mod 17 mcq june 2010

MODULE 17 PRACTICE MCQ

http://www.aircrafttechtrng.com

1

Which of the following propeller blades are most affected by fatigue?

Aluminium alloy Wood Composite a

When fitting a propeller to an engine that has a splined shaft

a master spline will determine the correct position

the splines in the hub will fit in any position on the shaft

the front and rear cones must not touch to cause interference

a

When engine power is increased, the constant-speed propeller tries to function so that it will

maintain the RPM, decrease the blade angle

increase the RPM, decrease the blade angle

maintain the RPM, increase the blade angle c

When engine power is increased the constant speed propeller will

maintain RPM by decreasing the blade angle

increase RPM by decreasing the blade angle

maintain the RPM by increasing the blade angle

c

When cleaning an aluminum propeller for inspection, use

mild soap and water steel wool MEK a

When a force is applied to the speeder spring, the blade angle

goes coarser goes finer does not alter b

Variable pitch propellers must be stored in a damp, cool environment to prevent seals drying

dry environment to prevent corrosion

dark environment to prevent oxidation b

Torque acts in opposition to the direction of rotation

in the same direction as the plane of rotation

at right angles to the plane of rotation a

Thrust produced on a propeller is a result of an area of low pressure on

the face of the propeller blades the back of the propeller blades

both surfaces of the propeller blades b

Thrust is generally greatest at 70 to 80% of prop length

equal along the entire length of the prop

greatest in the first 50% of prop length b

The use of a blade station is required when measuring blade angle indexing blades propeller balancing

The thrust face, or side, of a propeller blade is the

rear face or flat side front face or curved side root to which the gear segment is installed a

The synchronisation governor monitors prop tip speeds thrust tip speeds RPM c

The shelf life of a fixed pitch propeller is normally

up to 2 years up to 5 years indefinite c

The shank of the propeller is generally permitted to have

minor repairs no repairs no decals attached b



2

The purpose of prop twist is to maintain Angle of Attack at the same value along the blade

to maintain Blade Angle along the blade

coarsen the blade angle at the root a

The purpose of blade twist is to reduce the angle of attack at the blade root

even out thrust distribution across the propeller

ensure that tip speed does not go faster than Mach 1

b

The purpose of an arbor used in balancing a propeller is to

support the propeller on the balance knives

level the balance stand mark the propeller blades where weights are to be attached

a

The purpose of an accumulator in a double acting propeller system is to

provide back up to the governor pump

accelerate the un-feathering process

port oil to assist in feathering the propeller b

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

tail wheel on the ground tail wheel in the take off position

in the rigging position b

The propeller synchronising system is put into operation by

adjusting the engine RPM at required cruise speed then switching on the synchroniser

adjusting the engine RPM then prop RPM to required speed then switching on

switching on the synchroniser then adjust the engine RPM so that all engines adjust together

a

The propeller spinner is used for distributing anti ice fluid propeller balancing decreasing drag c

The propeller governor controls oil to and from the pitch changing mechanism

tension on the internal speeder spring

linkage and counterweight movement

a

The propeller control lever regulates the engine RPM fuel mixture power output a

The propeller blade angle is defined as the acute angle between the airfoil section chord line (at the blade reference station) and the

plane of rotation relative wind propeller thrust line

a

The primary purpose of front and rear cones for propellers that are installed on splined shafts is to

position the hub on the splined shaft

to prevent metal to metal contact between the hub and shaft

to relieve stress in the splines of the shaft a



3

The primary purpose of a feathering propeller is to

prevent engine damage if it is shut down in flight

prevent propeller damage if the engine is shut down in flight

eliminate drag created by a windmilling propeller of a failed engine

c

The primary purpose of a cuff on a propeller is to distribute anti-ice fluid strengthen the propeller shank

improve the airflow over the blade shank c

The power on a piston engine with a constant-speed propeller is measured by

Manifold Pressure RPM Torque a

The pitch angle of a propeller is the angle between the

propeller reference chord line and the relative airflow

reference chord line and the propeller plane of rotation

propeller reference chord line and the extremity of the propeller

b

The pitch angle of a constant-speed propeller decreases with increasing true air speed

only varies with engine RPM

increases with increasing true air speed c

The output of an anti-icing pump is controlled by a cyclic timer a switch the hand pump b

The optimum angle for a fixed-pitch propeller is 2 - 4 degrees 6 - 10 degrees 15 degrees a

The operational force that tends to increase the blade angle is the

centrifugal twisting force aerodynamic twisting force

thrust bending force b

The operational force that tends to bend the blades forward is the

thrust bending force torque bending force centifugal twisting force a

The operational force that causes the greatest stress on a propeller is the

aerodynamic twisting force centrifugal force thrust bending force b

The operational force that causes the blade tips to lag in the opposite direction to the rotation is the

thrust bending force aerodynamic twisting force

torque bending force c

The main advantage of a constant speed propeller compared to a fixed-pitch propeller is a

higher efficiency in all operating ranges

constant efficiency in all operating ranges

lower propeller blade stress a

The geometric pitch of a propeller is the distance the propeller would move forward in one revolution at the blade angle

angle the propeller chord makes to the plane of rotation

distance the propeller actually moves forward in one revolution a



4

The gear type pump in a constant speed unit (CSU) or PCU (prop control unit)

lubricates the entire propeller system

boosts engine oil system pressure

assists the governor valve to move b

The function of the automatic propeller synchronising system on a multi-engine aircraft is to control

the blade angle of all propellers.

the engine RPM to reduce vibration.

the power output of each engine to reduce noise.

b

The forces acting on a propeller are centrifugal, twisting, and bending

torsion, tension and thrust

torque, thrust and centrifugal c

The force that turns the blades towards fine pitch is

Torque ATM (aerodynamic twisting moment)

CTM (centrifugal twisting moment) c

The force that tends to decrease the blade angle of a propeller is the

aerodynamic twisting force centrifugal twisting force torque bending force b

The curved surface of a propeller blade is known as the

blade back blade front blade face a

The constant speed unit (CSU) governor works on the principle of

manual selection through a gearbox

centrifugal twisting moments

spring pressure acting against centrifugal force c

The centrifugal latches in a single acting propeller are used to prevent

centrifugal twisting moment (CTM)

feathering of the prop on shutdown

the propeller moving to superfine b

The centrifugal latch is installed to maintain RPM above ground idle

prevent overstress on propeller

prevent propeller feathering on shut down c

The cambered, or curved side of a propeller blade is identified as the blade

back chord leading edge a

The blade angle of a propeller is the angle between the

root chord and the tip chord of the propeller

chord and the airflow relative to the propeller

propeller chord and the plane of rotation of the propeller

c

the blade angle of a constant speed propeller will be greatest during

approach to landing climb high speed, high altitude cruise flight

The blade angle at the root is greater than the tip less than the tip same from tip to root a

The blade angle is constant along the propeller blade

decreases from root to tip

increases from root to tip b

The Beta range of a propeller is from the feather stop to the flight fine pitch stop

feather stop to the ground fine pitch stop

flight fine pitch stop to the reverse pitch stop c



5

The best method of inspecting an aluminium propeller to detect cracks is the use of

a bright light eddy current dye penetrant c

The angle-of-attack of a rotating propeller blade is measured between the blade chord or face and which of the following?

the plane of blade rotation full low-pitch blade angle the relative airstream

c

The angle of attack of a fixed-pitch propeller depends on

forward speed only forward speed and engine rotational speed

engine rotational speed only b

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

angle of attack helix angle or angle of advance

blade angle c

The alpha range of a variable pitch propeller is between

feather and flight fine pitch stop

feather and ground fine pitch stop

flight fine pitch stop and reverse stop a

The alpha range of a variable pitch propeller is between

feather and flight fine pitch stop

feather and ground fine pitch stop

flight fine pitch stop and reverse stop a

The actual distance a propeller moves through the air during one revolution is known as the

effective pitch geometric pitch relative pitch a

The "matrix" in a composite blade is the bonding material reinforcing material foam core a

Synchronisation is used to preset the phase angle of propellers

reduce vibration and noise

reduce the pitch of the fastest running blade b

Stored propellers must be maintained regularly to

replace seals restore them to "zero time since overhaul"

check the torque loadings a

Running an engine with a fixed-pitch propeller at full throttle, with the aircraft stationary and nose into a strong wind will result in

an increase in full throttle rev/min

full throttle rev/min being unaltered

a decrease in full throttle rev/min a

Reverse pitch propellers provide aerodynamic braking reverse the direction of rotation of the propeller

reduce drag a

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

tipping topping cropping c

Propeller blade stations are measured from the index mark on blade shank hub center line blade tip b



6

Propellers with adjustable blades can be adjusted

in flight on the ground with the engine running

on the ground with the engine stationary c

Propeller tracking is a procedure for stores acquisition vibration analysis determining blade tip clearance b

Propeller torque is the resistance offered by the propeller to

changing pitch rotation feathering b

Propeller torque is the tendency of the propeller to twist around its longitudinal axis

helical path of the propeller through the air

turning moment produced by the propeller about the axis of the crankshaft

c

Propeller slip rings convey oil for PCU (prop control unit) to pitch change mechanism

minimize Slip conduct electrical power for de icing c

Propeller defects such as nicks and scratches should be repaired promptly to prevent

corrosion unbalanced aerodynamics

fatigue failure c

Propeller blade tracking is the process of determining the

plane of rotation with respect to the aircraft longitudinal axis

blade angles are within the specified tolerance of each other

position of the blade tips relative to each other c

Propeller blade angle increases from root to tip decreases from root to tip

is constant along the blade length b

On a reversing prop moving to the max reversing angle, the prop goes from fine pitch, through plane of

rotation, fine reverse, then coarse reverse

fine pitch, through plane of rotation, coarse reverse, then fine reverse

coarse pitch, through plane of rotation, coarse, reverse, then fine reverse

a

On a piston engine aircraft with a constant speed propeller, the power is set with the

engine RPM and prop RPM manifold pressure and engine RPM gauge

torque and prop RPM gauge b

On a free turbine engine it is possible to vary the propeller RPM while the engine RPM remains constant by operating the

PCU (prop control unit) control lever

power lever reduction gearbox gear lever a

Oil pressure for propeller pitch actuation is provided by

the engine lubrication pump a variable displacement pump

a pump in the governor c



7

Most engine-propeller combinations have a critical range where continuous operation is not permitted, because it may cause

severe propeller vibration low to negative thrust conditions

inefficiency due to low pitch angles a

Minor transverse cracks on an alloy blade are not repairable may be dressed out with a combination of files

will be removed at overhaul a

Minor repairs to composite propellers may be carried out by

the operator any part 145 maintenance organization

any approved composite repair facility c

In the governor of a constant speed propeller, the pilot valve is activated by

engine oil pressure governor flyweights governor oil pressure b

In the event of an engine failure during flight, the blades of a constant speed propeller in a single engine airplane, not equipped with a feathering system, will move to

the lowest pitch position by centrifugal force

low pitch position by oil pressure created by the windmilling propeller

a predetermined pitch position depending on windmilling RPM

a

If pressure is increased on the speeder springs, the RPM increases and the blade angle

increases decreases remains unchanged b

If a blade of a metal propeller is shortened because of damage, repair to the tip of the remaining blade(s) must be

reset in blade angle to compensate

returned to manufacturer to be matched

shortened to conform with the shortened blade c

Ice is removed from propeller blades by boots that are heated in sequence through the action of a timer

a continuously heated electrical boot

rubber boots inflated in sequence using compressor hot air

a

High speed airfoils are employed at the tips the master station the root a

Ground adjustable propellers allow the propeller blade pitch angles to be set on the ground

the pilot to select only one pitch angle on the ground for local conditions

one adjustment only and cannot be changed

a

Geometric pitch of a propeller is the effective pitch minus slippage effective pitch plus slippage

angle between the blade chord and the airflow b

Geometric Pitch is the distance the propeller moves in one revolution

without slip when slip is maximum with the optimal pich setting a



8

For takeoff, a constant-speed propeller is normally set in the

high pitch, high RPM position low pitch, low RPM position

low pitch, high RPM position c

For take off, a constant speed propeller is set in the

high pitch high RPM position high pitch low RPM position

low pitch high RPM position c

Fluid and electrical de-icing equipment.

Effective pitch is geometric pitch minus slip distance moved in one revolution

pitch measured at the master station a

Dynamic balance is confirmed by use of knife edges and mandrel a tracking check a vibration analyzer c

During the take-off run, a fixed-pitch propeller is at

too coarse an angle for maximum efficiency

too fine an angle for maximum efficiency

the optimum angle for efficiency a

During take-off an increase in RPM at fixed throttle setting is caused by

the engine over-speeding a more efficient angle of attack of the blades

the propeller blades slipping b

De-icing of the propeller can be monitored by viewing the blade and observing ice falling off

an ammeter in the flight deck

viewing the de-icing boot pulsing action b

Counterweights on constant-speed propellers are generally used to aid in

increasing blade angle decreasing blade angle unfeathering the propellers a

Composite blades are protected against electro-static build up by

braided tapes in the core metal strips in the envelope

using carbon fibre spars b

Coarse pitch is used for take off and climb maximum economical cruise in level flight

landing and power checks b

Centrifugal twisting moment (CTM) in a propeller is a force that

acts at right angles to the plane of rotation of a propeller

twists the blade to fine twists the blade to coarse b

Centrifugal twisting moment (CTM) changes the pitch of a blade

about it’s twisting axis towards the feather plane

bending forward a

Blade station numbers increase from hub to tip tip to hub leading edge to trailing edge a

Blade cuffs are installed to the root of the blades to increase

thrust the strength of the blade flow of air around the blade shank c

Blade angle is taken from the chord and relative airflow propeller shaft plane of rotation c

Blade angle is measured using a bevel protractor propeller protractor clinometer b



9

As a safety precaution when tracking the propeller, it is advisable the engineer

removes the spark plugs stands well out of the arc of the blades

chocks the aircraft wheels a

As a propeller moves from fine pitch to feather, it passes through

reverse flight fine only coarse c

Anti icing fluid is fed to individual propeller blades by

a pump to each blade rubber feed boot

a pump to a slinger ring gravity to the slinger ring then on to the blade b

Aircraft electrical power for propeller de-icer systems is transferred from the engine to the propeller hub assembly by

slip-rings and segment plates slip-rings and brushes flexible electrical connectors b

Aerodynamic Thrust imbalance can be corrected by

correcting pitch setting static balancing blade tracking a

A vibration caused by a problem with the propeller installation, would have a vibrating frequency that is

higher than turbine vibration the same as turbine vibration

lower than turbine vibration c

A typical propeller governor has the following components

oil pump and cooler speeder spring and diaphragm

speeder spring and fly weights c

A turbo -prop aircraft, reverse thrust is obtained by pulling back the

power lever propeller speed lever condition lever a

A three piece spinner assembly consists of a dome, a

backplate and forward plate back bulkhead and forward bulkhead

backplate and forward bulkhead c

A right hand propeller rotates in a clockwise direction when viewed from the rear

cannot be installed on a left hand engine

rotates in an anti-clockwise direction when viewed from the rear

a

A propeller system BETA range is used to produce zero or negative thrust

is used to produce maximum thrust for take-off

refers to the most fuel efficient pitch range to use at a given RPM

a

A propeller is centralized on the propeller shaft by the

front dirt seal rear pre-load shims front and rear cones c

A propeller control unit (PCU) hydraulic system is supplied with oil from the

aircraft hydraulic system PCU (prop control unit) oil tank

engine lubrication system c



10

A propeller blade is twisted, so as to keep the local angle of attack constant along the blade

avoid the appearance of sonic phenomena

decrease the blade tangential velocity from the blade root to the tip

a

"Scurfing" a propeller blade is the process carried out to

re-profile the blade tips remove surface cracks prepare the surface for anodising b

"Resonant vibration" generally affects wooden blades aluminium alloy blades composite blades b

"Blending" of propeller blade defects refers to the

repainting of blade tips after cropping

corrosion prevention process of the repair

conversion of rough or sharp edges into smooth depressions

c

Aerodynamic twisting moment tends to turn the blades to a high angle of attack

bend the blades forward turn the blades to low angle of attack a

When un-feathering a propeller, to prevent overspeed, the blades should be put into

coarse pitch fine pitch negative pitch a

When tracking a propeller, it is rotated at idle RPM by hand at cruise RPM b

When the centrifugal force on the fly weights overcomes the tension of the speeder spring, the governor is

on speed underspeed overspeed c

When the fly weights fly outwards in a PCU (prop control unit), this is known as

on-speed under-speed over-speed c

When running up an aircraft into wind, the static RPM will

increase with an increase in wind speed

decrease with an increase in wind speed

remain constant with any wind speed a

When re-installing a propeller, the dynamic balance is maintained by

aligning index marks on the spinner

the location of the dowl pins

torqueing in the correct sequence a

When operating a constant speed propeller, it is usually preferable to have a

high manifold pressure and low engine RPM

high engine RPM and low manifold pressure

balanced prop and engine RPM b

When manufacturing aluminum blades, the final profile of the blade is obtained by

chemical etching milling machine, cutting the airfoil shape

twisting the blade c

When increasing true airspeed with a constant engine RPM, the angle of attack of a fixed-pitch propeller

stays constant increases reduces c



11

When in reverse pitch, centrifugal twisting moment (CTM) tends to move the propeller blades towards a

negative pitch positive pitch position depending on RPM b

Prior to using a universal propeller protractor check the date stamp for serviceability

determine the reference blade station

ensure the propeller blade is at the horizontal position

b

Operation of electric de-icing boots on individual propeller blades may best be determined by

feeling the boots to see if they are heating

observing the ammeter or load meter for current flow

checking the resistance of each slip ring a

One advantage of a wooden propeller is wood allows more efficient blade construction

does not have a fatigue life

is more cost effective b

On an engine which is operating in the constant speed range, moving the throttle further to the open position will

increase the blade angle increase the RPM have no effect on the blade angle a

On a spinner assembly, the index marks are used to align the

backplate and forward bulkhead with the spinner dome

hub and propeller assembly

hub and spinner dome a

On a scheduled servicing, a propeller spinner would normally be checked for

balance cracks correct lubrication b

In an ‘on speed’ condition of a constant speed unit, (CSU), oil flows

to the propeller from the propeller to the engine c

In a propeller with counterweights, the force used to move the propeller to fine pitch is the

aerodynamic twisting moment (ATM)

centrifugal force acting on the counterweights

governor oil pressure c

If the tension on the speeder spring is increased in the governor, the blade angle will

increase and RPM will decrease

decrease and RPM will decrease

decrease and RPM will increase c

If the speeder spring pressure of a constant speed unit (CSU) is increased the blade will

fine off coarsen off not move a

Synchronisation is used in flight at all times in flight except landing and take off

whenever the engine is running b

If the RPM and manifold pressure (MAP) levers are not moved and the true air speed (TAS) increases, the pitch angle of a constant speed propeller

first reduces and after a short time increases to its previous value

reduces increases

c



12

If the governor fly wheel overcomes the speeder spring, it indicates

over-speed under-speed on-speed a

If the blade angle is increased the pitch becomes finer. the pitch becomes coarser

lateral stability decreases. b

mod 17 mcq june 2010

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