By changing the angle of attack of a wing, the pilot can control the airplane's:

• A. Lift
• B. Weight
• C. Lift, airspeed, and drag
• D. Fuel efficiency

Answer: (C)

The main idea is that lift depends on the wing’s angle of attack. As you increase the angle of attack, the lift coefficient rises, so the wing can produce more lift—up to the point of stall. But lift isn’t the only thing that changes: drag also grows with higher angles of attack, especially induced drag, and the increased drag affects the airspeed needed to balance forces in steady flight. Since weight is fixed by the aircraft’s mass, changing the angle of attack doesn’t directly change weight, but it does change the lift you generate and the speed and drag required to stay in balance. Because of this, adjusting angle of attack lets you control lift directly and, through the resulting changes in speed and drag, the airplane’s flight state. Fuel efficiency isn’t a direct, primary control provided by angle of attack, even though it depends on drag and power.