Question regarding differences between 54A and 54C

[KlarSnow]

Command Inertial Active and Inertial Active is how the AMRAAM works, it is specific language to how the AMRAAM's operating concept works, it is not a term that is just thrown around.

Edited February 21, 2021 by KlarSnow

[Blaze1]

4 hours ago, captain_dalan said:

I can understand the tech, manufacturing and maintenance manuals, but user manuals? I mean, you can't actually build the missile or its components from one....

The user manuals are technical manuals and can describe functions and systems useful to an adversary, e.g operating frequencies, ECCM methods, sensitivity, fusing characteristics, seeker FoV etc.

[Blaze1]

16 hours ago, Naquaii said:

 

Well, yes and no. The AIM-7 is out of our hands as that's entirely ED. The AIM-54A we do have a bit of info on as that's what allowed us to implement what we have.

 

And I do agree that there needs to be a distinction between the -A and the -C, that's why we've been adamant that the -C need better chaff resistance. The fact that the AIM-54C is likely to have a lot in common with the early AIM-120c might mean that it can go active on its own but then again, it might not. We don't even know the reasoning behind the design of the seeker logic in the AIM-54A, just a bit of insight into how it actually did work.

 

When designing our AIM-54A we did so according to to the information we have and we're quite certain it's implemented according to that within the limitations of DCS. When implementing the -C we made the decision to make it work the same way as the -A but improve the chaff resistance (apart from rocket motor values). So in that way it's based on the information we have but improved slightly. To say that we should change the way it works because of a likely similarity to a later missile which we in itself do not know that much about to be fair, would be speculation.

 

What if the reason for the seeker active logic being the accuracy of the IFF and long range performance of the AWG-9? Maybe the -C even worked differently with the AN/APG-71? I'm not saying it did, but it might've.

 

In the end, I'm not saying that it couldn't go active without a command but I'm also not saying that it could. We've based our -C on our -A because that's the information we have and as it currently stands my opinion is that we do not have enough data on the missiles to make a change. I hope that do change but I'm not certain it will in the near future.

I completely understand yours/Heatblur's reluctance to simulate the -54C without hard data, however you could look at it both ways.  Considering you have no hard data, creating a -54C with slightly better chaff resistance, may be just as inaccurate as modelling a -54C based on the -120s guidance methodology.  So in a manner of speaking, this gives you a some freedom.

[Naquaii]

15 minutes ago, Blaze1 said:

I completely understand yours/Heatblur's reluctance to simulate the -54C without hard data, however you could look at it both ways.  Considering you have no hard data, creating a -54C with slightly better chaff resistance, may be just as inaccurate as modelling a -54C based on the -120s guidance methodology.  So in a manner of speaking, this gives you a some freedom.

 

I actually disagree. Because atm we model it off of the data we have on the -A but with logical improvements. Modelling it of off the -120 would be more speculative than what it is now. Even if I do agree with it not being implausible. You are kinda comparing the facts with have for the -A with a speculative connection to the -120.

 

If you look at the facts there really aren't much about the -C and it's -120 connection apart from speculations on forums and people making statements in articles.

[Blaze1]

I guess that's fair enough Naquaii.  I do understand your position.  Just to be clear, are you saying that you have no evidence of the -54C using command-inertial guidance or that you know it does, but don't really know what that means, that's to say, although it sounds the same, the basic guidance method could be very different from the AIM-120s?

[Skysurfer]

6 minutes ago, Blaze1 said:

I guess that's fair enough Naquaii.  I do understand your position.  Just to be clear, are you saying that you have no evidence of the -54C using command-inertial guidance or that you know it does, but don't really know what that means, that's to say, although it sounds the same, the basic guidance method could be very different from the AIM-120s?

 

Well, given simple physics and the limitations of chemical rocket motors there are only very few effective ways to guide an A2A missile - google proportional navigation if you want to find more. I think what they are saying is that apart from some articles, reports and SME mentions there are no actual, official documents to use as evidence. It's a fairly slipper slope, especially on the internet when you consider how much bs is out there ragerding other missiles. While, it makes sense that it behaves more like a 120C for various reasons, I dont think we'll get any factual, hard evidence for it anytime soon. Improving CCM alone by a good amount, making the guidence and especially de-loft more smooth and the INS more relaible will go a long way already when it comes to effectiveness of the C, regardless whether it goes active under STT or not. That is only a fairly minor aspect anyway when you think about the range advantage.

Edited February 21, 2021 by Skysurfer

[Blaze1]

I think Naquaii said it was a no-go from the SMEs, otherwise I assume they'd have implemented it.  Also what type of official documentation are we talking about and in what detail.  If for example a NAVAIR website mentions the -54C using command inertial guidance in some brief description of the weapon, would that be acceptable or are Heatblur looking for detailed technical reports specifically?

Edited February 21, 2021 by Blaze1
Clarity

[Naquaii]

47 minutes ago, Blaze1 said:

I guess that's fair enough Naquaii.  I do understand your position.  Just to be clear, are you saying that you have no evidence of the -54C using command-inertial guidance or that you know it does, but don't really know what that means, that's to say, although it sounds the same, the basic guidance method could be very different from the AIM-120s?

 

Yeah, that's more or less it. We don't really know what that means for the missile in DCS. Having command-intertial guidance does not automatically infer it should be able to go active on it's own. It could also have a lot in common with the AIM-120 in regards to hardware and software design and still work differently.

Edited February 21, 2021 by Naquaii

[Harker]

 
Yeah, that's more or less it. We don't really know what that means for the missile in DCS. Having command-intertial guidance does not automatically infer it should be able to go active on it's own. It could also have a lot in common with the AIM-120 in regards to hardware and software design and still work differently.

That's entirely possible. It's still an AIM-54 missile. Even if the guidance system and seeker are on par with early versions of the AIM-120, it could be that there are other limitations/considerations that never allowed the ability to go active on its own.

I recall reading somewhere that part of the reason why the Phoenix needs a command to go active, is the fact that it has such a long range, battery life, achieves such high speeds and has a large warhead. In the event that a target is lost early after launching, you don't want a missile with like that to go active on something random. It's dangerous enough with the much smaller AMRAAM, as IRL events have already shown.

I'm not saying that's the reason for the way it works, but it's food for thought.

[Blaze1]

9 minutes ago, Naquaii said:

 

Yeah, that's more or less it. We don't really know what that means for the missile in DCS. Having command-intertial guidance does not automatically infer it should be able to go active on it's own. It could also have a lot in common with the AIM-120 in regards to hardware and software design and still work differently.

 

I see.  If the issue was just about discovering (from official sources) whether the AIM-54C used command inertial guidance, then that's easy, the info is out there.  If finding out unequivocally whether the AWG-9 triggers the Phoenix's active radar, whether the missile does this autonomously or whether either could be the case depending on circumstance, is the unknown.

[GGTharos]

Switching to a digital platform is already a huge advantage - the missile can perform computations without being limited to programming via hardware changes.   This allows multiple and better mid-course guidance, which is why the 54C in considered to have better range capability for one.   A bunch of ECCM can be programmed in.  The digital INU increases accuracy, and command-inertial allows the missile to more effectively search and discriminate targets with the help of the data-link.  Like the 120, it may have included an MPRF active mode.

 

Being able to go active on its own - we don't know why it wasn't able to or it was chosen not to do it that way in the 54A to begin with.   Was the missile unable to measure distance in SARH mode?  That would be a huge weakness and is also unlikely since sparrow can do it just fine.  There is also the case that the missile would figure out frequencies to avoid interfering with the shooter's radar (clearly stated in the manual) and we know that this was negotiated with the radar in some way.   Leaving the active command to be sent by the radar may have been a way to allow the radar to include these frequencies into its ECCM plan until the missile would go active.

 

The 120 doesn't have this problem because it operates on a frequency at least 2GHz higher than the shooter's radar from what I've been able to gather.  Maybe the 54C's seeker would also be Ka/Ku-Band now, but we don't know.

9 minutes ago, Harker said:

In the event that a target is lost early after launching, you don't want a missile with like that to go active on something random.

 

You have the option to drop the track with the AWG-9, yes, but would you?   So without this action being taken, you're still at risk of hitting random things.

[Blaze1]

Interesting points GG.

[Skarp]

Could be too easy to beat the As radar than the Cs is the likely difference. The reason the C doesn't go active on its own is probably a good thing given how the TWS might not or does not correlate a lost track with a new track. So it will go pitbull miles away and probably kill some guy in a cessna.

[GGTharos]

There is no reason for the C not going active on its own other than 'we don't know that it does, and the A does not' - the DCS state of MP is not a consideration in its design.  There would be no random cessnas among the incoming bomber stream over the seas where this missile was designed to be used, so I doubt this was a consideration.

Edited February 21, 2021 by GGTharos

[Skysurfer]

Also, the argument for it not going active in STT but doing so in TWS (with even multiple missiles in the air) kinda defeats itself. Especially since you can control active distances with the target size switch. Just another grey-area I guess.

[Harker]

3 hours ago, GGTharos said:

You have the option to drop the track with the AWG-9, yes, but would you?   So without this action being taken, you're still at risk of hitting random things.

You have the option to drop it and ensure that the missile won't go active. Maybe you wouldn't drop the track in DCS, but RL doctrine could be different and maybe aircrews were not allowed to keep an uncorrelated track for more than X seconds before dropping it manually, exactly to make sure that the missile will not go active against a target it's not supposed to. You have the option of aborting the shot.

With an AMRAAM, you cannot do this, since the missile will go active by itself.

[GGTharos]

You're guessing at the doctrine to fit your own scenarios, which is my point.

Edited February 21, 2021 by GGTharos

[KlarSnow]

Yeah when designing a weapon system like this the links in the chain and implementation are there to get the missile to the target. There is little or no consideration for what if you shot at the wrong thing. Thats on aircrew/tactics to perform their IFF/ROE stuff before they pull the trigger, and thats why they go through training. It is not a consideration in employment or design of real air to air missiles of what if I shot the wrong thing. You should have figured that out before you shot the missile.

 

If trying to cancel a missile that was in the air was a consideration instead of all this wierd mechanical implementation, wouldn't they just put a giant ABORT MISSILE switch somewhere...... that doesnt exist on any of these systems... that should tell you that its not somethign they are "designed to do"

Edited February 21, 2021 by KlarSnow

[Grater Tovakia]

15 hours ago, captain_dalan said:

The wording of that snippet mostly makes me thing the improvements reflect the intent to use the missile against fighters in the future (solid state electronics, better reliability off the rails, better response during beaming scenarios), as for what exactly "active inertial" means..... i guess people that know aren't allowed to share. What makes me more puzzled though, is that after all these years, even the user manuals seam to be prohibited. I can understand the tech, manufacturing and maintenance manuals, but user manuals? I mean, you can't actually build the missile or its components from one....

IDK, mabye if a proper FOI request was filed the Navy would release them. Im not well read on how that process works though.

[Dragon1-1]

3 hours ago, KlarSnow said:

If trying to cancel a missile that was in the air was a consideration instead of all this wierd mechanical implementation, wouldn't they just put a giant ABORT MISSILE switch somewhere...... that doesnt exist on any of these systems... that should tell you that its not somethign they are "designed to do"

You have to consider the timeline on those systems. AIM-120A is 1991, AIM-54C 1986, and is derived from a missile originally fielded in 1974. Those are service entry dates, with development starting earlier. Either way, IFF had improved a lot between Phoenix and ARMAAM. Aborting a Sparrow is as easy as dropping the lock, and AIM-54A is the same. Perhaps when the AMRAAM was designed, they didn't think the ability to abort the missile was necessary, but that doesn't mean the same was also true earlier on, with less reliable IFF systems that were around when AIM-54C was designed.

[KlarSnow]

No, that is theorycrafting from a video game perspective a feature that you wish you had so fratting in a video game wouldn't happen or so you'd have an option to be more carefree with your shots.

 

IRL that is not how the thought process goes. It is hard enough to get the missile to get to the target on its own. The entire existence of the missile and the radar system is to get the missile to the target. The operator is supposed to be the QC that what they are shooting is the right thing, and then the missile gets there. There is no Abort missile option or thought process that goes into it. It doesn't exist on AMRAAM, it doesnt exist on sparrow, and it certainly didnt exist on the phoenix. if it was somethign they wanted, again with how complex this stuff and the mechanization is, they would not put it in some wierd use case scenario, it would just be an ABORT or SELF DESTRUCT button you could hit in the cockpit when your IFF return suddenly swapped. The solution to that problem is good employment, into a clear field of fire, not sloppy employment. Again this is not an issue nor a thing that aircrew have ever AFAIK wanted or asked for.

 

The common perception that you can "safely" fire a SARH missile into situations where an active missile might grab onto a friendly is flat out wrong, and is a common thought because of how they are mechanized in DCS, IRL you still would not want to shoot a SARH missile into a merge or into the near proximity of friendlies, it has about as much of a chance of guiding on a friendly as an active missile would, if not more. Locks can swap targets when jets are in close proximity, the radar beam is not a laser beam, it will be illuminating multiple things in close proximity. Active missiles can in fact be safer to shoot into those situations. The fact that you can cut the lock is also a simplification, what happens if you drop lock in the tomcat? It goes to flood mode, and if they are in your HUD theres a decent chance that missile might still get guided into something you dont want.

 

 

 

[nighthawk2174]

9 hours ago, GGTharos said:

There is no reason for the C not going active on its own other than 'we don't know that it does, and the A does not' - the DCS state of MP is not a consideration in its design.  There would be no random cessnas among the incoming bomber stream over the seas where this missile was designed to be used, so I doubt this was a consideration.

 

Yeah hence this thread I too see no reason the C can't go active on its own considering the similarities with the early amraam's.  

  

11 hours ago, Naquaii said:

 

Yeah, that's more or less it. We don't really know what that means for the missile in DCS. Having command-intertial guidance does not automatically infer it should be able to go active on it's own. It could also have a lot in common with the AIM-120 in regards to hardware and software design and still work differently.

 

I do have a question what's the name of the source that led to the current implementation?

Edited February 22, 2021 by nighthawk2174

[Csgo GE oh yeah]

9 hours ago, KlarSnow said:

No, that is theorycrafting from a video game perspective a feature that you wish you had so fratting in a video game wouldn't happen or so you'd have an option to be more carefree with your shots.

 

IRL that is not how the thought process goes. It is hard enough to get the missile to get to the target on its own. The entire existence of the missile and the radar system is to get the missile to the target. The operator is supposed to be the QC that what they are shooting is the right thing, and then the missile gets there. There is no Abort missile option or thought process that goes into it. It doesn't exist on AMRAAM, it doesnt exist on sparrow, and it certainly didnt exist on the phoenix. if it was somethign they wanted, again with how complex this stuff and the mechanization is, they would not put it in some wierd use case scenario, it would just be an ABORT or SELF DESTRUCT button you could hit in the cockpit when your IFF return suddenly swapped. The solution to that problem is good employment, into a clear field of fire, not sloppy employment. Again this is not an issue nor a thing that aircrew have ever AFAIK wanted or asked for.

 

The common perception that you can "safely" fire a SARH missile into situations where an active missile might grab onto a friendly is flat out wrong, and is a common thought because of how they are mechanized in DCS, IRL you still would not want to shoot a SARH missile into a merge or into the near proximity of friendlies, it has about as much of a chance of guiding on a friendly as an active missile would, if not more. Locks can swap targets when jets are in close proximity, the radar beam is not a laser beam, it will be illuminating multiple things in close proximity. Active missiles can in fact be safer to shoot into those situations. The fact that you can cut the lock is also a simplification, what happens if you drop lock in the tomcat? It goes to flood mode, and if they are in your HUD theres a decent chance that missile might still get guided into something you dont want.

 

 

 

You should be careful because it seems you're doing the exact same thing. (theory crafting)
You have no idea what weapon builders in the 80's were thinking, and you can't just 'assume' the phoenix worked exactly the same as an amraam because there is no '"giant abort button" . 



 

Edited February 22, 2021 by Csgo GE oh yeah

[near_blind]

13 minutes ago, Csgo GE oh yeah said:

You should be careful because it seems you're doing the exact same thing. (theory crafting)
You have no idea what weapon builders in the 80's were thinking, and you can't just 'assume' the phoenix worked exactly the same as an amraam because there is no '"giant abort button" . 

 

I think I'm going to lend more credence to the professional fighter crewmember who has is familiar with the doctrine and history of the AMRAAM because its part of their day job, over the internet poster who believes HB has designed the AIM-54 as part of a conspiracy to wreck their online K/D rate.

[Naquaii]

9 hours ago, nighthawk2174 said:

Yeah hence this thread I too see no reason the C can't go active on its own considering the similarities with the early amraam's.  

  

I do have a question what's the name of the source that led to the current implementation?

 

 

We have enough documentation to be pretty sure about our current -A implementation. This is why I'm much more willing to lean on the -C being similar to the -A than changing it because of supposed similarities with the -C.