Which statement about flaps is true?

• A. They do not affect lift
• B. They only increase drag
• C. They increase stall speed
• D. They increase camber and lift, and increase drag

Answer: (D)

Flaps work by increasing the wing’s camber (curvature) when extended. That higher camber raises the lift coefficient, so you can generate more lift at a lower airspeed, which is crucial for safe takeoff and landing. At the same time, the flap changes add surface area and disturb the airflow, which increases drag. So flaps don’t just add drag or leave lift unchanged; they boost lift (via higher camber) and also increase drag. They also lower stall speed by increasing the maximum lift coefficient, not raise it. That combination is why the statement that flap action increases camber and lift, while also increasing drag, is the correct one.