modül 17

17.1.1 Blade Element Theory

1-What is the function of the propeller?

a)To transfer power from the engine to the crankshaft

b) To convert engine power into useful thrust

c) It uses the power from the engine to direct the aircraft.

2-Which section of the engine are the propeller blades attached to?

a) They are directly attached to the engine turbine shaft.

b) They are fixed to the engine compressor section.

c) They are attached to a central hub which is mounted on an engine crankshaft.

3-Blade angle (or pitch angle) is ……..

a) the angle between the propeller’s plane of rotation and the chord line of the propeller’s airfoil section.

b) the angle between the air inflow and the chord line.

c) a decrease in the blade angle creates less thrust.

4- Which of the followings is wrong?

a) A decrease in the blade angle creates less thrust.

b) An increase in the blade angle increases the thrust.

c) A decrease or an increase in the blade angle doesn’t affect the thrust.

5- Which of the followings describes the chord line?

a) It is an imaginary line from the leading edge of the blade to its trailing edge.

b) It is the angle between air inflow and plane of rotation.

c) It is the section between the propeller central line and the plane of rotation.

6-Which of the followings describes the angle of attack?

a) To produce thrust, the airfoil section of a propeller must be slightly tilted in relation to the direction of airflow over it.

b) It is the angle between the air inflow and the plane of rotation.

c) It is the section between the propeller central line and the plane of rotation.

7- When the turboprop engine is at idle, the engine ……….

a) thrust is at maximum.

b) the blade angle is at maximum angle.

c) is a minimum load.

8- The possible highest blade angles…….

a) range from ground idle and take-off position.

b) range from a full reverse negative blade angle and a fully streamlined feathered position.

c) are limitied at ground idle.

9-Why is a blade angle limited?

a) It is limited for completely aerodynamic reasons.

b) It is limited for mechanical and aerodynamic reasons

c) The blade angle can not be limited.

10-What is the blade angle set to under conditions of emergency shut-down in the air?

a) It is set to its maximum, i.e. it is set to approx. 90o.

b) It is set to reverse or negative position.

c) It is set to ground idle or 0o position.

11-In order to maintain a constant angle of attack at a constant engine power, the blade angle must……….. when the aircraft speed increases.

a) remain constant

b) be decreased

c) be increased

12-With the blade angle being at ‘full reverse’ after touch down, ……………………………as aircraft spee decreases.

a) the angle of attack will remain constant

b) the angle of attack will decrease

c) the angle of attack will increase

13-…………is the distance in inches that a propeller section moves forward during one revolution.

a) Slip

b) Angle of attack

c) Pitch

14-What is the effective pitch?

a) It is the distance the aircraft moves during one revolution of the propeller.

b) It is the position that the blade angle is zero.

c)It is the distance the aircraft actually moves forward during one revolution of the propeller.

15- What is the geometric pitch?

a) It is the distance the aircraft mathematically moves during one revolution of the propeller.

b) It is the position that the blade angle is zero.

c) It is the distance the aircraft actually moves forward during one revolution of the propeller.

16- What is the slip?

a) It is the distance the aircraft moves during one revolution of the propeller.

b) It is the difference between the geometric pitch and effective pitch.

c) It is the distance the aircraft actually moves forward during one revolution of the propeller.

17- Which of the followings depends upon the amount of air that the propeller can move and on the amount of veloctiy given to the moving air?

a) Thrust amount produced

b) Centrifugal force

c) Centrifugal twisting amount

18-The distance moved forward along the flight path during one propeller revolution ………………for all sections of the propeller blade.

a) can not be measured

b) is different

c) is the same

19-The blade sections nearest to the tip travel………….. through the air than the sections at or near the blade root.

a) same distances

b) greater distances

c) smaller distances

20-To produce an even thrust along the whole length of the blade, the blade angle…………..

a) is varied from a small angle at the root to a large angle at the tip.

b) is varied from a large angle at the root to a small angle at the tip.

c) there is no difference between the angle at the root and at the tip.

21-What is the blade twist?

a) the variation between a large angle at the root and a small angle at the tip

b) Plane of rotation of a propeller

c) the variation between a small angle at the root and a large angle at the tip

22-Which of the followings causes the greatest stress on a propeller?

a)Thrust bending force

b) Torque bending force

c) Centrifugal force

23-Which of the followings is the force which tries to pull the blades out of the hub?

a) Thrust bending force

b) Centrifugal force

c) Aerodynamic twisting force

24-Which of the followings is the force creating stresses that may be greater than 7,500 times the weight of the propeller blade?

a) Centrifugal force

b) Thrust bending force


25-How does the torque bending force affect the propeller blade?

a) It tries to bend the propeller blade in the driection of rotation.

b) it tries to bend the propeller blade back into the direction opposite the direction of rotation.

c) It tries to pull the blades out of the hub.

26-How does the thrust bending force affect the blade?

a) It attempts to bend the propeller blades forward at the tips.

b) It attempts to bend the propeller blades backward at the tips.

c) It attempts to pull the blades out of the hub.

27- Which force opposes the torgue bending force to a certain degree?

a) Centrifugal force



28-Which of the followings tries to twist a blade to a higher angle?

a) Torque bending force



29- Which of the followings tries to decrease the blade angle?

a) Centrifugal twisting moment



30-Which of the followings is the force that tries to oppose the aerodynamic twisting moment?

a) Torque bending force

b) Centrifugal twisting moment


31- The force resulting in sections of the propeller blade breaking off in flight is………….

a) Centrifugal twisting moment

b) Vibrational force

c) Thrust bending force

32- What is the source of the mechanical vibrations that are considered to be more destructive in their effect than aerodynamic vibration?

a) The power pulses in a piston engine

b) A low blade angle

c) Propeller reduction gears

33- What does “D” stand for in the propeller geometry?

a) Radius

b) Diameter

c) Chord length

34-Which of the followings is wrong for the local incoming flow , seen by a segment of the propeller?

a) The circumferential component cuased by the rotation of the propeller

b) The axial velocity component v due to the movement of the aircraft

c) Airfoil drag coefficient of the wing

35-Which of the followings is wrong for the rotational component in the propeller geometry?

a) At the axis this component is zero.

b) At the blade tip it reaches its maximum value.

c) At the axis it is at maximum value

36-Due to the high Mach number, the airfoil thickness ……………

a) reduces the efficiency of the propeller.

b) increases the efficiency of the propeller.

c) doesn’t affect the efficiency of the propeller.

37-The Mach number, at which the flow reaches supersonic speed at same point on the airfoil ……..

a) is called as the propeller efficiency.

b) is called as the propeller inefficiency.

c) is called as the critical Mach number .

38-A reduction of the propeller diameter ……………….

a) also decreases the performance.

b) increases the performance.

c) doesn’t affect the performance.

39- How can we avoid the supersonic flow on the propellers?

a) By using metal propellers

b) By choosing the right airfoil thinness and the right diameter

c) By using thicker and cambered airfoil structures

40- Which of the following factors affects the thrust of a propeller?

a) The density of the medium

b) The volume of air accelerated per time unit and the amount of the acceleration

c) All of above are correct.

41- What happens to the thrust when the propeller diameter (D) increases?

a) The thrust decreases.

b) The thrust increases.

c) Propeller diameter doesn’t affect the thrust.

42- What happens to the thrust when the density of the medium increases?

a) The density of the medium doesn’t affect the thrust.

b) The thrust decreases.

c) The thrust increases

43-How does the acceleration amount increase affect the thrust?

a) The thrust increases.

b) The thrust decreases.

c) The thrust remains constant.

44- For a propeller of a fixed diameter, working in a certain medium at a certain speed ………..

a) the thrust doesn’t change with the propeller diameter.

b) the thrust depends on the velocity increase only.

c) the thrust doesn’t change with the medium density.

45-Which of the followings is the power formula?

a) T=P.v

b) P= T/v

c) P=T .v

46-…………….is defined as the ratio of available power to the engine power.

a) The efficiency of a propeller

b) The efficiency of an engine

c) The efficiency of a compressor

47-As long as an aircraft does not move, its propeller operate under…………. conditions.

a) dynamic

b) static

c) kinetic

48-It is achieved 80 to 90% of the thrust ,as predicted theoretically for the design point but under static conditions……………..

a) we can reach 85% or more of the predicted ideal thrust.

b) we can reach 50% or less of the predicted ideal thrust.

c) we can reach 100% of the predicted ideal thrust.

49- Which of the followings isn’t one of the advantages of the propeller tip shape?

a) Flight performance

b) Repairability

c) Easy demountability/reassembly

50-What is the main reason for the different propeller tip shapes?

a) To meet blade vibration resonance or special design

b) To provide high thrust

c) Fuel economy

51-Which diameter is used for the propellers designed for high airspeeds?

a) Larger diameters

b) The propeller diameter doesn’t have any effects.

c) Smaller diameters

52- Which diameter is used for the propellers designed for low airspeeds?

a) Larger diameters

b) The propeller diameter doesn’t have any effects.

c) Smaller diameters

53- Which of the followings is correct for the fixed-pitch propellers?

a) Fixed-pitch propellers are only used for ground test.

b) At he constant throttle setting, propeller and engine speed don’t change with air speed.

c) At he constant throttle setting, propeller and engine speed increase or decrease with air speed.

54-Which of the followings is correct for fixed-pitch propellers?

a) A governor is used to achieve the constant speed at the selected throttle setting.

b) There isn’t a governor on the constant-speed propellers.

c) Blade angle remains constant as the speed setting or engine power changes.

55-Which of the followings is the propeller whose blade angle automatically changes as the speed setting or engine power changes?

a) Fixed-pitch propeller

b) Constant-speed propeller

c) Ground adjustible propeller

17.2 Propeller Construction

1-Which of the following structures transforms the power of the engine into thrust in the most efficient way?

a) Governor

b) Propeller

c) Wing

2-Propellers for pylon racing engines usually …………..

a) are injection-moulded.

b) are made from metal.

c) are made from wood or composite materials.

3 Which of the following propeller materials poses a high risk?

a) Carbon fibre

b) Glass fibre

c) Metal

4-Which of the followings is wrong for carbon fibre?

a) All carbon fibre propellers are yellow.

b) It is light and strong.

c) Carbon is the easiest of all materials to work with.

5-Which of the following propeller materials flexes less under load, producing an increase in rpm and/or decrease in noise?

a) Carbon fibre

b) Nylon

c) Wooden

6-Which of the followings is a disadvantage of carbon?

a) Its expense and sometimes brittle nature.

b) It allows to thin down the propeller.

c) It is quieter.

7- Which of the followings is wrong for the glass fibre propellers?

a) They are less brittle than the carbon fibre.

b) They are stronger than the carbon fibre.

c) They are slightly heavier than the carbon fibre

8- Fibre contents for CRE or GRE propellers is…..

a) between 15% and 25%.

b) between 55% and 65%.

c) between 85% and 95%.

9-Which of the followings isn’t an advantage of the wooden propeller?

a) Suitability for any size of propeller

b) Light weight

c) To be prone to warping

10- Which of the followings is a disadvantage of the wooden propeller?

a) Light weight

b) To be machined easily

c) To be prone to warping

11-Which of the followings is a feature of the laminated wood propeller?

a) To be machined to shape which prevents the optimisation of the design

b) To allow to thin down the propeller

c) The easiest of all materials to work with

12- Why isn’t the nylon propeller used on a high performance engine?

a) It is expensive.

b) Design difficulty

c) The weight and size of the propeller stretch the propeller to the point of breakage

13- The downside to the manufacture of glass filled nylon propellers is…………

a) To be cheap

b) The more glass fibres in the nylon the more brittle and breakable the product becomes.

c) The more glass fibres in the nylon the stronger the product becomes.

14-The composite propeller blade…………

a) is composed of a titanium blade shank retention section into which is molded a low density foam core.

b) is composed of a steel blade shank retention section into which is molded a high density foam core.

c) is manufactured by nylon casting into the ferrous metal.

15-Leading edge of the composite propeller blade ………………..

a) is coated with the laminated wooden coating to protect the damage.

b) is coated with the electroformed nickel coating having an erosion shield.

c) is coated with the wooden coating to protect the damage and erosion.

16-…………..to limit lightning strike damage of the composite propeller blade.

a) A stainless steel wire mesh is incorporated in it.

b) Nylon filling material is used.

c) It is coated with wooden outer coating.

17-How is the horizontal plane balance of the composite propeller blade achieved?

a) Blade hold windings

b) Steel wire meshes

c) By the addition of lead wool to a centrally located balance tube

18- Fixed-pitch propellers ………….

a) are propellers whose blade angle is ground-adjustable.

b) are simple propellers whose blade angle cannot be changed during normal operation.

c) are used in the today’s multiengine aircrafts.

19- Which of the followings is wrong for the fixed-pitch propeller?

a) They are generally manufactured from the composite material.

b) They are usually found on light, single-engine aircraft.

c) They are propellers whose blade angle cannot be changed.

20- Which of the followings is wrong for the ground-adjustible propellers?

a) Their blade angles can be changed in flight.

b) Their blade angles cannot be changed in flight.

c) They can be rotated in the hub to change the blade angles.

21- Which of the followings is the common feature of the ground-adjustible propellers and fixed-pitch propellers?

a) They can be positioned to the reverse position in a short time.

b) Their blade angles cannot be changed in flight.

c) Their blade angles can be adjusted on the ground.

22- The controllable-pitch propellers………………..

a) blade angles are adjusted only during the installation on the ground.

b) allows the propeller to select a blade angle that gives the best performance for the particular flight condition.

c) blade angles cannot be changed in flight.

23-The number of pitch positions may be limited, or the pitch may be adjusted to any angle between the minimum and the maximum pitch settings of a given propeller. This type of propeller is called as………..

a) ground-adjustible propeller

b) fixed-pitch propeller

c) controllable-pitch propeller

24-Automatic propellers are usually ………….

a) termed constant-speed propellers.

b) termed ground-adjustible propellers.

c) termed fixed-pitch propellers.

25-Which of the followings is a feature of the reverse-pitch propellers?

a) They are used to reduce propeller drag during engine-off/failure-in flight operations.

b) Air is forced forward instead of backward and permits shorter landing roll

c) Blade angles can be adjusted during the installation on the ground.

26) Reverse-pitch propellers are used to ……………..

a) support the maneuvering

b) reduce speed after touchdown

c) reduce speed in flight

27) what area of propeller is loaded highest mechanically?

a) Blade hub

b) Blade root

c) Blade tip

28-Which of the following propeller types is used on multi-engine aircraft to reduce propeller drag during engine-off/failure-in-flight operations?

a) Feathering propellers

b) Controllable-pitch propeller

c) Fixed-pitch propeller

29- Which of the followings isn’t an engine crankshaft?

a) Flanged crankshaft

b) Splined crankshaft

c) Centrifugal crankshaft

30-Which engines are the flanged crankshafts used on?

a) Horizontally opposed and some turboprop engines

b) Older engines of low horsepower

c) Radial engines

31-If no position is specified on a 4-cylinder horizontally opposed engine, …………….

a) the propeller should be installed so that the blades are at the 8-o’clock and 4-o’clock positions when the engine is stopped.

b) the propeller should be installed so that the blades are at the 9-o’clock and 3-o’clock positions when the engine is stopped.

c) the propeller should be installed so that the blades are at the 10-o’clock and 4-o’clock positions when the engine is stopped.

32-Tapered crankshaft installations are generally ………….

a) found on in-line and even turboprop engines.

b) found on older engines of low horsepower.

c) found on horizontally opposed type engines.

33-Which crankshaft installation isn’t the Prussian blue marking method used for?

a) Tapered crankshaft

b) Flanged crankshaft

c) Grooved (splined) crankshaft

34-Which minimum dye transfer percentage should be indicated for the installation control of the crankshaft installation?

a) 80%

b) 100%

c) 70%

35- Splined crankshafts.……….

a) are found on radial engines and some horizontally opposed, in-line and even turboprop engines.

b) are used on horizontally opposed type engines.

c) are used on older engines of low horsepower.

36) Is blade root allowed for repair?

a) Yes, minor repair

b) Yes, major repair

c) No, repair is forbidden

17.3 Propeller Pitch Control

1- Propeller of a single-engine aircraft system with a reciprocating engine ………….on loss of engine oil pressure if the installation is aerobatic.

a) defaults to coarse pitch

b) defaults to fine pitch

c) Oil pressure doesn’t change the propeller pitch.

2-When a feather command is given in a twin-engine aircraft …………..

a) both of the engines will change to the feather position.

b) only one engine will change to the feather position.

c) feather position isn’t used in a twin-engine aircraft.

3- What happens when the feather position is selected in a single-engine aircraft?

a) The propeller changes to the fine pitch.

b) The propeller changes to the coarse pitch

c) There isn’t a feather position in a single-engine aircraft.

4-Which of the followings is a task of the governor?

a) It senses whether the engine/propeller is running at the correct rpm and either supplies or maintains oil flow to the propeller, or drains oil to the engine crankcase.

b) It makes the installation settings of the engine and propeller.

c) It matches the propeller diameter and rotation speed.

5-With a constant-speed (constant-rpm) system what must the pilot do to increase the aircraft speed?

a) The pilot cannot increase the aircraft speed in a constant-speed system.

b) The pilot must increase the blade angle by increasing the power with the power lever.

c) The pilot must decrease the blade engle by decreasing the power with the power lever.

6-A full-feathering propeller system ………………

a) is used on the single-engine powerful aircrafts.

b) is used on reciprocating single-engine aircrafts.

c) is used on twin-engine aircrafts.

7-What is the installation purpose of the full-feathering propeller system?

a) To enable that the propellers are turned to a very high pitch (approx. 90 o) to prevent the propellers from disturbing the aerodynamic balance of the aircraft if one of the engines fails in flight

b) It is installed to reach high speeds.

c) It is installed for providing low speed and low fuel consumption at the higher altitudes.

8-To prevent accidentally moving the propellers to the feather position during powered flight…………

a) the propellers don’t accidentally move to the feather position in flight.

b) the controls have detents at the low rpm (high pitch) end.

c) the feather position is achieved in the ground operations not in flight.

9-Full-feathering systems ……………… to reduce the pitch of the blades.

a) utilise hydraulic pressure

b) utilise a combination of spring and counterweight force

c) utilise a pneumatic system

10-Full-feathering systems …………..to increase the pitch of the blades.

a) utilise a combination of spring and counterweight force

b) utilise hydraulic pressure

c) utilise a pneumatic system

11-The range of blade angle is …….

a) from feather to flight idle.

b) from feather to maxreverse.

c) from flight idle to maxreverse.

12-When does the governing mode occur?

a) During flight

b) During ground operations

c) In the failure condition

13-When does the beta mode occur?

a) During flight

b) When a failure occurs on air

c) During ground operations (i.e. taxiing, reverse)

14- In the beta mode, the range of blade angle change is …………

a) from flight idle to maximum reverse.

b) from feather to maxreverse.

c) Blade angle doesn’t change in the beta mode.

15-Which of the followings is wrong for the propeller governor?

a) It responds to a change in system rpm by changing the blade angle.

b) It may be set up for a specific rpm by the cockpit propeller control.

c) It is the main component of the anti-icing system.

16-Which of the followings isn’t made by the propeller governor to return the system rpm to the original value?

a) It directs system oil to the propeller.

b) It pumps the system oil back to the oil sump.

c) It increases the fuel amount in the combustion chambers.

17-The propeller oil flow control mechanism………………

a) is mounted to the body of the governor.

b) is mounted to the head of the governor.

c) is at the base of the governor.

18-Which of the followings isn’t included by the propeller oil flow control mechanism?

a) Pressure relief valve

b) Oil passages and pilot valve

c) Pulley adjustment stop screw

19-Pressure rate of the the propeller oil flow control mechanism ……….

a) is set to 180 psi to 200 psi.

b) is set to 1800psi to 2000 psi.

c) is set to 18 psi to 20 psi.

20- Excess pressure built up by the booster pump of the propeller governor system………..

a) is returned to the outlet side of the pump by a pressure relief valve.

b) is returned to the inlet side of the pump by a pressure relief valve.

c) is expelled out by the flyweights.

21- Which of the followings isn’t a main component of the propeller governor?

a) Head and body

b) Base

c) Tail

22-Which part of the propeller governor contains the flyweight cup and the flyweights?

a) At the head of the governor

b) At the body of the governor

c) At the base of the governor

23- The position of the pilot valve of the propeller governor …………………

a) is determined by the action of the flyweights attached to the end of the drive shaft.

b) is adjusted according to the fuel consumption amount.

c) is determined by the electrical system attached to the end of the drive shaft.

24-What is the task of the pilot valve of the propeller governor?

a) To direct the fuel flow to adjust the blade angle to maintain the selected rpm.

b) To direct the air flow to adjust the blade angle to maintain the selected rpm.

c) To direct the oil flow to adjust the blade angle to maintain the selected rpm.

25-What happens to the pilot valve when the flyweights attached to the end of the drive shaft tilt outward?

a) The pilot valve is raised.

b) The pilot valve is lowered.

c) There is no change in the pilot valve position.

26-When flyweights attached to the drive shaft tilt outward, rpm ………….

a) is higher than the setting.*

b) is lower than the setting.

c) has the same level as the setting.

27- When the flyweights attached to the drive shaft tilt outward, the blade angles…………

a) must remain constant.

b) must be taken to coarse position.

c) must be taken to fine position.

28-What happens to the pilot valve when the flyweights attached to the drive shaft tilt inward?

a) There is no change in the pilot valve position.

b) The pilot valve is lowered.**

c) The pilot valve is raised.

29- When flyweights attached to the drive shaft tilt inward, rpm ………….

a) is higher than the setting.

b) is lower than the setting.**

c) has the same level as the setting.

30-When the flyweights attached to the drive shaft tilt inward, blade angles……………

a) must be taken to coarse position.

b) must be taken to fine position.**

c) must remain constant.

31-When the propeller rpm is the same as the governor setting,………….

a) the governor is in its on-speed condition.**

b) the governor is in its overspeed condition.

c) the governor is in its underspeed condition.

32-If the aircraft is in a cruise condition and the aircraft begins to climb,………..

a) the angle of attack of the propeller blades increase.**

b) the angle of attack of the propeller blades decrease.

c) there is no change in the angle of attack of the propeller blades.

33-If the aircraft is placed in a dive from cruising flight,………….

a) there is no change in the angle of attack of the propeller blades.

b) the angle of attack of the propeller blades increase.

c) the angle of attack of the propeller blades decrease.

34- Oil pressure loss in the single-acting propellers…………….

a) results in the propeller to go to a high blade angle.

b) results in the propeller to go to a low blade angle.

c) results in no change at the propeller blade angle.

35-Oil pressure loss in the dual-acting propellers ……..

a) results no change at the propeller blade angle.

b) results in the propeller to go to a high blade angle.

c) results in the propeller going uncontrolled to a low blade angle.

36-What is the beta mode of the dual-acting propellers?

a) from flight idle to maximum reverse

b) from maximum reverse to feather position

c) from flight idle to feather position

37-Operation range of the power lever of a single-acting propeller is………

a) from flight idle to maximuma

b) from ground idle to maximum reverse

c) from maximum reverse to feather position

38-When the speed lever is advanced to the high or take-off position……….

a) the underspeed governor is set to 97% rpm.

the propeller governor is set to 100% rpm.

b) the underspeed governor is set to 65% - 73% rpm.

the propeller governor is set to 94.5% - 96.5% rpm.

c) the underspeed governor is set to 100% rpm.


39- When the speed lever in the low or taxi position……………..

a) the underspeed governor is set to 65% - 73% rpm.

the propeller governor is set to 94.5% - 96.5% rpm.

b) the underspeed governor is set to 97% rpm.


c) the underspeed governor is set to 45%-63% rpm.


40-Why is it locked at a flat angle of approx. 2o when the engine is shut down on the ground?

a) To prevent excessive strain on the engine starter when the engine is being started.

b) To prevent the speed governor damage

c) To enable that the speed governor operates more precisely

41-Hartzell propeller is always installed or removed with blades in the……….

a)flight idle position

b) reverse position

c) feather position

42-Which position are the single-acting propellers spring-loaded to?

a) Feather

b) Flight idle

c) Reverse

43- RPM ranges typically for Beta and Alpha modes are ……………

a) beta mode from 95% to 100% rpm

alpha mode from 65% to 95% rpm

b) beta mode from 65% to 95% rpm


c) beta mode from 35% to 95% rpm


44- Where is the overspeed governor adjusted?

a) It is adjusted by the overhaul facility.

b) It is adjusted during the flight.

c) It is adjusted during a maneuver in the reverse position.

45-If the power turbine speed reaches 105%............

a) the power turbine governor will not monitor the turbine speed.

b) the power turbine governor will increase the fuel flow to the engine.

c) the power turbine governor will reduce the fuel flow to the engine.**

46-Which mode does the power turbine governor operate in?

a) Beta mode operation**

b) Alpha mode operation

c) Engine starting

47- Where is the power turbine control unit controlled?

a) From the cockpit

b) From the beta control valve

c) From the propeller pitch control mechanism

48-What is the pitch angle degree for the reverse and feather range of the dual-acting propellers?

a) 105

b) 95

c) 85

49-An automatic feathering system…………

a) is armed during cruising flight.

b) is armed for take-off and landing.

c) is armed in the reverse position.

50-When there is an engine failure, an automatic feathering system activates after …………….

a) 1 to 2 seconds

b) 12 to 20 seconds

c) 10 to 12 seconds

17.4 Propeller Synchronising

1- What is the purpose of the propeller synchronising system?

a) To prevent the ice formation on the blade leading edge

b) To prevent the ice formation on the blade trailing edge

c) To eliminate excess noise and vibration

2- How is the synchronising made?

a) By setting all engines of an aircraft to the same speed

b) By setting all propellers of an aircraft to exactly the same rpm

c) By using the propeller blades made of the same alloy

3- Which of the following flight operations is the synchronising used in?

a) It is used for all flight operations except for take-off and landing.

b) It is used only during take-off and landing.

c) It is used when one of the engines stalls.

4- Which of the following engine or engines are taken as a basis to make an operation in the synchronising system?

a) No engine is taken as a basis.

b) Slave engine

c) Master engine

5- Which of the following units generates the required signal for the synchronisation?

a) Oil pressure valve

b) Solenoid valve

c) Frequency generator

6- Which unit is the frequency generator generating synchronising signal built into?

a) Each propeller governor

b) Cockpit

c) Propeller blade

7- What does a comparison circuit in the control box of a synchronising system compare?

a) Phase signals of the slave and master engine

b) Rpm signals of the slave and master engine

c) Torque signals of the slave and master engine

8-The slave engine ……………………..of the master engine to enable synchronisation.

a) must be within approx. ±100 rpm

b) must be within approx. ±250 rpm

c) must be within approx. ±200rpm

9-What is the difference between the synchronisation and synchrophasing?

a) Synchronisation tries to equate engine rpms and synchrophasing allows the pilot to set the angular difference in the plane of rotation between the blades of the slave engine(s) and the blades of the master engine.

b) Synchronisation adjusts the angular difference and synchrophasing synchronises the master and slave engines.

c) There is no difference between the synchronisation and synchrophasing .

10-Which of the followings does the synchronisation governor monitor?

a) Propeller tip speed

b) Thrust tip speed

c) RPM**

11-What is the required operation sequence for the synchrophasing?

a) firstly synchrophasing and then synchronising

b) firstly synchronising and then synchrophasing

c) independent

12- What can reduce the propeller noise?

a) High RPM, high pressure load

b) Low RPM, high pressure load

c) Low RPM, large propeller diameter

13-What is the purpose of the synchrophasing system?

a) Passenger comfort **

b) Propeller efficiency

c) Engine efficiency

14- Which of the followings is required to synchronise the engines to a speed difference of zero?

a) The engines are manually synchronised to within ±100% of the rpm and the control knob is set to ON.

b) The engines are manually synchronised to within ±2% of the rpm and the control knob is set to ON.

c) The engines are manually synchronised to within ±2% of the rpm and the control knob is set to OFF.

15-When can the synchrophasing system be turned off?

a) In take-off, landing, single engine operation and in case of malfunction

b) During flight

c) Synchrohasing system can never be turned off.

16-Which part of the aircraft having the propeller de-icing are the speed pick-ups used in the synchrophasing system mounted on?

a) It is mounted on the de-icing brush block assembly.

b) It is mounted on the slipring.

c) It is mounted on the chemically de-icing tank

17.5 Propeller Ice Protection

1- Which of the followings isn’t used in the propeller system as a anti-icing method?

a) Chemical anti-icing

b) Electrothermal de-icing systems

c) Pneumatic

2- Which of the followings is the disadvantage of the chemical anti-icing system?

a) To use isopropyl alcohol

b) To be operated by an electric motor

c) Chemical amount to be carried by the tank is limited.

3-Which of the followings is the operation principle of the chemical anti-icing system?

a) It is operated by an electric motor which is controlled by a rheostat.

b) It is operated by an air pump.

c) It is operated by a centrifuge system operating with the aircraft vibrations during flight

4-Which of the following substances is used in the chemical anti-icing system?

a) Alcohol

b) Isopropyl alcohol

c) Diluted water

5- How does the chemical anti-icing system distribute the isopropyl alcohol to the propeller blades?

a) By a slinger ring that uses centrifugal force

b) By an air gun driven with air

c) By an assembly placed to the tip of the propeller blades

6-Which of the followings is wrong for the electrothermal de-icing system?

a) De-icing is achieved by the pump driven by an electric motor.

b) De-icing is achieved by heating the rubber boots with heater wires embedded in the rubber.

c) There is an ammeter to indicate the operation of the system.

7-Which blade part is the heater wires of the electrothermal de-icing system bonded to?

a) Trailing edges

b) Blade root

c) Leading edges

8- Which of the followings isn’t a component of the electrothermal de-icing system?

a) Slip ring and brush block assemblies that carry the current to the rotating propeller

b) An ammeter to indicate the operation of the system

c) Chemical tank pump driven by an electric motor

9-Current……………………through the outboard section of all blades in the electrothermal de-icing system.

a) flows for about a 1/2 minute

b) flows for 3 minutes

c) flows for 2 minutes

10-Which method is used to carry the ice away from the propeller blades in the electrothermal de-icing system?

a) By a hydraulic system

b) By a pneumatic system

c) By the centrifugal force and wind

11-Why is it important to heat the same blade part size at the same time?

a) For even isopropyl alcohol distribution

b) For preventing imbalance in the de-icing

c) For not effecting the rotation of the propeller blades

12- …………….monitors the operation of the system and assures the pilot that each heater element is taking the required amount of current.

a) Slip ring

b) Ampermeter

c) Circuit breakers

13-To prevent propeller imbalance due to uneven shedding of ice, the de-icing process………….. which ensure even de-icing.

a) is controlled by the circuit breakers

b) is controlled by the timers

c) is controlled by the ammeter

14-Why are the electrothermal de-icing systems for the left and right propellers independent of each other?

a) If one of the propellers fails, the electrical power is automatically removed to prevent overheating of the carbon-fibre propeller blades and it is enabled that the other propeller system operates regularly.

b) It is difficult to place the electrical circuit breakers.

c) To prevent the aerodynamic structure from failing

15-Electrical power controlled by the timers is transmitted to the de-icer mats via…………..

a) slip rings

b) circuit breakers

c) ammeter

16- Propeller de-icing systems have three positions. They are……….

a) BELOW -20ºC - OFF - ABOVE -1ºC.

b) BELOW -10ºC - OFF - ABOVE -10ºC

c) BELOW -5ºC - OFF - ABOVE -10ºC

17-Why are the metal oxide varistor modules installed?

a) To protect the aircraft’s electrical power supply if the propellers are struck by lightning

b) To control the fill rate of the chemical anti-icing tanks

c) To prevent the propeller blades from corrosion

18-How many electrical circuits are mounted in the electrothermal de-icing system?

a) 1

b) 2

c) 3

19-…………………to prevent any damage caused by the overheating of the carbon-fibre propeller blades.

a) if the propeller speed drops below 675 rpm ±25 rpm, any output to the de-icer mats is prevented.

b) if the propeller speed drops below 650rpm ±25 rpm, any output to the de-icer mats is prevented.

c) if the propeller speed drops below 625rpm ±25 rpm, any output to the de-icer mats is prevented.

20- To prevent the carbon-fibre propellers from damaging due to the overheating the mode BELOW -10oC is disabled at temperatures of………………

a) + 5oC and above

b) + 10oC and above

c) + 15oC and above

21-Operation power of the electrical de-icing circuits is ……………

a) 28 V DC**

b) 28 V AC

c) 220 V DC

17.6 Propeller Maintenance

1-The inspection, adjustment, installation and minor repair of a propeller and its related parts and appliances on the engine…………

a) are within the responsibility of a certificated repair station.

b) are within the responsibility of the powerplant technician.

c) are within the responsibility of the fuselage technician.

2-Which of the followings performs the 100-h inspection of the propeller and its related components?

a) Powerplant technician

b) A certificated repair station

c) Propeller manufacturer

3-………….. is authorized for the repair and overhaul of the propeller.

a) A certificated propeller repair station

b) A powerplant technician

c) A propeller importer company

4-…………..may approve that a propeller or accessory is returned to service after a major repair or alteration/modification.

a) An air carrier

b) A certificated propeller repair station

c) A powerplant technician

5-Which of the followings isn’t a type of preventive maintenance?

a) Replacement of defective safety wiring or cotter keys

b) Application of preservative or protective material to components where no disassembly is required and where the coating is not prohibited

c) Installation of the propeller de-icing system

6-Which maintenance type includes the installation of a governor or feathering system?

a) Preventive maintenance

b) Major alterations and repairs

c) 100-h maintenance

7-When a propeller or control device is overhauled, ………………..to certify that the item approved for return service.

a) it is cleaned and lubricated

b) it is approved by a powerplant technician

c) a maintenance release tag must be attached to the item

8-Which maintenance type includes the changes in the blade or hub design?

a) Major alteration and repair

b) Annual maintenance

c) Preventive maintenance

9-Application of preservative or protective material to components where no disassembly is required and where the coating is not prohibited is called ……………..

a) major alteration and repair

b) 10-h maintenance

c) preventive maintenance

10-Checking the propeller assembly for cracks, nicks, binds and oil leakages are made …………………

a) in the 100-hour or annual inspections.

b) in the 10-hour or monthly inspections.

c) after the propeller cleaning.

11- What must be made when there are cracks on the shank?

a) It must be changed

b) Minor maintenance procedures must be applied.

c) Cracks must be filled with the filling material.

12-Which of the followings isn’t an advantege of the aluminium alloy blades?

a) The low cost of maintenance owing to the hardness of the metal from which they are made

b) One-piece construction of the propellers

c) machining easily owing to the metal softness

13-Before inspecting the aluminium alloy blades …………………..

a) they are controlled by wiping with the alcohol.

b) they are to be cleaned with a solution of mild soap and water to remove all of the dirt, grease and grass stains.

c) surface grease and grass stains are removed by the fine sandpaper.

14-If cracks are suspected during the corrosion control for the aluminium alloy blades ……………….

a) the blades are changed.

b) they are controlled by wiping with the alcohol.

c) a dye-penetrant inspection should be performed.

15-The approx. max. allowable size of a repair edge defect is…………

a) 3.2 mm in depth and not more than 38 mm in length.

b) 38 mm in depth and more than 3.2 mm in length.

c)No repair is allowed.

16-Propellers with damage, dimensional wear or heavy corrosion in the boss area…..

a) should be made onsite repair and reinstalled.

b) should be transferred for repair to a repair station.

c) should be cleaned with a solution of water and soap.

17-If a blade bends, angle of bend and the blade station of the bend center……………

a) are measured by using a protractor.

b) are measured by using a ruler.

c) are measured by using a divider.

18-If the propeller hub appears to swing in a slight orbit,……………….

a) the vibration normally be caused by the engine strokes.

b) it can be said that it is a vibration-free propeller.

c) the vibration normally be caused by the propeller.

19- If the hub appears to rotate in a horizontal plane in the vibration controls ………..

a) the engine vibration is the most likely cause.

b) the vibration cause is the propeller.

c) there is no vibration.

20- If both the propeller tracking and the low blade angle setting are incorrect…………

a) the propeller is statically or dynamically balanced.

b) the propeller is statically balanced and dynamically unbalanced.

c) the propeller is statically or dynamically unbalanced.

21-Which of the followings isn’t a type of propeller imbalance ,which is a source of vibration in an aircraft?

a) Static imbalance

b) Dynamic imbalance

c) Variable imbalance

22-…………………….when the center of gravity of the propeller does not coincide with the axis of rotation.

a) Static propeller imbalance occurs

b) Dynamic propeller imbalance occurs.

c) Aerodynamic propeller imbalance occurs.

23- Which of the followings isn’t a static balancing method?

a) Suspension method

b) Knife-edge method

c) Spinner method

24-When does the aerodynamic imbalance occur?

a) When the thrust (or pull) of the blades is equal.

b) When the thrust (or pull) of the blades is unequal.

c) When the engine vibrations are unbalanced.

25- Which of the followings isn’t used in the wooden propeller cleaning?

a) Absolute alcohol

b) Mild soap

c) Warm water

26-If a aluminium alloy propeller has been subjected to salt water………..

a) it should be washed with alcohol.

b) No protection is required.

c) is should be flushed with fresh water until all traces of salt have been removed.

17.7 Propeller Storage and Preservation

1- If the propeller is to be storage in transport cases, relative humidity of air………

a) may be of 70-80%.

b) may be of 45-70%.

c) may be of 145-170%.

2- If the propeller is to be storage in transport cases, the cases must be placed free……………

a) minimum 20 cm above the floor and from the walls.

b) minimum 10 cm above the floor and from the walls.

c) minimum 5 cm above the floor and from the walls.

3- Room temperature of the room in which the propellers stored must be kept ………….

a) at range of 0 to +10C.

b) at range of +1 to +4C.

c) at range of +10 to +40C.

4-Which of the followings isn’t a propeller storage period when storage is carried out on the aircraft?

a) 30 days

b) from 3 months to 1 year

c) from 1 year to 30 months

5-What has to be done, if the storage time is expired?

a) No operation is required.

b) Recertification and release of a new Form 1 is required

c) The propeller loses its airworthiness.

6-Storage of an wooden prop should be done………..

a) cross

b) vertical

c) horizontal

modül 17

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