Chapter 1- Basic Aerodynamics

Question 1

(Refer to Figure 1.) The acute angle A is the angle of

a. incidence
b. attack
c. dihedral

Answer 1

b. attack

Question 2

The term “angle of attack” is defined as the angle

a. between the chord line and the relative wind
b. between the airplane’s climb angle and the horizon
c. formed by the longitudinal axis of the airplane and the chord line of the wing.

Answer 2

a. between the chord line and the relative wind

Question 3

The angle between the chord line of an airfoil and the relative wind is known as the angle of

a. life
b. attack
c. incidence

Answer 3

b. attack

Question 4

The term angle of attack is defined as the angle between the

a. chord line of the wing and the relative wind
b. airplane’s longitudinal axis and that of the air striking the airfoil
c. airplane’s center line and the relative wind

Answer 4

a. chord line of the wing and the relative wind

Question 5

Which statement relates to Bernoulli’s principal?

a. for every action and opposite reaction
b. an additional upward force is generated as the lower surface of the airfoil deflects air downward.
c. air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface

Answer 5

c. air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface

Question 6

The four forces acting on an airplane in flight are

a. lift, weight, thrust, and drag
b. lift, weight, gravity, and thrust
c. lift, gravity, power and friction

Answer 6

a. lift, weight, thrust, and drag

Question 7

What is the purpose of rudder on an airplane?

a. to control yaw
b. to control overbanking tendency
c. to control roll

Answer 7

a. to control yaw

Question 8

What is the relationship of lift, drag, thrust, and weight when the airplane is in straight-and-level flight?

a. lift equals weight and thrust equals drag
b. lift, drag, and weight equals thrust
c. lift and weight equal thrust and drag

Answer 8

a. lift equals weight and thrust equals drag

Question 9

When are the four forces that act on an airplane in equilibrium?

a. during unaccelerated flight
b. when the aircraft is accelerating
c. when the aircraft is at rest on the ground

Answer 9

a. during unaccelerated flight

Question 10

An airplane is said to be inherently stable will

a. be difficult to stall
b. require less effort to control
c. not spin

Answer 10

b. require less effort to control

Question 11

What determines the longitudinal stability of an airplane?

a. the location of the CG with respect to the center of lift
b. the effectiveness of the horizontal stabilizer, rudder, and the rudder trim tab
c. the relationship of thrust and lift to weight and drag

Answer 11

a. the location of the CG with respect to the center of lift

Question 12

What causes an airplane (except a T-tail) to pitch nose down when power is reduced, and controls are not adjusted?

a. the CG shifts forward when thrust and drag are reduced
b. the downwash on the elevators from the propeller slipstream is reduced and elevator effectiveness is reduced
c. when thrust is reduced to less than weight, lift is also reduced and the wings can no longer support the weight

Answer 12

b. the downwash on the elevators from the propeller slipstream is reduced and elevator effectiveness is reduced