3-40. When an aircraft in flight increases its angle of attack, which of the following actions is accomplished? 1. The aircraft pivots on its longitudinal axis 2. The aircraft pivots on its lateral axis 3. The aircraft will turn to the right 4. The aircraft will turn to the left 3-41. When an aircraft in flight encounters a strong gusty, quartering wind on its nose, it tends to drift off course. On what axis does the aircraft pivot when this action occurs? 1. The pitch axis 2. The yaw axis 3. The lateral axis 4. The longitudinal axis 3-42. The  main  difference  between  fixed-wing aircraft and rotary-wing aircraft is the way in which lift is achieved. 1. True 2. False 3-43. A helicopter uses two or more engine-driven rotors for lift and propulsion. 1. True 2. False 3-44. What is a symmetrical airfoil? 1. An airfoil that has a greater camber on the upper surface than on the lower surface 2. An airfoil that has less camber on the upper surface than on the lower surface 3. An airfoil that has a variable center of pressure 4. An airfoil that has a fixed center of pressure 3-45. On an unsymmetrical airfoil, in what direction does the center of pressure move when the angle of attack changes? 1. Forward only 2. Rearward only 3. Fore and aft 4. Inboard and outboard 3-46. What does a shifting center of pressure do to a rotor blade? 1. It causes it to move fore and aft un- con- trollably 2. It causes it to move up and down un- con- trollably 3. It causes the pitch of the blades to stabi- lize 4. It causes increased lift capabilities 3-47. By what means is lift controlled in a helicop- ter? 1. By increasing and decreasing the engine speed 2. By increasing and decreasing the rotor speed 3. By increasing the pitch or angle of attack of the rotor blades 3-48. What term is used when a helicopters main rotor is turning and no lift is being produced by the rotor blades? 1. Angle of attack 2. Ground idle 3. Zero thrust 4. Flat pitch 3-49. Directional control of a helicopter is achieved by what means? 1. By tilting the helicopter in the desired direction 2. By tilting the main rotor in the desired direction 3. By increasing the pitch of the tail rotor blades 4. By decreasing the pitch of the tail rotor blades 3-50. By what means is hovering achieved in a hel- icopter? 1. By equalizing lift and drag only 2. By equalizing lift and thrust only 3. By equalizing thrust and weight only 4. By equalizing lift, drag, thrust, and weight 3-51. As the helicopter's rotor turns in one direction, the body of the helicopter tends to rotate in the opposite direction. What law or principle explains this action? 1. Newton's third law 2. Newton's second law 3. Newton's principle 4. Bernoulli's principle 3-12