Which statement about extending flaps is correct?

Which statement about extending flaps is correct?

• A. Stall speed increases and glide distance increases.
• B. Stall speed decreases and glide distance decreases.
• C. Stall speed decreases and glide distance increases.
• D. Stall speed increases and glide distance decreases.

Answer: (B)

Extending flaps increases the wing’s lift at a given speed, so you can fly slower before reaching the stall chaos; that lowers stall speed. At the same time, the flap extension adds drag, which reduces the lift-to-drag ratio. A poorer lift-to-drag ratio means you cover less horizontal distance for each unit of altitude lost, i.e., glide distance decreases. So the correct statement is that stall speed decreases and glide distance decreases. The idea is you gain the ability to fly slower for landing, but you pay with more drag, which hurts gliding efficiency.

Extending flaps increases the wing’s lift at a given speed, so you can fly slower before reaching the stall chaos; that lowers stall speed. At the same time, the flap extension adds drag, which reduces the lift-to-drag ratio. A poorer lift-to-drag ratio means you cover less horizontal distance for each unit of altitude lost, i.e., glide distance decreases. So the correct statement is that stall speed decreases and glide distance decreases. The idea is you gain the ability to fly slower for landing, but you pay with more drag, which hurts gliding efficiency.