Propellers ( Conversion of engine torque to thrust ) 33

Refer to figure 081-31.In the attached diagram, select the letter which correctly represents the Angle of Advance (Helix Angle):

D blade angle/ pitch angle simbolo es en angulo de ataque

Which of the following statements about a constant speed propeller is correct?

The blade angle increases with increasing aeroplane speed.

The reference section of a propeller blade with radius R is usually taken at a distance from the propeller axis equal to:

0.75 R.

Which statement are correct or incorrect?
1) At a given RPM the propeller efficiency of a fixed pitch propeller is maximum at only one value of TAS.
2) A constant speed propeller maintains near maximum efficiency over a wider range of aeroplane speeds than a fixed pitch propeller.

1) is correct, 2) is correct.

Which statement about a propeller is correct or wrong?
1) A propeller with little blade twist is referred to as being in fine pitch.
2) A propeller with significant blade twist is referred to as being in coarse pitch.

1) is incorrect, 2) is incorrect.

Which statement are correct or incorrect when comparing a fixed pitch propeller with a constant speed propeller?
1) A fixed pitch propeller improves propeller efficiency over a range of cruise speeds
2) A coarse fixed pitch propeller is more efficient during take-off.

1) is incorrect, 2) is incorrect.

For a given RPM of a fixed pitch propeller, the blade angle of attack will:

decrease when the TAS increases.

The effective pitch of a propeller is the:

actual distance a propeller advances in one revolution.

Which statements are correct or incorrect when comparing a fixed pitch propeller with a constant speed propeller?
1) A fixed pitch propeller improves propeller efficiency over a range of cruise speeds.
2) A constant speed propeller improves take-off performance as compared with a coarse fixed pitch propeller.

1) is incorrect, 2) is correct.

Which statement are correct or incorrect when comparing a fixed pitch propeller with a constant speed propeller?
1) A constant speed propeller reduces fuel consumption over a range of cruise speeds.
2) A coarse fixed pitch propeller is more efficient during take-off.

1) is correct, 2) is incorrect

For a given RPM of a fixed pitch propeller, the blade angle of attack will:

increase when the TAS decreases.

During which of the following phases of flight is a fixed pitch propeller's angle of attack lowest?

High-speed glide.

Propeller efficiency is:

the ratio of power available (Thrust × TAS) to shaft power (Torque × RPM).

An aeroplane is fitted with a constant speed propeller. If the aeroplane speed decreases while manifold pressure remains constant, propeller pitch will ___ and propeller torque will ___.

decrease; remain constant

The angle of attack of a fixed pitch propeller blade decreases when:

forward velocity increases and RPM decreases.

If the propeller pitch, within its constant speed range and at constant power, during descent at constant IAS is increased, the aeroplane lift to drag ratio will:

increase and the rate of descent will decrease.

The angle of attack of a propeller blade element is the angle between the blade element chord line and the:

resultant air speed vector.

For any propeller:

thrust is the component of the total aerodynamic force on the propeller parallel to the rotational axis.

Propeller slip is the difference between the:

geometric pitch and the effective pitch.

With a fixed pitch propeller increasing speed will ___ propeller angle of attack. Increasing power and therefore propeller RPM will ___ propeller angle of attack.

decrease; increase

Which of these statements about propellers is correct or incorrect?
1) A cruise propeller has a smaller geometric pitch compared with a climb propeller.
2) A coarse pitch propeller is less efficient during take-off and in the climb, but more efficient in the cruise, when compared with a fine pitch propeller.

1) is incorrect, 2) is correct.

If the RPM lever of a constant speed propeller is moved forward during a glide with idle power and whilst maintaining constant airspeed, the propeller pitch will:

decrease and the rate of descent will increase.

How does the thrust produced vary along a conventional propeller blade from root to tip?

Thrust increases away from the root, where it is low, until the tip where it is zero

The geometric pitch of a propeller is the:

theoretical distance a propeller would advance in one revolution at zero blade angle of attack.

For a fixed-pitch propeller, the blade angle of attack:

can become negative during high-speed idle descent.

Propeller blade twist is the:

varying of the blade angle from the root to the tip of a propeller blade.

Along the blade of a propeller, at what point is most thrust generated?

At 3/4 propeller length.

The twisting of a propeller blade from root to tip has been made to:

provide a constant angle of attack from root to tip,

What happens to propeller efficiency and power absorption if the chord of its propeller blades increases?

Propeller efficiency decreases and power absorption increases.

For a fixed-pitch propeller designed for cruise, the angle of attack of each blade, measured at the reference section:

is optimum when the aircraft is in a stabilized cruising flight.

An aeroplane is fitted with a constant speed propeller. If the aeroplane speed increases while manifold pressure remains constant, propeller pitch will ___ and propeller torque will ___.

increase; remain constant

Which statement are correct or incorrect?
1) At a given RPM the propeller efficiency of a fixed pitch propeller is maximum at only one value of TAS.
2) A fixed pitch propeller maintains near maximum efficiency over a wider range of aeroplane speeds than a constant speed propeller.

1) is correct, 2) is incorrect.

Which statement are correct or incorrect?
1) A propeller with little blade twist is referred to as being in fine pitch.
2) A propeller with a large blade angle is referred to as being in coarse pitch.

1) is incorrect, 2) is correct.

Which of these statements about propellers is correct or incorrect?
1) A cruise propeller has a greater geometric pitch when compared with a climb propeller.
2) A coarse pitch propeller is less efficient during take off and in the climb, but more efficient in the cruise, when compared with a fine pitch propeller.

1) is correct, 2) is correct.

The first action in event of propeller runaway (overspeed condition), should be to:

close the throttle.

Does the pitch angle of a constant-speed propeller alter in medium horizontal turbulence?

Yes slightly.

During which of the following phases of flight is a fixed pitch propeller's angle of attack highest?

Take-off run.

A fixed pitch propeller is usually:

at too coarse an angle for take-off.

Which statement are correct or incorrect when comparing a fixed pitch propeller with a constant speed propeller?
1) A constant speed propeller improves propeller efficiency over a range of cruise speeds.
2) A coarse fixed pitch propeller is more efficient during take off.

1) is correct, 2) is incorrect

Which statements are correct or incorrect?
1) A propeller with a small blade angle is referred to as being in coarse pitch.
2) A propeller with a large blade angle is referred to as being in fine pitch.

1) is incorrect, 2) is incorrect.

The difference between a propeller's blade angle and its angle of attack is called:

the helix angle.

Which statement are correct or incorrect?
1) A propeller with a small blade angle is referred to as being in fine pitch.
2) A propeller with a large blade angle is referred to as being in coarse pitch.

1) is correct, 2) is correct.

For a fixed-pitch propeller, the blade angle of attack:

decreases during the take-off.

A typical fixed pitch propeller (e.g. C-172) is designed to achieve its optimum angle of attack at:

cruise speed.

Whilst flying in icing conditions, you realise you have started to build up ice on the propeller blades. What dangers are posed?

The thrust and obstacle clearance will both decrease.

Which statement are correct or incorrect when comparing a fixed pitch propeller with a constant speed propeller?
1) A constant speed propeller reduces fuel consumption over a range of cruise speeds.
2) A constant speed propeller improves take-off performance as compared with a coarse fixed pitch propeller.

1) is correct, 2) is correct.

The angle of attack of a fixed pitch propeller blade increases when:

forward velocity decreases and RPM increases.

Propeller efficiency can be expressed as:

power output divided by power input.

Which statement is correct?
I. A propeller with little blade twist is referred to as being in fine pitch.
II. A propeller with significant blade twist is referred to as being in coarse pitch.

I is incorrect, II is incorrect.

Which statement about propeller icing is correct?
I. Propeller icing reduces blade element drag and increases blade element lift.
II. Propeller icing reduces propeller efficiency.

I is incorrect, II is correct.

What happens to the blade pitch of a fixed pitch propeller on ground roll during takeoff?

Remains constant.

Which of these statements about propellers is correct or incorrect?
I. A cruise propeller has a greater geometric pitch compared with a climb propeller.
II. A coarse pitch propeller is more efficient during take-off and in the climb, but is less efficient in the cruise, when compared with a fine pitch propeller.

I is correct, II is incorrect.

Which one of the following statements is true regarding icing on a propeller?

Thrust is decreased by 20%.

Which definition of propeller parameters is correct?

Helix angle is the angle between the actual path of the propeller and the plane of rotation.

When operating at a constant RPM, the engine torque is _____ the propeller torque.

the same as

If the RPM lever of a constant speed propeller is moved forward during a glide with idle power and whilst maintaining constant airspeed, the propeller pitch will:

decrease and the rate of descent will increase.

Assuming that the RPM remains constant throughout, the angle of attack of a fixed pitch propeller will:

decrease with increasing airspeed.

Propeller efficiency is defined as the ratio between:

usable (power available) power of the propeller and shaft power.

How does icing affect a propeller?

Decrease thrust.

Consider a fixed-pitch propeller aeroplane at take-off. When the aeroplane accelerates during the take-off run phase, the blade angle of attack will (1) _____ and the thrust produced by the propeller will (2) _____.

(1) decrease; (2) decrease

Which definition of propeller parameters is correct?

Geometric pitch is the theoretical distance a propeller would advance in one revolution at zero blade angle of attack.

For a fixed-pitch propeller in flight at a given TAS, the blade angle of attack will:

decrease if RPM decreases.

The geometric pitch of a propeller is the:

theoretical distance a propeller would advance in one revolution at zero blade angle of attack.

Fixed-pitch propellers are usually designed for maximum efficiency at:

cruising speed

The angle of attack of a fixed pitch propeller blade decreases when:

forward velocity increases and RPM decreases.

For a given RPM of a fixed pitch propeller, the blade angle of attack will:

increase when the TAS decreases.

The difference between a propeller's blade angle and its angle of attack is called:

the helix angle.

One of the disadvantages of excessive increasing of the number of propeller blades (beyond a certain number) is:

Decreased propeller efficiency.

Propeller efficiency is:

the ratio of power available (Thrust TAS) to shaft power. (Torque RPM)

The angle of attack of a fixed pitch propeller blade increases when:

forward velocity decreases and RPM increases.

For any propeller:

thrust is the component of the total aerodynamic force on the propeller parallel to the rotational axis.

Assuming that the RPM remains constant throughout, the angle of attack of a fixed pitch propeller will:

increase with decreasing airspeed.

Blade angle decreases from the root to the tip. How does the thrust of a basic propeller vary from root to tip?

Thrust increases away from the root, where it is low, but reduces back to zero at the tip.

During a glide with idle power and constant IAS, if the RPM lever of a constant speed propeller is pushed full forward from its normal cruise position, the propeller pitch will:

decrease and the rate of descent will increase.

Which statement is correct when comparing a fixed pitch propeller with a constant speed propeller?
I. A constant speed propeller reduces fuel consumption over a range of cruise speeds.
II. A constant speed propeller improves take-off performance as compared with a coarse fixed pitch propeller.

I is correct, II is correct.

For an aeroplane equipped with a two-position variable pitch propeller it is advisable to select a:

fine pitch for take-off and climb.

Which of these statements about propellers is correct or incorrect?
I. A cruise propeller has a greater geometric pitch when compared with a climb propeller.
II. A coarse pitch propeller is less efficient during take-off and in the climb, but more efficient in the cruise, when compared with a fine pitch propeller.

I is correct, II is correct.

Which statement is correct?
I. A propeller with little blade twist is referred to as being in fine pitch.
II. A propeller with a large blade angle is referred to as being in coarse pitch.

I is incorrect, II is correct.

Which definition of propeller parameters is correct?

Blade angle is the angle between the blade chord line and the plane of rotation.

Which of these statements about propellers is correct or incorrect?
I. A cruise propeller has a smaller geometric pitch compared with a climb propeller.
II. A coarse pitch propeller is more efficient during take-off and in the climb, but is less efficient in the cruise, when compared with a fine pitch propeller.

I is incorrect, II is incorrect.

Which statement is correct?
I. At a given RPM the propeller efficiency of a fixed pitch propeller is maximum at only one value of TAS.
II. A constant speed propeller maintains near maximum efficiency over a wider range of aeroplane speeds than a fixed pitch propeller.

I is correct, II is correct.

Which of these statements about propellers is correct or incorrect?
I. A cruise propeller has a smaller geometric pitch compared with a climb propeller.
II. A coarse pitch propeller is less efficient during take-off and in the climb, but more efficient in the cruise, when compared with a fine pitch propeller.

I is incorrect, II is correct.

Which statement is correct?
I. At a given RPM the propeller efficiency of a fixed pitch propeller is maximum at only one value of TAS.
II. A fixed pitch propeller maintains near maximum efficiency over a wider range of aeroplane speeds than a constant speed propeller.

I is correct, II is incorrect.

You are the pilot flying an aircraft equipped with a constant speed propeller. While maintaining straight and level flight, the propeller angle of attack decreases. In these conditions, the propeller governor (1) _____ the pitch and the RPM eventually (2) _____.

(1) increases; (2) remains the same

Which statement is correct?
I. A propeller with a small blade angle is referred to as being in fine pitch.
II. A propeller with a large blade angle is referred to as being in coarse pitch.

I is correct, II is correct.

For a fixed-pitch propeller, the blade angle of attack:

can become negative during high-speed idle descent.

The blade angle of a propeller is usually referenced at:

75% of blade radius.

Select the option which correctly completes the following sentence: A constant-speed propeller...

maintains high efficiency across a range of speeds.

Which of the following statements about a constant speed propeller is correct?

The blade angle increases with increasing aeroplane speed.

During which of the following phases of flight is a fixed pitch propeller's angle of attack highest?

Take-off run.

Ice build-up on propeller blades..

reduces the generated thrust.

From the following types of propeller, which is most efficient over a wide range of true airspeeds?

Variable-pitch propeller

Propeller blade twist is the:

varying of the blade angle from the root to the tip of a propeller blade.

Which statement about propeller icing is correct?
I. Propeller icing reduces blade element drag and increases blade element lift.
II. Propeller icing does not affect propeller efficiency.

I is incorrect, II is incorrect.

For a fixed-pitch propeller, the blade angle of attack:

decreases during the take-off.

For a given RPM propeller efficiency is proportional to the ratio of:

Thrust to engine torque.

What is the effect of ice accretion on a propeller?

Icing forms on the inner part of the propeller and reduces its efficiency by 20%.

Which statement is correct when comparing a fixed pitch propeller with a constant speed propeller?
I. A constant speed propeller reduces fuel consumption over a range of cruise speeds.
II. A coarse fixed pitch propeller is more efficient during take-off.

I is correct, II is incorrect.

Consider an aircraft equipped with a variable pitch propeller. During the acceleration phase of the takeoff roll, the blade angle:

is increasing.

During which of the following phases of flight is a fixed pitch propeller's angle of attack lowest?

High-speed glide.