Powerplant 6

1. Which condition would be the least likely to be caused by failed or failing engine bearing?. High pressure. Lack of oil. To much temperature. Low oil temperature.

2. Nitriding the surface of metal engine parts?. Decrease the metal's resistance to wear. Looks shinning. Increase the wear. Increase the metal's resistance to wear.

3. Master rod bearings are generally of what type?. Roller. Double ball. Ball. Plain.

4. The comparison between the volume of a cylinder with the piston at bottom dead center (BDC) and the volume with the piston at top dead center (TDC) is called?. Compression ratio. Comparing ratio. Piston ratio. Dead ratio.

5. Some cylinder barrels are hardened by?. Anodizing W. Cold working. Flap penning. Nitriding.

6. Correct idle mixture adjustment will be indicated if, while the engine idling movement of the mixture control to idle cut-off?. Is not necessary the correction. A slight PSI increase prior to a normal drop. A slight RPM decrease prior to a normal drop. A slight RPM increase prior to a normal drop.

7. If the exhaust valve of a four stroke cycle engine is closed and the intake valve is just closing, the piston is in the?. Compression stroke. Top dead point. Compression side. Bottom dead point.

8. The application of carburetor heat during engine run up will produce?. A increase in MAP RPM. Rich mixture. A decrease in MAP PSI. A decrease in MAP RPM.

9. A light blue flame coming from the exhaust at night is a sign of ?. Normal. Heavy mixture. Too much air. Too much fuel.

10. Grinding the valves of a reciprocating engine to a feather edge is likely to result in?. Pre-ignition and burned valves. Pre-ignition and good valves. Post-ignition and burned valves. Ignition and burned valves.

11. What is the percentage of cylinder fin damage allowed?. Percentage of the total fin area and is established by the manufacturer. Percentage of the total fin area and is established by the mechanic. Percentage of the total fin area. 20%.

12. Chrome plated piston rings are used?. For the ability to withstand high temperatures. For the ability to decrease high temperatures. For the ability to increase high temperatures. For the ability to withstand low temperatures.

13. Which of the following is a characteristic of a thrust bearing used in most radial engine?. Deep groove valve. Only support axial load. Support axial and radial loads. Only support radial load.

14. The use of a time rite indicator in timing a magneto to an engine which had carbon built up on the piston would?. Not affect the timing. Affect the timing. Increase the timing. A slight RPM increase prior to a normal drop.

15. Which bearing is least likely to be a roller or ball bearing?. Deep fear. Master sharing bearing (radial engine). Master rod bearing (radial engine). Master roller bearing (radial engine).

16. What tool is generally used to measure the crankshaft rotation in degrees?. Timing disk. Inclinometer. Protractor. Compass.

17. Maximum pressure in an engine storage container is?. Ambient pressure. 5 PSI. 10 PSI. static pressure.

18. Which of the following will decrease volumetric efficiency in a reciprocating engine?. Improper valve timing in the induction system and low carburator air temperature. Improper valve timing, sharp bends in the induction system and high carburetor air temperature. High fuel/air mixture.

19. When spraying the cylinder for storage of a engine, the piston should be in the position?. Top dead center. Upper dead center. Lower dead center. Bottom dead center.

20. After installed a new set of piston rings on a piston, a test indicates excessive blow by, a possible reason for this could be?. Gaps of rings not staggered. Poor mixture. Rich mixture. Gaps of rings staggered.

21. During routine inspection of a magneto, the breaker points were found to be badly pitted and burned, the first item to suspect for this condition would be?. A faulty primary capacitor. The coil. Primary capacitor. The stator.

22. A four lobe cam rings installed in a nine cylinder radial engine will rotate at?. 1/2 crankshaft speed. 1/36 crankshaft speed. The same crankshaft speed. 1/8 crankshaft speed.

23. The operating valve clearance of an engine using hydraulic lifters should not exceed?. 0.00 inch. 0.010 inch. 0.001 inch. 0.10 inch.

24. The most effective angle of attack for a fixed pitch propeller is generally?. 3.0°-140°. 0.0°-7.0°. 2.0° - 4.0°. 0.8° - 4.4°.

25. During overhaul, reciprocating engine exhaust valves are checked for stretch with?. Contour or radius gauge. Filler gauge. Radius gauge. Contour gauge.

26. Setting of the clearance of both the intake and exhaust valves to less than that specific, would cause?. Both valves open early. Exhaust valve open late. Intake valve open early. Both valves late to open.

27. The difference between a cold and hot spark plug is the variation in?. Core nose. Diameter of the core nose. Gap of the core nose. Length of the core nose.

28. The primary concern in establishing the firing order for an opposed engine is to?. Provide for balance and eliminate vibration to the greatest extent posible. Provide for unbalance and eliminate vibration to the greatest extent posible. Provide for unbalance and provide vibration to the greatest extent posible. Provide for balance and eliminate vibration to the lowest extent posible.

29. Oil in a hydraulic valve lifter is?. Pressure oil from the oil sump. Pressure oil from the system. Pressure oil from the oil pump. Pressure oil.

30. If a engine with a stroke of 6 inches is operated at 2000 RPM, the piston movement within the cylinder will be?. At TOGA velocity. At idle velocity. At minimum velocity. At maximum velocity.

31. Fuel/air mixture ratio is expressed on the basis of?. Weight. Ratio. PSI. Units.

32. The type of ignition system incorporating a transformer coil near each spark plug is called?. High Tension. Low tension. Modified. Coil sparks plug.

33. A magneto is shut off by?. Grounding of the primary coil. Grounding of the coil. At 50% speed. Grounding of the secondary coil.

34. An engine reduction gear is designed to?. Provide a propeller RPM lower than of the engine. Provide a propeller or transmission RPM lower than of the engine. Provide a transmission RPM lower than of the engine. Provide a propeller RPM great than of the engine.

35. When starting a cold engine, the oil pressure will?. Register higher than normal with a reduction to normal as operating temperature is reach. Register lower than normal with a increase to normal as operating temperature is reach. Operating normal. Don't change.

36. The most effective engine cooling is provided by?. The size of cooling fins. The cooling reservoir. The fan. The heat exchange.

37. Desicant should be inspected every?. 30 days. Every day. According to the manufacturer. 7 days.

38. Piston rings are made of?. Cast iron. Stainless steel. Aluminum. Zinc.

39. Which statement is correct regarding engine crankshaft?. Fixed counterweights serve to reduce the vibration in a aircraft reciprocating engine. Moveable counterweights serve to reduce the vibration in an aircraft reciprocating engine. Moveable counterweights serve to reduce the vibration in an aircraft turbine engine. Moveable counterweights serve to reduce the vibration in an aircraft turbine engine.

40. Percentage of allowed engine degradation is?. 50%. 3%. 85%. 10%.

41. If fuel/air ratio is proper and ignition timing is correct, the combustion process should be completed?. Just after low dead center at the end of compression stroke. Just before top dead center at the end of compression stroke. Just after top dead center at the end of compression stroke.

42.When is the fuel/air mixture ignited in a conventional reciprocating engines?. Shortly after the piston reaches the top of the compression stroke. Before the piston reaches the top of the compression stroke. Shortly before the piston reaches the top of the compression stroke. Shortly before the piston reaches the bottom of the compression stroke.

43. Which strokes are both valves on a four stroke cycle reciprocating engine open?. Power and ignition. Exhaust and intake. Intake and compression. Pre-ignition and burned valves.

44. The density of the air depends upon?. Temperature and humidity. Volume, temperature and humidity. Pressure, temperature and wind. Pressure, temperature and humidity.

45. On which part of the cylinder walls of a normally operating engine will the greatest amount is wear occurs?. Near of the top of the ring. Near of the top of the cylinder. Near of the bottom of the cylinder. Far of the top of the cylinder.

46. A magneto impulse coupling is used to?. To provide a voltage retarded spark. To provide a high voltage retarded spark. To provide a high voltage advance spark. To provide a low voltage retarded spark.

47. Knuckles pins hinges the. Articulated rods to the master rod flanges. Rigid rods to the master rod end. Semi-articulated rods to the master rod flanges. Articulated rods with the master.

48. Improper setting of the E-gap angle during internal timing of a magneto will cause?. The main voltage to be lower than normal. The secondary voltage to be greater than normal. The secondary voltage to be lower than normal. The main voltage to be greater than normal.

49. What is the purpose of the snap ring on a splined on tapered propeller shaft?. Ensure the propeller is torque correctly. Maintains the proper keyway. Holds the retraining nut. Provide an aid for removing the propeller.

50. Gasoline may be regarded as having?. Convert velocity to pressure. Mechanical potential. Electrical energy. Potential energy.

51. One reason of the valve lead and valve lag is great in relation to bottom dead center than top dead center is because?. The inertia of the gas flow is lower at bottom dead center than at top dead center. The inertia of the gas flow is greater at bottom dead center than at top dead center. Remains the same gap. The inertia of the air flow is greater at bottom dead center than at top dead center.

52. The throat or venturi of a carburetor is designed to?. Decrease the air pressure at the fuel secondary nozzle. Increase the air pressure at the fuel discharge nozzle. Decrease the air pressure at the fuel discharge nozzle. Decrease the air pressure at the fuel primary nozzle.

53. Minimum pressure in an engine storage container is?. 5 PSI. 10 PSI. 1 PSI. Not need a minimum pressure.

54. Circlets, spring rings or plugs hold piston pin in place to prevent them from?. Scoring the cylinder wall. Scorching the cylinder wall. Crack the ring. Scratching the cylinder wall.

55. The recommended method of lowering the fuel level in a float type carburetor is by?. Gravity. Using a gear pump. Placing washer or shims under the float needle valve seat. Pressure pump.

56. Propeller blade angle nearest the hub will be?. Increase. Lowest. Highest. No change.

57. The gear of an oil scavenger pump are usually larger than the gear of the oil pressure pump to?. Ensure negative draining or scavenging of the crankcase. It is not true. Ensure positive draining or scavenging of the crankcase. Ensure positive pressure on the scavenging of the crankcase.

58. An aircraft reciprocating engine using hydraulic valve lifters is observed to have no clearance in its valve-operating mechanism after the minimum inlet oil cylinder head temperature for take off have been reached. When can this condition be expected?. During engine run up. During normal operations. During engine dry motoring 1. During take off.

59. A light brown deposit on a spark plug is a sign of?. Full mixture. Nothing, normal conditions. Gap on the spark plug. Burning, normal conditions.

60. What does the air bleed in the discharge nozzle of a carburetor?. Produce a more fuel/air mixture. Produce more air than fuel. Hot start. Helps produce a more uniform fuel/air mixture.

61. Exhaust augmentation provides?. Reduce exhaust back pressure and increase airflow. Reduce exhaust back smoke and increase airflow. Increase exhaust back pressure and increase airflow. Reduce exhaust back pressure and decrease airflow.

62. The RPM of a turbocharger maybe increased by?. Moving the wastegate toward to close position. Moving the wastegate upward to close position. Moving the wastegate backwards to close position. Moving the wastegate toward to open position.

63. The starter circuit is protected by?. fuse. circuit brake. wire protection. unprotected.

64. Direct cranking starter motors are usually?. Composite. Shunt. Series-shunt. Series.

65. A backfire through the indication system may be caused by?. An lack fuel mixture. An excessive lean mixture. An excessive fuel mixture. An lack lean mixture.

66. A fixed pitch propeller is best designed to give the best efficiency at?. Take off. Climb. One rotational and forward speed. Cruise.

67. Cylinder heads are usually made of?. stainless steel. Composite alloy. Aluminum alloy. Zinc alloy.

68. A compensated cam in the magneto of a radial engine rotates at?. 1/4 of the crankshaft speed. At crankshaft speed. 1/2 of the crankshaft speed. 2 times of the crankshaft speed.

69. During a differential pressure test (Motostat) on an aircraft engine, air escaping through the air intake would indicate poor conditions of the?. Too much air. Intake valve. Non adjustment rings. Worn crankshaft.

70. Afterfiring is caused by? (in the exhaust). Fuel mixture. Poor mixture. Rich mixture. Fuel/air mixture.

71. What horsepower is expended when 1000lb weight is lifted 33 feet in 2 minutes?. 2 HP. 1 HP. 1/2 HP. 33 HP.

72. Brake horsepower (HP ) is the?. Power delivered to propeller brakes. Power delivered to the propeller shaft for mechanical energy. Power delivery to the engine shaft. Power delivered to the propeller shaft for useful work.

73. What part of the blade is placed inside the propeller hub?. Back. Butt. Root. Blade shank.

74. The operating temperature valve clearance of a radial engine as compared to cold valve clearance is?. Double. The same. Lower. Greater.

75. Partial disassembly of a pressure injection carburetor for one correction of malfunction may be performed by?. Only by the manufacturer. Manufacturer or shop. Only by shop. Any mechanic.

76. The purpose of the supercharger diffuser vanes is to?. Convert pressure to velocity. Convert high pressure to low pressure. Convert low pressure to high pressure. Convert velocity to pressure.

77. Some aircraft engine manufacturers equip their products with chocked or taper ground cylinder in order to?. Provide a straight cylinder bore at normal temperature. Provide a straight cylinder wall at operational temperature. Provide a straight cylinder bore at operational temperature. Provide a straight cylinder bore at operational temperature in top dead.

78. The surge valve protects an oil cooler from high pressure by diverting?. Hot oil directly from the oil tank. Cold oil indirectly from the oil tank. Cold oil directly from the oil tank. Cold oil directly from the fuel tank.

79. What percentage of engine heat is removed by the exhaust system?. 50%. 80%. 75%. 100%.

80. What is the purpose of the safety circlet installed on some valve stems?. To prevent valves from failing into the cylinder. To prevent valves from failing into the piston. to hold the valves stems. to hold the cylinder rings.

81. What is the principal advantage of using propeller reduction gear?. To enable engine RPM to be decreased with an accompanying decrease in power and allow the propeller to remain at a lower more efficient RPM. To enable engine RPM to be decreased with an accompanying increase in power and allow the propeller to remain at a lower more efficient RPM. To enable engine RPM to be increased with an accompanying increase in power and allow the propeller to remain at a lower more efficient RPM. To enable engine RPM to be increased with an accompanying increase in power and allow the propeller to remain up a more efficient RPM.

82. The fourth Cylinder to fire on a nine cylinder radial engine is?. #7. #4. #9. #6.

83. The period of rotation during witch the breaker points are closed is called?. Breaker rotary. Period breaker point. Dwell. Combustion.

84. A fuel/air ratio that is expressed as 1:12, means?. 12 part of fuel to 1 parts of air by weight. 1 part of fuel to 12 parts of air by weight. 1 part of fuel is greater than 12 parts of air by weight. 1 part of fuel is greater 12 parts of air by PSI.

85. On seasonal commencement of oil dilution?. The oil filter must be inspected every day until it is clear of excessive sludge. The fuel filter must be inspected after each flight until it is clear of excessive sludge. No any change. The oil filter must be inspected after each flight until it is clear of excessive sludge.

86. Which statement is correct regarding a four stroke cycle aircraft engine?. The intake valve closes on the compression stroke. The exhaust valve open on the compression stroke. The exhaust valve closes on the compression stroke. The intake valve open on the compression stroke.

87. In the preparation of any magneto for installation, it is most important to check that the rotor is positioned at E-gap and that the breaker points are?. full opened. Full close. Just close. Just opening.

88. If a intake valve is opened too early in the cycle of operation for a four stroke cycle engine, it may result in?. Back firing into the induction system. Too much gap. Forward firing into the induction system. Back firing into the compressor system.

89. Which statement is true regarding bearing used in a high powered reciprocating engine?. There is less rolling friction when ball bearings are used than when roller bearings are employed. In reciprocating engine used only rotor and ball bearing. In reciprocating engine used only double ball bearing. There is less rolling friction when roller bearings are used than when ball bearings are employed.

90. The events of a four stroke cycle engine in the order of they occurrence are?. Intake, ignition, power, compresssion, exhaust. Intake, compression, ignition, power, exhaust. Compression, ignition, power, exhaust. Intake, compression, ignition, exhaust.

91. When adjusting valve clearance, the cam lobes should be correctly positioned by placing the piston at the beginning of the?. Power stroke. Crankshaft. Rings piston. Forward cam lobe.

92. The actual power delivered to the propeller of a aircraft engine is called?. Propeller thrust. BTU. Brake horsepower. Horsepower.

93. Valve overlap is defined as the number of degrees?. Intake valve are unseat. That both the intake and exhaust valve are unseat. Exhaust valve are unseat. That both the intake and exhaust valve are seat.

94. The working principle of the pressure injection carburetor is based on?. Upwards fuel pressure regulated by carburetor airflow. Metered fuel pressure regulated by carburetor rings. Bernoulli's law. Metered fuel pressure regulated by carburetor airflow.

95. A entry in the logbook read "Engine running uneven, low power, tending to cut during flight" but a ground run after troubleshooting procedures fails to reveal any irregularity, what could be the cause?. Dry motoring. Rich mixture. Carburetor icing. Lack of mixture.

96. How specific fuel consumption is calculated?. Dividing the weight of fuel per hour by the horsepower. Add the weight of fuel burned per hour by the horsepower. Dividing the weight of fuel burned per hour by the horsepower. Weight of fuel burned per hour by the horsepower.

97. To clear a hydraulically locked cylinder on a radial engine, the crankshaft should be turned through several revolutions?. In the direction of rotation after installed of the lower spark plug. In the opposite direction of rotation after removal of the lower spark plug. In the opposite direction of rotation after installed of the top spark plug. In the direction of rotation after removal of the lower spark plug.

98. A common cause of distributor flash over is?. Cracked insulator. Corrosion insulator. Leak. Crack.

99. The piston displacement of a cylinder having a bore and stroke of 6 inches is?. 644.169 C.I. 196.644 C.I. 169.644 C.l. 179.644 C.l.

100. A nine cylinder engine with a bore of 5.5 inches and a stroke of 6 inches, will have a total piston displacement of?. 1933.12 cubic inches. 1,283 cubic inches. 933.12 cubic inches. 1,273 cubic inches.