DIRCM-equipped helicopters total immunity to IRIS-T SLM and a full 8-missile salvo is 100% defeated, contradicting the IRIS-T manufacturer's stated resistance to laser jamming and exceeding the physical capacity of a 2-turret jammer

Machinery of War Discussion Ground Vehicle
,
1

In the current build, helicopters fitted with a laser DIRCM (Mi-28NM’s L370V28-5L, Ka-52, Z-10ME, and other DIRCM-equipped helis) are effectively immune to the IRIS-T SLM. Firing a full salvo of 8 IRIS-T SLM at a single DIRCM helicopter results in all 8 missiles being defeated by the jammer. The target cannot be killed by the IRIS-T at all — regardless of salvo size, range, or aspect — which makes IIR SPAA worthless against these helicopters and is balance-breaking. This contradicts real-world performance on two independent counts.

1. Seeker resistance to laser jamming. The IRIS-T uses a high-resolution imaging infrared (IIR) seeker with real-time image processing. Unlike reticle/spin-scan seekers, which track a single hot point and can be spoofed by a modulated IR/laser source, an imaging seeker resolves the whole scene on a 2D focal-plane array and uses image processing to reject localized interference. The manufacturer, Diehl Defence, explicitly states the IRIS-T’s IIR seeker renders countermeasures including blinding lasers ineffective. To actually blind a modern IIR focal-plane array you must saturate or damage a large fraction of its pixels — that requires laser-weapon-class irradiance, not the low-power, SWaP-constrained jammers helicopters carry, which are optimized against legacy reticle-seeker MANPADS. (The Vitebsk “invincibility” claims come from live fire against Igla-type reticle seekers, not IIR missiles.) Published engineering analysis (SPIE) and NATO STO work both conclude imaging seekers are highly resistant to the laser-jamming techniques in question. The realistic effect of laser DIRCM on an IIR seeker is a reduced kill probability, not a guaranteed defeat.

2. Salvo saturation is physically impossible to counter at this scale. Even granting some degradation, a laser DIRCM must slew a narrow beam (the L370-5 jams within roughly a 7° cone) and hold it precisely on each incoming seeker. These helicopters carry only two jammer turrets, each with a limited field of regard. Two turrets cannot simultaneously hold a blinding beam on eight separate seekers arriving on the same axis. The current in-game result — 8/8 defeated — models the jammer as an omnidirectional, infinite-capacity device, which no real DIRCM is. Finite turret count, finite beam width, and finite slew rate mean real DIRCM is defeatable by salvo/volume fire and by engagement from aspects outside the jammer’s coverage.

Requested fix: model laser DIRCM as a probabilistic Pk-reduction system rather than binary IR immunity — a per-missile chance to break lock driven by beam-on-seeker dwell time, aspect, and range; a hard cap on how many simultaneous threats the two turrets can service; and no effect against missiles outside the jammer’s field of regard. This keeps DIRCM strong against single shots (the intended behavior) while making salvo fire and multi-axis engagement viable and restoring IIR SPAA as a counter.

Steps to reproduce:

  1. Take an IRIS-T SLM SPAA (test drive or Ground RB).
  2. Engage a DIRCM-equipped helicopter (Mi-28NM / Ka-52 / Z-10ME) within range.
  3. Fire a full 8-missile salvo at the single target.
  4. Observe all 8 missiles defeated by the DIRCM; the helicopter survives. Result is unchanged from any range or aspect.

Note re: prior ruling. This is aware of the earlier report closed as “intended” on the basis that laser IRCM is designed to blind IIR seekers. That ruling did not address (a) the IRIS-T manufacturer’s own published resistance spec, which directly speaks to laser jamming of this specific seeker, or (b) the salvo-saturation limit — a 2-turret jammer cannot service an 8-missile salvo regardless of per-missile effectiveness. Both points stand independently of the contested question of whether a single laser can degrade a single IIR seeker.

Sources

  • Diehl Defence brochure (manufacturer spec on IIR laser-jam resistance): https://www.diehl.com/cms/files/Diehl_Defence_Broschüre2018_en.pdf
  • Saab IRIS-T page / Army Recognition IRIS-T SL: the “rendering countermeasures, including blinding lasers, ineffective” line.
  • SPIE — IR imaging seekers’ resistance to laser jamming: https://spie.org/news/5614-ir-imaging-seekers-may-be-very-resistant-to-laser-jamming
  • NATO STO SCI-192, “Infrared Countermeasure Techniques Against Imaging Seekers.”
  • Northrop Grumman AN/AAQ-24 DIRCM video — shows the single-beam, one-threat-at-a-time tracking mechanism (supports the saturation point).
  • TWZ on the Mi-28NM L370V28-5L DIRCM, and Key.Aero on the L370-5 7° jamming cone / two-turret layout.
13 Likes
2

image

10 Likes
3

3. The IRIS-T SLM uses INS + radar datalink midcourse guidance; the IR seeker is only active in the terminal phase. Per Gaijin’s own IRIS-T SLM development article, mid-course guidance is inertial with datalink updates, and the missile only switches to IR seeker tracking on approach to the target. The laser DIRCM can therefore only affect the final terminal seconds — the missile is flown to close proximity by radar/INS regardless of any IR jamming. With a proximity-fuzed fragmentation warhead, a seeker jam in the terminal phase should at worst degrade a direct hit into a proximity detonation with fragmentation damage, not produce a clean miss and zero damage to the target. The current behavior models the missile as a pure IR-homer that goes ballistic the moment the seeker is jammed, which contradicts the documented guidance architecture.

Additionally, a terminal-phase IR jam should not zero the missile’s guidance: it retains INS/datalink midcourse to the intercept basket and a proximity fuze, so a jammed seeker should still produce a proximity detonation and fragmentation damage at close range rather than a clean miss.

War Thunder official development blog, “IRIS-T SLM and Multi-Vehicle SAM Systems” — Gaijin’s own description of the INS + datalink midcourse / terminal IR architecture: https://warthunder.com/en/news/9529-development-iris-t-slm-and-multi-vehicle-sam-systems-en

1 Like
4

any LDIRCM nerf is good for me

1 Like
6

this post will be closed becaused is a repeted one

7

LDIRCM its not even suppossed to defeat 5th gen missiles like aim9x. Its just for manpads.

8

holy title stretching bro.
you couldve just said “inaccuracies of DIRCM against IRIS-T SLM”

9

image

12

AI title duh, didn’t even put any effort into it himself

1 Like
13

If you are going to rant , at least pour some real soul into it, not AI slop.

1 Like
14

The entire way the LDIRCM works is wrong in WT.
So, Mi28 somehow manages to sway the missile away from the chopper which actually doesn’t work, for the same reason why the Stinger in WT has a completely wrong flare rejection mechanism.
IRIST, like any other multichannel missile, works in multiple (two) channels. In this particular case it’s MWIR (3-5um) and LWIR (10.2um). MWIR locks on engine exhaust and the LWIR locks on the airframe. When target flares, IRIST compares MWIR and LWIR images and if both match, switches targets and if not rejects flare. Since flare can mimic engine exhaust, it’s relatively easy for the flare to force switch, but when it comes to LWIR target “picture”, that can’t really be done, which is why IIRs are notoriously difficult, practically impossible to flare.
This is why DIRCM has been developed and the whole idea is, if we already can’t jam the missile, let’s kill its guidance and that’s what LDIRCM like President from Mi28 does and this is where the problem lies.
So, in the most basic way, the way the LDIRCM works is it projects a laser beam into the missile’s seeker (FPA) hopefully causing energy spillage outside FPA elements (pixels) and so the missile gets blinded. This works great for the single channel (MWIR) IR missiles like AIM9 eg, but multichannel IIR (MWIR/LWIR) missiles like IRST, 9X, etc, are entirely different story.
Now for the IIR missile’s CCM. If the LDIRCM’s power is insufficient to flood the entire portion of the FPA that is used for tracking the target, ie. there’s enough margin on the seeker’s matrix to maintain the LWIR shape of the target, the missile maintains the guiding and the jammer actually becomes a beacon (HOJ). However, if the LDIRCM is powerful enough to cause the energy spillage out of target’s pixels (at closer ranges), thus turning the LWIR shape into a blob, or outright fries FPA lines, the missile instantly goes into INS (+DL if available), as it knows it’s been jammed/attacked.

The problem is, in WT, the missiles fly away from the Mi28/Z10/64E/whatever that has DIRCM and wander around, while the moment IRIST’s MWIR/LWIR pictures cease to match it should instantly go INS and detonate with as much error as the inbuilt INS+DL allow.
Now, some calculations show that if President on Mi28, indeed, has 200W laser, it can fry IRIST’s FPA at about 1-1.5km from the chopper. However, this is 1.5-2sec missile’s flight time on INS, so the ability for a chopper to move out of lethal blast radius is limited, particularly if it’s hovering like in game players usually do.

The fix is trivial as all that needs to be done is to ascertain IRIST’s INS drift and assign it to the missile, after which the missile detonates and the game determines effects and damage as per usual.

1 Like
15

Pointless lines of text, if you’re going to make the IRIS-T completely immume to LDIRCM, I won’t be there for it, but if you make it balanced, including against aircraft adn non LDIRCM helis then hmu.

Also IRIS-T keeps receiving DL while in track mode
IIR SAM/AAM missile are not even modeled

16

But it’s not immune. It loses tracking in the space before impact if/when LDIRCM manages to blind/fry the FPA. This is how system works. Also, if you actually fly the chopper and use terrain masking you should be fine. People hovering above the chopper airfield unloading and repeating while immune to everything is just laughably stupid and in the end, doesn’t work like that, at all. If something is in game, it should, at least somewhat, work like the actual counterpart, IMO.

Anyway, I just dropped this here so that ppl have some clue of why they get slaughtered by DIRCM choppers and why they can’t kill them and that the fix is really easy to do. It actually took more head gymnastics for GJ to do what they did, instead of making thing work like it actually works.

17

Yeah no, as a non LDIRCM helicopter you literally got no ways to actually defeat any IIR spaa.


All you can do right now is fire rockets or agm’s, which is a bug according to devs.

Why do you always talk in the third person?

18

Then such choppers should be put into separate brackets, IDK…I mean, why do you ask me that?
Was it me who put IRIST into the game, or was it GJ without any consideration how it’d affect the gameplay?
They did the same thing with Brimstone, btw.
I’m just saying how it works actually and how it works in game.
So, while your question is valid, it’s addressed at a wrong address.

…and crying about “balance”…
in GSB, IRIST runs a 30.2%WR and 0.87 kill ratio (GRB - 40%/1.33), while Mi28MN runs 71.7% WR with a 2.48 kill ratio (GRB - 60.6%/2.78) in 3 times more games (GRB about twice the games). I’d say there’s a lotsa room for “improvement” of IRIST, even from a balancing perspective, if you just won’t model it as it actually works, already.

19

“We clearly believe this is a marketing lie.”

20

Volunteer #1 added “not a bug” label
Volunteer #1 closed issue 16 minutes ago
Volunteer #1 closed comments 16 minutes ago

2 Likes