How does increasing flap setting affect approach speed and stall speed?

How does increasing flap setting affect approach speed and stall speed?

• A. More flaps raise stall speed and require a faster approach, reducing drag.
• B. More flaps lower stall speed and allow a slower approach, but increase drag.
• C. Flaps have no effect on stall speed or approach speed.
• D. More flaps decrease drag and increase stall speed.

Answer: (B)

Increasing flap setting increases the lift generated by the wing at a given speed, so you can achieve the required lift at a lower airspeed. Since stall occurs when lift equals weight, the stall speed drops as flaps are extended. A lower stall speed means you can fly a slower approach safely. However, extending flaps also increases drag, so while you can slow down more, you’ll experience more resistance and typically need more thrust to maintain the desired approach speed. That combination is why the best description is: more flaps lower stall speed and allow a slower approach, but increase drag.

Increasing flap setting increases the lift generated by the wing at a given speed, so you can achieve the required lift at a lower airspeed. Since stall occurs when lift equals weight, the stall speed drops as flaps are extended. A lower stall speed means you can fly a slower approach safely. However, extending flaps also increases drag, so while you can slow down more, you’ll experience more resistance and typically need more thrust to maintain the desired approach speed. That combination is why the best description is: more flaps lower stall speed and allow a slower approach, but increase drag.