EASA : Module17 Propeller Question - Answer

EASA : Module17 Propeller Question - Answer

On which type of turbo-propeller would you expect to find a parking brake

a) compounded twin spool

b) free turbine

c) direct coupled twin spool

Ans:b

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Propeller blade angle

a) increases from root to tip

b) decreases from root to tip

c) is constant along the blade length

Ans:b

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The purpose of the pitch change cams is to

a) convert linear motion to rotary motion.

b) convert rotary motion to linear motion.

c) prevent windmilling

Ans:a

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What does the torque meter reading indicate in a gas turbine engine?

a) Torque reaction at the reduction gear

b)  Engine torque

c) The ratio between engine thrust and engine torque

Ans:a

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The gear type pump in a C.S.U. or P.C.U

a) lubricates the entire propeller system

b)  boosts engine oil system pressure

c) assist the governor valve to move

Ans:b

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The gear segments on the blade roots of a hydromatic propeller mesh with the

a) stationary cam

b)  torque tubes and eye bolts

c) moving cam

Ans:c

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Coarse pitch is used for

a) take off and climb

b)  maximum economical cruise in level flight

c) landing and power checks

Ans:b

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A propeller is centralised on the propeller shaft by

a) the front git seal

b)  the rear pre-load shims

c) the front and rear cones

Ans:c

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Reduction gearing allows the

a) blade tips to operate above the speed of sound

b)  blade tips to rotate slower than the root of the propeller blade

c) blade tips to operate below the speed of sound

Ans:c

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TEST

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Effective pitch is

a) geometric pitch plus slip

b)  distance moved in one revolution

c) pitch measured at the master station

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Prior to using the universal propeller protractor

a) check date stamp for serviceability

b)  determine the reference blade station

c) ensure the propeller blade is at the horizontal

*

A windmilling Propeller has

a) a small positive blade angle

b)  a small positive angle of attack

c) a small negative angle of attack

*

Geometric Pitch is the distance moved

a) in one revolution without slip

b) in one revolution when slip is maximum

c) in one revolution

Ans:a

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As propeller rotation speed increases the centrifugal turning moment on the blades will

a) remain constant through r.p.m. range

b) increase

c) decrease.

Ans:b

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Propeller torque is the resistance offered by the propeller to

a) changing pitch

b) rotation

c) feathering

Ans:b

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The angle between the resultant airflow direction and the propeller blade plane of rotation is known as

a) angle of attack

b) helix angle or angle of advance

c) blade angle

Ans:b

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Which type of turbo-propeller engine is practically free from surge and requires low power for starting

a) directly coupled

b) one using a centrifugal compressor.

c) twin spool free turbine

Ans:c

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The propeller is “feathered” when the blades are at

a) 90o to plane of rotation.

b) 0o to plane of rotation

c) 20o to plane of rotation

Ans:a

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The constant speed unit (C.S.U.) governor works on the principle of

a) manual selection through a gearbox.

b) centrifugal twisting moments.

c) spring pressure acting against centrifugal force.

Ans:c

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At constant rpm, advance per revolution depends on

a) the angle of advance.

b) forward speed.

c) SHP

Ans:b

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Aerodynamic Twisting Moment

a) turns the blades to high pitch

b) turns the blade to low pitch.

c) turns the blade to windmill

Ans:a

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The thrust of a propeller is normally taken by the

a) propeller rear cone.

b) torque meter.

c) front bearing in the reduction gear

Ans:c

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Under normal operation the point of maximum stress on a propeller blade is at the

a) root

b)  tip

c) master station

Ans:a

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TEST

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The thrust face of a propeller blade is the

a) rear face or flat side

b)  front face or curved side

c) root to which the gear segment is fitted

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How is anti-icing fluid fed to the individual blades?

a) Pump to each blade rubber feed boot

b)  Pump to a slinger ring

c) Under gravity to the slinger ring then on to the blade

*

Ice is removed from blades by

a) inboard and outboard boot sections heated in sequence by action of the timer

b)  a continuously heated electrical boot

c) rubber boots inflated in sequence using compressor hot air

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If pressure is increased on the speeder spring, rpm increases. What happens to the blade angle?

a) Increases

b) Decreases

c) Remains unchanged

Ans:b

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From reverse pitch, to return to normal pitch it

a) passes through fine

b) passes through coarse

c) passes through coarse then fine

Ans:a

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In a prop with counterweights, what is used to make it move to fine pitch?

a) ATM

b) Centrifugal force acting on the counterweight

c) Governor oil pressure

Ans:c

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If a propeller is in fine pitch and then moves to feather it will

pass through

a) reverse

b) flight fine only

c) coarse

Ans:c

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When in reverse pitch, CTM will tend to move the propeller blades towards

a) a negative pitch

b) a positive pitch

c) a position depending on rpm

Ans:b

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If the blade angle is increased

a) the pitch becomes finer

b) the pitch becomes coarser

c) lateral stability decreases

Ans:b

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A “double” acting propeller has

a) oil pressure on one side of piston

b) oil pressure on two sides of piston

c) nitrogen or air on one side of piston

Ans:b

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During normal propeller operation, oil pressure for the governor is provided by

a) the engine driven pump

b) a variable volume pump

c) a pump in the governor

Ans:c

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Oil for an ‘on-speed’ condition passes through

a) the coarse pitch line

b) the fine pitch line

c) neither of the lines

Ans:c

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If the spur gear pump in a single acting propeller governor failed, the

a) blades would turn to a coarse pitch

b) blades would rotate to a fine pitch

c) blades would move to the feather position

Ans:a

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The hydromatic variable pitch propeller is operated on the principle of

a) oil pressure moving a piston

b) an electrical motor moving a gear segment

c) a venturi or “u” tube with mercury

Ans:a

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Blending of propeller blade defects refers to the

a) repainting of blade tips after cropping

b) matching of paint finishes for appearances

c) conversion of rough or sharp edges into smooth depres-sions

Ans:c

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Removal of material from the propeller blade tips, resulting in a reduction in propeller diameter is called

a) tipping

b) topping

c) cropping

Ans:c

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The minimum percentage seating on a propeller rear cone should be

a) 95%

b) 90%

c) 70%

Ans:c

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As a propeller blade moves through the air, forces are produced, which are known as

a) lift and drag

b) lift and torque

c) thrust and torque

Ans:c

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A rotating propeller imparts rearwards motion to a

a) small mass of air at high velocity

b) large mass of air at low velocity

c) small mass of air at low velocity

Ans:b

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Propeller efficiency

a) the ratio of the useful work done by the propeller to work done by the engine on the propeller

b) the ratio of the work applied to the geometric pitch to useful work on the C.S.U.

c) ratio of output speed to input propeller speed

Ans:a

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TEST

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To fit a new front cone to a prop shaft firstly

a) Coat in Engineers blue to ensure seating in the propeller front boss

b)  Etch the propeller serial number to the rear face

c) Cut in half with a hacksaw and etch a unique serial number to both halves

*

When fitting a propeller to a tapered shaft

a) Locate the master spline

b)  Ensure fully seated

c) Ensure the master spline and blade alignment are in accordance with the MM

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Blade tracking is adjusted by

a) reseating the propeller on the front and rear cones

b)  adding lead wool tothe blade shank

c) by fitting shims to the propeller shaft hub

*

What are the purpose of small holes at the tip of wooden propellers?

a) Balancing

b)  Pivot points used during manufacture

c) Drainage

*

Pitch control using torque measuring is for

a) increasing drag

b) reducing drag in engine failure

c) reducing drag in binding

Ans:b

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If force is applied to the speeder spring, what will happen?

a) Blade angle coarsen

b) Blade angle finer

c) Blade angle is frozen in last known position

Ans:b

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Propeller vibration due to a problem with propeller installations would have a vibrating frequency of

a) higher frequency than turbine vibration

b) the same frequency as turbine vibration

c) lower frequency than turbine vibration

Ans:c

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Insulation checks on propeller electrical heating elements should be carried out frequently due to

a) short/open circuits in the heating system wires along the propeller blade

b) oxidation of slip ring and brush gear assembly

c) deposits formed due to the wear of slip ring and brush gear assembly

Ans:c

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Preloading propeller blades before installation prevents

a) blade flutter

b) aerodynamic imbalance on the blades

c) blade distortion

Ans:a

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When is superfine pitch used?

a) In cruise

b) Landing and takeoff

c) Engine starting to reduce propeller torque loading on starter motor

Ans:c

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When unfeathering a propeller, the blade should be put into what position to stop propeller over speed?

a) Coarse pitch

b) Fine pitch

c) Negative pitch

Ans:a

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Blade angle is measured using a

a) bevel protractor

b) propeller protractor

c) clinometer

Ans:b

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What forces act on a propeller blade?

a) Thrust and torque

b) Bending, centrifugal CTM and ATM

c) Bending, thrust, torque

Ans:b

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When the fly weights fly outwards in a PCU, this is known as

a) on speed

b) under speed

c) overspeed

Ans:c

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In an ‘on speed’ condition, oil in the tube

a) flows out of the tubes

b) flows in the tubes

c) remains constant

Ans:c

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Where is the de-icing boot?

a) Root

b) Tip

c) Trailing edge

Ans:a

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On a reversing prop moving to the max reversing angle, the prop goes

a) from fine pitch through plane of rotation, fine reverse then course reverse

b) from fine pitch through plane of rotation, course reverse then fine reverse

c) from course pitch through plane of rotation course,fine reverse then course reverse

Ans:a

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In the Beta range,angle of attack increases. The fuel flow increases, and what else?

a) RPM and EGT

b) EPR and fuel temperature

c) Fuel temp

Ans:a

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CTM will

a) turn the blade about the lateral axis

b) try to bend the blade away from the engine

c) cause the tips to rotate at supersonic speeds

Ans:a

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With a propeller defect, will the frequency be

a) higher than a turbine defect

b) higher than a auxiliary gearbox defect

c) lower than a turbine defect

Ans:c

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Torque sensing is used to

a) reduce drag

b) reduce drag following engine shutdown

c) synchronise blade angles

Ans:b

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Synchronising can only be achieved if the slave propeller is

a) a within 20 rpm of the master

b) within 100 rpm of the master

c) the same speed as the master

Ans:b

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Synchronising is carried out to

a) match engine rpm

b) match prop tip speed

c) match blade phase angle difference

Ans:a

Forces acting on a propeller are

a) centrifugal, twisting, and bending

b) torsion, tension and thrust

c) torque Thrust and Centrifugal

Ans:a

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Aerodynamic Correction Factor (ACF)

a) is indicated in the form of degrees and minutes of pitch

b) corrects for dynamic balance

c) corrects for static balance

Ans:a

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The blade angle at the root is

a) greater than the tip

b) less than the tip

c) same from tip to root

Ans:a

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A propeller with an adjustable blade can be adjusted

a) in flight

b) on the ground with the engine running

c) on the ground with the engine stationary

Ans:c

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What force on a propeller blade turns the blades to a fine pitch?

a) Torque

b) ATM

c) CTM

Ans:c

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When on the ground with the engine idling the prop control should be

a) fully forward with the mixture at idle

b) fully aft with the mixture at idle

c) fully aft with the mixture at rich

Ans:c

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Operation with the engine at maximum boost should be limited to

a) prop at fine to prevent overstressing the engine

b) prop at course to prevent overstressing the engine

c) prop at windmill to prevent overstressing the engine

Ans:b

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On an underspeed condition the blades are turned to

a) feather

b) coarse

c) fine

Ans:c

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The synchronisation governor monitors

a) prop tip speeds

b) thrust tip speeds

c) RPM

Ans:c

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The purpose of prop twist is

a) to maintain Angle of Attack at the same value along the blade.

b) to maintain Blade Angle along the blade

c) coarsen the blade angle at the root

Ans:a

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Synchronisation is used to

a) preset the phase angle of propellers

b) reduce vibration and noise

c) reduce the pitch of the fastest running blade

Ans:b

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In a hydromatic propeller with counterweights what is used to make the propeller move to fine pitch

a) ATM

b) centrifugal force acting on the counterweight

c) engine oil

Ans:c

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The forces acting on a propeller blade are

a) thrust and torque

b) bending twisting and centrifugal

c) thrust aerodynamic and tension

Ans:b

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Damage to a leading edge can be blended in comparison to a blade face

a) by maintaining a smooth depression

b) by not exceeding 25% of the chord

c) at a steeper angle

Ans:c

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The longitudinal clearance between the nose wheel and the propeller on a tricycle geared propeller is

a) 18 inches

b)  9 inches

c) 1/2 inch

Ans:c

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Relaxing tension on the governor spring will result in the blade coarsening and

a) RPM increasing manifold pressure increasing

b) manifold pressure constant, RPM decreasing

c) RPM decreasing , manifold pressure increasing

Ans:c

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A tracking check compares

a) 2 Opposite blades

b)  2 Adjacent blades

c) any 2 blades

Ans:c

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Blade cuffs are fitted to the root of the blades

a) to increase thrust

b) to increase the strength of the blade

c) to increase flow of cooling air into the engine nacelle.

Ans:c

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The ground fine pitch stop is

a) removed on the ground

b) never removed

c) removed during flight

Ans:a

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Low torque sensing is used to

a) increase power

b) increase pitch

c) initiate auto-feather

Ans:c

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A line of indentations at one blade section can be

a) declared unserviceable

b) left for up to 12 months

c) blended within limits

Ans:a

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On an electrical de-icing system fast cycle is used

a) at Low Air Temperature

b) at High Air Temperature

c) on the Ground

Ans:b

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Blade angle at the root is

a) low

b) high

c) master blade angle

Ans:b

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If governor fly wheel overcomes the speeder spring, it indicates

a) overspeed

b) underspeed

c) onspeed

Ans:a

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Blade angle is taken from the chord and

a) relative airflow

b) propeller shaft

c) plane of rotation

Ans:c

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Synchronisation is used

a) in flight

b) in flight except landing and take off

c) on the ground

Ans:b

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Thrust and camber faces of a propeller should be blended out to

a) 5 times the depth of damage

b) 10 times to the depth of damage

c) 30 times to the depth of damage

Ans:c

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Leading edges should be blended out to

a) 5 times the depth of damage

b) 10 times the depth of damage

c) 30 times the depth of damage

Ans:b

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The shank of the propeller is permitted to have

a) minor repairs

b) no repairs

c) no decals fitted

Ans:b

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Wooden propellers are permitted

a) no repairs

b) repairs using sawdust and aeroglue

c) repairs that do not affect weight and balance

Ans:b

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Composite propellers may have minor repairs carried outby

a) the operator

b) any approved 3rd party maintenance organization

c) any approved composite repair facility

Ans:c

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Details of propeller overhaul may be found in

a) Airworthiness Notice 75

b) the AMM

c) Airworthiness Notice 55

Ans:a

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The tip clearance of a single engine tail wheel aircraft is measured with the aircraft

a) tail wheel on the ground

b) tail wheel in the take off position

c) in the rigging position

Ans:b

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The tip clearance of a multi-engine aircraft

a) is taken between the engines with the props aligned.

b) is taken between the prop and the fuselage

c) is taken from the ground

Ans:b

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The tip clearance of a sea plane is

a) 9 inches

b) 1 inch

c) 18 inches

Ans:c

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Cropping is permitted to a maximum of

a) ½ inch on one blade only

b) ½ inch on all blades

c) 1 inch on all blades

Ans:c

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Dynamic balance is confirmed by use of

a) knife edges and mandrel

b) a tracking check

c) a vibration analyser

Ans:c

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Synchrophasing reduces vibration by the use of

a) pulse probes and a single synchrophase unit

b) tachometers and correction motors

c) coordinating the rpm of each engine

Ans:a

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A metal propeller may be statically balanced by

a) removing metal from the opposite blade

b) adding varnish to the lighter blade

c) adding or removing lead wool to the hollow blade roots

Ans:c

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When in the windmill position ATM

a) assists CTM

b) opposes CTM

c) is not related to CTM

Ans:a

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A hydraulic pitch lock is utilised in a hydromatic propeller to

a) lock out the course pitch oil line in the event of underspeeding

b) prevent the propeller overspeeding in the event of oil supply failure

c) lock out the fine pitch oil line in the event of overspeeding

Ans:c

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Electronic torque measuring systems utilise

a) stress gauges in the reduction gear

b) pressure transducers in the reduction gear

c) strain gauges in the reduction gear

Ans:c

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A conventional turboprop torque meter uses

a) engine oil as the pressure medium

b) hydraulic oil as the pressure medium

c) coiled spring levers as the pressure medium

Ans:a

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When in the beta range the propeller pitch is controlled

a) directly from the pitch change mechanism to the PCU

b) indirectly from the power lever

c) directly from the power lever

Ans:c

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The advantage of the beta range is it allows

a) low fine pitch settings with high power

b) low power settings with higher than normal pitch setting for ground manoeuvres

c) high power settings with higher than normal pitch settings when in flight

Ans:b

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Electrically de-iced propeller slip rings have regular resistance checks for

a) open circuit heating elements

b) wear between brushes and slip ring

c) oxidisation due to altitude

Ans:a

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The optimum angle for a fixed pitch propeller is

a) 2 - 4 degrees

b) 6 - 10 degrees

c) 15 degrees

Ans:a

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A left handed propeller is one that

a) rotates clockwise when viewed from the front

b) rotates clockwise when viewed from the rear

c) is fitted to an engine on the left side of the aircraft

Ans:a

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If the speeder spring pressure of a CSU is increased the blade will

a) fine off

b) coarsen off

c) will not move

Ans:a

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Mechanical vibration relating to propellers in a piston powered aircraft

a) is due to the lead lag of the propeller compared to the engine

b) is due to the power stroke of the engine and may have a more detrimental effect than aerodynamic vibration

c) is due to the crankshaft at intermittent power settings

Ans:b

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Prop anti-icing may be achieved by

a) a using hot air from the compressor

b) using commercial de-icing fluid sprayed on the pro

c) using iso-propyl alcohol de-icing fluid sprayed on the blade

Ans:c

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De-icing of the propeller can be monitored by

a) viewing the blade and observing ice falling off the blade

b) an ammeter in the flight deck

c) viewing the deicing fluid level sight glass

Ans:b

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Metal at the tip and along the leading edge of a wooden propeller is

a) for protection

b) for Anti-icing

c) for balancing

Ans:a

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Insulation testing of electrical de-icing systems should be periodically carried out because of

a) oxidation due to atmospheric conditions

b) wear on the slip rings

c) an open circuit in one of the blades

Ans:c