SPC Student Pilot Basic Aerodynamics 2 — Questions and Answers
Question 1: Which aerodynamic force acts perpendicular to the relative wind?
- Drag
- Thrust
- Lift (Correct answer)
- Weight
Correct answer: Lift
Lift always acts perpendicular to the relative wind, regardless of the aircraft's attitude.
Question 2: What happens to induced drag as airspeed increases?
- It increases proportionally
- It remains constant
- It decreases (Correct answer)
- It doubles with each knot
Correct answer: It decreases
Induced drag decreases as airspeed increases because less angle of attack is needed to generate the required lift.
Question 3: The chord line of a wing is defined as:
- The curved upper surface of the wing
- An imaginary line from the leading edge to the trailing edge (Correct answer)
- The angle between the wing and the horizon
- The distance from wingtip to wingtip
Correct answer: An imaginary line from the leading edge to the trailing edge
The chord line is a straight imaginary line connecting the leading edge to the trailing edge of an airfoil.
Question 4: What term describes the angle between the chord line and the relative wind?
- Dihedral angle
- Angle of incidence
- Angle of attack (Correct answer)
- Sweepback angle
Correct answer: Angle of attack
Angle of attack is the angle between the chord line of the wing and the direction of the relative wind.
Question 5: During a coordinated level turn, total lift must be greater than weight because:
- Bank angle reduces the effectiveness of the rudder
- Only the vertical component of lift supports the aircraft's weight (Correct answer)
- The horizontal component of lift causes the aircraft to climb
- Increased speed reduces lift efficiency
Correct answer: Only the vertical component of lift supports the aircraft's weight
In a bank, lift is divided into vertical and horizontal components, so the vertical component must equal weight, requiring total lift to increase.
Question 6: What is the primary cause of parasite drag?
- Generation of lift by the wings
- Interference between airflow and aircraft structure/skin friction (Correct answer)
- Wing vortices trailing from the wingtips
- Changes in angle of attack
Correct answer: Interference between airflow and aircraft structure/skin friction
Parasite drag results from skin friction, form drag, and interference drag — all caused by the aircraft's physical structure moving through air.
Question 7: What is the stagnation point on an airfoil?
- The point of maximum thickness
- The point where airflow velocity is zero and pressure is highest (Correct answer)
- The point where turbulent flow begins
- The trailing edge where airflow rejoins
Correct answer: The point where airflow velocity is zero and pressure is highest
The stagnation point is where the oncoming airflow splits around the airfoil, with velocity momentarily at zero and static pressure at maximum.
SPC Student Pilot Basic Aerodynamics 2
Which aerodynamic force acts perpendicular to the relative wind?