Propellers (Theory + Recips) Flashcards
What variables affect the angle of attack?
Forward speed and engine RPM
Define blade or pitch angle:
The angle between the plane of rotation and the chord line of the prop blade.
Five forces that act on propellers:
Centrifugal.
Thrust bending force.
Torque bending force.
Aerodynamic twisting force.
Centrifugal twisting force.
_______ causes one side of the propeller to produce more thrust than the other.
Asymmetrical loading.
Define yaw:
Rotation of the aircraft around its vertical axis.
The ______ is the engine of a twin engine plane whose loss would cause the greatest yawing effect.
Critical engine.
Two things that change on a prop blade from the root to the tip:
Cross section.
Pitch.
3 types of fixed pitch propellers:
Climb.
Cruise.
Standard.
T\F
A climb prop will have a higher pitch than a cruise prop.
False.
Climb props have the lowest pitch of the three types of fixed props.
On a counterweight constant speed prop, oiled directed INTO the prop does what to the pitch of the blades?
Lowers pitch.
On a counterweight constant speed prop, oiled directed OUT of the prop does what to the pitch of the blades?
Increases pitch.
Counterweights assist in feathering
On a non-counterweight prop, oil directed INTO the prop does what to the pitch?
Increases pitch.
Assisted by aerodynamic twisting force.
On a non-counterweight prop, oil directed out of the prop does what to the pitch?
Lowers the pitch.
Assisted by centrifugal twisting force and a spring.
Three important parts of the governor:
Oil pump.
Pilot valve.
Flyweights.
What component is used on some feathering propellers to speed up unfeathering action?
Accumulator.
