Why Are Flaps Used in Some Soft-field Takeoffs?

Who said flaps don't increase lift? Flaps do increase lift. Reference Chapter 6 of the Pilot’s Handbook of Aeronautical Knowledge, which states, "Flaps are the most common high-lift devices used on aircraft. These surfaces, which are attached to the trailing edge of the wing, increase both lift and induced drag for any given angle of attack (AOA)."

Meg Godlewski

Tuesday, September 20, 2022 at 08:49 AM ET

Verified

A Cessna 170B with flaps extended. [Credit: Adobe Stock]

Key Takeaways:

Flaps are high-lift devices that increase both lift and induced drag, and they lower an aircraft's stall speed.
A minimal flap setting is often recommended for soft-field takeoffs to allow the aircraft to lift off at a lower airspeed.
The specific flap settings required for takeoff vary by aircraft and situation, and are detailed in the Pilot's Operating Handbook (POH).
Using excessive flaps can increase drag too much, diminishing the usefulness of lift and hindering takeoff performance.

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Question: If flaps don’t increase lift, then why is a small amount of flaps used in soft-field takeoffs for some aircraft?

Answer: Who said flaps don’t increase lift? Flaps do increase lift. Reference Chapter 6 of the Pilot’s Handbook of Aeronautical Knowledge, which states, “Flaps are the most common high-lift devices used on aircraft. These surfaces, which are attached to the trailing edge of the wing, increase both lift and induced drag for any given angle of attack (AOA).”