AIM-54C vulnerability to chaff

I've been playing a mission over and over for the past few days. In the mission, the client is an F-14B engaging first 4 community A-4 Skyhawks, and a bit later there are 4 Su-33s. The AIM-54C is almost completely ineffective against the A-4s; if I fire off 4 at around 20-25 miles and ~ 20,000+ ft., if I am lucky 1 will hit a target. I've looked in track files and watched one follow the target (locked in STT in this case, but I usually do TWS), then spontaneously and violently veer of course.

As an experiment, tonight I removed all the chaff from the A-4s and tried again. Firing 4 missiles in similar conditions, I had 4 kills. I even managed to strafe the Su-33s on the ground as they were taxiing to the runway.

I'm not sure if there is something particular with my mission, or with the A-4 as a target, that influences this outcome. I do recall the most recent patch was supposed to make the AIM-54 more resistant to chaff and/or ECM. Maybe the small size, maybe smaller RCS of the A-4 makes it easier for the missile to go for chaff? Otherwise I don't see how it would ever be effective for the intended fleet defense purpose, in a presumably heavy ECM environment.

I'm aware there are issues with ED missile tracking, and I do see the missiles do the "weather-vane" behavior that I think corresponds to that issue. But they still hit the targets.

Is the behavior here normal and expected?

Normal for the AI. It always knows it has been launched upon (TWS or passive guidance doesn't matter). This it will proceed to launch CM immediately. As CM work as a simple probabilistic variable in programming, the more you launch them, the greater the chance at least one will spoof the missile.

big changes coming for missile guidance... new API is in the pipe, very soon, but ED time frames are not always ideal :)

"Soon"

the a seems more likely to chase chaff now than it did before aswell, only got a small sample size atm though.

ive never had 3 out of 3 missiles go after chaff before and that happened a few days ago

the a seems more likely to chase chaff now than it did before aswell, only got a small sample size atm though.

ive never had 3 out of 3 missiles go after chaff before and that happened a few days ago

That is interesting because the chaff resistence got increased by a factor of 10 (same as 120) in the game files. There probably is some code deeper down that we can't see though. Let's hope we can finally get the new guidence API implemeted fairly soon since we were supposed to get it around the same time last year...

We actually increased the chaff resistance for all 3 missiles to the value of the aim120charlie. So it is not possible that there is a difference between the 3 atm (this will get adjusted, the Charlie ofc is more resistant than the other two). That's likely just player perception.

We actually increased the chaff resistance for all 3 missiles to the value of the aim120charlie. So it is not possible that there is a difference between the 3 atm (this will get adjusted, the Charlie ofc is more resistant than the other two). That's likely just player perception.

I don't know man, I think there's more to CCM in DCS than just this one line (value). Me and others did several tests, and the ccm doesnt really seem any better than before, while the 120's is definitely a lot better now.

I don't know man, I think there's more to CCM in DCS than just this one line (value). Me and others did several tests, and the ccm doesnt really seem any better than before, while the 120's is definitely a lot better now.

I haven't seen more than 1 or 2 missiles going for chaff since the fix. (and it is the only value we can access btw). What is happening though is missiles losing lock during terminal phase much more, we noticed that, too.

It's not just "perception" - I have many tacview files for this mission. As long as the A-4s have chaff, my hit rate with AIM-54C is under 25% when launching from around <25 miles. The hit rate was 100% if I remove the opponent's chaff.

I don't know if this is due to some modeled behavior of which I am unaware, or an issue specific to the A-4, or a bug in ED's missile logic, or something else. But the behavior is 100% reproducible.

I can post a mission or tacview file if that is useful. (Is there a way to attach a file here?)

but ED time frames are not always ideal :)

Heh, understatement of the year. :thumbup:

We actually increased the chaff resistance for all 3 missiles to the value of the aim120charlie. So it is not possible that there is a difference between the 3 atm (this will get adjusted, the Charlie ofc is more resistant than the other two). That's likely just player perception.

MMm based on what? I mean, did you have motive to think the phoeninx should have the same chaff resistance of a much newer 120C missile?

I don't say it as questioning you, just wondering the thought principle followed. I guess the radar in the phoenix is bigger and more powerful in terms of antenna size and peak power, on the other hand I'd think that CM rejection techniques through Digital signal processing would be miles ahead in the aim120C vs the phoenix given it is a much newer design. But it is an interesting topic to me.

Based on waht Pepin? Your wealth of astoundingly comprehensive, accurate & concise contrary evidential data?

Oh, wait....

The 54C is all digital, its electronics can absolutely be compared to the 120, having more space for a more powerful processor and seeker. And again, the one line for the ccm value doesn't seem to have done much or anything after several hundreds tests. The new guidence, including terminal guidence and the notch gate should hopefully make this missile actually lethal. ;)

MMm based on what? I mean, did you have motive to think the phoeninx should have the same chaff resistance of a much newer 120C missile?

 

I don't say it as questioning you, just wondering the thought principle followed. I guess the radar in the phoenix is bigger and more powerful in terms of antenna size and peak power, on the other hand I'd think that CM rejection techniques through Digital signal processing would be miles ahead in the aim120C vs the phoenix given it is a much newer design. But it is an interesting topic to me.

There's enough literature and sources which state that any post 90's missile shouldn't really ever go for chaff at all. You think engineers would simply ignore the existence and efectiveness of chaff for many years without any counter? The same way modern fox two's ignore pretty much any amount of flares and DIRCM.

There's enough literature and sources which state that any post 90's missile shouldn't really ever go for chaff at all. You think engineers would simply ignore the existence and efectiveness of chaff for many years without any counter? The same way modern fox two's ignore pretty much any amount of flares and DIRCM.

Mmmm i don't think that is true at all. One thing, is that a modern missile could in theory and under ideal conditions discern between a chaff and a plane. And a different story is to think that chaff does not degrade missile effectivenes. In addition chaff stays in the air for a long time creating lots of noise and degrading the SNR of radars and SARH receivers. That is not simulated in DCS but should be a factor in real life.

You think engineers would simply ignore the existence and efectiveness of chaff for many years without any counter?

That is a strange point. Let me flip it to see where we arrive? XD

"Don't you think there are lots of engineers, just in a different building, trying to create more advanced chaffs, to sell it to whoever wants to buy that very same unspoofable missile? The marketing could be like this: Our missile is unspoofable... unless you use our new chaff...XD

Now, getting back to the real world, yeah, i'd imagine there are lots of engineers trying to solve the problem of a missile that cannot be defeated by chaffs... but that does not mean they have solved the problem right?

Mmmm i don't think that is true at all. One thing, is that a modern missile could in theory and under ideal conditions discern between a chaff and a plane. And a different story is to think that chaff does not degrade missile effectivenes. In addition chaff stays in the air for a long time creating lots of noise and degrading the SNR of radars and SARH receivers. That is not simulated in DCS but should be a factor in real life.

 

 

 

 

That is a strange point. Let me flip it to see where we arrive? XD

"Don't you think there are lots of engineers, just in a different building, trying to create more advanced chaffs, to sell it to whoever wants to buy that very same unspoofable missile? The marketing could be like this: Our missile is unspoofable... unless you use our new chaff...XD

 

Now, getting back to the real world, yeah, i'd imagine there are lots of engineers trying to solve the problem of a missile that cannot be defeated by chaffs... but that does not mean they have solved the problem right?

Chaff is a very simple, rudimentary countermeasure, literally pieces of aluminum or metal to reflect simple RF. Modern countermeasures are slmost purely based on EW/ECM or decoys. Chaff dates back to the 70's and 60's if not earlier.

We've already said the aim120c value was a stop gap measure, the values will be adjusted in the next patch.

Chaff, in case no one noticed, is super basic in DCS. These values are super basic and it is an approximation. It is very fair to compare aim120 seekers and phoenix seekers. Airhunter listed some good reasons for that.

However ofc the aim120c is better than the phoenixes, it is a much newer missile. But otoh the seeker technology is also not a quantum leap away from the phoenix.

Chaff and chaff resistance is a guesstimate for all missiles in DCS. And anyone who comes along here saying differently or that he knows how it should be, doesn't, because he didn't even understand this simple fact.

The new values will be set at 0.05 for the charlie and 0.06 for the As.

Thanks IronMike, i was not aware of the stop gap measure. Sounds right to me.

About the 120C, Chizh stated in the Russian forum that the AMRAAM is using a different, new chaff model, which is why simply cranking the ccm_k0 on missiles on the old model down isnt going to make it AIM-120 levels of ccm resistance. Im going to try and find the quote.

EDIT: Here it is

About the 120C, Chizh stated in the Russian forum that the AMRAAM is using a different, new chaff model, which is why simply cranking the ccm_k0 on missiles on the old model down isnt going to make it AIM-120 levels of ccm resistance. Im going to try and find the quote.

 

EDIT: Here it is

Chaff didnt change, but how seekers react to it, means the probability calculation as he says. We talked with Chizh of course before changing the values. But chaff is still the same as it was and the same for all missiles.

If it doesnt affect our missiles just yet as it should, it is likely due to the fact that the new API doesnt affect them yet either. We'll get there, I am sure.