SAAF JAS-39C Technical Data and Discussion

I don’t know how to feel about this, I’m not particularly against it, as I want accurate flight models but it seems more of a gameplay-issue than FM issue?

Yes, and likely also the Su-27, Mirage 2000… they are all incorrectly modeled at the moment but the Gripen has a unique feature - the canard. The canard providing lift actually causes the instability. When the canard is stalled (artificially, or from angle of attack / airspeed)… the aircraft becomes neutrally or fully stable. This allows it to recover from excursions and departures easily without fear of deep stall like the F-16.

These would be much more violent IRL. See the Gripen FLCS failure video…

The Gripen has a unique feature thanks to the canards…
Essentially it can stabilize itself long enough for safe pilot ejection, which is seen above.

It would make instantaneous turns at low speed much better. Currently full pitch on afterburner with full fuel and 2x wingtip missiles results in ~195 knots minimum airspeed and you’re unable to tighten down to the point of stall in horizontal turn. It would allow you to essentially “Cobra” (although the FLCS has a mode to prevent you from overshooting ~40 degrees AoA for safety reasons). It will auto deploy the airbrake above 35 degrees AoA and deflect the canards back down.

In-game this would mean better agility, response, and nose authority at low speed… allowing you to trade energy for nose authority. It would feel much more like the Su-27’s nose pointing ability at low speed instead of just locking into a tight turn radius with no ability to pull the nose anywhere.

At speeds where the instant turn does not require so much AoA, you’d notice an increase in instant turn rate. This would be especially noticeable at high speed, where it currently feels like it can’t tighten down the turn circle or dump speed as quick as it should.

Guess we’ll find out together. The others would have you thinking the former.

I do too! Hopefully Gaijin can adjust their instructor soon to allow for these unstable designs to be fully realized. There is lots of testing and reporting ahead of us.

Yes, this is the issue. Fully unstable modeling bricks mouse aim according to them.

Not the CANARD! WOA! Update Canard Winter 2023.

You are really hung up on the F-16 huh.

All aircraft deep stall. Especially Deltas. Canard’s help. But you are getting way into it. You did not know what a canard was last week and thought the M2K had them. You had no idea they provide lift and thought they serve only to energize airflow.

But go off it’s an interesting read.

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I just feel like there has to be some level of stability even in mouse-aim for gameplay purposes… Like we can’t have people get into those FLCS failure situations like in that video when just pressing the SAS button at low speeds… Question is where you draw the line.

Well, even you have to admit that’s true to some regard

Anyways, I can’t say you’re wrong with these reports you’ve made. It’s more a question of how much control you should allow the player to have in mouse aim than an issue of performance where sources are of more importance.

If delta wings like M2K’s, Drakens and Su27’s have it, I can see why someone would want F16’s and Gripens to have it as well. Dev decision at the end of the day so we will see.

Canards generate lift and are known as a foreword wing. When aircraft such as the Grippen or Kfir’s are discussed, they have two sets of wings. Main wings and forward wings.

The foreword wings have nothing to do with improving airflow over the main wings as a leading-edge flap.

The Mirage 2k does not have a canard. it has strakes. Strakes do not provide lift or improve airflow over the wings. they energize it. Vortex generators serve to stimulate airflow \ and maintain the boundary layer in high angles of attack thus delaying the point of stall.

Kind of flip-flop every week on your belief it seems @MiG_23M

Now he is an expert/authority in the field of the Gripen and the “canard” and speaks with such air of superiority.
I do not recommend you let him come near this model. Because I guarantee you, that eventually he will want to nerf it beyond all hell and call it a UFO too.

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Su-27 for example will start doing backflips in-game rn (albeit rather slowly). Just turn SAS or mouse aim on and it flies straight where you point it. Simple solution. Although the conventional designs are easier to model I suppose with some margin of relaxed stability than the canard-delta type. That’s why the Mirage 2000 and Gripen are performing kinda weird at low speeds and hence the reports.

I’m actually still working on other reports and issues for the Gripen right now on top of what has already been submitted. It’s got some weird oscillatory issue going on at speeds and AoA where it shouldn’t really be stalling… I think it has to do with the Canard deflecting upwards instead of just being neutral… Canard is stalling and causing the oscillations.
https://community.gaijin.net/issues/p/warthunder/i/a5jgVAWuxdNV

Hopefully to fix the issue they will compromise by partially reducing the static margin, make it so full pitch doesn’t require upward deflection of the canard and thus allow smooth turns at low speed… at least until you stall the primary wing, lol.

One can easily check the Cm curve to see if the canard or elevator continues to generate pitch-up moment until a certain AOA. For example, the Cm curve from the SAAB FCS document indicates that the aircraft is able to consistently pitch-up until 65 deg AOA, with canard deflecting full-up. If the lateral-directional stability were augmented enough to exclude any unwanted roll-yaw motions, the aircraft would be able to sustain such a high AOA.
https://img-forum-wt-com.cdn.gaijin.net/original/3X/0/5/05fa3de0321ea3cb8d964bcd013145c744474af7.jpeg

Likewisely, you’ve got the Cm curve for the small tail F-16A and the pitch-up moment can also be generated consistently until 65 deg AOA.

And there’s also the moments of inertia come into play, so that the dynamic attainment of AOA would be higher than those indicated in the Cm curve. This is pure flight dynamics and didn’t consider the use of flight control system and the AOA limiter.

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Ofcourse it’s wrong.
Nobody knows what is right.

The entire flight model is a speculation and arguing for changes based on assumptions, feelings and graphs with no scale or reference is completely backwards.

There is a lot about the FM that is more than speculation. Calling it just speculation is the only thing wrong here.

We have all of the sufficient information on airfoil type, wing area, etc to correctly model this aircraft in a video game. The issue is not the correct modeling - it is the games’ limitations. Right now they are unable to properly model the unstable aircraft… and imo that should put a high level of priority on fixing the instructor as to not be bricked in mouse aim when modeling these aircraft properly.

i have never seen so many skill issued players in a single video…

I mean, this is literally average battle at top tier… only issue is, they are so bad, they die to fast often so you barely get to action… 16v16 was the stupidest thing gaijin ever did to air RB.

I think people blaming 16v16 are wrong, I have had no issues with the number of players… only the size of the maps. Even if they want to keep the small maps… longer games would allow me the time to strategically play and fight multiple enemies without having to resort to aggressive tactics.

16v16 is the problem as long as they refuse to redesign air rb mode itself. The large maps could support even 20 or 25v25… but with proper spaced objectives and airfields. Not that crap in the middle of map. We have huge map with ONLY long flight time to fight on same sized area like on normal map.

This why we get nerf can’t have su27 be worse then the gripen in any way

It is worse in-game, they aren’t making modeling decisions like that.

So the Su-27 has always been better in all respects.
It is not inferior in maneuver (and most likely even superior), it flies further, it has a more powerful radar and more weapons.
The Su-27 is still an icon of what a modern aircraft should look like for a reason.

Let me remind you that the Gripen still maintains speed in a maneuver too well for its aerodynamics.
Stop crying NATOboy, you’re already flying on overperfoming planes

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hate to burst your bubble, but European delta wings are highly capable aircraft that routinely outperform US and Soviet counterparts in most respects.

But hey, soviets wanted a BVR truck and you’ve got one.

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All icons of what a modern aircraft should be

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i hope we can get some cooler pictures as well

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