Chapter Two Review Questions

HELICOPTER AERODYNAMICS WORKBOOK

CHAPTER 2

CHAPTER TWO REVIEW QUESTIONS

1. Draw and label a blade element diagram for powered flight.

2. Angle of attack is found between the chord line and the__________________.

3. The _______________________ is defined by the plane described by the rotating tips of the

rotor blades.

4. The vertical flow of air through the rotor system is_______________________.

5. In powered flight, increased rotational flow with constant induced flow shifts the relative

wind vector toward the____________________.

6. In powered flight, as relative wind shifts toward the horizontal plane, the angle of attack

__________________.

Changes in the pitch angle directly/inversely affect angle of attack.

_______________________drag is created as a result of the production of lift.

9. Regardless of angle of attack, the upper surface lift and lower surface lift of a symmetrical

airfoil will act _______________ each other, and a twisting force on the blade is/is not

present.

10. Pitching moments are characteristic of the __________________ airfoil.

11. The type of rotor system which is limited to two rotor blades is the ____________________.

12. The _______________________ rotor system does not incorporate mechanical hinges for

flapping or lead/lag motion.

13. A vertical hinge pin is provided for lead/lag in the _______________________ rotor system.

14. Unequal radii of rotor blade centers of mass cause_________________________________.

15. Compensation for lead/lag motion in the semi-rigid rotor system is accomplished by blade

__________________.

16. _______________________compensates for increased rotational velocity from blade root to

tip by increasing/decreasing blade pitch from root to tip.

ROTOR BLADE AERODYNAMICS 2-13