Subject R - Propellers Flashcards
what is the purpose of a propeller?
To create thrust and either push or pull the airplane through the air.
What are two types of propeller configurations?
The tractor type and pusher type.
What type of propeller has a blade angle built into the propeller and cannot be changed?
A fixed pitch propeller.
What is the purpose of the metal tipping on a leading edge of a wooden propeller?
It is to protect the propeller from damage caused by FOD in the air, during landing, taxiing and takeoff.
What tool is used to determine propeller blade angle?
A universal propeller protractor.
What are the aerodynamic forces and loads acting on a rotating propeller blade?
A rotating propeller is acted upon by centrifugal force, aerodynamic twisting force, centrifugal twisting, torque bending, and thrust bending forces.
What is the meaning of propeller blade back and face?
The curved side of the propeller is called the blade back. This is the side that faces away from the engine. The flat side of the propeller is known as the blade face, this side of the blade faces the engine. If you are sitting in the cockpit you will be looking at the face of the blade.
What should be used to clean aluminum and steel propeller blades and Hubs?
They should be washed with a 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 , than the horizontal position
Can a fixed pitch propellers pitch be changed?
No, they are fixed at a specific pitch angle.
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. This is particularly important if the airplane engine will not be operated for several days.
Why are cones installed on splined shafts with a propeller?
The cones center the propeller on the shaft as they are forced toward each other by the tightening of the retaining nut.
How is feathering accomplished on a constant speed counterweight propeller?
By releasing 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 slinger ring on some propeller installations?
Propeller deicing fluid is ejected from a stationary nozzle on the engine into a U-shaped channel attached to the rear of the the propeller assembly. The U-shaped channel is called a slinger ring. The fluid under pressure of centrifugal force is transferred through small tubes to the propeller’s leading edge.
