Propellers Flashcards
The propeller control system is divided into two types of control, what are they?
Flight and Ground operations
What is the purpose of a propeller?
To create thrust
What are two types of propeller configurations?
Tractor and pusher type
What type of propeller has the blade angle built into the propeller and cannot be changed?
Fixed pitch
What is the purpose of the metal tipping on the leading edge of a wooden propeller?
Protect the propeller from FOD damage
What tool is used to determine propeller blade angle?
Universal propeller protractor
What are the aerodynamic forces and loads acting on a rotating propeller blade?
Centrifugal force, aerodynamic twisting, centrifugal twisting, torque bending, and thrust bending forces
What is the meaning of propeller blade “back” and “face”?
The curved side is called the blade back. The flat side is called the blade face
What should be used to clean aluminum and steel propeller blades and hubs?
Suitable cleaning solvent using a brush or cloth
What positions are used on a balance stand to check a two bladed propeller for static balance?
First the vertical position, then the horizontal position
Can a fixed pitch propeller’s pitch be changed?
No
Why do you put the blades of a counterweight propeller into high pitch before stopping the engine?
In this position the piston is protected from dirt and moisture in the air
Why are cones installed on splined shafts with a propeller?
The cones center the propeller on the shaft
How is feathering accomplished on a constant speed counterweight propeller?
By releasing the governor oil pressure on the counterweights. The feathering spring moves the blades to the feathered position and the oil returns to the engine.
What types of systems are used for deicing propellers?
Fluid or electrical deicing systems
What is the purpose of a slinger ring on some propeller installations?
Deicing fluid is ejected from a stationary nozzle on the engine into a u-shaped channel, known as the slinger ring, attached to the rear of the propeller assembly
What is blade tracking?
Determining the position of the tips of the propeller blades relative to each other
Do the counterweights on a constant speed propeller increase or decrease the blade angle?
Increase the pitch of the blades
What should you adjust if a pilot requests 50 more RPM on an aircraft equipped with a constant speed propeller?
Governor’s prop-level set screw
What adjustments are powerplant mechanics allowed to make to the prop governor?
Maximum RPM stop
Why are propellers indexed to the crankshaft for an engine?
Reduce vibrations
Can transverse cracks in a propeller be repaired?
No
What is the alpha range and beta range of a propeller?
Beta range is the condition of the propeller during ground operations and in the reverse pitch position. Alpha range is propeller position in flight.
When changing metal bushings on a wooden propeller assembly, a thorough inspection of the bolt holes should be accomplished. Why?
Check for elongation
How are wooden propellers cleaned?
Soap and water
What happens to a constant speed feathering propeller when the propeller governor’s oil pressure drops to zero PSI?
Returns to the feathered position
What is the purpose of an arbor when balancing a propeller?
Support the propeller on the balance knives
What two forces are balanced in a propeller governor in an on-speed condition?
Speeder spring and flyweights
How do you determine the repairability of a damaged propeller blade?
Reference the manufacturer’s maintenance manual
When engine vibration is reported, what should be checked to determine if it is caused by the engine or the propeller?
Blade tracking and blade angle setting
What positions of a two blade propeller are used during a static balance test?
Vertical and horizontal
What three things does a typical constant speed propeller governor accomplish when operating?
Boosts engine oil pressure before it enters the propeller hub, controls the amount of oil that flows to the propeller, senses the rotational speed of the engine
What pitch will a constant speed propeller move into at constant power when going into a nosedive?
High pitch.
What is the device that reduces vibrations in an aircraft with multiple propellers?
Propeller synchronizers.
Why is an oil accumulator connected to the prop governor?
To assist with unfeathering the propeller.
