What is the deflection of the oncoming airstream upward and over the airwing?

• A. Angle of attack
• B. Relative wind
• C. Downwash
• D. Upwash

Answer: (D)

This question tests how the wing redirects the incoming air. As the airplane moves, the wing’s shape and angle guide the oncoming air upward as it flows over the top surface. This upward deflection of the approaching airstream is called upwash. Behind the wing, the air is deflected downward (downwash), which contributes to lift, but the term in question refers to the upward deflection before the air passes over the wing. The other terms describe different ideas: angle of attack is the tilt between the wing’s chord and the relative wind, and relative wind is simply the airflow’s direction relative to the airplane. So the upward deflection of the oncoming air as it approaches is upwash.