AIM-120B (somehow) actively searches and destroys incoming A2A missiles

[Cmptohocah]

Looks like the AMRAAM got a new role as a search and destroy weapon not only for aircraft but for missiles too.

 

Scenario #1:

1. AIM-120B is fired at a distance of around 25.5km from the target and soon after the launching platform (F/A-18) breaks TWS [fig. 1-1]. The AMRAAM initially goes towards me [fig. 1-2], but then at some point it decides that my ET is a juicier target [fig. 1-3]. It successfully tracks and destroys my R-27ET [fig. 1-4]: "Splash one."

Fig. 1-1

 

Fig. 1-2

 

Fig. 1-3

 

Fig. 1-4

 

Scenario #2:

Very similar to the previous case where the F/A-18 turns away very soon after AIM-120B get fired, but this time there is a larger height difference and the AMRAAM goes for a loft. Then it "zooms" down to my R-77.

 

 

Edited January 7 by Cmptohocah

[QuiGon]

Hasn't it always been like that? You can look up DCS videos on youtube of missiles interceoting other missiles from years ago. I've seen that happening myself a few times.

[dundun92]

What QuiGon said is correct, but I must add, you will be seeing this more often than before. The reason is that AMRAAMs, if the lock is dropped before active, no longer only go after the original target with the old magical ±60° FoV. Now, with the realistic updates, unsupported AMRAAMs have a) a much smaller either 15° or ±15° FoV (not sure which one it was), and b) will lock the first target that it finds, as it essentially goes maddog if unsupported, as it should. The biggest issue here is how far it can detect and AAM, it shouldnt be seeing AAMs at the full 15km. But again, this is a universal simplification for all ARH missiles (R-77/SD-10 included), target RCS doesnt matter, so this isnt an AMRAAM OP kinda thing, this is just how ARH in DCS works.

[Cmptohocah]

37 minutes ago, dundun92 said:

What QuiGon said is correct, but I must add, you will be seeing this more often than before. The reason is that AMRAAMs, if the lock is dropped before active, no longer only go after the original target with the old magical ±60° FoV. Now, with the realistic updates, unsupported AMRAAMs have a) a much smaller either 15° or ±15° FoV (not sure which one it was), and b) will lock the first target that it finds, as it essentially goes maddog if unsupported, as it should. The biggest issue here is how far it can detect and AAM, it shouldnt be seeing AAMs at the full 15km. But again, this is a universal simplification for all ARH missiles (R-77/SD-10 included), target RCS doesnt matter, so this isnt an AMRAAM OP kinda thing, this is just how ARH in DCS works.

 

1 hour ago, QuiGon said:

Hasn't it always been like that? You can look up DCS videos on youtube of missiles interceoting other missiles from years ago. I've seen that happening myself a few times.

My problem is that is not tracking the missile per se, although as you have mentioned it's highly questionable, but that it's switching from the original target it acquired to a missile that is outside its FOV. In particular in the second scenario, what magic is used to find my incoming missile? It lofts high as it's trying to gain on me, I presume, and then it climbs down almost vertically to an incoming missile.

Same thing, in the first scenario. Goes for the target but intercepts something else that is not even in it's FOV. Or does AIM-120B track and search for new targets simultaneously?

This is not unrealistic, this is a joke.

 

The DCS manual should be updated saying: "When facing an opponent, make sure you fire at least 3 AIM-120s: 1 for the opponent, and 2 for the opponents incoming missiles - just in case."

[dundun92]

2 hours ago, Cmptohocah said:

but that it's switching from the original target it acquired to a missile that is outside its FOV.

 

The thing is, an unsupported AMRAAM, as of the last couple patches, has no clue what an "original target" is, and it shouldnt without appropriate radar support. It looks like the AMRAAM was tracking you initially, but it wasnt, it was simply using the 5(?) seconds of onboard autopilot/memory mode extrapolation of the last known datalink signal. But it went after the first target it saw with its own radar; the AMRAAM never saw you. Whats questionable here isnt the root behavior per se, its the fact that it can magically see an AAM at 15km.

Also, IRL im sure the missile, based on the last known datalink position, would probably know not to go for another target 11° away and much closer than the last known position, the target simply couldnt have moved that far in those few seconds. But until we see a fully modeled INS/Datalink interaction thats not happening, and it still wont fix the problem entirely until RCS affects ARH detection range.

 

Edited January 7 by dundun92

[GGTharos]

On 1/7/2021 at 3:45 PM, dundun92 said:

The thing is, an unsupported AMRAAM, as of the last couple patches, has no clue what an "original target" is, and it shouldnt without appropriate radar support. It looks like the AMRAAM was tracking you initially, but it wasnt, it was simply using the 5(?) seconds of onboard autopilot/memory mode extrapolation of the last known datalink signal. But it went after the first target it saw with its own radar; the AMRAAM never saw you. Whats questionable here isnt the root behavior per se, its the fact that it can magically see an AAM at 15km.

 

What's more questionable is that it didn't perform a search to pick up a target that best matches the last known doppler shift - ie. the target is not speed-gated.  Either way I would expect the missile to be well out of this since it wasn't the original target, even if the doppler gate was thrown wide open.

 

 

On 1/7/2021 at 3:45 PM, dundun92 said:

Also, IRL im sure the missile, based on the last known datalink position, would probably know not to go for another target 11° away and much closer than the last known position, the target simply couldnt have moved that far in those few seconds. But until we see a fully modeled INS/Datalink interaction thats not happening, and it still wont fix the problem entirely until RCS affects ARH detection range.

 

 

 

I would not mind an additional range gate as well ... all of this stuff serves to ensure that the missile takes care to select the right target as much as possible.