Questions and Answers - Aircraft Powerplant Ignition and Starting Systems | Aircraft Systems

Questions and Answers - Aircraft Powerplant Ignition and Starting Systems

1. When a magneto is disassembled, keepers are usually placed across the poles of the rotating magnet to reduce the loss of magnetism. These keepers are usually made of
a. chrome magnet steel.
b. soft iron.
c. cobalt steel.

2. How is the strength of a magneto magnet checked?
a. Hold the points open and check the output of the primary coil with an ac ammeter while operating the magneto at a specified speed.
b. Check the ac voltage reading at the breaker points.
c. Check the output of the secondary coil with an ac ammeter while operating the magneto at a specified speed.

3. The E-gap angle is usually defined as the number of degrees between the neutral position of the rotating magnet and the position
a. where the contact points close.
b. where the contact points open.
c. of greatest magnetic flux density.

4. The greatest density of flux lines in the magnetic circuit of a rotating magnet-type magneto occurs when the magnet is in what position?
a. Full alignment with the field shoe faces.
b. A certain angular displacement beyond the neutral position, referred to as E-gap angle or position.
c. The position where the contact points open.

5. Magneto breaker point opening relative to the position of the rotating magnet and distributor rotor (internal timing) can be set most accurately
a. during the magneto-to-engine timing operation.
b. during assembly of the magneto before installation on the engine.
c. by setting the points roughly at the required clearance before installing the magneto and then making the fine breaker point adjustment after installation to compensate for wear in the magneto drive train.


6. Why are high-tension ignition cables frequently routed from the distributors to the spark plugs in flexible metallic conduits?
a. To eliminate high altitude flashover.
b. To reduce the formation of corona and nitric oxide on the cable insulation.
c. To reduce the effect of the high-frequency electromagnetic waves emanated during operation.

7. What will be the results of increasing the gap of the breaker points in a magneto?
a. Retard the spark and increase its intensity.
b. Advance the spark and decrease its intensity.
c. Retard the spark and decrease its intensity.

8. What is the purpose of a safety gap in some magnetos?
a. To discharge the secondary coil's voltage if an open occurs in the secondary circuit.
b. To ground the magneto when the ignition switch is off.
c. To prevent flashover in the distributor.

9. When timing a magneto internally, the alignment of the timing marks indicates that the
a. breaker points are just closing.
b. magnets are in the neutral position.
c. magnets are in the E-gap position.

10. When internally timing a magneto, the breaker points begin to open when the rotating magnet is
a. fully aligned with the pole shoes.
b. a few degrees past full alignment with the pole shoes.
c. a few degrees past the neutral position.

11. What is the electrical location of the primary capacitor in a high-tension magneto?
a. In parallel with the breaker points.
b. In series with the breaker points.
c. In a series with the primary and secondary winding.

12. In a high-tension ignition system, the current in the magneto secondary winding is
a. conducted from the primary winding via the discharge of the capacitor.
b. induced when the primary circuit is interrupted.
c. induced when the primary circuit discharges via the breaker points.

13. When a "Shower of Sparks" ignition system is activated at an engine start, a spark plug fires
a. as soon as the advance breaker points open.
b. only while both the retard and advance breaker points are closed.
c. only while both the retard and advance breaker points are open.

14. What is the radial location of the two north poles of a four-pole rotating magnet in a high-tension magneto?
a. 180" apart.
b. 270" apart.
c. 90" apart.

15. Magneto timing drift is caused by erosion of the breaker points and
a. excessive spark plug gap.
b. wear of the cam followers.
c. loss of magnetism in the rotor.

16. Capacitance afterfiring in most modern spark plugs is reduced by the use of
a. fine wire electrodes.
b. a built-in resistor in each plug.
c. aluminum oxide insulation.

17. What components make up the magnetic system of a magneto?
a. Pole shoes, the pole shoe extensions, and the primary coil.
b. Primary and secondary coils.
c. Rotating magnet, the pole shoes, the pole shoe extensions, and the coil core.

18. In an aircraft ignition system, one of the functions of the capacitor is to
a. regulate the flow of current between the primary and secondary coil.
b. facilitate a more rapid collapse of the magnetic field in the primary coil.
c. stop the flow of magnetic lines of force when the points open.

19. When will the voltage in the secondary winding of a magneto, installed on a normally operating engine, be at its highest value?
a. Just prior to spark plug firing.
b. Toward the latter part of the spark duration when the flame front reaches its maximum velocity.
c. Immediately after the breaker points close.

20. When the switch is off in a battery ignition system, the primary circuit is
a. grounded.
b. opened.
c. shorted.


21. As an aircraft engine's speed is increased, the voltage induced in the primary coil of the magneto
a. remains constant.
b. increases.
c. varies with the setting of the voltage regulator.

22. When internally timing a magneto, the breaker points begin to open when
a. the piston has just passed TDC at the end of the compression stroke.
b. the magnet poles are a few degrees beyond the neutral position.
c. the magnet poles are fully aligned with the pole shoes.

23. The purpose of a safety gap in a magneto is to
a. prevent burning out the primary winding.
b. protect the high-voltage winding from damage.
c. prevent burning of contact points.

24. A defective primary capacitor in a magneto is indicated by
a. a fine-grained frosted appearance of the breaker points.
b. burned and pitted breaker points.
c. a weak spark.

25. How many secondary coils are required in a low-tension ignition system on an 18-cylinder engine?
a. 36
b. 18
c. 9

26. A magneto ignition switch is connected
a. in series with the breaker points.
b. parallel to the breaker points.
c. in series with the primary capacitor and parallel to the breaker points.

27. The spark is produced in a magneto ignition system when the breaker points are
a. fully open.
b. beginning to open.
c. fully closed.

28. Shielding is used on spark plug and ignition wires to
a. protect the wires from short circuits as a result of chafing and rubbing.
b. prevent outside electromagnetic emissions from disrupting the operation of the ignition system.
c. prevent interference with radio reception.

29. What is the purpose of using an impulse coupling with a magneto?
a. To absorb impulse vibrations between the magneto and the engine.
b. To compensate for backlash in the magneto and the engine gears.
c. To produce a momentary high rotational speed of the magneto.

30. The purpose of staggered ignition is to compensate for
a. short ignition harness.
b. rich fuel/air mixture around exhaust valve.
c. diluted fuel/air mixture around exhaust valve.

31. Aircraft magneto housings are usually ventilated in order to
a. prevent the entrance of outside air which may contain moisture.
b. allow heated air from the accessory compartment to keep the internal parts of the magneto dry.
c. provide cooling and remove corrosive gases produced by normal arcing.

32. Failure of an engine to cease firing after turning the magneto switch off is an indication of
a. an open high tension lead.
b. an open P-lead to ground.
c. a grounded magneto switch.

33. Alignment of the marks provided for internal timing of a magneto indicates that the
a. breaker points are just beginning to close for No. 1 cylinder.
b. magneto is in E-gap position.
c. No. 1 cylinder is on TDC of compression stroke.

34. When using a timing light to time a magneto to an aircraft engine, the magneto switch should be placed in the
a. BOTH position.
b. OFF position.
c. LEFT or RIGHT position (either one).

35. What is the difference between a low-tension and a high-tension engine ignition system?
a. A low-tension system produces relatively low voltage at the spark plug as compared to a high-tension system.
b. A high-tension system is designed for high-altitude aircraft, while a low-tension system is for low- to medium-altitude aircraft.
c. A low-tension system uses a transformer coil near the spark plugs to boost voltage, while the high-tension system voltage is constant from the magneto to the spark plugs.

36. What test instrument could be used to test an ignition harness for suspected leakage?
a. A high-tension lead tester.
b. A high voltage dc voltmeter.
c. A high amperage dc ammeter.

37. The amount of voltage generated in any magneto secondary coil is determined by the number of windings and by the
a. rate of buildup of the magnetic field around the primary coil.
b. rate of collapse of the magnetic field around the primary coil.
c. amount of charge released by the capacitor.

38. Magneto breaker points must be timed to open when the
a. rotating magnet is positioned a few degrees before neutral.
b. greatest magnetic field stress exists in the magnetic circuit.
c. rotating magnet is in the full register position.

39. In reference to a "Shower of Sparks" ignition system,
(1) the retard breaker points are designed to keep the affected ignition system operating if the advance breaker points should fail during normal engine operation (after start).
(2) the timed opening of the retard breaker points is designed to prevent engine "kickback" during start.

Regarding the above statements,
a. only No. 1 is true.
b. only No. 2 is true.
c. both No. 1 and No. 2 are true.

40. The capacitor-type ignition system is used almost universally on turbine engines primarily because of its high voltage and
a. low amperage.
b. long life.
c. high-heat intensity.

41. In a low-tension ignition system, each spark plug requires an individual
a. capacitor.
b. breaker assembly.
c. secondary coil.

42. A certain nine-cylinder radial engine used a noncompensated single-unit, dual-type magneto with a four pole rotating magnet and separately mounted distributors. Which of the following will have the lowest RPM at any given engine speed?
a. Breaker cam.
b. Engine crankshaft.
c. Distributors.

43. What will be the effect if the spark plugs are gapped too wide?
a. Insulation failure.
b. Hard starting.
c. Lead damage.

44. When removing a shielded spark plug, which of the following is most likely to be damaged?
a. Center electrode.
b. Shell section.
c. Core insulator.

45. What likely effect would a cracked distributor rotor have on a magneto?
a. Ground the secondary circuit through the crack.
b. Fire two cylinders simultaneously.
c. Ground the primary circuit through the crack.

46. How does the ignition system of a gas turbine engine differ from that of a reciprocating engine?
a. One igniter plug is used in each combustion chamber.
b. Magneto-to-engine timing is not critical.
c. A high-energy spark is required for ignition.

47. In a turbine engine dc capacitor discharge ignition system, where are the high-voltage pulses formed?
a. At the breaker.
b. At the triggering transformer.
c. At the rectifier.

48. Which of the following breaker point characteristics is associated with a faulty capacitor?
a. Crowned.
b. Fine grained.
c. Coarse grained.

49. How are most radial engine spark plug wires connected to the distributor block?
a. By use of cable-piercing screws.
b. By use of self-locking cable ferrules.
c. By use of terminal sleeves and retaining nuts.

50. Thermocouples are usually inserted or installed on the
a. front cylinder of the engine.
b. rear cylinder of the engine.
c. hottest cylinder of the engine.


51. Capacitance afterfiring of a spark plug is caused by
a. the stored energy in the ignition shielded lead unloading after normal timed ignition.
b. excessive center electrode erosion.
c. constant polarity firing.

52. If it is found that a shielded ignition system does not adequately reduce ignition noise, it may be necessary to install
a. a second layer of shielding.
b. a filter between the magneto and magneto switch.
c. bonding wires from the shielding to ground.

53. 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 distributor gear teeth are wearing on the rotor gear teeth.
c. The cam follower wears and/or the breaker points wear.

54. Why are turbine engine igniters less susceptible to fouling than reciprocating engine spark plugs?
a. The high-intensity spark cleans the igniter.
b. The frequency of the spark is less for igniters.
c. Turbine igniters operate at cooler temperatures.

55. The constrained-gap igniter plug used in some gas turbine engines operates at a cooler temperature because
a. it projects into the combustion chamber.
b. the applied voltage is less.
c. the construction is such that the spark occurs beyond the face of the combustion chamber liner.

56. What should be used to clean grease or carbon tracks from capacitors or coils that are used in magnetos?
a. Solvent.
b. Acetone.
c. Naphtha.

57. Generally, when removing a turbine engine igniter plug, in order to eliminate the possibility of the technician receiving a lethal shock, the ignition switch is turned off and
a. disconnected from the power supply circuit.
b. the igniter lead is disconnected from the plug and the center electrode grounded to the engine after disconnecting the transformer-exciter input lead and waiting the prescribed time.
c. the transformer-exciter input lead is disconnected and the center electrode grounded to the engine after disconnecting the igniter lead from the plug and waiting the prescribed time.

58. Great caution should be exercised in handling damaged hermetically sealed turbine engine igniter transformer units because
a. compounds in the unit may become a fire or explosion hazard when exposed to the air.
b. some contain radioactive material.
c. some contain toxic chemicals.

59. 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. are not placed directly into the combustion chamber.
c. do not require continuous operation.

60. The electrical circuit from the spark plug back to the magneto i s completed by grounding through the
a. engine structure.
b. P-lead.
c.cockpit switch.

61. Spark plugs are considered worn out when the
a. electrodes have worn away to about one-half of their original dimensions.
b. center electrode edges have become rounded.
c. electrodes have worn away to about two-thirds of their original dimensions.

62. Which of the following could cause damage to the nose ceramic or to the electrode of an aircraft sparkplug?
a. Plug installed without a copper gasket.
b. Improper gapping procedures.
c. Excessive magneto voltage.

63. 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.

64. In a high-tension ignition system, a primary capacitor of too low a capacity will cause
a. excessive primary voltage.
b. excessively high secondary voltage.
c. the breaker contacts to burn.

65. 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- 1,700 RPM, OFF-0 RPM.
c. BOTH- 1,700 RPM, R-0 RPM, L- 1,675 RPM, OFF-0 RPM.

66. If an aircraft ignition switch is turned off and the engine continues to run normally, the trouble is probably caused by
a. an open ground lead in the magneto.
b. arcing magneto breaker points.
c. primary lead grounding.

67. Which statement is correct regarding the ignition system of a turbine engine?
a. The system is normally de-energized as soon as the engine starts.
b. It is energized during the starting and warmup periods only.
c. The system generally includes a polar inductor type magneto.

68. When the ignition switch of a single (reciprocating) engine aircraft is turned to the OFF position,
a. the primary circuits of both magnetos are grounded.
b. the secondary circuits of both magnetos are opened.
c. all circuits are automatically opened.

69. A spark plug's heat range is the result of
a. the area of the plug exposed to the cooling airstream.
b. its ability to transfer heat from the firing end of the spark plug to the cylinder head.
c. the heat intensity of the spark.

70. If staggered ignition timing is used, the
a. spark plug nearest the exhaust valve will fire first.
b. spark will be automatically advanced as engine speed increases.
c. spark plug nearest the intake valve will fire first.

71. The term "reach," as applied to spark plug design and/or type, indicates the
a. linear distance from the shell gasket seat to the end of the threads on the shell skirt.
b. length of center electrode exposed to the flame of combustion.
c. length of the shielded barrel.

72. The numbers appearing on the ignition distributor block indicate the
a. sparking order of the distributor.
b. relation between distributor terminal numbers and cylinder numbers.
c. firing order of the engine.

73. When testing a magneto distributor block for electrical leakage, which of the following pieces of test equipment should be used?
a. A high-tension harness tester.
b. A continuity tester.
c. A high-range ammeter.

74. (1) The platinum and iridium ground electrodes used on fine wire spark plugs are extremely brittle and can be broken if they are improperly handled or adjusted.
(2) When gapping massive-electrode spark plugs, a wire gauge should be inserted between the center and ground electrodes while moving the ground electrode in order to avoid setting the gap too close.

Regarding the above statements,
a. only No. 1 is true.
b. only No. 2 is true.
c. both No. 1 and No. 2 are true.

75. Hot spark plugs are generally used in aircraft powerplants
a. with comparatively high compression or high operating temperatures.
b. with comparatively low operating temperatures.
c. which produce high power per cubic inch displacement.

76. If a spark plug lead becomes grounded, the
a. magneto will not be affected.
b. distributor rotor finger will discharge to the next closest electrode within the distributor.
c. capacitor will break down.

77. Which of the following statements regarding magneto switch circuits is NOT true?
a. In the BOTH position, the right and left magneto circuits are grounded.
b. In the OFF position, neither the right nor left magneto circuits are open.
c. In the RIGHT position, the right magneto circuit is open and the left magneto circuit is grounded.

78. Which of the following statements most accurately describes spark plug heat range?
a. The length of the threaded portion of the shell usually denotes the spark plug heat range.
b. A hot plug i s designed so that the insulator tip is reasonably short to hasten the rate of heat transfer from the tip through the spark plug shell to the cylinder head.
c. A cold plug i s designed so that the insulator tip is reasonably short to hasten the rate of heat transfer from the tip through the spark plug shell to the cylinder head.

79. When does battery current flow through the primary circuit of a battery ignition coil?
a. Only when the breaker points are open.
b. At all times when the ignition switch is on.
c. When the breaker points are closed and the ignition switch is on.

80. In order to turn a magneto off, the primary circuit must be
a. grounded.
b. opened.
c. shorted.

81. When performing a magneto ground check on an engine, correct operation is indicated by
a. a slight increase in RPM.
b. no drop in RPM.
c. a slight drop in RPM.

82. Defective spark plugs will cause the engine to run rough at
a. high speeds only.
b. low speeds only.
c. all speeds.

83. A spark plug is fouled when
a. its spark grounds by jumping electrodes.
b. it causes preignition.
c. its spark grounds without jumping electrodes.

84. Which of the following would be cause for rejection of a spark plug?
a. Carbon fouling of the electrode and insulator.
b. Insulator tip cracked.
c. Lead fouling of the electrode and insulator.

85. What will be the result of using too hot a spark plug?
a. Fouling of plug.
b. Preignition.
c. Burned capacitor.

86. Upon inspection of the spark plugs in an aircraft engine, the plugs were found caked with a heavy black soot. This indicates
a. worn oil seal rings.
b. a rich mixture.
c. a lean mixture.

87. Spark plug heat range is determined by
a. the reach of the spark plug.
b. its ability to transfer heat to the cylinder head.
c. the number of ground electrodes.

88. Ignition check during engine runup indicates excessive RPM drop during operation on the right magneto. The major portion of the RPM loss occurs rapidly after switching to the right magneto position (fast drop). The most likely cause is
a. faulty or fouled spark plugs.
b. incorrect ignition timing on both magnetos.
c. one or more dead cylinders.

89. If new breaker points are installed in a magneto on an engine, it will be necessary to time the
a. magneto internally and the magneto to the engine.
b. breaker points to the No. 1 cylinder.
c. magneto drive to the engine.

90. Using a cold spark plug in a high-compression aircraft engine would probably result in
a. normal operation.
b. a fouled plug.
c. detonation.

91. Spark plug fouling caused by lead deposits occurs most often
a. during cruise with rich mixture.
b. when cylinder head temperatures are relatively low.
c. when cylinder head temperatures are high.

92. In a four-stroke cycle aircraft engine, when does the ignition event take place?
a. Before the piston reaches TDC on compression stroke.
b. After the piston reaches TDC on power stroke.
c. After the piston reaches TDC on compression stroke.

93. When installing a magneto on an engine, the
a. piston in the No. 1 cylinder must be a prescribed number of degrees before top center on the compression stroke.
b. magneto breaker points must be just closing.
c. piston in the No. 1 cylinder must be a prescribed number of degrees after top center on the intake stroke.

94. The spark occurs at the spark plug when the ignition's
a. secondary circuit is completed.
b. primary circuit is completed.
c. primary circuit is broken.

95. The type of ignition system used on most turbine aircraft engines is
a. high resistance.
b. low tension.
c. capacitor discharge.

96. Ignition check during engine runup indicates a slow drop in RPM. This is usually caused by
a. defective spark plugs.
b. a defective high-tension lead.
c. incorrect ignition timing or valve adjustment.

97. If the ground wire of a magneto is disconnected at the ignition switch, the result will be the
a. affected magneto will be isolated and the engine will run on the opposite magneto.
b. engine will stop running.
c. engine will not stop running when the ignition switch is turned off.

98. Which of the following are advantages of dual ignition in aircraft engines?
1. Gives a more complete and quick combustion of the fuel.
2. Provides a backup magneto system.
3. Increases the output power of the engine.
4. Permits the use of lower grade fuels.
5. Increases the intensity of the spark at the spark plugs.

a. 2, 3, 4
b. 2, 3, 5
c. 1, 2, 3

99. How does high-tension ignition shielding tend to reduce radio interference?
a. Prevents ignition flashover at high altitudes.
b. Reduces voltage drop in the transmission of high-tension current.
c. Receives and grounds high-frequency waves coming from the magneto and high-tension ignition leads.

100. Which of the following are distinct circuits of a high-tension magneto?
1. Magnetic.
2. Primary.
3. E-gap.
4. P-lead.
5. Secondary.

a. 1, 2, 5
b. 1, 3, 4
c. 2, 4, 5

101. What are two parts of a distributor in an aircraft engine ignition system?
1. Coil.
2. Block.
3. Stator.
4. Rotor.
5. Transformer.

a. 2 and 4.
b. 3 and 4.
c. 2 and 5.

102. What is a result of "flashover" in a distributor?
a. Intense voltage at the spark plug.
b. Reversal of current flow.
c. Conductive carbon trail.

103. What is the relationship between distributor and crankshaft speed of aircraft reciprocating engines?
a. The distributor turns at one-half crankshaft speed.
b. The distributor turns at one and one-half crankshaft speed.
c. The crankshaft turns at one-half distributor speed.

104. Why do turbine engine ignition systems require high energy?
a. To ignite the fuel under conditions of high altitude and high temperatures.
b. Because the applied voltage is much greater.
c. To ignite the fuel under conditions of high altitude and low temperatures.

105. Which of the following are included in a typical turbine engine ignition system?
1. Two igniter plugs.
2. Two transformers.
3. One exciter unit.
4. Two intermediate ignition leads.
5. Two low-tension igniter leads.
6. Two high-tension igniter leads.

a. 2, 3, 4
b. 1, 4, 5
c. 1, 3, 6

106. At what RPM is a reciprocating engine ignition switch check made?
a. 1,500 RPM.
b. The slowest possible RPM.
c. Full throttle RPM.

107. What is the approximate position of the rotating magnet in a high-tension magneto when the points first close?
a. Full register.
b. Neutral.
c. A few degrees after neutral.

108. What component of a dual magneto is shared by both ignition systems?
a. High-tension coil.
b. Rotating magnet.
c. Capacitor.

109. What would be the result if a magneto breaker point mainspring did not have sufficient tension?
a. The points will stick.
b. The points will not open to the specified gap.
c. The points will float or bounce.

110. The secondary coil of a magneto is grounded through the
a. ignition switch.
b. primary coil.
c. grounded side of the breaker points.

111. In the aircraft magneto system, if the P-lead i s disconnected, the magneto will be
a. on regardless of ignition switch position.
b. grounded regardless of ignition switch position.
c. open regardless of ignition switch position.

112. (Refer to figure 1.) Placing the engine master switch and battery switch to the on position and advancing the power lever, allows current to flow from the bus to the
a.fuel valve, start switch, power lever switch, power lever relay coil, fuel pumps, and one side of the ignition relay contactor.
b. fuel valve, external power receptacles, undercurrent relay contacts, starter relay coil, and ignition relay contacts.
c. fuel valve, external power receptacles, power lever switch, power lever relay coil, and ignition relay coil.

Aircraft powerplant starting system
Figure 1. Starter-Generator Circuit

113. (Refer to figure 1.) With power applied to the bus bar, what switch changes will allow the ignition exciters test switch to function?
a. Engine master switch and power lever switch.
b. Engine master switch, start switch, and test switch.
c. Engine master switch, battery switch, and power lever switch.

114. (Refer to figure 1.) The type of system depicted is capable of operating with
a. external power only.
b. either battery or external power.
c. battery power and external power simultaneously.

115. (Refer to figure 1.) If wire No.8 i s broken or disconnected after rotation i s initiated, and the power lever is advanced, the
a. starting sequence will continue normally.
b. starter will shut down, but the igniters will continue to fire.
c. starting sequence will discontinue.

116. (Refer to figure 1.) When an external power source is connected to the aircraft,
a. the battery cannot be connected to the bus.
b. both battery power and external power are available to the bus.
c. the start relay coil has a path to ground.

117. The purpose of an under current relay in a starter-generator system is to
a. provide a backup for the starter relay
b. disconnect power from the starter-generator and ignition when sufficient engine speed i s reached.
c. keep current flow to the starter-generator under the circuit capacity maximum.

118. In a typical starter-generator system, under which of the following starting circumstances may it be necessary to use the start stop switch?
a. Hung start.
b. Hot start.
c. Contacts stick open.

119. (Refer to figure 1.) Which malfunctions will allow the igniters to operate when tested but be inoperative during a start attempt?
1. Conductor No. 10 broken.
2. Conductor No. 11 broken.
3. Ignition relay inoperative.
4. Conductor No. 12 broken.

a. 2 or 3
b. 1 or 3
c. 1 or 4

120. (Refer to figure 1.) Which malfunctions will allow the igniters to operate normally during start but be inoperative when tested?
1. Conductor No. 14 broken.
2. Conductor No. 10 broken.
3. Conductor No.15 broken.
4. Conductor No. 12 broken.

a. 2 or 4
b. 1 or 3
c. 3 or 4

121. When using an electric starter motor, current usage
a. is highest at the start of motor rotation.
b. remains relatively constant throughout the starting cycle.
c. is highest just before starter cutoff (at highest RPM).

122. When using an electric starter motor, the current flow through it
a. is highest at the start of motor rotation.
b. remains relatively constant throughout the starting cycle.
c. is highest just before starter cutoff (at highest RPM.).

123. The primary advantage of pneumatic (air turbine) starters over comparable electric starters for turbine engines is
a. a decreased fire hazard.
b. reduction gearing not required.
c. high power-to-weight ratio.

124. A clicking sound heard at engine coast-down in a pneumatic starter incorporating a sprag clutch ratchet assembly is an indication of
a. gear tooth and/or pawl damage.
b. one or more broken pawl springs.
c. the pawls re-contacting and riding on the ratchet gear.

125. Pneumatic starters are usually designed with what types of airflow impingement systems?
a. Radial inward flow turbine and axial-flow turbine.
b. Centrifugal compressor and axial-flow compressor.
c. Double entry centrifugal outward flow and axial-flow turbines.

126. Inspection of pneumatic starters by maintenance technicians usually includes checking the
a. oil level and magnetic drain plug condition.
b. stator and rotor blades for FOD.
c. rotor alignment.

127. Air turbine starters are generally designed so that reduction gear distress or damage may be detected by
a. characteristic sounds from the starter assembly during engine start.
b. breakage of a shear section on the starter drive shaft.
c. inspection of a magnetic chip detector.

128. Airflow to the pneumatic starter from a ground unit is normally prevented from causing starter overspeed during engine start by
a.- stator nozzle design that chokes airflow and stabilizes turbine wheel speed.
b. activation of a flyweight cutout switch.
c. a preset timed cutoff of the airflow at the source.

129. A safety feature usually employed in pneumatic starters that is used if the clutch does not release from the engine drive at the proper time during start is the
a. flyweight cutout switch.
b. spring coupling release.
c. drive shaft shear point.

130. A safety feature usually employed in pneumatic starters that is used to prevent the starter from reaching burst speed if inlet air does not terminate on schedule is the
a. drive shaft shear point.
b. stator nozzle design that chokes airflow and stabilizes turbine wheel speed.
c. spring coupling release.

131. In the event a pneumatic start valve will not operate and the manual override must be used, the starter T handle must be closed at scheduled starter drop out because
a. the starter will overheat.
b. the starter will overspeed at a given N2.
c. the starter oil will be blown over board.



SUPPORTING LESSONS

YOU MAY ALSO LIKE