What is the function of a propeller?
Create thrust to pull or push an airplane through air.
What is the difference between a fixed pitch propeller and a controllable pitch propeller?
Fixed pitch propeller has a built-in blade angle that cannot be changed by the pilot; controllable pitch propeller blade angle can be changed by the pilot, usually controlled by a governor that maintains a constant speed. Some controllable propellers also provide reverse pitch and feathering.
How are some wooden propeller blades protected from wear and damage?
Metal tipping fastened to the leading edge and tip.
What happens to the blade angle of a constant speed propeller during a constant power dive?
Blade angle increases to prevent over speed.
What are the functions of a constant speed propeller governor?
Boosts engine oil pressure before it enters propeller hub, senses rotational speed of the propeller, and adjusts oil flow to propeller hub to change pitch and speed of the propeller.
What is the purpose of a propeller counterweight?
Centrifugal force acting on counterweights causes blade angle to increase.
What is meant when a propeller governor is in an on speed condition?
Governor is not accelerating or decelerating and the speeder spring and flyweight forces are in balance.
How is a constant speed feathering propeller feathered?
Releasing oil pressure in the governor. Counterweights and feathering spring move the propeller into feather, happens automatically if the governor oil pressure drops to zero following an engine failure in most turbo props or can be manually controlled by the pilot moving the propeller control into a feathering detent.
What is an unfeathering accumulator?
Oil accumulator that provides oil pressure to unfeather the propeller.
What is an alpha range and beta range and where are they found?
Alpha and beta ranges pertain to operating modes of turbo prop reversible pitch propellers. Alpha range the propeller is in standard constant speed mode in flight. Beta range propeller is in zero or minimum thrust range and negative thrust or reverse thrust mode usually on the ground.
What systems are commonly used for propeller ice control?
Fluid or alcohol and electrical heat applied to the propeller blades root.
What propeller repairs can be performed by a certified mechanic with a powerplant rating?
Only minor repairs and alterations can be performed by a certified mechanic with a powerplant rating. Propeller manufacturer’s maintenance manual outlines scope of repairs.
How are wooden propellers generally cleaned?
Brush or cloth, warm water, mild soap.
Where would you find the correct method and technique for cleaning an aluminum propeller and hub?
Propeller manufacturer’s maintenance instructions.
What type of non-destructive testing should be accomplished to a propeller after blending?
Procedure is recommended by the manufacturer.
What are the two criteria used by many manufacturers to determine the amount of bent damage that can be repaired by cold bending an aluminum propeller?
Extent of the bend and blade station location.
How can repair file marks be removed from an aluminum propeller?
Very fine sandpaper.
When performing a static balance on a two-liter propeller what positions must the propeller be placed in when measurements are taken?
Vertical and horizontal positions.
What is the propeller protractor used for?
Measuring propeller blade angle.
What blade conditions can cause engine vibration?
Out of track or balance, incorrect blade angle setting.
What is blade tracking?
Procedure that compares position of propeller blade tips relative to each other.
What controls both manifold pressure and RPM on an engine equipped with a fixed pitch propeller?
Throttle.
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Reciprocating Engines10
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Recip Engines Operation Instruments, Maintenance And Overhaul27
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Turbine Engines23
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Turbine Operation Instruments/maint Overhaul11
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Induction Systems22
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Exhaust Systems22
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Engine Fuel And Metering37
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Electrical Start And Ignition Systems37
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Lubrication Systems21
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Cooling Systems14
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Propellers22
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Powerplant And Propeller Airworthiness Inspections10
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Powerplamt Troubleshooting2
