During a stall, which describes lift, drag, and angle of attack?

During a stall, which describes lift, drag, and angle of attack?

• A. Lift increases, drag increases, and angle of attack reaches a critical value.
• B. Lift decreases drastically, drag increases, and angle of attack reaches a critical value.
• C. Lift decreases, drag decreases, and angle of attack remains unchanged.
• D. Lift remains constant, drag constant, angle of attack unchanged.

Answer: (B)

When a wing stalls, the angle of attack has been increased beyond the point where the airflow remains attached. At that critical angle, the lift generated by the wing falls off sharply because the flow separates from the upper surface, so lift decreases dramatically. Meanwhile, the separated flow creates more resistance, so drag rises significantly. In short, lift drops, drag goes up, and the angle of attack is at or beyond the critical value. The other descriptions would imply lift or drag behaving opposite to what actually happens or imply no change in angle of attack, which doesn’t describe a stall.

When a wing stalls, the angle of attack has been increased beyond the point where the airflow remains attached. At that critical angle, the lift generated by the wing falls off sharply because the flow separates from the upper surface, so lift decreases dramatically. Meanwhile, the separated flow creates more resistance, so drag rises significantly. In short, lift drops, drag goes up, and the angle of attack is at or beyond the critical value. The other descriptions would imply lift or drag behaving opposite to what actually happens or imply no change in angle of attack, which doesn’t describe a stall.