F15 with "Pitch Changers":
Pitch Changers

The J20 with "Pitch Changers":
Pitch Changers

Now, it looks odd when you see a plane with "Pitch Changers" on the front.
So what are they and why they are on the front in the J20 ? Does that configuration effect the "Dogfight Performance" ?

  • $\begingroup$ Both airplanes have the vertical stabilizer(s) on the back. Perhaps you are referring to to elevator, or horizontal stabilizer. In the J-20 case it's a canard. $\endgroup$
    – Steve Kuo
    Commented Dec 6, 2017 at 16:25
  • 2
    $\begingroup$ When the elevator is on the front, it's not a stabilizer any more because it destabilizes the airplane. $\endgroup$ Commented Dec 6, 2017 at 16:27
  • $\begingroup$ Wait a minute please, It will take me to edit the photos $\endgroup$ Commented Dec 6, 2017 at 16:32
  • 1
    $\begingroup$ OK I Revised the Q $\endgroup$ Commented Dec 6, 2017 at 16:39

1 Answer 1


The items you pointed out on the J-20 are canards. They are usually combined with delta wings, to alleviate some of the drawbacks of the delta.

Its main purpose is similar to the horizontal tailplane, but the canard can provide lift as well.

Depending on the aircraft, canards can be fixed or movable.

Pitch control in a canard type may be achieved either by the canard surface, as on the control-canard or in the same way as a tailless aircraft, by control surfaces at the rear of the main wing, as on the Saab Viggen.

On the J-20, the canards seem to be movable:

One important design criterion for the J-20 describes high instability.[26][27] This requires sustained pitch authority at a high angle of attack, in which a conventional tail-plane would lose effectiveness due to stalling. On the other hand, a canard can deflect opposite to the angle of attack, avoiding stall and thereby maintaining control.[28] A canard design is also known to provide good supersonic performance, excellent supersonic and transonic turn performance, and improved short-field landing performance compared to the conventional delta wing design.[29][30]


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