Safety and Fundamentals

Question 1

_______ is the flat part of the blade that faces the pilot.

Answer 1

Blade face

Question 2

Convert engine brake horsepower to thrust horsepower.

Answer 2

Purpose of propeller

Question 3

The propeller is able to convert about ____% of the brake horsepower to thrust horsepower.

Answer 3

85%

Question 4

______ is the difference between the Geometric and Effective Pitches. The less the losses the more efficient the propeller.

Answer 4

Propeller Slip

Question 5

________ is the distance the propeller should travel in ONE REVOLUTION THROUGH A SOLID (no losses).

Answer 5

Geometric Pitch

Question 6

______ is the actual distance the propeller travels in one revolution through the air (friction drag & weight).

Answer 6

Effective Pitch

Question 7

______ prop located front end of an engine and PULLS aircraft forward.

Answer 7

Tractor Propeller

Question 8

______ prop located aft end of the engine and PUSHES aircraft forward.

Answer 8

Pusher Propeller

Question 9

How does a propeller rotate?

Answer 9

Engine power into thrust

Question 10

Birch
ash
oak
black cherry
black walnut

Answer 10

Woods used for propeller

Question 11

When we select the wood, what should we do first?

Answer 11

coat with tough protective layer of RESIN

Question 12

____ converts rotational engine power to thrust in both reciprocating and turboshaft engines.

Answer 12

Propellers

Question 13

How do we protect the propeller?

Answer 13

Alodining - chemical bath

Anodizing - chemical bath with electrical stuff

Question 14

Most effective angle of attack for a prop blade?

Answer 14

2 and 4 degrees

Question 15

Stalling degrees on prop blade?

Answer 15

If exceeded to 15 degrees

Question 16

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.

Answer 16

2 and 4

Question 17

______ enables a propeller to provide a fairly constant AOA along most of the length of the blade.

Answer 17

Pitch distribution/TWIST

Question 18

______ is the greatest force acting on a propeller and described as the force tending to pull the blades out of the hub.

Answer 18

centrifugal force

Question 19

______ ______ force tends to bend the propeller blades forward at the tips. Prop blades are typically thinner at the tips.

Answer 19

Thrust Bending force

Question 20

______ ______ force occur as air RESISTANCE opposes the rotational motion of the propeller blades.

BENDS the blades opposite the direction of rotation.

Answer 20

Torque Bending force

Question 21

______ ______ force tends to increase a propeller’s blade angle.

Used to help change the blade angle on the propeller.

Answer 21

Aerodynamic twisting force

Question 22

______ ______ force opposes aerodynamic twisting force. When a propeller rotates centrifugal force tends to decrease its blade angle.

Answer 22

centrifugal twisting force