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 increase both lift and induced drag, a fact confirmed by the *Pilot’s Handbook of Aeronautical Knowledge*, and deploying them lowers an aircraft's stall speed.
For soft-field takeoffs, a minimal flap setting is sometimes recommended because it allows the aircraft to lift off at a lower airspeed.
The specific flap settings for takeoff vary by aircraft and situation (e.g., soft-field), must always be confirmed in the Pilot's Operating Handbook (POH), as too much flap can significantly increase drag and hinder 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).”