17.1.5

NOTE

TO CHECK YOUR PREPARATION ,PLZ WRITE DOWN THE SELECTED OPTIONS ON ROUGH PAGE AND  AT THE END OF QUIZ , VERIFY YOUR SELECTED OPTION WITH THE CORRECT OPTIONS GIVEN BELOW 

Question number. 31. Windmilling causes.

Option a. Propeller underspeeding.

 Option b. Maximum propeller drag.

Option c. Centrifugal twisting moment.

Question number. 32. Torque acts.

Option a. In the same direction as the plane of rotation.

 Option b. At right angles to the plane of rotation.

Option c. In opposition to the direction of rotation.

Question number. 33. The purpose of blade twist is to.

Option a. Reduce angle of attack at the blade root.

Option b. To ensure that tip speed does not go faster than mach 1.

Option c. To even out thrust distribution across the propeller.

Question number. 34. Thrust is greatest.

Option a. At 70 to 80% of propeller length.

 Option b. In the first 50%.

Option c. The same all along the length.

Question number. 35. Ctm changes the pitch of a blade.

Option a. About its twisting axis. Option b. Bending forward.

 Option c. Towards the feather plane.

 Question number. 36. The velocity of the slipstream behind the aircraft in relation to the ambient air is.
Option a. Less.

Option b. Greater.

Option c. Equal.

Question number. 37. High speed aerofoils are employed at.

Option a. The master station.
Option b. The tips.

 Option c. The root.

 Question number. 38. A right hand propeller.

 Option a. Rotates clockwise when viewed from the rear.

 Option b. Is always fitted to the starboard engine.

 Option c. Rotates clockwise when viewed from the front.

Question number. 39. Given that blade angle is measured from the centre of the hub, the blade angle at the hub is considered to be.

Option a. Lowest.

Option b. Master station value.

Option c. Highest.

 Question number. 40. A windmilling propeller will create.

Option a. More drag in feather.

Option b. More drag in fine pitch.

Option c. More drag in coarse pitch.

ABOVE QUESTIONS WITH ANSWERS 

Question number. 31. Windmilling causes.

Option a. Propeller underspeeding.

 Option b. Maximum propeller drag.

Option c. Centrifugal twisting moment.

Correct answer is. Maximum propeller drag.

Question number. 32. Torque acts.

Option a. In the same direction as the plane of rotation.

 Option b. At right angles to the plane of rotation.

Option c. In opposition to the direction of rotation.

Correct answer is. In opposition to the direction of rotation.

Question number. 33. The purpose of blade twist is to.

Option a. Reduce angle of attack at the blade root.

Option b. To ensure that tip speed does not go faster than mach 1.

Option c. To even out thrust distribution across the propeller.

Correct answer is. To even out thrust distribution across the propeller.

Question number. 34. Thrust is greatest.

Option a. At 70 to 80% of propeller length.

 Option b. In the first 50%.

Option c. The same all along the length.

Correct answer is. At 70 to 80% of propeller length. Explanation. Beyond this point the blade chord is reduced to lessen tip thrust.

Question number. 35. Ctm changes the pitch of a blade.

Option a. About its twisting axis. Option b. Bending forward.

 Option c. Towards the feather plane.

Correct answer is. About its twisting axis.

 Explanation. Ctm reduces pitch towards the plane of rotation, about the twisting axis.

 Question number. 36. The velocity of the slipstream behind the aircraft in relation to the ambient air is. Option a. Less.

Option b. Greater.

Option c. Equal.

Correct answer is. Greater.

Explanation. If there was not a difference then no thrust would be produced. T = mass ( vout-vin).

Question number. 37. High speed aerofoils are employed at.

Option a. The master station. Option b. The tips.

 Option c. The root.

Correct answer is. The tips.

Explanation. On helicopters they are called berp tips.

 Question number. 38. A right hand propeller.

 Option a. Rotates clockwise when viewed from the rear.

 Option b. Is always fitted to the starboard engine.

 Option c. Rotates clockwise when viewed from the front.

Correct answer is. Rotates clockwise when viewed from the rear.

Explanation. Left or right is determined by sitting in the cockpit and viewing the rotation.

Question number. 39. Given that blade angle is measured from the centre of the hub, the blade angle at the hub is considered to be.

Option a. Lowest.

Option b. Master station value.

Option c. Highest.

 Correct answer is. Highest.

 Question number. 40. A windmilling propeller will create.

Option a. More drag in feather.

Option b. More drag in fine pitch.

Option c. More drag in coarse pitch.

 Correct answer is. More drag in fine pitch.

 Explanation. A windmilling propeller is always in fine pitch.