Safety and Fundamentals Flashcards
_______ is the flat part of the blade that faces the pilot.
Blade face
Convert engine brake horsepower to thrust horsepower.
Purpose of propeller
The propeller is able to convert about ____% of the brake horsepower to thrust horsepower.
85%
______ is the difference between the Geometric and Effective Pitches. The less the losses the more efficient the propeller.
Propeller Slip
________ is the distance the propeller should travel in ONE REVOLUTION THROUGH A SOLID (no losses).
Geometric Pitch
______ is the actual distance the propeller travels in one revolution through the air (friction drag & weight).
Effective Pitch
______ prop located front end of an engine and PULLS aircraft forward.
Tractor Propeller
______ prop located aft end of the engine and PUSHES aircraft forward.
Pusher Propeller
How does a propeller rotate?
Engine power into thrust
Birch ash oak black cherry black walnut
Woods used for propeller
When we select the wood, what should we do first?
coat with tough protective layer of RESIN
____ converts rotational engine power to thrust in both reciprocating and turboshaft engines.
Propellers
How do we protect the propeller?
Alodining - chemical bath
Anodizing - chemical bath with electrical stuff
Most effective angle of attack for a prop blade?
2 and 4 degrees
Stalling degrees on prop blade?
If exceeded to 15 degrees
Propeller with a fixed blade angle are designed to produce AOA between _____ and ______ degrees at either climb or cruise airspeed with a specific speed setting.
2 and 4
______ enables a propeller to provide a fairly constant AOA along most of the length of the blade.
Pitch distribution/TWIST
______ is the greatest force acting on a propeller and described as the force tending to pull the blades out of the hub.
centrifugal force
______ ______ force tends to bend the propeller blades forward at the tips. Prop blades are typically thinner at the tips.
Thrust Bending force
______ ______ force occur as air RESISTANCE opposes the rotational motion of the propeller blades.
BENDS the blades opposite the direction of rotation.
Torque Bending force
______ ______ force tends to increase a propeller’s blade angle.
Used to help change the blade angle on the propeller.
Aerodynamic twisting force
______ ______ force opposes aerodynamic twisting force. When a propeller rotates centrifugal force tends to decrease its blade angle.
centrifugal twisting force
