Which wing device produces a large increase in camber and increases both lift and drag?

• A. Slats
• B. Spoilers
• C. Ailerons
• D. Flaps

Answer: (D)

Increasing camber means making the wing’s curvature more pronounced. Flaps do that by deflecting the trailing edge downward (and sometimes rearward), which steepens the wing’s curvature and, in many flap designs, even increases wing area. That larger camber boosts the lift coefficient at lower speeds, letting the airplane generate more lift without needing a higher angle of attack. At the same time, the extra surface and disturbed airflow raise drag, so both lift and drag go up when flaps are deployed.

Slats change the leading edge to improve lift and delay stall but don’t produce as big a camber change as flaps. Spoilers disrupt lift and add drag without increasing camber, and ailerons mainly control roll with little impact on overall camber.