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Down-pitch instability?

50.3k Graingy  yesterday

An age-old problem.
Building a simple fighter jet, generally going well, except that when pitching down (but not up!) it becomes immensely unstable. Reducing the stabilator deflection for down pitch helps, but doesn't totally eliminate the problem nor does it actually help me find the root cause.

This aircraft also noses down rather quickly naturally, which I suspect is a thrust issue... scratch that, tail airfoil and orientation issue. It's rather annoying how there's no way to easily tell if a wing is upside down or not...

Anyways, why do planes do this? What causes pitching down specifically to result in instability? Does the flat bottom airfoil behave differently when pitching down? Does it stall easily when nosing down?

I'm rather annoyed by this. I've been playing for what is almost two months to the day away from nine years and I still don't have a reliable answer to this short of sacrifice and prayer.

Help greatly appreciated.

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    50.3k Graingy

    @MonsNotTheMonster But still nobody seems to know why it’s an asymmetrical effect…

    22 hours ago
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    Try messing with the CoM a bit. If it's near the CoL it really tends to do that

    yesterday
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    8,343 Bugati87

    Hmm... That can be fixed (I don't know how).

    yesterday
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    50.3k Graingy

    This game is a bloody curse.
    Make a plane.
    All goes well.
    Problem.
    Fix problem.
    Bigger problem.
    Bigger problem requires FT to fix.
    There's no resource for how to actually use FT; stock VR craft are basically black magic.
    Have to abandon project.
    Rinse and repeat.

    yesterday
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    50.3k Graingy

    @OverlordPrime It's a rather conventional design, and this problem is very general.
    It's very, very noticeable in New Pigpen.

    yesterday
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    @Graingy can i see the unlisted? Or a picture

    yesterday
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    50.3k Graingy

    @OverlordPrime Evidently not.
    And "use FT" is, essentially, saying "just fix it". Not very helpful, especially when doing much with FT requires you to be half engineer, half programmer, of which I am neither.

    yesterday
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    Or use ft

    yesterday
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    It's nose heavy
    You could either fiddle with the com position or the liftScale

    yesterday