POF - Propellers

The propeller is a rotating aerofoil:

• True

• False

Blade angle is:

• Angle between the chord line and the plane of rotation

• Angle between the blade back and the plane of rotation

• Angle between the chord line and RAF

• Angle between the RAF and the blade back

The blade face is:

• The side of the propeller blade facing away from the pilot

• The side of the propeller blade facing toward the pilot

• The leading edge of the propeller

• Where the blade and the spinner meet

The angle between the RAF and the plane of rotation is known as:

• AoA

• Blade angle

• Helix angle

• Angle of incidence

What is the purpose of helical twist?

• A reduction in blade angle towards the propeller tip to maintain best thrust/torque ratio

• An increase in blade angle towards the propeller tip to maintain best thrust/torque ratio

• A reduction in blade angle towards the propeller tip to maintain 16° AoA for the entire blade length

• An increase in blade angle towards the propeller tip to 16° AoA for the entire blade length

The most useful thrust is produced at approximately:

• 50% to blade radius

• 25% blade radius

• 75% blade radius

• The entire blade radius assuming the propeller is twisted to maintain best AoA

An aircraft with a fixed pitch propeller is cruising at 120 knots and best cruise rpm. If the speed is increase without changing RPM what will happen to the AoA and efficiency of the propeller?

• AoA will decrease and efficiency will increase

• AoA will increase and efficiency will increase

• AoA will decrease and efficiency will decrease

• AoA will increase and efficiency will increase

The purpose of a constant speed unit is to:

• Maintain the best thrust/torque ratio over a wide range of airspeeds

• Maintain the lift/drag to torque ratio over a wide range of airspeeds

• Maintain the best thrust/weight ratio over a wide range of airspeeds

• Maintain 2700rpm at all airspeeds on all aircraft

In an aircraft with a CSU what is the correct technique to increase power?

• Pitch/Rich/Power

• Power/Pitch/Rich

• Rich/Pitch/Power

• Power/Rich/Pitch

A fixed pitch propeller with a coarse pitch will be more efficient at

• High Speeds

• Low Speeds

• High Altitudes

• Low Altitudes