Questions - Propellers

Fill in the Blanks

1. The basic function of a propeller on an airplane is to convert engine torque into ___________.

2. Propeller blade angle is the angle between the chord of the propeller blade and the ___________ of ___________.

3. Propeller blade stations are measured, in inches, from the ___________ of the ___________.

4. A ___________ (what unit) is designed primarily to increase the flow of cooling air to the engine nacelle.

5. The gradual twist in the propeller blade from shank to tip is known as ___________.

6. Because of vibration problems encountered with certain engine/propeller combinations, the critical range is indicated on the tachometer by a ___________.

7. The difference between geometric pitch and effective pitch is called ___________.

8. Automatic propellers are usually termed ___________ propellers.

9. An aircraft manufacturer may specify two models of a propeller for the same installation, a ___________ and ___________ a propeller.

10. ___________-pitch propellers are simple propellers whose blade angle cannot be changed in normal operation.

11. Most wooden propellers are now made of ___________ or ___________.

12. A McCauley propeller designated as 1B90/CM7448 has a diameter of ___________ inches and a pitch of inches at the 75% station.

13. The propeller governor is an ___________ (what variable) sensing device.

14. An aircraft with a constant-speed propeller system will use the ___________ gauge to indicate the throttle setting, and the ____________ to indicate the propeller setting.

15. The ___________ valve directs oil through ports in the drive shaft to or from the propeller to vary the blade angle.


1. The flat surface of a propeller blade is called the face of the blade. TRUE/FALSE

2. On a given propeller blade, the blade angle nearest the hub will be the lowest. TRUE/FALSE

3. Thrust bending force tries to bend the tip of a propeller blade rearward. TRUE/FALSE

4. Torque bending force tries to bend the propeller blades in the opposite direction of their rotation. TRUE/FALSE

5. Aerodynamic twisting moment tries to move the propeller blades toward a high pitch angle. TRUE/FALSE

6. Centrifugal twisting moment tries to move the propeller blades toward a high pitch angle. TRUE/FALSE

7. The geometric pitch is the distance, in inches, that a propeller would move forward in a medium that allowed no slip. TRUE/FALSE

8. The effective pitch is the distance, in inches, that the aircraft actually moves forward in one revolution of the propeller. TRUE/FALSE

9. Pusher propellers are those mounted on the upstream end of a drive shaft in front of the supporting structure. TRUE/FALSE

10. Aluminum propeller blanks are cast from high strength aluminum alloy. TRUE/FALSE

Knowledge Application

1. The six forces that act on rotating propeller are:
a. ___________________
b. ___________________
c. ___________________
d. ___________________
e. ___________________
f. ___________________

2. The two series of McCauley constant-speed propellers are:
a. ___________________
b. ___________________

3. Hartzell produces two styles of constant-speed propellers, they are:
a. ___________________
b. ___________________

4. The Hamilton-Standard propeller governor is divided into these three parts:
a. ___________________
b. ___________________
c. ___________________

5. The Hydromatic propeller is made up of three major assemblies, they are:
a. ___________________
b. ___________________
c. ____________________

6. Two undesirable conditions that are minimized by using synchrophasing are:
a. ___________________
b. ___________________

7. Two variables enter into the determination of whether a bent aluminum alloy propeller blade can be
straightened. They are:
a. ___________________
b. ___________________

8. The two types of propeller unbalance that are possible are:
a. ___________________
b. ___________________

9. What is the function of a propeller?

10. What is the difference between a fixed pitch propeller and a controllable pitch propeller?

11. How are some wooden propeller blades protected from wear and damage?

12. What happens to the blade angle of a constant speed propeller during a constant power dive?

13. What are the functions of a constant speed propeller governor?

14. What is the purpose of propeller counterweights?

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

Multiple Choices

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.

FAA powerplant mechanic knowledge test
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