Module 17 Practice MCQ PDF - June 2010

MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com Which of the following propeller blades are most Aluminium alloy Wood Composite a...

MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com Which of the following propeller blades are most Aluminium alloy Wood Composite affected by fatigue? a When fitting a propeller to an engine that has a a master spline will determine the splines in the hub the front and rear cones splined shaft the correct position will fit in any position on must not touch to cause a the shaft interference When engine power is increased, the constant- maintain the RPM, decrease increase the RPM, maintain the RPM, speed propeller tries to function so that it will the blade angle decrease the blade increase the blade angle c angle When engine power is increased the constant maintain RPM by decreasing increase RPM by maintain the RPM by speed propeller will the blade angle decreasing the blade increasing the blade c angle angle When cleaning an aluminum propeller for mild soap and water steel wool MEK a inspection, use When a force is applied to the speeder spring, goes coarser goes finer does not alter the blade angle b Variable pitch propellers must be stored in a damp, cool environment to dry environment to dark environment to prevent seals drying prevent corrosion prevent oxidation b Torque acts in opposition to the direction of in the same direction as at right angles to the rotation the plane of rotation plane of rotation a Thrust produced on a propeller is a result of an the face of the propeller blades the back of the propeller both surfaces of the area of low pressure on blades propeller blades b Thrust is generally greatest at 70 to 80% of prop equal along the entire greatest in the first 50% length length of the prop 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 rear face or flat side front face or curved side root to which the gear the 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 up to 2 years up to 5 years indefinite c normally The shank of the propeller is generally permitted minor repairs no repairs no decals attached b to have 1  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com The purpose of prop twist is to maintain Angle of Attack at to maintain Blade Angle coarsen the blade angle the same value along the along the blade at the root a blade The purpose of blade twist is to reduce the angle of attack at even out thrust ensure that tip speed the blade root distribution across the does not go faster than b propeller Mach 1 The purpose of an arbor used in balancing a support the propeller on the level the balance stand mark the propeller propeller is to balance knives blades where weights a are to be attached The purpose of an accumulator in a double provide back up to the accelerate the un- port oil to assist in acting propeller system is to governor pump feathering process feathering the propeller b The propeller tip clearance of a single engine tail tail wheel on the ground tail wheel in the take off in the rigging position wheel aircraft is measured with the aircraft position b The propeller synchronising system is put into adjusting the engine RPM at adjusting the engine switching on the operation by required cruise speed then RPM then prop RPM to synchroniser then adjust switching on the synchroniser required speed then the engine RPM so that a switching on all engines adjust together 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 tension on the internal linkage and changing mechanism speeder spring counterweight a movement The propeller control lever regulates the engine RPM fuel mixture power output a The propeller blade angle is defined as the plane of rotation relative wind propeller thrust line acute angle between the airfoil section chord a line (at the blade reference station) and the The primary purpose of front and rear cones for position the hub on the splined to prevent metal to to relieve stress in the propellers that are installed on splined shafts is shaft metal contact between splines of the shaft a to the hub and shaft 2  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com The primary purpose of a feathering propeller is prevent engine damage if it is prevent propeller eliminate drag created to shut down in flight damage if the engine is by a windmilling shut down in flight propeller of a failed c engine The primary purpose of a cuff on a propeller is to distribute anti-ice fluid strengthen the propeller improve the airflow over shank the blade shank c The power on a piston engine with a constant- Manifold Pressure RPM Torque speed propeller is measured by a The pitch angle of a propeller is the angle propeller reference chord line reference chord line and propeller reference between the and the relative airflow the propeller plane of chord line and the b rotation extremity of the propeller The pitch angle of a constant-speed propeller decreases with increasing true only varies with engine increases with air speed RPM 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 centrifugal twisting force aerodynamic twisting thrust bending force blade angle is the force b The operational force that tends to bend the thrust bending force torque bending force centifugal twisting force blades forward is the a The operational force that causes the greatest aerodynamic twisting force centrifugal force thrust bending force stress on a propeller is the b The operational force that causes the blade tips thrust bending force aerodynamic twisting torque bending force to lag in the opposite direction to the rotation is force c the The main advantage of a constant speed higher efficiency in all constant efficiency in all lower propeller blade propeller compared to a fixed-pitch propeller is a operating ranges operating ranges stress a The geometric pitch of a propeller is the distance the propeller would angle the propeller distance the propeller move forward in one revolution chord makes to the actually moves forward at the blade angle plane of rotation in one revolution a 3  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com The gear type pump in a constant speed unit lubricates the entire propeller boosts engine oil system assists the governor (CSU) or PCU (prop control unit) system pressure valve to move b The function of the automatic propeller the blade angle of all the engine RPM to the power output of synchronising system on a multi-engine aircraft propellers. reduce vibration. each engine to reduce b is to control noise. The forces acting on a propeller are centrifugal, twisting, and torsion, tension and torque, thrust and bending thrust centrifugal c The force that turns the blades towards fine Torque ATM (aerodynamic CTM (centrifugal pitch is twisting moment) twisting moment) c The force that tends to decrease the blade angle aerodynamic twisting force centrifugal twisting force torque bending force of a propeller is the b The curved surface of a propeller blade is known blade back blade front blade face a as the The constant speed unit (CSU) governor works manual selection through a centrifugal twisting spring pressure acting on the principle of gearbox moments against centrifugal force c The centrifugal latches in a single acting centrifugal twisting moment feathering of the prop on the propeller moving to propeller are used to prevent (CTM) shutdown superfine b The centrifugal latch is installed to maintain RPM above ground prevent overstress on prevent propeller idle propeller feathering on shut down c The cambered, or curved side of a propeller back chord leading edge blade is identified as the blade a The blade angle of a propeller is the angle root chord and the tip chord of chord and the airflow propeller chord and the between the the propeller relative to the propeller plane of rotation of the c propeller the blade angle of a constant speed propeller approach to landing climb high speed, high altitude will be greatest during 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 decreases from root to increases from root to blade tip tip b The Beta range of a propeller is from the feather stop to the flight fine feather stop to the flight fine pitch stop to pitch stop ground fine pitch stop the reverse pitch stop c 4  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com The best method of inspecting an aluminium a bright light eddy current dye penetrant propeller to detect cracks is the use of c The angle-of-attack of a rotating propeller blade the plane of blade rotation full low-pitch blade angle the relative airstream is measured between the blade chord or face c and which of the following? The angle of attack of a fixed-pitch propeller forward speed only forward speed and engine rotational speed depends on engine rotational speed only b The angle between the resultant airflow direction angle of attack helix angle or angle of blade angle and the propeller blade plane of rotation is advance c known as the The alpha range of a variable pitch propeller is feather and flight fine pitch feather and ground fine flight fine pitch stop and between stop pitch stop reverse stop a The alpha range of a variable pitch propeller is feather and flight fine pitch feather and ground fine flight fine pitch stop and between stop pitch stop reverse stop a The actual distance a propeller moves through effective pitch geometric pitch relative pitch the air during one revolution is known as the 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 reduce vibration and reduce the pitch of the propellers noise fastest running blade b Stored propellers must be maintained regularly replace seals restore them to "zero check the torque to time since overhaul" loadings a Running an engine with a fixed-pitch propeller at an increase in full throttle full throttle rev/min being a decrease in full throttle full throttle, with the aircraft stationary and nose rev/min unaltered rev/min a into a strong wind will result in Reverse pitch propellers provide aerodynamic braking reverse the direction of reduce drag rotation of the propeller a Removal of material from the propeller blade tipping topping cropping tips, resulting in a reduction in propeller diameter c is called Propeller blade stations are measured from the index mark on blade shank hub center line blade tip b 5  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com Propellers with adjustable blades can be in flight on the ground with the on the ground with the adjusted engine running 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 changing pitch rotation feathering propeller to b Propeller torque is the tendency of the propeller to helical path of the turning moment twist around its longitudinal propeller through the air produced by the axis propeller about the axis c of the crankshaft Propeller slip rings convey oil for PCU (prop minimize Slip conduct electrical power control unit) to pitch change for de icing c mechanism Propeller defects such as nicks and scratches corrosion unbalanced fatigue failure should be repaired promptly to prevent aerodynamics c Propeller blade tracking is the process of plane of rotation with respect blade angles are within position of the blade tips determining the to the aircraft longitudinal axis the specified tolerance relative to each other c of each other Propeller blade angle increases from root to tip decreases from root to is constant along the tip blade length b On a reversing prop moving to the max fine pitch, through plane coarse pitch, through reversing angle, the prop goes from fine pitch, through plane of of rotation, coarse plane of rotation, rotation, fine reverse, then a reverse, then fine coarse, reverse, then coarse reverse reverse fine reverse On a piston engine aircraft with a constant engine RPM and prop RPM manifold pressure and torque and prop RPM speed propeller, the power is set with the engine RPM gauge gauge b On a free turbine engine it is possible to vary the PCU (prop control unit) control power lever reduction gearbox gear propeller RPM while the engine RPM remains lever lever a constant by operating the Oil pressure for propeller pitch actuation is the engine lubrication pump a variable displacement a pump in the governor provided by pump c 6  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com Most engine-propeller combinations have a severe propeller vibration low to negative thrust inefficiency due to low critical range where continuous operation is not conditions pitch angles a permitted, because it may cause Minor transverse cracks on an alloy blade are not repairable may be dressed out with will be removed at a combination of files overhaul a Minor repairs to composite propellers may be the operator any part 145 any approved composite carried out by maintenance repair facility c organization In the governor of a constant speed propeller, engine oil pressure governor flyweights governor oil pressure the pilot valve is activated by b In the event of an engine failure during flight, the the lowest pitch position by low pitch position by oil a predetermined pitch blades of a constant speed propeller in a single centrifugal force pressure created by the position depending on a engine airplane, not equipped with a feathering windmilling propeller windmilling RPM system, will move to If pressure is increased on the speeder springs, increases decreases remains unchanged the RPM increases and the blade angle b If a blade of a metal propeller is shortened reset in blade angle to returned to shortened to conform because of damage, repair to the tip of the compensate manufacturer to be with the shortened blade c remaining blade(s) must be matched Ice is removed from propeller blades by boots that are heated in a continuously heated rubber boots inflated in sequence through the action of electrical boot sequence using a a timer compressor hot air High speed airfoils are employed at the tips the master station the root a Ground adjustable propellers allow the propeller blade pitch the pilot to select only one adjustment only and angles to be set on the ground one pitch angle on the cannot be changed ground for local a conditions Geometric pitch of a propeller is the effective pitch minus slippage effective pitch plus angle between the blade slippage chord and the airflow b Geometric Pitch is the distance the propeller without slip when slip is maximum with the optimal pich moves in one revolution setting a 7  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com For takeoff, a constant-speed propeller is high pitch, high RPM position low pitch, low RPM low pitch, high RPM normally set in the position position c For take off, a constant speed propeller is set in high pitch high RPM position high pitch low RPM low pitch high RPM the position position c Fluid and electrical de-icing equipment. Effective pitch is geometric pitch minus slip distance moved in one pitch measured at the revolution 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 too coarse an angle for too fine an angle for the optimum angle for at maximum efficiency maximum efficiency efficiency a During take-off an increase in RPM at fixed the engine over-speeding a more efficient angle of the propeller blades throttle setting is caused by attack of the blades slipping b De-icing of the propeller can be monitored by viewing the blade and an ammeter in the flight viewing the de-icing observing ice falling off deck boot pulsing action b Counterweights on constant-speed propellers increasing blade angle decreasing blade angle unfeathering the are generally used to aid in propellers a Composite blades are protected against electro- braided tapes in the core metal strips in the using carbon fibre spars static build up by envelope b Coarse pitch is used for take off and climb maximum economical landing and power cruise in level flight checks b Centrifugal twisting moment (CTM) in a propeller acts at right angles to the twists the blade to fine twists the blade to is a force that plane of rotation of a propeller coarse b Centrifugal twisting moment (CTM) changes the about it’s twisting axis towards the feather bending forward pitch of a blade plane 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 thrust the strength of the blade flow of air around the to increase 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 8  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com As a safety precaution when tracking the removes the spark plugs stands well out of the chocks the aircraft propeller, it is advisable the engineer arc of the blades wheels a As a propeller moves from fine pitch to feather, it reverse flight fine only coarse passes through c Anti icing fluid is fed to individual propeller a pump to each blade rubber a pump to a slinger ring gravity to the slinger ring blades by feed boot then on to the blade b Aircraft electrical power for propeller de-icer slip-rings and segment plates slip-rings and brushes flexible electrical systems is transferred from the engine to the connectors b propeller hub assembly by Aerodynamic Thrust imbalance can be corrected correcting pitch setting static balancing blade tracking a by A vibration caused by a problem with the higher than turbine vibration the same as turbine lower than turbine propeller installation, would have a vibrating vibration vibration c frequency that is A typical propeller governor has the following oil pump and cooler speeder spring and speeder spring and fly components diaphragm weights c A turbo -prop aircraft, reverse thrust is obtained power lever propeller speed lever condition lever by pulling back the a A three piece spinner assembly consists of a backplate and forward plate back bulkhead and backplate and forward dome, a forward bulkhead bulkhead c A right hand propeller rotates in a clockwise direction cannot be installed on a rotates in an anti- when viewed from the rear left hand engine clockwise direction when viewed from the a rear A propeller system BETA range is used to produce zero or is used to produce refers to the most fuel negative thrust maximum thrust for efficient pitch range to a take-off use at a given RPM A propeller is centralized on the propeller shaft front dirt seal rear pre-load shims front and rear cones c by the A propeller control unit (PCU) hydraulic system aircraft hydraulic system PCU (prop control unit) engine lubrication is supplied with oil from the oil tank system c 9  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com A propeller blade is twisted, so as to keep the local angle of attack avoid the appearance of decrease the blade constant along the blade sonic phenomena tangential velocity from a the blade root to the tip "Scurfing" a propeller blade is the process re-profile the blade tips remove surface cracks prepare the surface for carried out to anodising b "Resonant vibration" generally affects wooden blades aluminium alloy blades composite blades b "Blending" of propeller blade defects refers to repainting of blade tips after corrosion prevention conversion of rough or the cropping process of the repair sharp edges into smooth c depressions Aerodynamic twisting moment tends to turn the blades to a high angle bend the blades forward turn the blades to low of attack angle of attack a When un-feathering a propeller, to prevent coarse pitch fine pitch negative pitch overspeed, the blades should be put into 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 on speed underspeed overspeed overcomes the tension of the speeder spring, c the governor is When the fly weights fly outwards in a PCU on-speed under-speed over-speed (prop control unit), this is known as c When running up an aircraft into wind, the static increase with an increase in decrease with an remain constant with RPM will wind speed increase in wind speed any wind speed a When re-installing a propeller, the dynamic aligning index marks on the the location of the dowl torqueing in the correct balance is maintained by spinner pins sequence a When operating a constant speed propeller, it is high manifold pressure and high engine RPM and balanced prop and usually preferable to have a low engine RPM low manifold pressure engine RPM b When manufacturing aluminum blades, the final chemical etching milling machine, cutting twisting the blade profile of the blade is obtained by the airfoil shape c When increasing true airspeed with a constant stays constant increases reduces engine RPM, the angle of attack of a fixed-pitch c propeller 10  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com When in reverse pitch, centrifugal twisting negative pitch positive pitch position depending on moment (CTM) tends to move the propeller RPM b blades towards a Prior to using a universal propeller protractor check the date stamp for determine the reference ensure the propeller serviceability blade station blade is at the horizontal b position Operation of electric de-icing boots on individual feeling the boots to see if they observing the ammeter checking the resistance propeller blades may best be determined by are heating or load meter for current of each slip ring a flow One advantage of a wooden propeller is wood allows more efficient blade does not have a fatigue is more cost effective construction life b On an engine which is operating in the constant increase the blade angle increase the RPM have no effect on the speed range, moving the throttle further to the blade angle a open position will On a spinner assembly, the index marks are backplate and forward hub and propeller hub and spinner dome used to align the bulkhead with the spinner assembly a dome On a scheduled servicing, a propeller spinner balance cracks correct lubrication would normally be checked for b In an ‘on speed’ condition of a constant speed to the propeller from the propeller to the engine unit, (CSU), oil flows c In a propeller with counterweights, the force aerodynamic twisting moment centrifugal force acting governor oil pressure used to move the propeller to fine pitch is the (ATM) on the counterweights c If the tension on the speeder spring is increased increase and RPM will decrease and RPM will decrease and RPM will in the governor, the blade angle will decrease decrease increase c If the speeder spring pressure of a constant fine off coarsen off not move speed unit (CSU) is increased the blade will a Synchronisation is used in flight at all times in flight except landing whenever the engine is and take off running b If the RPM and manifold pressure (MAP) levers first reduces and after a short reduces increases are not moved and the true air speed (TAS) time increases to its previous c increases, the pitch angle of a constant speed value propeller 11  MODULE 17 PRACTICE MCQ http://www.aircrafttechtrng.com If the governor fly wheel overcomes the speeder over-speed under-speed on-speed spring, it indicates a If the blade angle is increased the pitch becomes finer. the pitch becomes lateral stability coarser decreases. b 12