:

a) provide for balance and eliminate vibration to the greatest extent possible.
b) keep the power impulses on adjacent cylinders as close as possible in order to obtain the greatest mechanical efficiency.
c) keep power impulses on adjacent cylinders as far apart as possible in order to obtain the greatest mechanical efficiency.
3. How are the teeth of the gears in the accessory section of an engine normally lubricated?

a) By submerging the load bearing portions in oil.
b) By splashed or sprayed oil.
c) By surrounding the load bearing portions with baffles or housings within which oil pressure can be maintained.
4. Motor driven impeller and turbine fuel flow transmitters are designed to transmit data:

a) mechanically.
b) by fuel pressure.
c) using aircraft electrical system power.
5. Which of the following engine servicing operations generally requires engine pre oiling prior to starting the engine?

a) Replacement of oil lines.
b) Engine oil and filter change.
c) Engine installation.
6. (Refer to Powerplant figure 1.) Determine which portion of the AD is applicable for Model O-690 series engine, serial No. 5863-40 with 283 hours` time in service.



a) (A).
b) (B), (1).
c) (B), (2).
7. The velocity of subsonic air as it flows through a convergent nozzle:

a) decreases.
b) inceases.
c) remains constant.
8. If an aircraft ignition switch is turned off and the engine continues to run normally, the trouble is probably caused by:

a) arcing magneto breaker points.
b) an open ground lead in the magneto.
c) primary lead grounding.
9. What is the principal advantage of using propeller reduction gears?

a) To enable the engine RPM to be increased with an accompanying increase in power and allow the propeller to remain at a lower, more efficient RPM.
b) To enable the propeller RPM to be increased without an accompanying increase in engine RPM.
c) To enable the engine RPM to be increased with an accompanying increase in propeller RPM.
10. Shielding is used on spark plug and ignition wires to:

a) prevent outside electromagnetic emissions from disrupting the operation of the ignition system.
b) prevent interference with radio reception.
c) protect the wires from short circuits as a result of chafing or rubbing.
11. What effect does high atmospheric humidity have on the operation of a jet engine?

a) Has little or no effect.
b) Decreases engine pressure ratio.
c) Decreases compressor and turbine RPM.
12. What are the positions of the pressurization valve and the dump valve in a jet engine fuel system when the engine is shut down?

a) Pressurization valve open, dump valve open.
b) Pressurization valve closed, dump valve open.
c) Pressurization valve closed, dump valve closed.
13. Where physical separation of the fuel lines from electrical wiring or conduit is impracticable, locate the fuel line:

a) above the wiring and clamp the line securely to the airframe structure.
b) inboard of the wiring and clamp both securely to the airframe structure.
c) below the wiring and clamp the line securely to the airframe structure.
14. If the ignition switch is moved from BOTH to either LEFT or RIGHT during an engine ground check, normal operation is usually indicated by a:

a) slight drop in RPM
b) momentary interuption of both ignition systems.
c) a large drop in RPM.
15. If an engine is equipped with a float type carburetor and the engine runs excessively rich at full throttle, a possible cause of the trouble is a clogged:

a) atmospheric vent line.
b) back suction line.
c) main air bleed.
16. If an engine cylinder is to be removed, at what position in the cylinder should the piston be?

a) Top dead center.
b) Bottom dead center.
c) Halfway between top and bottom dead center.
17. An indication of unregulated power changes that result in continual drift of manifold pressure indication on a turbosuper-charged aircraft engine is known as:

a) Waste gate fluctuation.
b) Bootstrapping.
c) Overshoot.
18. The density of air is very important when mixing fuel and air to obtain a correct fuel to air ratio. Which of the following weighs the most?

a) 100 parts of dry air.
b) 50 parts of dry air and 50 parts of water vapor.
c) 75 parts of dry air and 25 parts of water vapor.
19. Sodium filled valves are advantageous to an aviation engine because they:

a) dampen valve impact shocks.
b) dissipate heat well.
c) are lighter.
20. What precaution should be taken when putting thread lubricant on a tapered pipe plug in a carburetor float bowl?

a) Do not use thread lubricant on any carburetor fitting.
b) Put the thread lubricant only on the first thread.
c) Engage the first thread of the plug, then put a small amount of lubricant on the second thread and screw the plug in.
21. The propeller governor controls the:

a) spring tension on the boost pump speeder spring.
b) oil to and from the pitch changing mechanism.
c) linkage and counterweights from moving in and out.
22. The primary condition(s) that allow(s) microorganisms to grow in the fuel in aircraft fuel tanks is (are):

a) the presence of water.
b) the presence of dirt or other particulate contaminants.
c) warm temperatures and frequent fueling.
23. Which of the following is identified as the cambered or curved side of a propeller blade, corresponding to the upper surface of a wing airfoil section?

a) Blade back.
b) Blade chord.
c) Blade face.
24. How are most aircraft turbine engine fire extinguishing systems activated?

a) Electrically discharged cartridges.
b) Pushrod assembly.
c) Manual remote control valve.
25. What will result if an oil filter becomes completely blocked?

a) Oil will flow at the normal rate through the system.
b) Oil will flow at a reduced rate through the system.
c) Oil flow to the engine will stop.
26. What is the smallest terminal stud allowed for aircraft electrical power systems?

a) No. 10.
b) No. 6.
c) No. 8.
27. When aircraft turbine blades are subjected to excessive heat stress, what type of failures would you expect?

a) Torsion and tension.
b) Stress rupture.
c) Bending and torsion.
28. Aircraft electrical wire size is measured according to the:

a) Technical Standard Order system.
b) Military Specification system.
c) American Wire Gauge system.
29. After a fire is extinguished, or overheat condition removed in aircraft equipped with a Systron-Donner fire detector, the detection system:

a) must be manually reset.
b) sensing component must be replaced.
c) automatically resets.
30. (Refer to Powerplant figure 7.) What is the purpose of the fuel transfer ejectors?



a) To supply fuel under pressure to the engine driven pump.
b) To assist in the transfer of fuel from the main tank to the boost pump sump.
c) To transfer fuel from the boost pump sump to the wing tank.
31. The blending of blades and vanes in a turbine engine:

a) may sometimes be accomplished with the engine installed, ordinarily using power tools.
b) should be performed parallel to the length of the blade using smooth contours to minimize stress points.
c) is usually accomplished only at engine overhaul.
32. Select a characteristic of a good weld on exhaust stacks.

a) Porousness or projecting globules should show in the weld.
b) The weld should be built up 1/8 inch.
c) The weld should taper off smoothly into the base metal.
33. An aircraft carburetor is equipped with a mixture control in order to prevent the mixture from becoming too:

a) rich at high altitudes.
b) lean at high altitudes.
c) rich at high speeds.
34. Increased water vapor (higher relative humidity) in the incoming air to a reciprocating engine will normally result in which of the following?

a) A leaning effect on engines which use non automatic carburetors.
b) Decreased engine power at a constant RPM and manifold pressure.
c) Increased power output due to increased volumetric efficiency.
35. Some aircraft engine manufacturers equip their product with choked or taper-ground cylinders in order to:

a) provide a straight cylinder bore at operating temperatures.
b) flex the rings slightly during operation and reduce the possibility of the rings sticking in the grooves.
c) increase the compression pressure for starting purposes.
36. During ground operation of an engine, the cowl flaps should be in what position?

a) Fully closed.
b) Opened according to ambient conditions.
c) Fully open.
37. The horsepower developed in the cylinders of a reciprocating engine is known as the:

a) shaft horsepower
b) indicated horsepower
c) brake horsepower
38. If the oil pressure gauge fluctuates over a wide range from zero to normal operating pressure, the most likely cause is:

a) air lock in the scavenge pump intake.
b) broken or weak pressure relief valve spring.
c) low oil supply.
39. Some cylinder barrels are hardened by:

a) Nitriding
b) Shot peening
c) Tempering
40. Which of the following is the ultimate limiting factor of turbine engine operation?

a) Compressor inlet air temperature.
b) Turbine inlet temperature.
c) Burner can pressure.
41. What type of turbine blade is most commonly used in aircraft jet engines?

a) Impulse-reaction.
b) Reaction.
c) Impulse.
42. The function of the exhaust cone assembly of a turbine engine is to:

a) straighten and collect the exhaust gases into a solid exhaust jet.
b) swirl and collect the exhaust gases into a single exhaust jet.
c) collect the exhaust gases and act as a noise suppressor.
43. Sharp bends should be avoided in ignition leads primarily because:

a) weak points may develop in the insulation through which high tension current can leak.
b) ignition lead wire conductor material is brittle and may break.
c) ignition lead shielding effectiveness will be reduced.
44. (1) Welding and straightening of turbine engine rotating airfoils does not require special equipment.
(2) Welding and straightening of turbine engine rotating airfoils is commonly recommended by the
manufacturer.
Regarding the above statements:

a) only No. 1 is true.
b) neither No. 1 nor No. 2 is true.
c) only No. 2 is true.
45. If a full flow oil filter is used on an aircraft engine, and the filter becomes completely clogged, the:

a) oil supply to the engine will be blocked.
b) oil will be bypassed back to the oil tank hopper where larger sediments and foreign matter will settle out prior to passage through the engine.
c) bypass valve will open and the oil pump will supply unfiltered oil to the engine.
46. What does valve overlap promote?

a) A backflow of gasses across the cylinder.
b) Better scavenging and cooling characteristics.
c) Lower intake manifold pressure and temperatures.
47. Direct mechanical push pull carburetor heat control linkages should normally be adjusted so that the stop located on the diverter valve will be contacted:

a) before the stop at the control lever is reached in both HOT and COLD positions.
b) after the stop at the control lever is reached in both HOT and COLD positions.
c) before the stop at the control lever is reached in the HOT position and after the stop at the control lever is reached in the COLD position.
48. If a fire starts in the induction system during the engine starting procedure, what should the operator do?

a) Continue cranking the engine.
b) Turn off the fuel switches to stop the fuel.
c) Turn off all switches.
49. Why must a float type carburetor supply a rich mixture during idle?

a) Because of reduced mechanical efficiency during idle.
b) Engine operation at idle results in higher than normal volumetric efficiency.
c) Because at idling speeds the engine may not have enough airflow around the cylinders to
provide proper cooling.
50. What is the position of the cowl flaps during engine starting and warmup operations under normal conditions?

a) Full closed at all times.
b) Full open at all times.
c) Open for starting, closed for warmup.
51. What must be done after the fuel control unit has been replaced on an aircraft gas turbine engine?

a) Retrim the engine.
b) Recalibrate the fuel nozzles.
c) Perform a full power engine run to check fuel flow.
52. The primary purpose of baffles and deflectors installed around cylinders of air-cooled aircraft engines is to:

a) increase the volume of air used to cool the engine.
b) force cooling air into close contact with all parts of the cylinders.
c) create a low pressure area aft of the cylinders.
53. What is the function of a fire detection system?

a) To discharge the powerplant fire extinguishing system at the origin of the fire.
b) To identify the location of a powerplant fire.
c) To activate a warning device in the event of a powerplant fire.
54. Which two elements make up the axial flow compressor assembly?

a) Stator and diffuser.
b) Rotor and stator.
c) Compressor and manifold.
55. What type of imbalance will cause a two blade propeller to have a persistent tendency to come to rest in a horizontal position (with the blades parallel to the ground) while being checked on a propeller balancing beam?

a) Horizontal.
b) Vertical.
c) Harmonic.
56. A fuel or oil fire is defined as a:

a) Class B fire.
b) Class A fire.
c) Class C fire.
57. Engine operating flexibility is the ability of the engine to:

a) deliver maximum horsepower at a specific altitude.
b) meet exacting requirements of the efficiency and low weight per horsepower ratio.
c) run smoothly and give the desired performance at all speeds.
58. The purpose of the flow control valve in a reciprocating engine oil system is to

a) direct oil through or around the oil cooler.
b) deliver cold oil to the hopper tank.
c) compensate for volumetric increases due to foaming of the oil.
59. Why is it unnecessary to flash the field of the exciter on a brushless alternator?

a) Permanent magnets are installed in the main field poles.
b) Brushless alternators do not have exciters.
c) The exciter is constantly charged by battery voltage.
60. What is the purpose of the last chance oil filters?

a) To assure a clean supply of oil to the lubrication system.
b) To filter the oil immediately before it enters the main bearings.
c) To prevent damage to the oil spray nozzle.
61. Which of the following engine variables is the most critical during turbine engine operation?

a) Compressor inlet air temperature.
b) Turbine inlet temperature.
c) Compressor RPM.
62. What is the best indication of worn valve guides?

a) Low oil pressure.
b) Low compression.
c) High oil consumption.
63. Which fuel/air mixture will result in the highest engine temperature (all other factors remaining constant)?

a) A mixture leaner than a rich best power mixture of 0.085
b) A mixture leaner than a manual lean mixture of 0.060
c) A mixture richer than a full rich mixture of 0.087
64. If an engine with a stroke of 6 inches is operated at 2,000 RPM, the piston movement within the cylinder will be:

a) constant during the entire 360° of crankshaft travel.
b) at maximum velocity around TDC.
c) at maximum velocity 90° after TDC.
65. When will the voltage in the secondary winding of a magneto, installed on a normally operating engine, be at its highest value?

a) Toward the latter part of the spark duration when the flame front reaches its maximum velocity.
b) Just prior to spark plug firing.
c) Immediately after the breaker points close.
66. Newton's First Law of Motion, generally termed the Law of Inertia, states:

a) To every action there is an equal and opposite reaction.
b) Force is proportional to the product of mass and acceleration.
c) Every body persists in its state of rest, or of motion in a straight line, unless acted upon by some outside force.
67. When the centrifugal force acting on the propeller governor flyweights overcomes the tension on the speeder spring, a propeller is in what speed condition?

a) On speed.
b) Overspeed.
c) Underspeed.
68. Which of the following is a primary engine instrument?

a) Tachometer.
b) Fuel flowmeter
c) Airspeed indicator
69. The Brayton cycle is known as the constant:

a) mass cycle.
b) temperature cycle.
c) pressure cycle.
70. Kerosene is used as turbine engine fuel because:

a) kerosene has more heat energy per gallon and lubricates fuel system components.
b) Where physical separation of the fuel lines from electrical wiring or conduit is impracticable, locate the fuel line.
c) kerosene has very high volatility which aids in ignition and lubrication.
71. Using standard atmospheric conditions, the standard sea level temperature is:

a) 59 °F.
b) 59 °C.
c) 29 °C.
72. How is aircraft electrical power for propeller deicer systems transferred from the engine to the propeller hub assembly?

a) By flexible electrical connectors.
b) By slip rings and brushes.
c) By slip rings and segment plates.
73. Low oil pressure can be detrimental to the internal engine components. However, high oil pressure:

a) has a negligible effect.
b) should be limited to the engine manufacturer's recommendations.
c) will not occur because of pressure losses around the bearings.
74. The actual distance a propeller moves forward through the air during one revolution is known as the:

a) relative pitch.
b) effective pitch.
c) geometric pitch.
75. A clicking sound heard at engine coast-down in a pneumatic starter incorporating a sprag clutch ratchet assembly is an indication of:

a) one or more broken pawl springs.
b) gear tooth and/or pawl damage.
c) the pawls re-contacting and riding on the ratchet gear.
76. At what stage in a turbine engine are gas pressures the greatest?

a) Compressor outlet.
b) Turbine outlet.
c) Compressor inlet.
77. Possible failure related ferrous metal particles in turbine engine oil cause an (electrical) indicating type magnetic chip detector to indicate their presence by:

a) generating a small electric current that is caused by the particles being in contact with the dissimilar metal of the detector tip.
b) bridging the gap between the detector center (positive) electrode and the ground electrode.
c) disturbing the magnetic lines of flux around the detector tip.
78. Which of the following statements concerning the installation of a new fixed pitch wood propeller is true?

a) Inspect the bolts for tightness after the first flight and again after the first 25 hours of flying.
b) If a separate metal hub is used, final track should be accomplished prior to installing the hub in the propeller.
c) NAS close tolerance bolts should be used to install the propeller.
79. What type of lubricant may be used to aid in pulling electrical wires or cables through conduits?

a) Soapstone talc.
b) Rubber lubricant.
c) Silicone grease.
80. Capacitance afterfiring in most modern spark plugs is reduced by the use of:

a) fine wire electrodes.
b) aluminum oxide insulation.
c) a built-in resistor in each plug.
81. The economizer system in a float type carburetor:

a) functions only at cruise and idle speeds.
b) increases the fuel/air ratio at high power settings.
c) keeps the fuel/air ratio constant.
82. (1) A mechanic certificate with a powerplant rating authorizes the holder to repair deep scars, nicks, and dents on aluminum propeller blades.
(2) A mechanic certificate with a powerplant rating authorizes the holder to perform minor straightening of steel propeller blades.
Regarding the above statements:

a) only No. 1 is true.
b) both No. 1 and No. 2 are true.
c) neither No. 1 nor No. 2 is true.
83. Electric motors are often classified according to the method of connecting the field coils and armature. Aircraft engine starter motors are generally of which type?

a) Compound.
b) Series.
c) Shunt (parallel)
84. If a flanged propeller shaft has dowel pins:

a) install the propeller so that the blades are positioned for hand propping.
b) check carefully for front cone bottoming against the pins.
c) the propeller can be installed in only one position.
85. The air passing through the combustion chamber of a turbine engine is:

a) used to support combustion and to cool the engine.
b) entirely combined with fuel and burned.
c) speeded up and heated by the action of the turbines.
86. The maximum allowable voltage drop between the generator and the bus bar is:

a) 2 percent of the regulated voltage.
b) less than the voltage drop permitted between the battery and the bus bar.
c) 1 percent of the regulated voltage.
87. The thrust produced by a rotating propeller is a result of:

a) an area of low pressure behind the propeller blades.
b) the angle of relative wind and rotational velocity of the propeller.
c) an area of decreased pressure immediately in front of the propeller blades.
88. Failure of an engine to cease firing after turning the magneto switch off is an indication of:

a) an open P-lead to ground.
b) a grounded magneto switch.
c) an open high tension lead.
89. When starting a turbine engine, a hung start is indicated if the engine:

a) fails to reach idle RPM.
b) exhaust gas temperature exceeds specified limits.
c) RPM exceeds specified operating speed.
90. Main bearing oil seals used with turbine engines are usually what type(s)?

a) Teflon and synthetic rubber.
b) Labyrinth and/or silicone rubber.
c) Labyrinth and/or carbon rubbing.
91. The active clearance control (ACC) portion of an EEC system aids turbine engine efficiency by:

a) automatically adjusting engine speed to maintain a desired EPR.
b) ensuring turbine blade to engine case clearances are kept to a minimum by controlling case temperatures.
c) adjusting stator vane position according to operating conditions and power requirements.
92. What would be the possible cause if a gas turbine engine has high exhaust gas temperature, high fuel flow, and low RPM at all engine power settings?

a) Loose or corroded thermocouple probes for the EGT indicator.
b) Turbine damage or loss of turbine efficiency.
c) Fuel control out of adjustment.
93. To what altitude will a turbo charged engine maintain sea level pressure?

a) Critical altitude.
b) Pressure altitude.
c) Service ceiling.
94. What type of nuts are used to hold an exhaust system to the cylinders?

a) Brass or heat-resistant nuts.
b) High-temperature fiber self-locking nuts.
c) High-temperature aluminum self-locking nuts.
95. Which of the following, obtained during magneto check at 1,700 RPM, indicates a short (grounded) circuit between the right magneto primary and the ignition switch?

a) BOTH-1,700 RPM; R-1,625 RPM; L-1,700 RPM; OFF-1,625 RPM.
b) BOTH-1,700 RPM; R-0 RPM; L-1,675 RPM; OFF-0 RPM.
c) BOTH-1,700 RPM; R-0 RPM; L-1,700 RPM; OFF-0 RPM.
96. When an electric primer is used, fuel pressure is built up by the:

a) suction at the main discharge nozzle.
b) booster pump.
c) internal pump in the primer solenoid.
97. 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.

a) 1, 3, 4.
b) 1, 2, 3, 4, 5.
c) 1, 2, 3, 4.
98. What is the frequency of most aircraft alternating current?

a) 115 Hertz.
b) 400 Hertz
c) 60 hertz
99. The explosive cartridge in the discharge valve of a fire extinguisher container is:

a) not a life dated unit.
b) a life dated unit.
c) mechanically fired.
100. Where do stress rupture cracks usually appear on turbine blades?

a) Across the blade root, parallel to the fir tree.
b) Along the leading edge, parallel to the edge.
c) Across the leading or trailing edge at a right angle to the edge length.
101. Which of the following defects would likely cause a hot spot on a reciprocating engine cylinder?

a) Cowling air seal leakage.
b) Too much cooling fin area broken off.
c) A cracked cylinder baffle.
102. The turbine section of a jet engine:

a) utilizes heat energy to expand and accelerate the incoming gas flow.
b) drives the compressor section.
c) increases air velocity to generate thrust forces.
103. Which statement is true regarding a thermocouple type cylinder head temperature measuring system?

a) When the master switch is turned on, a thermocouple indicator will move off scale to the low side.
b) The voltage output of a thermocouple system is determined by the temperature difference between the two ends of the thermocouple.
c) The resistance required for cylinder head temperature indicators is measured in farads.
104. Fuel scheduling during APU start and under varying pneumatic bleed and electrical loads is maintained:

a) automatically by an aircraft main engine fuel control unit.
b) manually through power control lever position.
c) automatically by the APU fuel control system.
105. What device is used to convert alternating current, which has been induced into the loops of the rotating armature of a dc generator, to direct current?

a) An inverter
b) A rectifier.
c) A commutator.
106. Hot spots in the combustion section of a turbojet engine are possible indicators of:

a) dirty compressor blades.
b) malfunctioning fuel nozzles.
c) faulty igniter plugs.
107. Fuel is discharged for idling speeds on a float type carburetor:

a) through the idle discharge air bleed.
b) from the idle discharge nozzle.
c) in the venturi.
108. Generally, a small crack just started in a cylinder baffle:

a) may be stop drilled.
b) requires repair by reinforcing, such as installation of a doubler over the area.
c) requires no action unless it grows or is branched into two cracks.
109. Which method is commonly used to adjust the level of a float in a float type carburetor?

a) Add or remove shims under the needle valve seat.
b) Lengthening or shortening the float shaft.
c) Change the angle of the float arm pivot.
110. If the points in a vibrator type voltage regulator stick in the closed position while the generator is operating, what will be the probable result?

a) Generator output voltage will increase.
b) Generator output voltage will not be affected.
c) Generator output voltage will decrease.
111. Cold straightening a bent aluminum propeller blade may be accomplished by:

a) an appropriately rated repair station or the manufacturer.
b) the holder of a mechanic certificate with a powerplant rating.
c) a person working under the supervision of the holder of a mechanic certificate with both airframe and powerplant ratings.
112. What is a function of the automatic propeller synchronizing system on multiengine aircraft?

a) To control engine RPM and reduce vibration.
b) To control the tip speed of all propellers.
c) To control the power output of all engines.
113. When does valve overlap occur in the operation of an aircraft reciprocating engine?

a) At the end of the power stroke and the beginning of the exhaust stroke.
b) At the end of the compression stroke and the beginning of the power stroke.
c) At the end of the exhaust stroke and the beginning of the intake stroke.
114. Which of the following defects is cause for rejection of wood propellers?

a) Solder missing from screw heads securing metal tipping.
b) An oversize hub or bolthole, or elongated boltholes.
c) No protective coating on propeller.
115. When is the fuel/air mixture ignited in a conventional reciprocating engine?

a) When the piston reaches top dead center on the compression stroke.
b) When the piston has reached top dead center of the intake stroke.
c) Shortly before the piston reaches the top of the compression stroke.
116. The diffuser section of a jet engine is located between:

a) the burner section and the turbine section.
b) station No. 7 and station No. 8.
c) the compressor section and the burner section.
117. On an aircraft turbine engine, operating at a constant power, the application of engine anti-icing will result in:

a) a false EPR reading.
b) an increase in EPR.
c) noticeable shift in EPR.
118. Which statement is true regarding bearings used in high powered reciprocating aircraft engines?

a) There is less rolling friction when ball bearings are used than when roller bearings are employed.
b) Crankshaft bearings are generally of the ball-type due to their ability to withstand extreme loads without overheating.
c) The outer race of a single row, self aligning ball bearing will always have a radius equal to the radius of the balls.
119. What maintenance record(s) is/are required following a major repair of an aircraft engine?

a) Entry in logbook.
b) Entries in the engine maintenance record and FAA Form 337.
c) Entries in engine maintenance records and a list of discrepancies for the FAA.
120. Reciprocating engines used in helicopters are cooled by:

a) blast tubes on either side of the engine mount.
b) the downdraft from the main rotor.
c) a fan mounted on the engine.
121. Full floating piston pins are those which allow motion between the pin and:

a) both the piston and the small end of the connecting rod.
b) the piston.
c) both the piston and the large end of the connecting rod.
122. One of the advantages of inspecting an aluminum propeller utilizing dye-penetrant inspection procedure is that:

a) it indicates overspeed condition.
b) defects just below the surface are indicated.
c) it shows whether visible lines and other marks are actually cracks rather than scratches.
123. In regard to using a turbine engine oil analysis program, which of the following is NOT true?

a) Generally, an accurate trend forecast may be made after an engine's first oil sample analysis.
b) It is best to start an oil analysis program on an engine when it is new.
c) A successful oil analysis program should be run over an engine's total operating life so that normal trends can be established.
124. Generally, the practice when trimming an engine is to:

a) turn all accessory bleed air off.
b) make adjustments (as necessary) for all engines on the same aircraft with accessory bleed air settings the same--either on or off.
c) turn all accessory bleed air on.
125. (Refer to Powerplant figure 6.) Which curve most nearly represents an aircraft engine`s fuel/air ratio throughout its operating range?



a) 2.
b) 3.
c) 1.
126. Which of the following is a characteristic of a thrust bearing used in most radial engines?

a) Deep groove ball.
b) Tapered roller.
c) Double row ball.
127. Between each row of rotating blades in a turbine engine compressor, there is a row of stationary blades which act to diffuse the air. These stationary blades are called:

a) stators.
b) rotors.
c) buckets.
128. A constant speed propeller provides maximum efficiency by:

a) increasing blade pitch as the aircraft speed decreases.
b) increasing the lift coefficient of the blade.
c) adjusting blade angle for most conditions encountered in flight.
129. As an aid to cold weather starting, the oil dilution system thins the oil with:

a) kerosene.
b) alcohol.
c) gasoline.
130. Repairs of aluminum alloy adjustable pitch propellers are not permitted to be made on which of the following propeller blade areas?

a) Face.
b) Shank.
c) back.
131. Upon inspection of the spark plugs in an aircraft engine, the plugs were found caked with a heavy black soot. This indicates:

a) a lean mixture.
b) a rich mixture.
c) worn oil seal rings.
132. A spark plug's heat range is the result of:

a) the heat intensity of the spark.
b) its ability to transfer heat from the firing end of the spark plug to the cylinder head.
c) the area of the plug exposed to the cooling airstream.
133. Propeller blade tracking is the process of determining:

a) the plane of rotation of the propeller with respect to the aircraft longitudinal axis.
b) that the blade angles are within the specified tolerance of each other.
c) the positions of the tips of the propeller blades relative to each other.
134. The hot section of a turbine engine is particularly susceptible to which of the following kind of damage?

a) Galling.
b) Pitting.
c) Cracking.
135. Which statement is true regarding proper throttle rigging of an airplane?

a) The throttle control is properly adjusted when neither stop makes contact.
b) The stop in the cockpit must be contacted before the stop on the carburetor.
c) The throttle stop on the carburetor must be contacted before the stop in the cockpit.
136. When removing a shielded spark plug, which of the following is most likely to be damaged?

a) Shell section.
b) Core insulator
c) Center electrode.
137. Grease used in aircraft propellers reduces the frictional resistance of moving parts and is easily molded into any form under pressure. This statement defines:

a) antifriction and chemical stability of grease.
b) antifriction and plasticity characteristics of grease.
c) viscosity and melting point of grease.
138. Thermocouple leads:

a) are designed for a specific installation and may not be altered.
b) may be repaired using solderless connectors.
c) may be installed with either lead to either post of the indicator.
139. What are the three basic regulating components of a sea level boosted turbocharger system?
1. Exhaust bypass assembly.
2. Compressor assembly.
3. Pump and bearing casing.
4. Density controller.
5. Differential pressure controller.

a) 2, 3, 4.
b) 1, 2, 3.
c) 1, 4, 5.
140. (Refer to Powerplant figure 5.) The type of system depicted is capable of operating with:



a) external power only.
b) battery power and external power simultaneously.
c) either battery or external power.
141. What operational force tends to bend the propeller blades forward at the tip?

a) Thrust bending force.
b) Torque bending force.
c) Centrifugal twisting force.
142. The pulling out (or down) of an illuminated fire handle in a typical large jet aircraft fire protection system commonly accomplishes what events?

a) Closes fuel shutoff, closes hydraulic shutoff, closes the oxygen shutoff, disconnects the generator field, and arms the fire-extinguishing system.
b) Closes fuel shutoff, closes hydraulic shutoff, disconnects the generator field, and arms the fire extinguishing system.
c) Closes all firewall shutoff valves, disconnects the generator, and discharges a fire bottle.
143. During overhaul, the disassembled parts of an engine are usually degreased with some form of mineral spirits solvent rather than water mixed degreasers primarily because:

a) solvent degreasers are much more effective.
b) water-mixed degreasers cause corrosion.
c) water mixed degreaser residues may cause engine oil contamination in the overhauled engine.
144. When the starter switch to the aircraft gas turbine engine starter-generator is energized and the engine fails to rotate, one of the probable causes would be the:

a) starter solenoid is defective.
b) power lever switch is defective.
c) undercurrent solenoid contacts are defective.
145. The fuel systems of aircraft certificated in the standard classification must include which of the following?

a) A positive means of shutting off the fuel to all engines.
b) An engine driven fuel pump and at least one auxiliary pump per engine.
c) A reserve supply of fuel, available to the engine only after selection by the flightcrew, sufficient to operate the engines at least 30 minutes at METO power.
146. (Refer to Powerplant figure 4.) In a 28-volt system, what is the maximum continuous current that can be carried by a single No. 10 copper wire 25 feet long, routed in free air?



a) 35 amperes.
b) 20 amperes.
c) 28 amperes.
147. Who establishes the recommended operating time between overhauls (TBO) of a turbine engine used in general aviation?

a) The engine manufacturer.
b) The FAA.
c) The operator (utilizing manufacturer data and trend analysis) working in conjunction with the FAA.
148. If the thermocouple leads were inadvertently crossed at installation, what would the cylinder temperature gauge pointer indicate?

a) Moves off scale on the high side of the meter.
b) Moves off scale on the zero side of the meter.
c) Normal temperature for prevailing condition.
149. Which of the following can inspect and approve an engine major repair for return to service?

a) Certificated mechanic with inspection authorization.
b) Certificated mechanic with airframe and powerplant ratings.
c) Certificated mechanic with a powerplant rating.
150. An increase in manifold pressure with a constant RPM will cause the bearing load in an engine to:

a) remain relatively constant.
b) decrease.
c) increase.
151. Compared to normally aspirated engines, turbocharged engine exhaust systems operate at:

a) similar temperatures and higher pressures.
b) similar temperatures and pressures.
c) higher temperatures and higher pressures.
152. 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.
153. The abbreviation Pt7 used in turbine engine terminology means:

a) the total pressure at station No. 7.
b) the total inlet pressure.
c) pressure and temperature at station No. 7.
154. A method commonly used to prevent carburetor icing is to:

a) mix alcohol with the fuel.
b) preheat the intake air.
c) electrically heat the venturi and throttle valve.
155. Which of the following is regulated in a generator to control its voltage output?

a) Speed of the armature.
b) Number of windings in the armature.
c) The strength of the field.
156. Which of the following generally renders an aluminum alloy propeller unrepairable?

a) Any slag inclusions or cold shuts.
b) Any repairs that would require shortening and re-contouring of blades.
c) Transverse cracks of any size.
157. Where is the engine fuel shutoff valve usually located?

a) Aft of the firewall.
b) Adjacent to the fuel pump.
c) Downstream of the engine driven fuel pump.
158. As an aircraft engine's speed is increased, the voltage induced in the primary coil of the magneto:

a) increases.
b) varies with the setting of the voltage regulator.
c) remains constant.
159. A term commonly used when two or more electrical terminals are installed on a single lug of a terminal strip is:

a) stacking.
b) stepping.
c) strapping.
160. Which of the following conditions would most likely lead to detonation?

a) Late ignition timing.
b) use of fuel with too low an octane rating.
c) Use of fuel with too high an octane rating.
161. Igniter plugs used in turbine engines are subjected to high intensity spark discharges and yet they have a long service life because they:

a) operate at much lower temperatures.
b) do not require continuous operation.
c) are not placed directly into the combustion chamber.
162. Boost manifold pressure is generally considered to be any manifold pressure above:

a) 50 inches Hg.
b) 14.7 inches Hg.
c) 30 inches Hg.
163. The primary purpose of the air bleed openings used with continuous flow fuel injector nozzles is to:

a) lean out the mixture.
b) aid in proper fuel vaporization.
c) provide for automatic mixture control.
164. An advantage of the axial flow compressor is its:

a) low starting power requirements.
b) high peak efficiency.
c) low weight.
165. When a magneto is operating, what is the probable cause for a shift in internal timing:

a) The rotating magnet looses its magnetism.
b) The cam follower wear and/or the breaker points wear.
c) The distributor gear teeth are wearing on the rotor gear teeth.
166. Defective spark plugs will cause the engine to run rough at:

a) all speeds.
b) high speeds only.
c) low speeds only.
167. How can a steel propeller hub be tested for cracks?

a) By magnetic particle inspection.
b) By etching.
c) By anodizing.
168. What is the radial location of the two north poles of a four pole rotating magnet in a high tension magneto?

a) 270° apart.
b) 90° apart.
c) 180° apart.
169. What is the function of a blast tube as found on aircraft engines?

a) A device to cool an engine accessory.
b) A tube used to load a cartridge starter.
c) A means of cooling the engine by utilizing the propeller backwash.
170. (Refer to Powerplant figure 2.) Determine the fire extinguisher container pressure limits when the temperature is 75 °F.



a) 326 minimum and 415 maximum.
b) 338 minimum and 424 maximum.
c) 330 minimum and 419 maximum.
171. Which condition would be the least likely to be caused by failed or failing engine bearings?

a) High oil temperatures.
b) Excessive oil consumption.
c) Low oil temperatures.
172. (1) Cast iron piston rings may be used in chrome plated cylinders.
(2) Chrome plated rings may be used in plain steel cylinders.
Regarding the above statements,

a) neither No. 1 nor No. 2 is true.
b) both No. 1 and No. 2 are true.
c) only No. 1 is true.
173. What is the relationship between distributor and crankshaft speed of aircraft reciprocating engines?

a) The distributor turns at one and one half crankshaft speed.
b) The distributor turns at one half crankshaft speed.
c) The crankshaft turns at one half distributor speed.
174. How is the oil collected by the piston oil ring returned to the crankcase?

a) Through holes drilled in the piston oil ring groove.
b) Down vertical slots cut in the piston wall between the piston oil ring groove and the piston skirt.
c) Through holes drilled in the piston pin recess.
175. Engine crankshaft runout is usually checked:
1. during engine overhaul.
2. during annual inspection.
3. after a 'prop strike' or sudden engine stoppage.
4. during 100-hour inspection.

a) 1, 2, and 3.
b) 1 and 3.
c) 1, 3, and 4.
176. Why is high nickel chromium steel used in many exhaust systems?

a) Corrosion resistance and low expansion coefficient.
b) High heat conductivity and flexibility.
c) Corrosion resistance and high heat conductivity.
177. What carburetor component measures the amount of air delivered to the engine?

a) Automatic mixture control.
b) Venturi.
c) Economizer valve.
178. The fuel flowmeter used with a continuous-fuel injection system installed on an aircraft horizontally opposed reciprocating engines measures the fuel pressure drop across the:

a) metering valve.
b) fuel nozzles.
c) manifold valve.
179. What is the primary advantage of an axial flow compressor over a centrifugal compressor?

a) Less expensive.
b) Greater pressure ratio.
c) High frontal area.
180. In addition to causing accelerated wear, dust or sand ingested by a reciprocating engine may also cause:

a) acid formation.
b) sludge formation.
c) silicon fouling of spark plugs.
181. A fixed pitch wooden propeller that has been properly installed and the attachment bolts properly torqued exceeds the out of track allowance by 1/16 inch. The excessive out of track condition may be corrected by:

a) slightly overtightening the attachment bolts adjacent to the most forward blade.
b) placing shims between the inner flange and the propeller.
c) discarding the propeller since out of track conditions cannot be corrected.
182. Which of the following would be cause for rejection of a spark plug?

a) Lead fouling of the electrode and insulator.
b) Insulator tip cracked.
c) Carbon fouling of the electrode and insulator.
183. On which part of the cylinder walls of a normally operating engine will the greatest amount of wear occur?

a) Wear is normally evenly distributed.
b) Near the top of the cylinder.
c) Near the center of the cylinder where piston velocity is greatest.
184. What is the electrical location of the primary capacitor in a high-tension magneto?

a) In series with the primary and secondary winding.
b) In series with the breaker points.
c) In parallel with the breaker points.
185. When in operation, the speed of an APU

a) is controlled by a cockpit power lever.
b) remains at or near rated speed regardless of the load condition.
c) remains at idle and automatically accelerates to rated speed when placed under load.
186. In what units are turbine engine tachometers calibrated?

a) Percent of engine pressure ratio.
b) Percent of engine RPM.
c) Actual engine RPM.
187. The vortex dissipators installed on some turbine-powered aircraft to prevent engine FOD utilize:

a) variable inlet guide vanes (IGV) and/or variable first stage fan blades.
b) variable geometry inlet ducts.
c) a stream of engine bleed air blown toward the ground ahead of the engine.
188. On most reciprocating multiengine aircraft, automatic propeller synchronization is accomplished through the actuation of the:

a) throttle levers.
b) propeller governors.
c) propeller control levers.
189. What retains the nitrogen charge and fire extinguishing agent in a high rate of discharge (HRD) container?

a) Pressure gauge and cartridge.
b) Breakable disk and fusible disk.
c) Pressure switch and check tee valve.
190. Select the Airworthiness Directive applicability statement which applies to an IVO 355 engine, serial number T8164, with 2,100 hours' total time and 300 hours since rebuilding.

a) Applies to all IVO 355 engines, serial numbers T8000 through T8900 with 2,400 hours or more total time.
b) Applies to all I.O. and TV10-355 engines, all serial numbers regardless of total time or since overhaul.
c) Applies to all IVO 355 engines, serial numbers T8000 through T8300, having less than 2,400 hours' total time.
191. Which of the following instrument discrepancies require replacement of the instrument?
1. Red line missing from glass.
2. Glass cracked.
3. Case paint chipped.
4. Will not zero out.
5. Pointer loose on shaft.
6. Mounting screw loose.
7. Leaking at line B nut.
8. Fogged.

a) 1, 2, 4, 7.
b) 2, 4, 5, 8.
c) 2, 3, 7, 8.
192. When using a timing light to time a magneto to an aircraft engine, the magneto switch should be placed in the:

a) OFF position.
b) LEFT or RIGHT position (either one).
c) BOTH position.
193. Proper operation of electric deicing boots on individual propeller blades may best be determined by:

a) feeling the boots to see if they are heating.
b) feeling the sequence of boot heating and have an assistant observe the loadmeter indications.
c) observing the ammeter or loadmeter for current flow.
194. The primary purpose of a feathering propeller is to:

a) prevent propeller damage when an engine fails in flight.
b) prevent further engine damage when an engine fails in flight.
c) eliminate the drag created by a windmilling propeller when an engine fails in flight.
195. What section in the instructions for continued airworthiness is FAA approved?

a) Engine overhaul manual or section.
b) Airworthiness limitations section.
c) Engine maintenance manual or section.
196. What is the maximum number of bonding jumper wires that may be attached to one terminal grounded to a flat surface?

a) Four
b) Two.
c) Three.
197. Minor surface damage located in a repairable area, but not on the leading or trailing edges of aluminum blades, may be repaired by first:

a) filing with a riffle file.
b) rough sanding and applying a proper filler.
c) filing with a half round or flat file.
198. What is a basic advantage of using ac for electrical power for a large aircraft?

a) AC systems operate at lower voltage than dc systems and therefore use less current and can use smaller and lighter weight wiring.
b) AC systems operate at higher voltage than dc systems and therefore use more current and can use smaller and lighter weight wiring.
c) AC systems operate at higher voltage than dc systems and therefore use less current and can use smaller and lighter weight wiring.
199. The five events of a four stroke cycle engine in the order of their occurrence are:

a) intake, compression, ignition, power, exhaust.
b) intake, ignition, compression, power, exhaust.
c) intake, power, compression, ignition, exhaust.
200. A characteristic of dyna focal engine mounts as applied to aircraft reciprocating engines is that the:

a) shock mounts eliminate the torsional flexing of the powerplant.
b) engine attaches to the shock mounts at the engine's center of gravity.
c) shock mounts point toward the engine's center of gravity.
201. In turbine engines that utilize a pressurization and dump valve, the dump portion of the valve:

a) drains the engine manifold lines to prevent fuel boiling and subsequent deposits in the lines as a result of residual engine heat (at engine shutdown).
b) dumps extra fuel into the engine in order to provide for quick engine acceleration during rapid throttle advancement.
c) cuts off fuel flow to the engine fuel manifold and dumps the manifold fuel into the combustor to burn just before the engine shuts down.
202. Which type of fuel control is used on most of today's turbine engines?

a) Electromechanical.
b) Mechanical.
c) Hydromechanical or electronic.
203. Aircraft copper electrical wire is coated with tin, silver, or nickel in order to:

a) prevent oxidization.
b) add strength.
c) improve conductivity.
204. What is the purpose of a power check on a reciprocating engine?

a) To determine if the fuel/air mixture is adequate.
b) To determine satisfactory performance.
c) To check magneto drop.
205. Why does one type of Fenwal fire detection system use spot detectors wired in parallel between two separate circuits?

a) To provide an installation that is equal to two separate systems, a primary system and a secondary, or back-up system.
b) So that a double fault may exist in the system without sounding a false alarm.
c) So that a single fault may exist in the system without sounding a false alarm.
206. When installing electrical wiring parallel to a fuel line, the wiring should be:

a) above the fuel line.
b) in metal conduit.
c) in a non-conductive fire-resistant sleeve.
207. Fuel is normally supplied to an APU from:

a) its own independent fuel supply.
b) the airplane's main fuel supply.
c) the airplane's reserve fuel supply.
208. How does a dual axial flow compressor improve the efficiency of a turbojet engine?

a) More turbine wheels can be used.
b) Higher compression ratios can be obtained.
c) The velocity of the air entering the combustion chamber is increased.
209. Propeller blade angle is the angle between the:

a) chord of the blade and the relative wind.
b) relative wind and the rotational plane of the propeller.
c) chord of the blade and the rotational plane of the propeller.
210. 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.
b) indicates an imminent component failure.
c) indicates accelerated generalized wear.
211. The type of oil pumps most commonly used on turbine engines are classified as:

a) constant speed.
b) positive displacement.
c) variable displacement.
212. What method(s) is/are used to provide clean air to the engines of helicopters and turboprop airplanes that have particle (sand and ice) separators installed?

a) Air/moisture separators, and 'washing' the air clean utilizing water droplets.
b) Sharp airflow directional change to take advantage of inertia and/or centrifugal force, and filters or engine inlet screens.
c) Positive and negative charged areas to attract and/or repel particulates out of the airflow.
213. 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:

a) extended cylinder skirts.
b) routing the valve operating mechanism lubricating oil to a separate scavenger pump.
c) reversed oil control rings.
214. Which of the following should a mechanic consult to determine the maximum amount of cylinder cooling fin that could be removed when cracks are found?

a) AC 43.13-1A.
b) Engine structure repair manual.
c) Engine manufacturer's service or overhaul manual.
215. Grinding the valves of a reciprocating engine to a feather edge is likely to result in:

a) preignition and burned valves.
b) normal operation and long life.
c) excessive valve clearance.
216. What are the principal advantages of the duplex fuel nozzle used in many turbine engines?

a) Restricts the amount of fuel flow to a level where more efficient and complete burning of the fuel is achieve.
b) Provides better atomization and uniform flow pattern.
c) Allows a wider range of fuels and filters to be used.
217. During inspection, turbine engine components exposed to high temperatures may only be marked with such materials as allowed by the manufacturer. These materials generally include:
1. layout dye.
2. commercial felt tip marker.
3. wax or grease pencil.
4. chalk.
5. graphite lead pencil.

a) 1, 2, and 4.
b) 2, 4, and 5.
c) 1, 3, and 4.
218. Which type valve prevents oil from entering the main accessory case when the engine is not running?

a) Bypass.
b) Check.
c) Relief.
219. Dislodged internal muffler baffles on a small reciprocating engine may:

a) cause the engine to run excessively cool.
b) obstruct the muffler outlet and cause excessive exhaust back pressure.
c) cause high fuel and oil consumption.
220. Master rod bearings are generally what type?

a) Plain
b) Roller
c) Ball
221. As a general rule, starter brushes are replaced when they are approximately:

a) one-third their original length.
b) two-thirds their original length.
c) one half their original length.
222. (1) Electrical circuit protection devices are rated based on the amount of current that can be carried without overheating the wiring insulation.
(2) A 'trip free' circuit breaker makes it impossible to manually hold the circuit closed when excessive current is flowing.
Regarding the above statements:

a) both No. 1 and No. 2 are true.
b) only No. 1 is true.
c) only No. 2 is true.
223. A nine cylinder radial engine, using a multiple point priming system with a central spider, will prime which cylinders?

a) All cylinders.
b) One, two, three, eight, and nine.
c) One, three, five, and seven.
224. The type of ignition system used on most turbine aircraft engines is:

a) capacitor discharge.
b) high resistance.
c) low tension.
225. A broken cooling fin on a cylinder head:

a) may be filed to smooth contours if damage and/or repair limits are not exceeded.
b) is cause for rejection of the head.
c) should be left alone.
226. A Bourdon tube instrument may be used to indicate
1. pressure.
2. temperature.
3. position.
4. quantity.

a) 1 and 2.
b) 1 and 3.
c) 2 and 4.
227. The generally acceptable way to obtain accurate on-site temperature prior to performing engine trimming is to:

a) call the control tower to obtain field temperature.
b) hang a thermometer in the shade of the nose wheel-well until the temperature reading stabilizes.
c) observe the reading on the aircraft Outside Air Temperature (OAT) gauge.
228. Vortex dissipator systems are generally activated by:

a) an engine inlet airflow sensor.
b) a landing gear switch.
c) a fuel pressure switch anytime an engine is operating.
229. What is the possible cause of an engine running rich at full throttle if it is equipped with a float type carburetor?

a) Clogged main air bleed.
b) Float level too low.
c) Clogged atmospheric vent.
230. Inspection of pneumatic starters by maintenance technicians usually includes checking the:

a) stator and rotor blades for FOD.
b) oil level and magnetic drain plug condition.
c) rotor alignment.
231. Dirt particles in the air being introduced into the compressor of a turbine engine will form a coating on all but which of the following?

a) Inlet guide vanes.
b) Casings.
c) Turbine blades.
232. Compression ratio is the ratio between the:

a) piston travel on the compression stroke and on the intake stroke.
b) cylinder volume with piston at bottom dead center and at top dead center.
c) combustion chamber pressure on the combustion stroke and on the exhaust stroke.
233. Straightening nitrided crankshafts is:

a) Recommended.
b) approved by the manufacturer.
c) Not recommended.
234. The primary purpose of a cuff on a propeller is to:

a) strengthen the propeller.
b) increase the flow of cooling air to the engine nacelle.
c) distribute anti icing fluid.
235. An engine misses in both the right and left positions of the magneto switch. The quickest method for locating the trouble is to:

a) perform a compression check.
b) check for one or more cold cylinders.
c) check each spark plug.
236. It is important that nicks in aluminum alloy propeller blades be repaired as soon as possible in order to:

a) equalize the centrifugal loads between the blades.
b) eliminate stress concentration points.
c) maintain equal aerodynamic characteristics between the blades.
237. In a fixed fire-extinguishing system, there are two small lines running from the system and exiting overboard. These line exit ports are covered with a blowout type indicator disc. Which of the following statements is true?

a) When the red indicator disc is missing, it indicates the fire extinguishing system has been normally discharged.
b) When the yellow indicator disc is missing, it indicates the fire extinguishing system has been normally discharged.
c) When the green indicator disc is missing, it indicates the fire extinguishing system has had a thermal discharge.
238. What is a function of the idling air bleed in a float type carburetor?

a) It vaporizes the fuel at idling speeds.
b) It provides a means for adjusting the mixture at idle speeds.
c) It aids in emulsifying/vaporizing the fuel at idle speeds.
239. One function of the nozzle diaphragm in a turbine engine is to:

a) direct the flow of gases to strike the turbine blades at the desired angle.
b) decrease the velocity of exhaust gases.
c) center the fuel spray in the combustion chamber.
240. Which of the following contains a table that lists the engines to which a given propeller is adaptable?

a) Aircraft Type Certificate Data Sheets.
b) Engine Type Certificate Data Sheets.
c) Propeller Type Certificate Data Sheets.
241. Which of the following would be a factor in the failure of an engine to develop full power at takeoff?

a) Improper adjustment of carburetor heat valve control linkage.
b) Failure of the economizer valve to remain closed at takeoff throttle setting.
c) Excessively rich setting on the idle mixture adjustment.
242. Which statement is generally true regarding thrust reverser systems?

a) It is possible to move some aircraft backward on the ground using reverse thrust.
b) Mechanical blockage system design permits a deployment position aft of the exhaust nozzle only.
c) Engine thrust reversers on the same aircraft usually will not operate independently of each other (must all be simultaneously).
243. Apparent engine roughness is often a result of propeller unbalance. The effect of an unbalanced propeller will usually be:

a) greater at high RPM.
b) greater at low RPM.
c) approximately the same at all speeds.
244. Usually, most of the load placed on an APU occurs when:

a) an electrical load is placed on the generator(s).
b) the bleed air valve is opened.
c) the bleed air valve is closed.
245. A defective primary capacitor in a magneto is indicated by:

a) a weak spark.
b) a fine grained frosted appearance of the breaker points.
c) burned and pitted breaker points.
246. Maximum taper contact between crankshaft and propeller hub is determined by using:

a) bearing blue color transfer.
b) a surface gauge.
c) a micrometer.
247. What prevents pressure within the lubricating oil tank from rising above or falling below ambient pressure (reciprocating engine)?

a) Oil pressure relief valve.
b) Oil tank vent.
c) Oil tank check valve.
248. Oil picks up the most heat from which of the following turbine engine components?

a) Turbine bearing.
b) Compressor bearing.
c) Rotor coupling.
249. After spark plugs from an opposed engine have been serviced, in what position should they be reinstalled?

a) Next in firing order to the one from which they were removed.
b) Next in firing order to the one from which they were removed and swapped bottom to top.
c) Swapped bottom to top.
250. If the oil pressure of a cold engine is higher than at normal operating temperatures, the

a) engine's lubrication system is probably operating normally.
b) oil dilution system should be turned on immediately
c) oil system relief valve should be readjusted.
251. What is the primary factor which controls the pressure ratio of an axial flow compressor?

a) Number of stages in compressor.
b) Compressor inlet temperature.
c) Compressor inlet pressure.
252. On a carburetor without an automatic mixture control as you ascend to altitude, the mixture will:

a) not be affected.
b) be enriched.
c) be leaned.
253. Spark plugs are considered worn out when the:

a) center electrode edges have become rounded.
b) electrodes have worn away to about two-thirds of their original dimensions.
c) electrodes have worn away to about one-half of their original dimensions.
254. What could be a result of undetected exhaust system leaks in a reciprocating engine powered airplane?

a) A rough-running engine with increased fuel consumption.
b) Pilot/passenger incapacitation caused by carbon monoxide entering the cabin.
c) Too low exhaust back pressure resulting in the desired power settings not being attained.
255. You are performing a 100-hour inspection on an R985-22 aircraft engine. What does the '985' indicate?

a) The total piston displacement of one cylinder.
b) The pistons will pump a maximum of 985 cubic inches of air per crankshaft revolution.
c) The total piston displacement of the engine.
256. What is the major function of the turbine assembly in a turbojet engine?

a) Supplies the power to turn the compressor.
b) Directs the gases in the proper direction to the tailpipe.
c) Increases the temperature of the exhaust gases.
257. What part of an aircraft in flight will begin to accumulate ice before any other?

a) Wing leading edge.
b) Carburetor.
c) Propeller spinner or dome.
258. Thrust reversers utilizing a pneumatic actuating system usually receive operating pressure from:

a) the engine bleed air system.
b) high pressure air reservoirs.
c) an on board hydraulic or electrical powered compressor.
259. The most satisfactory extinguishing agent for a carburetor or intake fire is:

a) methyl bromide.
b) dry chemical.
c) carbon dioxide.
260. On an aircraft that utilizes an exhaust heat exchanger as a source of cabin heat, how should the exhaust system be inspected?

a) Hydrostatically tested.
b) X rayed to detect any cracks.
c) With the heater air shroud removed.
261. Increased engine heat will cause volumetric efficiency to:

a) remain the same.
b) increase.
c) decrease.
262. Basically, the indicator of a tachometer system is responsive to change in:

a) voltage.
b) current flow.
c) frequency.
263. When using an electric starter motor, the current flow throug:h it

a) is highest just before starter cutoff (at highest RPM.)
b) is highest at the start of motor rotation.
c) remains relatively constant throughout the starting cycle.
264. What type of oil do most engine manufacturers recommend for new reciprocating engine break in?

a) Semi synthetic oil.
b) Straight mineral oil.
c) Ashless dispersant oil.
265. When using an electric starter motor, current usage:

a) is highest just before starter cutoff (at highest RPM).
b) remains relatively constant throughout the starting cycle.
c) is highest at the start of motor rotation.
266. What is the primary purpose of the oil to fuel heat exchanger?

a) De aerate the oil.
b) Cool the fuel.
c) Cool the oil.
267. Alternators (ac generators) that are driven by a constant-speed drive (CSD) mechanism are used to regulate the alternator to a constant:

a) amperage output.
b) voltage output.
c) hertz output.
268. Under which of the following conditions will the trimming of a turbine engine be most accurate?

a) High wind and high moisture.
b) No wind and low moisture.
c) High moisture and low wind.
269. Which of the following contains a minimum checklist for 100-hour inspections of engines?

a) Engine Specifications or Type Certificate Data Sheets.
b) 14 CFR Part 33 Appendix A.
c) 14 CFR Part 43 Appendix D.
270. Which statement is true regarding jet engines?

a) The thrust delivered per pound of air consumed is less at high altitude than at low altitude.
b) At the higher engine speeds, thrust increases rapidly with small increases in RPM.
c) At the lower engine speeds, thrust increases rapidly with small increases in RPM.
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