investigating AIM-7 not guiding on launch ? - UPDATE WITH TRACK & TacView

[jojo]

I'm trying to have a little bit of fun on instant mission 8 Vs 8 on Caucasus.

 

At least half of my AIM-7 doesn't guide on launch, even with target at 12 o'clock and 10Nm and prior STT lock.

 

Am I the only one ?

 

Edit: https://we.tl/t-INeJOsfNTy

Edited March 3, 2021 by jojo
Added track & TacView

[pyhg]

I have the same problem I think.
I am repeating the Alert5 mission (from the Challenger campaign) to try and nail the issue.

Almost every single time I reproduce the same situation that looks really odd :

- I bug the frontmost Mig29 in TWS, from 30-35nm, crank a little bit right while closing in

- at around 10nm (but I have tried with other distances like 8nm, 6nm), I still have the bandit bugged and I placed it in the middle of my hud (so I confirm visually that the lock is on the right contact)

- I shoot an AIM-7, the radar switches to STT automatically

- the missile lofts, ok, but most of the time seems to take a flight path that completely ignores my lock

- when I replay in Tacview, it looks like the AIM-7 actually targets one of the Su-24s un behind the Mig29 I still have a solid lock on that Mig though !

- I tried shooting 4 missiles at different distances while keeping the lock : 11nm, 9nm, 7nm : last time, the one shot at 11nm and the one at 7nm when to the bandit, but the one in between flew completely off course (too high, and not in the right azimuth).

 

Since the AIM-7 is not an active missile, I do not get how it can pursue any target different from the one I lock.

In the tacview, it looks like the crazy AIM-7s really lock on the Su-24 (that I have never locked) : I can see the Su-24 manoeuvering, and the missiles adjusting their paths accordingly.

 

To me that looks really odd. I read the AIM-7 are retty unreliable, but here how can they target something I am not even illuminating ?

 

Note : I also tried to switching explicitely into STT manually (sensor switch right) prior to lauching the missiles (thinking maybe the automatic STT was happening too late after missile launch) ....not better

Edited March 2, 2021 by pyhg

[jojo]

I disable loft on AIM-7. It's doing more bad than good as far as I'm concerned.

[pyhg]

I will try again without loft. It was left on by default. But I remember doing the same tests a couple of times without the loft mode, and also switch the rcs to small. Both did not make much difference. I will try again. Judging by the trajectories on the tacview it really looks like the aim7s do as if I was locking a different bandit.

[pyhg]

It looks like all those 4 missiles (fired between 7 and 4 nm respectively) want is that Su-24 in the back ....

That Su-24 even chaffes, although I do not have any STT lock on him. The TD box is on the Mig29 and the MFD display clearly shows I am still locking him (speed, altitude, bearing....).

 

[jojo]

Radar missiles in DCS are eager for chaff, no matter what the range aspect. 

But yes, on that mission, I have a missile going dumb for no reason. Only saw in TacView. No chaff at all !

Edited March 2, 2021 by jojo

[ruddy122]

AIM-7 are finecky missiles

The planets have to align to get a perfect shot if your doing everything right

Eagle Dynamics did something to the AIM120C only to undo the update


Sent from my iPhone using Tapatalk

[jojo]

5 hours ago, ruddy122 said:

Eagle Dynamics did something to the AIM120C only to undo the update


Sent from my iPhone using Tapatalk

What are you talking about ?

[ruddy122]

Long ago like December 20 there was an Open Beta Update to make the missiles more realistic

The missiles were completely trashed

The next update fixed the AMRAAM


Sent from my iPhone using Tapatalk

[jojo]

https://we.tl/t-INeJOsfNTy

 

Here it is.

 

Alert 5 mission.

First one with LOFT option, second flight with LOFT disabled.

 

Both time STT lock before firing at 10Nm.

Both time the MiG-29 doesn't defend, it doesn't release any chaff at all and both time the AIM-7 goes chasing a Su-27 behind !!!

After a crank a,d recommit there is no doubt, the STT target was the MiG-29 

 

So it's beyond finicky... 

 

@pyhgYou were right 

 

PS: second time I had to stop because I lost picture in my Rift S headset. The cable is dead: if you're wondering...don't buy this headset !

Edited March 3, 2021 by jojo

[pyhg]

I think your explanation about chaff precedence explains exactly what is going on.

 

Clearly, it looks like as soon as some aircraft behind my locked target chaffes, the missile sees nothing but that remote chaff.

Which sounds a bit extreme since :

- that Su-24 is pretty far behind

- it is not really in the FOV of the missile (or the FOV is much greater than what I would expect ?)

 

If missiles are that much subject to 'remote chaffing', I do not really see the point of using them in this situation.

I would load only heat seeking missiles, fly fast, manoeuver to survive the merge, turn back and only shoot aim9s and guns. Which is what I end up doing.

Or fly towards my target with angles so that there is no other guy in the FOV background (e.g. fly low and pull up hard to shoot from below my target, with only skies in the background).

 

And if I were the attackers, I would always have a few guys in the background (5-6 nm behind) fully loaded with chaffs and chaffing everywhere (and call this tactic 'remote chaff screen').

 

I can't imagine Aim7s are that useless ...

 

I recorded a track yesterday, but used time acceleration so ... it replays realy wierdly.

Tracks are already not deterministic, and I read on the forum that time compression messes a lot.

 

I will try to do another one.

Anyway, I played yours and we are clearly talking about the same issue, thanks for the confirmation that I am not the only one seeing this @jojo

[pyhg]

I recorded a few tracks and tacviews, without any acceleration : https://we.tl/t-bNCZL2FiGK
When I replay the track, the outcome at some point is completely different from what happened in the actual flight, but I guess those are known issues with the replayability of the track recording system so we have to live with it ...

 

Anyway, before I get killed I can clearly see the missiles going in directions completely different from expected.
And the tacviews are even more explicit.

 

Interestingly, when I shoot 3 aim7s at the same locked target, quite often the first two are getting lost 'called' by the chaffs in the back, but the third one gets to the target.
As if after a few seconds the chaffs in the back are too old and thus ignored by a new missile launched.

 

Also, as visible in the tacviews (not in the track as the story ends too early due to replay issues), the aim-7s I shoot later in conditions, where all aircrafts are scattered in different bearings/ranges never suffer with this problem.

 

So it really feels like there is something strange when facing a group of aircrafts and some chaffing in the back.

Hence the idea to just avoid wasting missiles before the merge, hopefully pass the merge and then use even the aim7 after the merge ..... in that situation they work really well.

 

But is that the point of using aim7s ? Shouldn't we be able to kill some bandits before the merge with them ?

[BIGNEWY]

Track replays, replay inputs, AI can behave differently which can make it difficult to show an issue sometimes. 

 

If this is related to chaff I do already have a report in for the team. 

 

thank you

[pyhg]

Thanks for the feedback Bignewy. Yes it clearly looks related to chaff. Good to know that there is a known issue about chaff.

 

 

[dorianR666]

i confirm this problem

 

aim-7 is going for chaff that is completely off axis from the line to target. whats however interesting is that the target i shot at did NOT throw chaff, and the target nobody was shooting at DID throw chaff.

 

so this seems NOT to be problem with chaff, but with the missile genuinly guiding on a completely different target for some reason.

 

 

 

2 hours ago, BIGNEWY said:

Track replays, replay inputs

attached

i also attached tacview. you can see me shooting a second aim-7 afterwards - thats me shooting at the same exact target i was shooting the first aim-7 at, i didnt exit STT.

aim7_guidance_failure.trk Tacview-20210303-154843-DCS-Hornet 1989-Alert 5.zip.acmi

Edited March 3, 2021 by dorianR666

[dorianR666]

This puts Hornet in a very problematic state. Neither AMRAAMs nor Sparrows work right at the moment, so BVR is broken.

 

Hopefully the march update will address this.

[BIGNEWY]

7 minutes ago, dorianR666 said:

This puts Hornet in a very problematic state. Neither AMRAAMs nor Sparrows work right at the moment, so BVR is broken.

 

Hopefully the march update will address this.

 

BVR is not broken, you need to support your missiles until they go active, however we are working on coupled INS and DATA link improvements, please keep the bug report for data.

 

thanks

[jojo]

2 hours ago, BIGNEWY said:

 

BVR is not broken, you need to support your missiles until they go active, however we are working on coupled INS and DATA link improvements, please keep the bug report for data.

 

thanks

 

Even when supporting the AIM-120C until pitbull, sometimes it does strange things close to the target. It's most noticeable with AI on "Ace" level and pumping chaffs at maximum rate.

But I'll get back to you when I will have it on track. 
 

@dorianR666 Yes, it's the same case I submitted. The missile doesn't track the locked target. The locked target doesn't defend, the Su-24 which isn't locked is defending 

[pyhg]

Thanks for writing this dorianR666 : I was also exacty wondering why this one Su-24 is chaffing that much and the other aircrafts are not. The targeted Mig29 is not even chaffing in most of my tests.
I guess the Su-24's RWR is telling him there is a strong lock on him.
But why ? My STT is clearly not on him. My wingman maybe ? I did not clear him to engage though. The coincidence is troubling anyway as he chaffes right when I shoot.

 

Which makes me wonder if it is just a chaff issue ... or if somehow my radar is locking him along with my target (the Mig29) .... does that make any sense ?

The Aim7 is not active, so it is clearly not the missile that is showing up on his RWR, right ?

 

 

4 hours ago, dorianR666 said:

 

 

aim-7 is going for chaff that is completely off axis from the line to target. whats however interesting is that the target i shot at did NOT throw chaff, and the target nobody was shooting at DID throw chaff.

 

 

[BIGNEWY]

Hi all, 

 

We are going to need clearer examples to investigate this, I have attach a mission below, head to head with a group in Mig-29A's 

they are set to use chaff and flare, and use passive defence. 

 

Please use the mission to reproduce the issue and attach the track replays. 

 

thanks

AIM7TEST.miz

[Harker]

i confirm this problem
 
aim-7 is going for chaff that is completely off axis from the line to target. whats however interesting is that the target i shot at did NOT throw chaff, and the target nobody was shooting at DID throw chaff.
 
so this seems NOT to be problem with chaff, but with the missile genuinly guiding on a completely different target for some reason.
 

 
 
attached
i also attached tacview. you can see me shooting a second aim-7 afterwards - thats me shooting at the same exact target i was shooting the first aim-7 at, i didnt exit STT.
aim7_guidance_failure.trk Tacview-20210303-154843-DCS-Hornet 1989-Alert 5.zip.acmi

That should absolutely not be happening, unless DCS doesn't simulate a range gate at all.

[jojo]

1 hour ago, Harker said:

That should absolutely not be happening, unless DCS doesn't simulate a range gate at all.

 

And missiles shouldn't go for chaff behind a "hot" target if "speed gate" was used 

[Harker]

 
And missiles shouldn't go for chaff behind a "hot" target if "speed gate" was used 

Yeah, that's what I'm saying. Considering it's a SARH, I'd maybe understand if the guy behind was just a couple of miles off, but this wasn't the case here.

[pyhg]

I tried the mission AIM7TEST. Problem not reproduced : all my missiles go to my tracked target.

 

But in Tacview, I can see that none of the two background Mig29 ever chaffes ... so I do not see how this test is proving anything as far as chaffing is concerned.

 

Is there any way I can force one of them to chaff ? Should I lock the Mig29 in the middle for instance ? Or lock them alternatively ?

Tacview-20210304-082913-DCS-AIM7TEST.zip.acmi TestMission1.trk TestMission2.trk Tacview-20210304-083349-DCS-AIM7TEST.zip.acmi

[BIGNEWY]

strange they chaffed for me, will check the mission 

 

please try this one, chaff working for me on mig-29

 

2AIM7TEST.miz