# Aerodynamics Flight Control Questions

See the answers at the end of the Aerodynamics questionnaires.

1. The majority of high-speed commercial aircrafts use __.
a. variable sweep wings b. forward sweep wings
c. variable sweep wings d. swept back wings
2. What is the angle between the Mach wave and the flight path of an
aircraft at supersonic speeds?
a. Angle of attack b. Angle of incidence
c. Mach angle d. Angle of drape
1. In powered flight (hovering, vertical, forward, sideward, or
rearward)…
a. the total lift and thrust forces of a rotor are perpendicular to the
rotor disk.
b. the total lift of a rotor is parallel to the rotor disk.
c. the total lift of a rotor is parallel to the rotor disk.
d. the total lift and thrust forces of a rotor are parallel to the rotor disk.
1. Find the temperature at 5 statute miles at standard atmosphere.
a. 419.15 K b. 430.42 R
c. -31.58 F d. -16.97 C
2. Rate of descent can be minimized when the
a. Parasite drag equals three times the induced drag
b. Parasite drag equals one third of the induced drag
c. Parasite drag equals three times the induced drag
d. Parasite drag equals the induced drag
3. When landing behind a large aircraft, the pilot should avoid wake
turbulence by staying
a. Below the large aircraft’s final approach path and landing before the
large aircraft’s touchdown point.
b. Above the large aircraft’s final approach path and landing beyond the
large aircraft’s touchdown point.
c. Above the large aircraft’s final approach path and landing before the
large aircraft’s touchdown point.
d. Below the large aircraft’s final approach path and landing beyond the
large aircraft’s touchdown point.
4. The aerodynamic drag of a body, placed in certain airstream
depends amongst others on __
a. The airstream velocity
b. The specific mass of the body
c. The specific mass of the body
d. The weight of the body
5. __ designs utilize concepts of two lifting surfaces. the canard
acts as a control surface near the nose of the aircraft designed to
create lift to pitch the nose up.
a. v-tail design b. t-tail design
c. canard d. stabilator
6. Which control surface is used to counteract the effects of engine
torque on a single-engine propeller aircraft?
a. Ailerons b. Rudder
c. Elevators d. Trim tabs
7. Laminar flow is more likely to occur at:
a. High temperatures b. High velocities
c. Low velocities d. Low viscosities
8. It refers to the demonstrated ratio of the change in height during a
portion in climb in still air.
a. Lapse rate b. Height differential
c. Height differential d. Climb gradient
9. During takeoff, __ cause/s the rotor disk to cone upward.
a. Centrifugal force
b. Lift
c. Combination of centrifugal force and lift
d. Combination of centrifugal force and torque
10. In small airplanes, normal recovery from spins may become difficult
if the
a. CG is too far rearward, and rotation is around the CG
b. CG is too far rearward, and rotation is around the longitudinal axis
c. A stall is entered before the spin developed
d. Spin is entered before the stall is fully developed
11. In Prandtl-Glauert transformation, what happens to the shock
waves that occur at supersonic speeds?
a. They become weaker b. They become stronger
c. They become weaker d. They vanish
12. Continuity equation states that if the area of a tube is increasing,
the speed of the subsonic and incompressible flow inside is
a. Increasing b. Constant
c. Constant d. Decreasing
13. Deflection of the leading edge flaps will:
a. increase critical angle of attack.
b. decrease CLmax.
c. decrease drag.
d. not affect critical angle of attack.
14. Every object persists in its state of rest or uniform motion in a
straight line unless it is compelled to change that state by forces
impressed on it.
a. Newton’s second law of motion
b. Pascal’s law
c. Newton’s first law of motion
d. Newton’s third law of motion
15. As for the other type of ailerons, __ may be designed to
function differentially and does not eliminate the effects of adverse
yaw.
a. frise-type ailerons b. flaperons
c. flaperons d. differential ailerons
16. For __, small holes are incorporated in the surface of a wing
upstream of the separation point where the air in the boundary layer is
sucked into the wing.
a. boundary layer suction b. both a and b
c. both a and b d. boundary layer blowing
17. Which type of drag dominates at high supersonic speeds?
a. Parasitic drag b. Form drag
c. Induced drag d. Wave drag
18. On most aircraft, how are the ailerons controlled by the pilot?
a. By using a separate lever
b. By pushing and pulling on the control yoke or stick
c. By using foot pedals
d. By using foot pedals
19. In the context of Prandtl-Glauert transformation, when the flow
speed approaches the speed of sound (Mach 1), the transformed
variable becomes:
a. Zero b. Constant
c. Infinite d. Constant
20. Induced drag can be reduced by
a. Shiny surfaces
b. High aspect ratio wings
c. Flying at minimum sink
d. Flying at minimum sink
21. The minimum value of V2 must exceed “air minimum control speed”
by:
a. 0.15 b. 0.1
c. 0.3 d. 0.2
22. Changes in the center of pressure of a wing affects the airplane’s
a. Pitching moment
b. CG location
c. L/D ratio
d. Aerodynamic balance and controllability
1. These are the other terms for First-Order Approximation, except?
a. Exact Theory b. First-Order Theory
c. Ackeret d. First-Order Theory
2. The greatest stress on a rotating propeller occurs
a. at about 75% of the length
b. at the root
c. at the tip
d. at about 75% of the length
3. Which of the following is not a disadvantage of the blow-through
tunnel?
a. Short running time
b. Requiring great power
c. Variation of stagnation parameters
d. Short running time
4. Wind tunnels for intermittent operation may be of the
a. neither of the two types
b. both types
c. suction type only
d. low-through only

1. D
2. C
3. A
4. C
5. B
6. B
7. A
8. C
9. B
10. C
11. D
12. C
13. A
14. D
15. D
16. A
17. C
18. A
19. A
20. D
21. B
22. C
23. B
24. B
25. D
26. A
27. B
28. B
29. B