I have a wing with an airfoil s1223 which is an airfoil with a lot of camber. the take off distance is limited so I want to implement flaps for this issue but I have the doubt if this is a good idea.

  • $\begingroup$ What is the application? The S1223 is a very thick, heavily cambered airfoil. Does your aircraft cruise at more than 60 knots? How slow do you want to fly? You may try airfoil tools and look for an even thicker, more heavily cambered airfoil, and see if you can add in slats and flaps for better short field performance. Note on the polars, these wings start lifting at negative AOA. $\endgroup$ Mar 13 '19 at 0:26

Flaps generally help with short field take-off distance, but you should check the takeoff performance charts in the POH to understand your aircraft's limits and the effect of flaps.

  • $\begingroup$ Flaps generally increase field performance (lower speed ok for same weight), but reduce climb performance (higher drag for same lift). $\endgroup$ Mar 12 '19 at 19:57
  • $\begingroup$ Good point. I edited my answer to be specific to "short field take off distance". $\endgroup$ Mar 12 '19 at 20:32

The S1223 airfoil is very similar to a birds wing and is already designed (and limited) to low speed flight. Heavily undercambered wings were popular in the early days of flight as they offered high lift at low speeds. Modern airliners still use this configuration to land at 1/3 their cruising speed. However, as speed increases, this configuration is very draggy. This is why airliners "fold up" and decamber to cruise. Towards the 1920s designers began to reduce camber, particularly undercamber, with thinner wings and a "straight across" bottom.

So to improve your short field take off distance, the list as follows.

  1. More power. A larger engine can accelerate the aircraft to flying speed faster.
  2. Bigger wing. Same design, just bigger.
  3. Lower aspect ratio. Surprisingly, lower aspect wings, though less efficient, stall at lower airspeed.
  4. End capping your wing tips. This helps maintain higher air pressure under the wing.
  5. Slotted full span flaps or flaperons, found on Ju-52 "doppel wing". Ancestor of Fowler flaps. May be better than simple flaps for heavily undercambered wing.
  6. Slats and flaps together. Produce the highest possible Lift coefficient.
  7. Ask Peter Kampf, he always has some good ideas.

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