Dale Crane Q's Flashcards
Two variables in the angle of attack of a propeller are:
- engine RPM (rotational speed)
- Forward velocity (speed of aircraft)
The curved surface of a propeller blade is the ______
(back or face)
back
The pitch angle and the angle of attack of a propeller blade _______ the same.
(are or are not)
are not
(would only be the same if no forward velocity)
Propeller blade stations are measured in inches from the _______ (hub or tip)
hub
The actual distance a propeller advances in one revolution in theair is the _________ pitch
(effective or geometric)
effective
The difference between the geometric and effective pitch of a propeller is called _____
slip
Five factors that affect the amount of thrust produced by a propeller blade are:
- Airfoil shape
- Air density
- Angle of Attack
- Velocity of airflow
- Area of airfoil
Two things that change on a propeller blade from the root to the tip are:
- Blade pitch angle
- Cross section of the blade
Increasing the engine RPM with the forward speed remaining constant _________ the angle of attack
(increases or decreases)
increases
Five forces acting on a propeller turning at a high speed are:
- Centrifugal force
- Thrust bending force
- Torque bending force
- Aerodynamic twisting force
- Centrifugal twisting force
The greatest force acting on a propeller is _______ force
centrifugal
The force that tries to bend a propeller blade forward is the _____ bending force
thrust
The force that tries to bend a propeller blade in its plane of rotation is the ___________ force
Torque bending force
Aerodynamic twisting force (ATF) tries to _______ the blade angle
(increase or decrease)
increase
Centrifugal twisting force (CTF) tries to ______ the blade angle
(increase or decrease)
decrease
The twisting force that has the greater effect on propeller operation is _______ (ATF or CTF)
CTF
A fixed-pitch climb propeller has a ______ pitch angle than a cruise propeller
(higher or lower)
lower
Centrifugal force acting on the counterweights on a two-position-pitch propeller rotate the blades toward _______ pitch
(high or low)
high
The basic difference between a two-position controllable-pitch propeller and a constant-speed propeller is in the control.
In a constant-speed propeller, a ______ replaces the two position valve
governor
Multiengine airplanes were made appreciably safer than their single-engine counterpart by the development of the ______ propeller
feathering
The blade pitch angle when a propeller is feathered is near _______ degrees
90
(88 degrees)
A reversible propeller is a constant-speed propeller whose ______ (low or high) pitch stops can be released so the blades can be moved to an angle that produces thrust in the reverse direction
low
The wood used for most commercially made wood propellers is ______
Birch
Modern metal propellers are forged from high-strength ________ alloy, and after being ground to their finished dimensions and pitch, they are ______ to protect them from corrosion
aluminium
anodized
The two types of propellers that are found on almost all modern airplanes are:
- ________
- ________
- Fixed pitch
- Constant speed
The pitch on all modern constant-speed propellers is changed ________ (electrically or hydraulically)
hydraulically
(oil)
