JA37C / JA37D - Rb99 Discussion & Future changes

Since the last dev-server gave us a taste of upcoming ARH missiles it’s no question that the Rb99 family (AIM-120) will soon come to the Swedish tech-tree. With this, I want to bring up my suggestion of implementing these missiles to the JA37D, and why the JA37C should effectively take its place once it does.

JA37D carring four Rb99 missiles. Captured 1999

So why introduce them at all if the Viggen is outmatched compared to its current rivals? Well it comes down to a lot of reasons; all of them relating to its JA37C sibling in some way or another. I think its important to adress why the JA37D exists in the first place, and also what the JA37C is capable of in comparison. I will use most of my quotes from aef.se, since while their accuracy can vary, they provide the most convenient referencing, and if someone wants more detailed documentation I could provide more accurate dates and documents when necessary.

The JA37C was a modernisation program introduced on all JA37 Fighterviggens between 1989 and 1990. While the modernisation was rather huge from a logistical perspective replacing a lot of electronics and software, the direct difference in War Thunder terms is unnoticable. The reason we got the C-mod in-game specifically is because the countermeasure dispensers were introduced in a 1992 upgrade, meaning the JA37C was the only designation in use at the time.

The JA37D was a 1998-2001 life extension program introduced on some JA37C airframes, meant to extend the life cycle of the JA37 platform. It is somewhat confused to be a stopgap for the JAS39, and while it did essentially end up acting as one, SAAB predicted the Fighterviggen would be used up until the mid 2010s. This means that although the JA37D had a short lifespan, the actual changes introduced on the small number of aircraft were quite extensive. A new tactical display, new flight computer, Rb99 missiles as well as the U95 jammer pod being some of the noteworthy equipment introduced in this upgrade.

Now lets talk about weapons.

The current difference between the JA37C and JA37D is the ability to carry Rb74 all-aspect sidewinders (AIM-9L), and utilizing the BOL301 chaff dispenser. This gives them a BR difference of .3 at the time of writing this. While the flight performance is identical, and both utilize the Rb71 Skyflash SARH missile as their primary radar missile, there is little differentiating the two planes. Once you have one there is little incentive to spade the other as they play identically. However, using the Rb24J at 11.0 is severely hindering compared to the Rb74, as most planes found at this BR has some sort of all-aspect on offer while having similar performance to the JA37C. Similarly, while the 48 countermeasures doesn’t directly hinder the JA37C it definitely inconveniences the plane compared to its bigger sibling which has the luxury of applying periodic dispensing whenever things get crowded, giving it more leverage to stay alive.

The JA37D is not overtiered with its current armament. While the radar can be troublesome at times the flight performance, countermeasures, and missiles more than make up for it. A .3 bump doesn’t come too much into play when compared to its predecessor, as they both tend to fight planes from the 11.3-12.0 range most commonly.

So why introduce the Rb99 on the JA37D?

Lets go back to dates but focus on weaponry. The Rb74 was introduced into Swedish service starting in 1986, four years BEFORE the JA37C. Similarly, the Rb99 missile was introduced in 1999, the same period as the JA37D conversion started. One of the main reason the JA37D program even materialised was the introduction of ARH missiles which should be enough of a reason why the plane should feature them. As it currently stands the JA37D is essentially acting as the JA37C while the JA37C is acting as a JA37C with expired missiles. While yea both planes CAN carry the Rb24J these were not seen as the main weaponry at the time, misrepresenting the JA37Cs capabilities in-game.

What about the countermeasures?

The CM Mod-upgrade listed by aef is part of the JA37C conversion, as mentioned before. Both the BOY and BOL dispensers are mentioned as being part of this package, which makes sense given that a secondary CM upgrade isn’t listed on either variants, meaning the JA37C should likely be able to carry the BOL chaff dispenser.

Conclusion / TLDR:

  • The JA37C is completely capable of carrying the JA37Ds current weaponry and missiles

  • The JA37D was introduced into service to primarily carry the Rb99 missile

  • The performance & battle rating difference between the JA37C/JA37D makes little difference to the current missile limitation of both aircraft.

My though is essentially that when Sweden gets the Rb99 missile, the JA37C should be reworked to feature the current JA37Ds weaponry, while the JA37D gets the Rb99 to differentiate the two, while adding a bit more challenge to those who want to fly it.

Please add your own thoughts as I am only giving my own opinion after having flown the Viggen for quite a while.


/ Rubbry


You should ask Smin on the Rumor thread if they’ll give JA37D some fox 3s

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I’ve heard from more than a few people that they won’t add it to the JA37D for “balancing purposes”


I don’t think anyone ever asked Smin directly if any current vehicle would get ARHs besides the ones that were showcased.

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Idk, I just remember someone saying it wouldn’t get them, on the Leak files. IMO, I would like it to get them, but decompress the range to keep it from being “unbalanced” for the higher BR (as in its flight performance isn’t good enough for that BR, even though the Vigg could probably easily handle itself in modern combat with newer weaponry, and a slight engine tuneup.)


Nice write-up! I definitely agree that JA37C should get it’s realistic armament with 9L, and the JA37D getting it’s RB99’s


I really think they should add the JA37 in the JA37C’s place if they do this. It would allow for a decent progression keeping the Viggen prevalent wherever it is supposed to be. The one problem is the lack of countermeasures but honestly IMO they should just give it countermeasures anyway because its a game, and these kind of aircraft need countermeasures.


I agree that it can feel a bit weird to bump the JA37D higher up in battle rating because of its weaponry but it feels like the biggest downside currently experienced by the Viggen isn’t the lack of flight performance but that of capable weaponry. Active radar homing missiles would better compliment the current multipath issues the plane has and thus let it act more aggressively.

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It’d be seriously cool to see a JA37 early in-game though I doubt it would be easy to balance given how the avionics and flight performance is still miles ahead of anything that could let it be bumped down in battle-rating. Maybe if radar missiles became more hampered and early heatseekers didn’t still require flares to the same extent.

Maybe a JA37 with an external flare dispenser if any image of that surfaces could be a possibility. A lot of ideas to throw at a wall to see what sticks.

RB99s won’t be added to JA37D as that would make it 12.7+ in BR and becomes unplayable. Then Ja-37C becomes unplayable, and Sweden loses out.
There’s no reason to support such missiles on them unless we hate Swedish players.

I’d honestly never play Viggens in War Thunder if those missiles were added.

And there is no Viggen before the C with flares.

I don’t see why making the JA37D any different would hamper the JA37C. If the JA37D gets a huge bump in battle-rating it will more so act as an analogue to the JAS39A than interfere with its older counterpart.

The point of this change was that there is no reason to keep the current JA37C/JA37D structure as the JA37C could offer the same experience as the current JA37D without removing a unique vehicle.

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Except the JAS39A is superior in every way.
There’s no reason to ruin the JA37D with a higher BR just cause you can give it non-meta ARHs.

If the ARH missiles turn out to be non-meta the JA37D wont get a huge BR increase. If they turn out to be meta you’ll essentially get a stopgap vehicle that forces you to plan engagements more while still having the same punching power as the JAS39A. If anything there’s plenty of ways to adjust the JA37D after the fact as it opens up the possibility to equip jammer pods and multilock several targets at once.

I think these would be nice changes.


I think it would be more akin to like the F-4J/S and MiG-23M in terms of performance. I don’t know exactly though. As for the countermeasures, in my opinion it would be a semihistorical thing where “it could technically happen” and would be more for gameplay reasons than any actual countermeasures. Kind of like how the F-5A/C get flares where the AN/ALE-40 was fitted on some jets but not others so they put it on all on a technicality.
If that doesn’t work they can make a separate JA37C/E and JA37C where the /E (Early) is the one that is in game right now and the just C (not early) version is the one that gets 9Ls and stuff.

The JA37D had a speciallised mounting point for the RB99 that had additional flares. So itd be similar to the gripen ig

I was specifically referring to the JA37C and how I think that if they move it up and give it better munitions, the space it is currently in would be a void. Which is why I was talking about the JA37 or JA37C/E, to fill that spot (basically the same as the one in game right now but with a new name), while the JA37C gets its 9Ls, and the JA37D gets its 9Ms and 120As.

or don’t give it a higher BR? i mean looking at how aim120’s perform it looks like it’s a slightly better sparrow.

the aim120 will definitely give a huge bump in performance since they don’t require a constant lock to fire, and can even be guided by the TWS mode. For the JA37D this would completely offset the current weakness of having to use Skyflashes as a primary weapon.

Then you don’t give it AMRAAMs, simple as.