These are portions of the leading edge moved forward and down to create a path for air similar to a slot, providing additional lift and delaying separation. What are they called?

• A. Slats
• B. Slots
• C. Flaps
• D. Vortices

Answer: (A)

This item tests how high‑lift devices on the wing work to delay stall. Leading‑edge slats are movable pieces that extend forward and down to create a small gap between the slat and the wing. That gap acts like a slot, letting air from below the wing flow onto the upper surface at higher angles of attack. This re-energizes the boundary layer, delays separation, and increases lift when you’re near stall—useful for takeoff and landing.

Slots are fixed openings, which achieve the same airflow effect but without a movable surface. Flaps are on the trailing edge and increase camber to boost lift, not the leading-edge air path. Vortices are swirling air patterns, not a wing device. So the best term for the described feature is slats.