Overyaw Issues with the Newest NAFA-5 model

[Noname117]

I am experiencing significant "over-yaw" issues with the newest models of the NAFA-5. If I hold a yaw with the aircraft, it quickly starts naturally and uncontrollably yawing to that side (Even if I have let go of the yaw key.), entering a spin shortly afterwards. The larger the tailfin control surface the quicker it experiences overyaw, but it is still experiencing it with a relatively small tailfin control surface. I honestly have no clue what is going on here, though I think it relates to the aerodynamics of the aircraft in some way over-exaggerating a yaw movement.

I have some pictures of a couple overyaw events below. I tried to do a couple full overyaws and then a partial as well, but the first partial didn't last long and the second turned into a full overyaw movement.

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Downloads for the NAFA-5-F3 and -F4

https://www.dropbox.com/s/nr21wv2z7ylkyl0/NAFA-5-F3%20Wailing%20Banshee.craft?dl=0

https://www.dropbox.com/s/cjfatnq04cmiqji/NAFA-5-F4%20Wailing%20Banshee.craft?dl=0

EDIT: Some pictures of my NAFA-4 (which does not have the problem) in full yaw for comparison:

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Edited August 14, 2015 by Noname117
Solution found

[Xannari Ferrows]

I see you have a ton of torque wheels...

[Noname117]

I had less back when I updated the NAFA-5 to 1.0, and it still suffered from the same issue. I did remove a lot of sideways facing wings, which eliminated the problem for awhile, but I think the problem has returned because I moved the center of lift closer to the center of mass in this newest version, making the aircraft overall less stable. I'll still try flying it without reaction wheels on though.

EDIT: Here is a picture from the before-mentioned test:

Having the reaction wheels off did decrease the amount of yaw the aircraft had, but it still entered a spin. What is worse is that having the reaction wheels off actually gave the aircraft no method of pulling out of said spin, and both pilots were forced to eject.

My conclusion: Modern fighter jets should be equipped with reaction wheels in case they stall.

Edited August 14, 2015 by Noname117

[Xannari Ferrows]

Wow, this is really weird. It looks like your center of mass is well balanced in the middle somewhere. If it were near the back, that would explain it.

I've seriously never had this problem before, even with similar craft. Although I've never used the giant control surface either.

[Noname117]

To make aerodynamic differences between yawing and overyawing more apparent (which could help fix my problem), I have taken a few screenshots of the NAFA-4 in a full yaw.

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The blue arrows seem to be far shorter with the NAFA-4's yaw than with the NAFA-5's, which could be the problem.

I'll also update the main post with this album.

[Jon144]

Most modern aircraft have anti-stall parachutes instead of reaction wheels. Real reaction wheels would never be powerful enough to keep a fighter jet from entering a spin. At least not for any practical amount of money.

[Noname117]

Most modern aircraft have anti-stall parachutes instead of reaction wheels. Real reaction wheels would never be powerful enough to keep a fighter jet from entering a spin. At least not for any practical amount of money.

I think I was trying to be sarcastic with that post.

[GoSlash27]

noname117,

First of all, you should not attempt to steer with yaw. That's just there to coordinate your turns.

Second, a suggestion: Try disabling the rudder from responding to yaw inputs. You have plenty of authority from the reaction wheels.

Good luck,

-Slashy

[Noname117]

The yaw seems to be working fine in coordinated turns, disabling the rudder actually helped them out (re-enabling it causes the same problem to happen in said turns). I'm still concerned about the aircraft having a defect as bad as this, which could be a major issue on takeoff, landing, or in certain situations in dogfights. I still kind of want to know exactly what is wrong.

[Xannari Ferrows]

Well, the game does model lift based on the wing values rather than their surface area. Maybe it's due to you using all those wings? I see 6 total.

[Noname117]

If you are excluding the canards and horizontal stabilizers, then there are another 2 wings located at the bottom of the aircraft. Both of these should just be acting as normal lifting surfaces though.

[ajburges]

The yaw seems to be working fine in coordinated turns, disabling the rudder actually helped them out (re-enabling it causes the same problem to happen in said turns). I'm still concerned about the aircraft having a defect as bad as this, which could be a major issue on takeoff, landing, or in certain situations in dogfights. I still kind of want to know exactly what is wrong.

Unless your crazy, yaw instability in a turn should be a non-issue for landing.

Looking at the vectors, your CoP is ahead of your CoM at high speed due to body lift. Do one of the three:

> limit high speed AoA

> add more horizontal stabilizer

> reduce control authority

[Noname117]

Maybe more horizontal stabilizer would help. I think I'll try that next.

EDIT: Problem solved! The added stability helped the aircraft out.

Edited August 14, 2015 by Noname117