enter image description hereI was just looking at an airplane take off, and when it was taking off, some flaps were facing down at the back of the main wings-

Are these Ailerons or elevators please? I did some research but the internet said that the tail flaps are elevators only?

What am I missing and why did the pilot bring those flaps down when taking off?

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    $\begingroup$ Hi I added an image $\endgroup$ Mar 30, 2022 at 21:10
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    $\begingroup$ One arrow points to an inboard flap, the other to an aileron. Which arrow are you asking about? $\endgroup$ Mar 31, 2022 at 1:01
  • $\begingroup$ Hi both actually, I thought that it would be better to just have one long flap, and use that just for take off, and so take off would be much easier? $\endgroup$ Mar 31, 2022 at 8:15

1 Answer 1


Wikipedia has a useful page on flight control surfaces, which includes this image:

enter image description here

(Credit: Wikimedia Commons)

The item labeled inboard flap may be the items you are asking about. From that page:

Flaps are mounted on the trailing edge on the inboard section of each wing (near the wing roots). They are deflected down to increase the effective curvature of the wing. Flaps raise the maximum lift coefficient of the aircraft and therefore reduce its stalling speed. They are used during low speed, high angle of attack flight including take-off and descent for landing.

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    $\begingroup$ +1 for illustrating with the mighty 727! $\endgroup$
    – Ralph J
    Mar 30, 2022 at 16:04
  • $\begingroup$ Hi, thanks for the link and explanation! Why doesn’t that wing flag go the whole way along the back of the wing please? Wouldn’t that help more? $\endgroup$ Mar 30, 2022 at 21:12
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    $\begingroup$ @JonathanChing The trailing edge of the wing also needs room for the aileron which rolls or banks the aircraft resulting in a turn. The ailerons move in opposite directions, if the left is deflected downward then the left is deflected upward (and vice versa) which your image shows en.wikipedia.org/wiki/Aileron $\endgroup$ Mar 30, 2022 at 22:23
  • $\begingroup$ Is there a reason why the take off flap is longer than the the flap used for turning (aileron) please? $\endgroup$ Mar 31, 2022 at 8:16
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    $\begingroup$ The force required for roll is smaller than the force required for lift, therefore the ailerons don't need to be as big as the flaps. By the way, ailerons are not referred to as flaps. See en.wikipedia.org/wiki/Flap_(aeronautics) and en.wikipedia.org/wiki/Aileron . However, sometimes (rarely) they are combined into one device: en.wikipedia.org/wiki/Flaperon $\endgroup$ Mar 31, 2022 at 8:33

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