what is the function of a propeller
the propeller blades create thrust to pull or push an airplane through the air
what is the difference between a fixed pitch propeller and a controllable pitch propeller
a fixed pitch propeller is one that has a built-in blade angle that cannot be changed by the pilot a controllable pitch propeller is one that can be changed by the pilot and is 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
by metal tipping fasten to the leading edge and tip
what happens to the blade angle of a constant speed propeller during a constant power dive
the blade angle increases to prevent and over speed
what are the functions of a constant speed propeller governor
it boosts engine oil pressure before it enters the propeller hub it senses rotational speed of the propeller and then adjusts the oil flow to the propeller hub to change pitch and therefore speed of the propeller
what is the purpose of a propeller counterweight
centrifugal force acting on the counterweights causes the blade angle to increase
what is meant when a propeller governor is in an on speed condition
the governor is not accelerating or decelerating and the speed or spring and flyweight forces are in balance
how was a constant speed feathering propeller feathered
by releasing oil pressure in the governor the counterweights and feathering spring move the propeller into feather this 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
it is an oil accumulator used to provide oil pressure to unfeather the propeller
what is an alpha range and beta range and where are they found
the alpha and beta ranges pertain to the operating modes of a turbo prop reversible pitch propellers in the alpha range the propeller is operating in the standard constant speed mode which is usually in flight in the beta range the propeller is operating in the zero or minimum thrust range and negative thrust or reverse thrust mode which is 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 power plant rating
only minor repairs and alterations can be performed by a certified mechanic with a power plan rating major repairs can be performed by the manufacturer or certified repair station the propeller manufacturer’s maintenance manual outlines the scope of the repairs
how are wooden propellers generally cleaned
with a brush or cloth and warm water with mild soap
where would you find the correct method and technique for cleaning an aluminum propeller and hub
the propeller manufacturer’s maintenance instructions
what type of non-destructive testing should be accomplished to a propeller after blending
the 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
the extent of the bend and its blade station location
how can repair file marks be removed from an aluminum propeller
with 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
is used for measuring the propeller blade angle
what blade conditions can cause engine vibration
vibration can be caused by a propeller being out of track and or balance as well as incorrect blade angle setting
what is blade tracking
blade tracking is a procedure that compares the position of the propeller blade tips relative to each other
what controls both manifold pressure and rpm on an engine equipped with a fixed pitch propeller
the throttle
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RECIPROCATING ENGINES10
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RECIPROCATING ENGINE OPERATION27
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TURBINE ENGINES24
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TURBINE ENGINE OPERATION11
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INDUCTION SYSTEMS22
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EXHAUST SYSTEMS22
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ENGINE FUEL SYSTEMS37
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ELECTRICAL AND STARTING SYSTEMS37
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LUBRICATION SYSTEMS22
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COOLING SYSTEMS14
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ENGINE FIRE PROTECTION SYSTEMS16
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PROPELLERS22
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POWERPLANT AIRWORTHINESS10
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POWERPLANT TROUBLESHOOTING1
