So i recently saw an image of the natf-23 a modified(more like completely redesigned) yf-23 and one of the interesting things it had were canards that were angled. What would the benefits and drawback be?

natf-23 model

a model of the natf-23

if we go into fictional aircraft i also noticed it on the maneuvrability focused mode of the x-02 wyvern from the ace combat series. enter image description here

  • $\begingroup$ Angling them up or down will wreak havoc with directional stability. This is plain silly. $\endgroup$ Commented Aug 5, 2022 at 21:25
  • $\begingroup$ Given that this is your third very similar question about fictional designs, I would vote for Peter's comment as an answer $\endgroup$ Commented Aug 6, 2022 at 5:01

1 Answer 1


When you have horizontal stabilizing surfaces with dihedral/anhedral, there is an effect on yaw stability from the effective vertical profile created by the angled surface. That vertical profile is as if you put a vertical fin there of equivalent area on the fuselage at that location.

The effective vertical surface area moves the vertical Neutral Point, the aerodynamic centre of the overall body, forward, reducing yaw stability (weathervaning tendency in yaw). This problem requires extra fin area on seaplanes when put on floats, which do the same thing to the vertical NP.

If the effective surface area is enough to move the NP to the C of G, the plane will just want point in any direction while flying (neutrally stable), and if forward of the C of G, it will want to switch ends like a dart you threw with the pointy bit toward you (in the plane's case, unstable in yaw, and once it's flipped around to point backwards, it will now be stable in yaw, going backwards).

If a designer wanted to make the plane neutrally or negatively stable in yaw on purpose, with active computer generated stability, rather than angle the canard surface, just making the existing vertical tails smaller would achieve the same end, and save a bunch of weight.

On the other hand, in theory, you could have those surfaces with variable anhedral/dihedral, and get a variable natural yaw stability effect, high stability when flat, less stability when angled, if that was an objective (you will also have to deal with a stability side effect in the pitch axis for the same reason, because it will also shift the pitch Neutral Point fore/aft to some degree, to the extent that the surfaces' horizontal footprint is increase/decreased by the change in angle).

Nobody appears to have found a reason or justification to implement such a feature on a real fighter so far.

Anyway, it's important not to assume any consideration was given to how airplanes fly on the part of game developers, when you look at these fantasy configurations.

  • $\begingroup$ In addition, I wonder if there will be any additional fancy vortices stuff going on which has influence (good or bad) on the wing aerodynamics $\endgroup$
    – U_flow
    Commented Aug 7, 2022 at 10:46
  • $\begingroup$ That, plus rolling moments created during side slip, and I'm sure other effects that don't actually show up until you try out the real thing, that the computer models may or may not predict. $\endgroup$
    – John K
    Commented Aug 7, 2022 at 12:28
  • $\begingroup$ the funny thing is that the natf-23 was an actual proposed design irl at one point $\endgroup$ Commented Aug 8, 2022 at 8:09

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