Propellers Flashcards
(119 cards)
1
Q
How the fuck is aircraft electrical power for propeller deicer systems transferred from the engine to the propeller hub assembly?
A
By slip rings and brushes.
2
Q
How is anti-icing fluid ejected from the slinger ring on a propeller?
A
By centrifugal force.
3
Q
On most reciprocating multiengine aircraft, automatic propeller synchronization is accomplished through the actuation of the what?
A
propellers governors.
4
Q
Propellers fluid anti-icing systems generally use which of the following?
A
Isopropyl alcohol.
5
Q
What is a function of the automatic propeller synchronizing system on multiengine aircraft?
A
To control engine RPM and reduce vibration.
6
Q
Ice formation on a propeller blade will…
A
produce unbalance and vibration.
7
Q
What unit in the propeller anti-icing system controls the output of the pump?
A
Rheostat.
8
Q
Proper operation of electric deicing boots on individual propeller blades may best be determined by what?
A
feeling the sequence of boot heating and have an assistant observe the load meter indications.
9
Q
A propeller synchrophasing system allows a pilot to reduce noise and vibration by what?
A
adjusting the phase angle between the propellers on an aircraft’s engines.
10
Q
Which of the following determines oil and grease specifications for lubrication of propellers?
A
Propellers manufacturer’s instructions.
11
Q
Grease used in aircraft propellers reduces the frictional resistance of moving parts and is easily molded into any form under pressure. This statement defines what?
A
antifriction and plasticity characteristics of grease.
12
Q
What type of imbalance will cause a two-blade propeller to have a persistent tendency to come to rest in a horizontal position (with the blades parallel to the ground) while being checked on a propeller balancing beam?
A
Vertical.
13
Q
What is the purpose of an arbor used in balancing a propeller?
A
To support the propeller on the balance knives.
14
Q
If a blade of a particular metal propeller is shortened because of damage to the tip, the remaining blade(s) must be what?
A
reduced to conform with the shortened blade.
15
Q
The application of more protective coating on one blade than the other when refinishing a wood propeller…
A
may be necessary to achieve final balancing.
16
Q
Apparent engine roughness is often a result of propellers unbalance. The effect of an unbalanced propeller will usually be what?
A
greater at high RPM.
17
Q
Which of the following is used to correct horizontal unbalance of a wood propeller?
A
Solder.
18
Q
Propellers aerodynamic (thrust) imbalance can be largely eliminated by what?
A
correct blade contouring and angle setting.
19
Q
A powerplant using hydraulic controlled constant-speed propeller is operating within the propeller’s constant-speed range at a fixed throttle setting. If the tension of the propeller governor control spring (speeder spring) is reduced by movement of the cockpit propeller control, the propellers blade angle will what?
A
increase, engine manifold pressure will increase, and engine RPM will decrease.
20
Q
Why is the pulley stop screw on a propeller governor adjustable?
A
To limit the maximum engine speed during takeoff.
21
Q
During engine operation at speeds lower than those for which the constant speed propeller control can govern in the INCREASE RPM position, the propellers will what?
A
remain in the full LOW PITCH position.
22
Q
When engine power is increased, the constant-speed propeller tries to function so that it will what?
A
maintain the RPM, increase the blade angle, and maintain a low angle of attack.
23
Q
The propellers governor controls the what?
A
oil to and from the pitch changing mechanism.
24
Q
During the on-speed condition of a propeller, the…
A
centrifugal force of the governor flyweights is equal to the speeder spring force.
25
What actuates the pilot valve in the governor of a constant-speed propeller?
Governor flyweights.
26
What action takes place when the cockpit control lever for a hydromatic, constant-speed propeller is actuated?
Compression of the speeder spring is changed.
27
What will happen to the propellers blade angle and the engine RPM if the tension on the propellers governor control spring (speed spring) is increased?
Blade angle will decrease and RPM will increase.
28
How does the propellers over speed governor on a turboprop engine decrease propeller RPM?
As oil pressure increases, the servo piston is pushed forward, and the feather spring is compressed.
29
How is the speed of a constant-speed propeller changed in flight?
By changing the load tension against the flyweights in the governor.
30
When the centrifugal force acting on the propellers governor flyweights overcomes the tension on the speeder spring, a propeller is in what speed condition?
Over speed.
31
What operational force causes the greatest stress on a propeller?
Centrifugal force.
32
What operational force tends to increase propeller blades angle?
Aerodynamic twisting force.
33
How is a propeller controlled in a large aircraft with a turboprop installation?
By the engine power lever.
34
How does the aerodynamic twisting force affect operating propeller blades?
It tends to turn the blades to a high blade angle.
35
Which of the following best describes the blade movement of a propeller that is in the high RPM position when reversing action is begun?
Low pitch directly to reverse pitch.
36
Propellers exposed to salt spray should be flushed with what?
Fresh water.
37
How can a steel propeller hub be tested for cracks?
By magnetic particle inspection.
38
Which of the following functions requires that use of a propeller blades station?
Measuring blade angle.
39
The propellers blade angle is defined as the acute angle between the airfoil section chord line (at the blade reference station) and which of the following?
The plane of rotation.
40
During which of the following conditions of flight will the blade pitch angle of a constant-speed propeller be the greatest?
High-speed, high-altitude cruising flight.
41
The actual distance a propeller moves forward through the air during one revolution is known as the what?
effective pitch.
42
The pitch-changing mechanism of the hydromatic propeller is lubricated by what?
the pitch-changing oil.
43
What is the result of moving the throttle on a reciprocating engine when the propeller is in the constant-speed range with the engine developing cruise power?
Opening the throttle will cause an increase in blade angle.
44
Propellers blade stations are measured from the what?
hub centerline.
45
The thrust produced by a rotating propeller is a result of what?
an area of decreased pressure immediately in front of the propeller blades.
46
Why is constant-speed counterweight propeller normally placed in full HIGH PITCH position before the engine is stopped?
To prevent exposure and corrosion of the pitch changing mechanism.
47
The low pitch stop on a constant-speed propeller is usually set so that what?
the engine will turn at its rated takeoff RPM at sea level when the throttle is opened to allowable takeoff manifold pressure.
48
The angle-of-attack of a rotating propeller blade is measured between the blade chord of face and which of the following?
Relative airstream.
49
The centrifugal twisting moment of an operating propeller tends to what?
reduce the pitch angle.
50
Which of the following is identified as the cambered or curved side of a propeller blades, corresponding to the upper surface of a win airfoil section?
Blade back.
51
Which of the following best describes the blade movement of a full-feathering, constant-speed propeller that is in the LOW RPM position when the feathering action is begun?
High pitch directly to feather position.
52
The holding coil on a hydromatic propeller feathering button switch holds a solenoid relay closed that applies power to the propellers...
feathering pump motor.
53
What is the primary purpose of the metal tipping which covers the blade tips and extends along the leading edge of each wood propeller blade?
To prevent impact damage to the tip and leading edge of each wood propeller blades.
54
Blade angle is an angle formed by a line perpendicular to the crankshaft and a line formed by the what?
chord of the blade.
55
Propellers blade stations numbers increase from what?
hub center line to tip.
56
The aerodynamic force acting on a rotating propeller blades operating at a normal pitch angle tends to what?
increase the pitch angle.
57
Which of the following forces or combination of forces operates to move the blades of a constant-speed counterweight-type propeller to the HIGH PITCH position?
Centrifugal force acting on the counterweights.
58
The purpose of permanently sealing and partially filling some models of McCauley propeller hubs with dyed oil is to what?
make the location of cracks readily apparent.
59
Which of the following best describes the blade movement of a feathering propeller that is in the HIGH RPM position when the feathering action is begun?
Low pitch through high pitch to feather position.
60
The blade angle of a fixed-pitch propeller
is smallest at the tip.
61
During operational check of an aircraft using hydromatic full-feathering propellers, the following observations are made:
The feather button, after being pushed, remains depressed until the feather cycle is complete, then opens.
When unfeathering, it is necessary to manually hold the button down until unfeathering is accomplished.
Both feather cycle and unfeather cycle are functioning properly.
62
Inspection of aluminum propeller blades by dye-penetrant inspection is accomplished to detect what?
fatigue failure.
63
What controls the constant-speed range of a constant-speed propeller?
The mechanical limits in the propellers pitch range.
64
For takeoff, a constant-speed propeller is normally set in the what?
LOW PITCH, high RPM position.
65
Where are the high and low pitch stops of a Hamilton Standard constant-speed or two-position counterweight propeller located?
In the counterweights assembly.
66
Which of the following statements about constant-speed counterweight propellers is also true when referring to two-position counterweight propellers?
Blade angle changes are accomplished by the use of two forces, one hydraulic and the other centrifugal.
67
Most engine-propeller combinations have one or more critical ranges within which continuous operation is not permitted. Critical ranges are established to avoid what?
severe propeller vibrations.
68
Which of the following defects is cause for rejection of wood propellers? 1
An oversized hub or bolt hole, or elongated bolt holes.
69
Which of the following defects is cause for rejection of wood propellers?
Bonding or separation of the trailing edge of the propeller blade.
70
An aircraft's propeller system beta range...
is used to produce zero or negative thrust.
71
The primary purpose of a cuff on a propeller is to what?
increase the flow of cooling air to the engine nacelle.
72
The purpose of a three-way propeller valve is to what?
direct oil from the engine oil system to the propellers cylinder.
73
The primary purpose of a propeller is to what?
change engine horsepower to thrust.
74
A constant-speed propeller provides maximum efficiency by what?
adjusting blade angle for most conditions encountered in flight.
75
The centrifugal twisting force acting on a propeller blade is what?
greater than the aerodynamic twisting force and tends to move the blade to a lower angle.
76
Geometric pitch of a propeller is defined as the what?
effective pitch plus slippage.
77
Propellers blade angle is the angle between the what?
chord of the blade and the rotational plane of the propeller.
78
What operational force causes propeller blades tips to lag in the opposite direction of rotation?
Torque-bending force.
79
What operational force tends to bend the propeller blades tips forward at the tip?
Thrust-bending force.
80
What are the rotational speed and blade pitch angle requirements of a constant-speed propeller during takeoff?
High speed and low-pitch angle.
81
(1) A mechanic certificate with a powerplant rating authorizes the holder to repair deep scars, nicks, and dents on aluminum propeller blades.
(2) A mechanic certificate with a powerplant rating authorizes the holder to perform minor straightening of steel propeller blades.
Neither 1 nor 2 is true.
82
(1) During takeoff, propeller thrust (pull) is greatest if the blade angle of attack is low and the engine power settings is high.
(2) With the aircraft stationary, propeller thrust is greatest if the blade angle of attack is high and the engine power setting is high.
Only 1 is true.
83
Longitudinal (fore and aft) clearance of constant-speed propeller blades or cuffs must be at least 1/2 inch (12.7 mm) between propeller parts and stationary parts of the aircraft. This clearance is with the propellers blades...
feathered or in the most critical pitch configuration.
84
Constant-speed non-feathering McCauley, Hartzeil, and other propellers of similar design without counterweights increase pitch angle using what?
oil pressure.
85
Counterweights on constant-speed propellers are generally used to aid in what?
increasing blade angle.
86
When lubricating a Hartzell propeller blades with grease, to prevent damage to the blade seals, the service manual may recommend on some models to what?
remove one of the two zerk fittings for the blade and grease the blade through the remaining fitting.
87
When lubricating a newly overhauled steel hub propeller, you should lubricate the propellers...
after one to two hours of operation.
88
The primary purpose of a feathering propeller is to what?
eliminate the drag created by a windmilling propeller when an engine fails in flight.
89
What normally prevents a Hartzell Compact propeller from going to feather when the engine is shut down on the ground?
A latch mechanism composed of springs and lock pins.
90
When running-up an engine and testing a newly installed hydromatic propeller, it is necessary to exercise the propellers by moving the governor control through its entire travel several times to what?
free the dome of any entrapped air.
91
Which of the following occurs to cause front cone bottoming during propeller installation?
The front cone contacts the ends of the shaft splines, preventing the front and rear cones from being tightened against the cone seats in the propellers hub.
92
What is indicated when the front cone bottoms while installing a propeller?
Rear cones should be moved forward.
93
How is the oil pressure delivery on a hydromatic propeller normally stopped after the blades have reached their full-feathered position?
Electric cutout pressure switch.
94
The primary purpose of the front and rear cones for propellers that are installed on splined shafts is to what?
position the propellers hub on the splined shafts.
95
Which of the following statements concerning the installation of a new fixed-pitch wood propellers is true?
Inspect the bolts for proper torque after the first flight and after the first 25 hours of flying.
96
If propeller cones or hub cone seats show evidence of galling and wear, the most likely cause is what?
The propeller retaining nut was not tight enough during previous operation.
97
On aircraft equipped with hydraulically operated constant-speed propellers, all ignition and magneto checking is done with the propellers in which position?
HIGH RPM.
98
Oil leakage around the rear cones of a hydromatic propeller usually indicates a defective what?
spider-shaft oil seal.
99
Maximum taper contact between crankshaft and propeller hub is determined by using what?
bearing blue color transfer.
100
Propeller blades tracking is the process of determining what?
the position of the tips of the propeller blades relative to each other.
101
What is the basic purpose of the three small holes (No. 60 drill) in the tipping of wood propellers blades?
To allow the moisture which may collect between the tipping and the wood to escape (vent the tipping).
102
A fixed-pitch wooden propeller that has been properly installed and the attachment bolts properly torqued exceeds the out-of-track allowance by 1/16 inch. The excessive out-of-track condition may be corrected by what?
placing shims between the inner flange and the propeller.
103
Manually feathering a hydromechanical propeller means to what?
port governor oil pressure from the cylinder of the propeller.
104
In what position is the constant-speed propellers control placed to check the magnetos?
Full increase, low propeller blade pitch angle.
105
If a flanged propellers shaft has dowel pins...
the propellers can only be installed in a given position.
106
Repairs of aluminum alloy adjustable pitch propellers are not permitted to be made on which of the following propeller blade areas?
Shank.
107
Which of the following methods is used to straighten a bent aluminum propeller blades that is within repairable limits?
Cold straightening only.
108
It is important that nicks in aluminum alloy propeller blades be repaired as soon as possible in order to what?
eliminate stress concentration points.
109
Generally, unless otherwise specified by the manufacturer, repairs of nicks, scratches, gouges, etc., on aluminum propeller blades must be made...
parallel to the length of the blade.
110
Minor surface damage located in a repairable area, but not on the leading or trailing edges of aluminum blades, may be repaired by first...
filing with a rifle file.
111
After proper removal of aluminum blade damage, the affected surface should be polished with what?
very fine sandpiper or crocus cloth.
112
When preparing a propeller blades for inspection it should be cleaned with what?
mild soap and water.
113
What method would be used to inspect an aluminum propeller blade when a crack is suspected?
Dye-penetrant.
114
Removal of propeller blades tips within Type Certificate Data Sheet limits when correcting a defect is what?
a major repair.
115
Surface treatment to counter the effects of dye-penetrant inspection on a propeller is accomplished by what?
washing off with solvent.
116
One of the advantages of inspecting an aluminum propeller utilizing dye-penetrent inspection procedure is that...
it shows whether visible lines and other marks are actually cracks rather than scratches.
117
The primary reason for careful inspection and prompt repairing of minor surface defects such as scratches, nicks, gouges, etc. on aluminum alloy propellers is to prevent what?
fatigue failure.
118
Which of the following generally renders an aluminum alloy propellers unrepairable?
Transverse cracks of any size.
119
Cold straightening a bent aluminum propeller blade may be accomplished by what?
an appropriately rated repair station or the manufacturer.
