Questions and Answers - Propellers (Part 1) | Aircraft Systems

Questions and Answers - Propellers (Part 1)

1. How is aircraft electrical power for propeller deicer systems transferred from the engine to the propeller hub assembly?
a. By slip rings and segment plates.
b. By slip rings and brushes.
c. By flexible electrical connectors.

2. How is anti-icing fluid ejected from the slinger ring on a propeller?
a. By pump pressure.
b. By centripetal force.
c. By centrifugal force.

3. 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.

4. Propeller fluid anti-icing systems generally use which of the following?
a. Ethylene glycol.
b. Isopropyl alcohol.
c. Ethyl alcohol.

5. What is a function of the automatic propeller synchronizing system on multiengine aircraft?
a. To control the tip speed of all propellers.
b. To control engine RPM and reduce vibration.
c. To control the power output of all engines.


6. Ice formation on propellers, when an aircraft is in flight, will
a. decrease thrust and cause excessive vibration.
b. increase aircraft stall speed and increase noise.
c. decrease available engine power.

7. What unit in the propeller anti-icing system controls the output of the pump?
a. Pressure relief valve.
b. Rheostat.
c. Cycling timer.

8. Proper operation of electric deicing boots on individual propeller blades may best be determined by
a. feeling the sequence of boot heating and have an assistant observe the loadmeter indications.
b. observing the ammeter or loadmeter for current flow.
c. feeling the boots to see if they are heating.

9. A propeller synchrophasing system allows a pilot to reduce noise and vibration by
a. adjusting the phase angle between the propellers on an aircraft's engines.
b. adjusting the plane of rotation of all propellers.
c. setting the pitch angle of all propellers exactly the same.

10. Which of the following determines oil and grease specifications for lubrication of propellers?
a. Airframe manufacturers.
b. Engine manufacturers.
c. Propeller manufacturers.

11. 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 plasticity characteristics of grease.
b. antifriction and chemical stability of grease.
c. viscosity and melting point of grease.

12. 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. Vertical.
b. Horizontal.
c. Harmonic.


13. What is the purpose of an arbor used in balancing a propeller?
a. To support the propeller on the balance knives.
b. To level the balance stand.
c. To mark the propeller blades where weights are to be attached.

14. If a blade of a particular metal propeller is shortened because of damage to the tip, the remaining blade(s) must be
a. reset (blade angle) to compensate for the shortened blade.
b. returned to the manufacturer for alteration.
c. reduced to conform with the shortened blade.

15. The application of more protective coating on one blade than the other when refinishing a wood propeller
a. has little or no effect on operating characteristics.
b. should never be done.
c. may be necessary to achieve final balancing.

16. Apparent engine roughness is often a result of propeller unbalance. The effect of an unbalanced propeller will usually be
a. approximately the same at all speeds.
b. greater at low RPM.
c. greater at high RPM.

17. Which of the following is used to correct horizontal unbalance of a wood propeller?
a. Brass screws.
b. Shellac.
c. Solder.

18. Propeller aerodynamic (thrust) imbalance can be largely eliminated by
a. correct blade contouring and angle setting.
b. static balancing.
c. keeping the propeller blades within the same plane of rotation.

19. A powerplant using a hydraulically controlled constant-speed propeller is operating within the propeller's constant-speed range at a fixed throttle setting. If the tension of the propeller governor control spring (speeder spring) is reduced by movement of the cockpit propeller control, the propeller blade angle will
a. increase, engine manifold pressure will increase, and engine RPM will decrease.
b. decrease, engine manifold pressure will increase, and engine RPM will decrease.
c. decrease, engine manifold pressure will decrease, and engine RPM will increase.

20. Why is the pulley stop screw on a propeller governor adjustable?
a. To limit the maximum engine speed during takeoff.
b. To maintain the proper blade angle for cruising.
c. To limit the maximum propeller pitch for takeoff.

21. During engine operation at speeds lower than those for which the constant-speed propeller control can govern in the INCREASE RPM position, the propeller will
a. remain in the full HIGH PITCH position.
b. maintain engine RPM in the normal manner until the HIGH PITCH stop is reached.
c. remain in the full LOW PITCH position.

22. When engine power is increased, the constant-speed propeller tries to function so that it will
a. maintain the RPM, decrease the blade angle, and maintain a low angle of attack.
b. increase the RPM, decrease the blade angle, and maintain a low angle of attack.
c. maintain the RPM, increase the blade angle, and maintain a low angle of attack.

23. The propeller governor controls the
a. oil to and from the pitch changing mechanism.
b. spring tension on the boost pump speeder spring.
c. linkage and counterweights from moving in and out.

24. During the on-speed condition of a propeller, the
a. centrifugal force acting on the governor flyweights is greater than the tension of the speeder spring.
b. tension on the speeder spring is less than the centrifugal force acting on the governor flyweights.
c. centrifugal force of the governor flyweights is equal to the speeder spring force.

25. What actuates the pilot valve in the governor of a constant-speed propeller?
a. Engine oil pressure.
b. Governor flyweights.
c. Governor pump oil pressure.

26. What action takes place when the cockpit control lever for a hydromatic, constant-speed propeller is actuated?
a. Compression of the speeder spring is changed.
b. The governor booster pump pressure is varied.
c. The governor bypass valve is positioned to direct oil pressure to the propeller dome.


27. What will happen to the propeller blade angle and the engine RPM if the tension on the propeller governor control spring (speeder spring) is increased?
a. Blade angle will decrease and RPM will decrease.
b. Blade angle will increase and RPM will decrease.
c. Blade angle will decrease and RPM will increase.

28. How is the speed of a constant-speed propeller changed in flight?
a. By varying the output of the governor booster Pump.
b. By advancing or retarding the throttle.
c. By changing the load tension against the flyweights in the governor.

29. 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. Under-speed.
c. Over-speed.

30. What operational force causes the greatest stress on a propeller?
a. Aerodynamic twisting force.
b. Centrifugal force.
c. Thrust bending force.

31. What operational force tends to increase propeller blade angle?
a. Centrifugal twisting force.
b. Aerodynamic twisting force.
c. Thrust bending force.

32. How is a propeller controlled in a large aircraft with a turboprop installation?
a. Independently of the engine.
b. By varying the engine RPM except for feathering and reversing.
c. By the engine power lever.

33. How does the aerodynamic twisting force affect operating propeller blades?
a. It tends to turn the blades to a high blade angle.
b. It tends to bend the blades forward.
c. It tends to turn the blades to a low blade angle.

34. Which of the following best describes the blade movement of a propeller that is in the high RPM position when reversing action is begun?
a. Low pitch directly to reverse pitch.
b. Low pitch through high pitch to reverse pitch.
c. Low pitch through feather position to reverse pitch.

35. Propellers exposed to salt spray should be flushed with
a. stoddard solvent.
b. fresh water.
c. soapy water.

36. How can a steel propeller hub be tested for cracks?
a. By anodizing.
b. By magnetic particle inspection.
c. By etching.

37. Which of the following functions requires the use of a propeller blade station?
a. Measuring blade angle.
b. Indexing blades.
c. Propeller balancing.

38. The propeller blade angle is defined as the acute angle between the airfoil section chord line (at the blade reference station) and which of the following?
a. The plane of rotation.
b. The relative wind.
c. The axis of blade rotation during pitch change.

39. During which of the following conditions of flight will the blade pitch angle of a constant-speed propeller be the greatest?
a. Approach to landing.
b. Climb following takeoff.
c. High-speed, high-altitude cruising flight.

40. The actual distance a propeller moves forward through the air during one revolution is known as the
a. effective pitch.
b. geometric pitch.
c. relative pitch.

41. The pitch-changing mechanism of the hydromatic propeller is lubricated by
a. the pitch-changing oil.
b. using an approved-type grease in a grease gun at intervals prescribed by the propeller manufacturer.
c. thoroughly greasing, necessary only during propeller overhaul.

42. What is the result of moving the throttle on a reciprocating engine when the propeller is in the constant-speed range with the engine developing cruise power?
a. Opening the throttle will cause an increase in blade angle.
b. The RPM will vary directly with any movement of the throttle.
c. Movement of the throttle will not affect the blade angle.

43. Propeller blade stations are measured from the
a. index mark on the blade shank.
b. hub centerline.
c. blade base.

44. The thrust produced by a rotating propeller is a result of
a. an area of low pressure behind the propeller blades.
b. an area of decreased pressure immediately in front of the propeller blades.
c. the angle of relative wind and rotational velocity of the propeller.

45. Why is a constant-speed counterweight propeller normally placed in full HIGH PITCH position before the engine is stopped?
a. To prevent exposure and corrosion of the pitch changing mechanism.
b. To prevent hydraulic lock of the piston when the oil cools.
c. To prevent overheating of the engine during the next start.

46. The low pitch stop on a constant-speed propeller is usually set so that
a. the engine will turn at its rated takeoff RPM at sea level when the throttle is opened to allowable takeoff manifold pressure.
b. maximum allowable engine RPM cannot be exceeded with any combination of manifold pressure, altitude, or forward speed.
c. the limiting engine manifold pressure cannot be exceeded with any combination of throttle opening, altitude, or forward speed.

47. The angle-of-attack of a rotating propeller blade is measured between the blade chord or face and which of the following?
a. Plane of blade rotation.
b. Full low-pitch blade angle.
c. Relative airstream.

48. The centrifugal twisting moment of an operating propeller tends to
a. increase the pitch angle.
b. reduce the pitch angle.
c. bend the blades in the direction of rotation.

49. 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.

50. Which of the following best describes the blade movement of a full-feathering, constant-speed propeller that is in the LOW RPM position when the feathering action is begun?
a. High pitch through low pitch to feather position.
b. High pitch directly to feather position.
c. Low pitch through high pitch to feather position.

51. The holding coil on a hydromatic propeller feathering button switch holds a solenoid relay closed that applies power to the propeller
a. governor.
b. dome feathering mechanism.
c. feathering pump motor.

52. What is the primary purpose of the metal tipping which covers the blade tips and extends along the leading edge of each wood propeller blade?
a. To increase the lateral strength of the blade.
b. To prevent impact damage to the tip and leading edge of the blade.
c. To increase the longitudinal strength of the blade.

53. Blade angle is an angle formed by a line perpendicular to the crankshaft and a line formed by the
a. relative wind.
b. chord of the blade.
c. blade face.

54. Propeller blade station numbers increase from
a. hub to tip.
b. tip to hub.
c. leading edge to trailing edge.

55. The aerodynamic force acting on a rotating propeller blade operating at a normal pitch angle tends to
a. reduce the pitch angle.
b. increase the pitch angle.
c. bend the blades rearward in the line of flight.

56. Which of the following forces or combination of forces operates to move the blades of a constant-speed counterweight-type propeller to the HIGH PITCH position?
a. Engine oil pressure acting on the propeller piston-cylinder arrangement and centrifugal force acting on the counterweights.
b. Centrifugal force acting on the counterweights.
c. Prop governor oil pressure acting on the propeller piston-cylinder arrangement.

57. The purpose of permanently sealing and partially filling some models of McCauley propeller hubs with dyed oil is to
a. provide an always clean separate lubrication of the internal parts.
b. dampen pressure surges and prevent too rapid changes in propeller blade angle.
c. make the location of cracks readily apparent.

58. Which of the following best describes the blade movement of a feathering propeller that i s in the HIGH RPM position when the feathering action i s begun?
a. High pitch through low pitch to feather position.
b. Low pitch through reverse pitch to feather position.
c. Low pitch through high pitch to feather position.

59. The blade angle of a fixed-pitch propeller
a. is greatest at the tip.
b. is smallest at the tip.
c. increases in proportion to the distance each section is from the hub.

60. During operational check of an aircraft using hydromatic full-feathering propellers, the following observations are made: The feather button, after being pushed, remains depressed until the feather cycle is complete, then opens. When unfeathering, it is necessary to manually hold the button down until unfeathering is accomplished.
a. Both feather cycle and unfeather cycle are functioning properly.
b. Both feather and unfeather cycles indicate malfunctions.
c. The feather cycle is correct. The unfeather cycle indicates a malfunction.



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