DCS: F-14 Development Update - AIM-54 Phoenix Improvements & Overhaul - Guided Discussion

[Gareth Barry]

Yeah but that doesnt really contradict what Karon was saying- the budget allowed for either aim 120 or lantirn, not both. Going lantirn gave the tomcat at least another 10 years of life- going the other way round would have led to an even earlier retirement.

[Machalot]

On 11/23/2024 at 4:34 PM, Katsu said:

new corrections were made according to the NASA simulations we saw earlier in this thread, making the missile perhaps more realistic. However, after the adjustments that brought the missile closer to the NASA documents, more and more adjustments were made, reducing the missile's thrust to the point where NASA's own study was no longer valid.

These later adjustments were made on a “trust me, bro” basis, with no public data available for validation. 

This is not how I remember it. What I remember is that based on a new source, they adjusted the overperforming motor down to make it mortal, got the two motors to match total impulse, and gave them slightly different burn times. Then Klarsnow commented how well the DCS Phoenix matches that NASA study even though they never attempted to do so (I suspect they both used the same source).  I don't know of any further changes. Was that discussed in this thread? I've tried to keep up but it's been going a very long time. 

Edited November 28, 2024 by Machalot

[WarthogOsl]

On 11/24/2024 at 12:38 PM, TomcatFan1976 said:

Actually the AIM-120 testing was changed to the lantern due to Dale Snodgrass and his team presenting it to congress that the Tomcat had the Phoenix and didn't need the AIM-120 so they spent the money on making it the Bombcat with the lantern capabilities. I can't find the video right now of him describing the plan, It was in the Tomcat Tales on YouTube. it wasn't cause of money constraints and cuts, they were going to ungrade to AIM-120, but took that money for bombing capabilities....

I think the deal was, after the (first?) Gulf War, they realized that the Tomcat just wasn't getting tasked for it's primary role of air-to-air (for a variety of reasons).  I think Snort's reasoning was that taking on the air to ground role with LANTIRN gave the F-14 continued relevance, and more chance to continue in service than if it had stayed primarily air to air with the AMRAAM.

Edited November 28, 2024 by WarthogOsl

[tavarish palkovnik]

12 hours ago, Machalot said:

…is that based on a new source, they adjusted the overperforming motor down to make it mortal, got the two motors to match total impulse, and gave them slightly different burn times. 

I do believe all that was done with good intentions, but from some reason something happened, either accidental error in calculation of theirs, wrong reading of sources or just simply not understanding of principles. And Frankenstein of motor (motors in their case) appeared and flooded internet.

Reverse engineering of motors with significant lack of inputs is not easy, luckily here we managed to collect so many so valuable stuffs that final touch was not problematic. It took lot of time, lot of from today’s perspective wasted attempts to figure it out what is inside, but at the end everything just settled on their place.

Russian motors of air-to-air missiles are so much easier to understand and to make reverse engineering, literally there are only three propellant grain configurations used, internally/externally burning cylinder, internally burning star and classic finocyl…and Americans oppositely had/have variety of sometimes abstractive shapes and geometrical acrobatics from who knows what reason 

 

Administration…this is my graphic, so please don’t add extra warning points or ban actions

Anyway, Americans practiced so many various shapes resulting with various motor’s outputs and even here in these radial crosscuts Phoenix just pokes eyes in extra. Simply this motor is unique in several characteristics so it’s not surprising if mistakes happens when trying to understand it

[Katsu]

On 11/24/2024 at 2:59 PM, tavarish palkovnik said:

@Katsu

Russian reverse engineering delusion they said  Where it was, why you didn’t call me to participate in that nice conversation 

Internet is such a great thing, so many valuable things you can find and learn on it (in my time I had to go in library and wait my time to get a books when return from others), but like in wrongly “used” democracy where everyone has rights to “open mouth” , also so many rubbish, unfortunately rubbish long time ago overtook it. I like your point, the one when having no solid answers in written form, to find it using same principles used by developers of that thing of interest, in this case rocket motor. Although rocket motors are not simple to understand, still everything inside of it are just simple physical processes…fun fact…those are same on east and on west 

Indeed I use some formulas described by one Russian scientist long time ago, before these guys called that as delusion, most probably haven’t been born. 
I was reading recently Warthunder forum, mostly same discussion about Phoenix and motor particularly because motors are of highest interest of mine. There were some good things to read there…unfortunately I was not able to write there because that forum is just for those playing that game  …but also so many…hmmm…how to say and to be polite.

Few weeks it’s silence there, and they have been so close to figure it out. Of course, over there is like you described, discussion between developers “fan club” and those who questioning  One guy was so close, it was topic for who knows how many times started and never ended, specific impulse of motor…and on literally next page from literature he shared everything is crystal clear, how specific impulse is changing with altitude, pressures and nozzle expansion ratio…but fan club concluded…it is same old motor like early Mk36 of Sidewinder and old motors are…just old  and having low specific impulse of something about 230s or 240s…OMG 

Fun fact again…even propellant in historically old HVAR rocket had 235s impulse, but propellant useless for wide temperature range. What I want to say…actually I will not…it can’t be said shortly and there are so many variables.

Phoenix…why it’s vanished…because war theater (threat) is changed. One of primary tasks of Phoenix was fighting fast flying high altitude targets no other missile can reach (Phoenix was designed that way to have such possibilities…nozzle expansion ratio etc etc) but low flying cruise missiles also appeared, local conflicts with targets of different kinds…Phoenix became unnecessary assets…of course traditional American sense of business made its job as well 

So, no matter of anything, Phoenix deserves truth. This motor although I’m not huge fan of American principles of building rocket motors is actually really nice piece of work 

 

In fact it was becoming just more like intimidation based on an appeal to authority and ironies and not a healthy discussion, so I decided that it wouldn't be worth my time anymore to keep trying to argue anything  

But if you want to stir up the hornet's nest, they're there on developers Discord, but don't question where the data comes from 

Well, I think there's not much more to be done here, you've done everything and delivered valuable research that can help them, if I ever find more sources I'll post it here just like I posted earlier about the publicly released average of the missile's total thrust. 

It's up to them to continue not being transparent about the data, or to present something else that can prove the current state of the missile is correct and everything presented here is incorrect, I think it's the least that can be done.

When that's proven, I'll shut up, admit that I was wrong and I apologize because this is what you expect when you learn something. 

 impulse modulation may not even be corrected but total impulse can be corrected independently of these other factors.  

But I believe that nothing will be corrected just as it hasn't been during these almost 6 years of many inconsistencies, always blamed on other factors such as (AI, API, even lack of player skill ), but now here we're not talking about other factors, we're talking about the total impulse that the missile is missing. 

Regardless, I wish everyone the best.

Just to be clear for who dont know what is happening and why a 2 years olds topic is still alive:

This is the actual impulse of the missile in game: 



Here are 2 sources talking about total missile impulse: 

And here we have a complete study of the engine's propulsion based on the original engine blueprint showing that both thrust and burn time are probably modeled incorrectly in game: 

All credits to: @tavarish palkovnik

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Full study can be found earlier in this thread searching for Tavarish posts.

Edited November 29, 2024 by Katsu

[DSplayer]

3 hours ago, Katsu said:

Here are 2 sources talking about total missile impulse: 

 

Those images are from the same source (the Outsiders thesis) and that source document specifically discusses the information provided/cited could be invalid:
 

Spoiler

I would not take the information taken from that document as the definitive final word on what the motor performance of the AIM-54 should be.

[Katsu]

7 hours ago, DSplayer said:

would not take the information taken from that document as the definitive final word on what the motor performance of the AIM-54 should be.

Yes, the same sourced used to took that “validation” shot mentioned as a performance validation metric earlier in this topic.

So the "validation shot" used by developer shouldn't be taken into consideration, since they come from the same source, right? 

Spoiler

null

In this case, as I mentioned above, as there is no consistency in the data (where many can be altered by psyops) the best way is to use calculations based on engine studies to check the approximate thrust. 

Edited November 29, 2024 by Katsu

[DSplayer]

59 minutes ago, Katsu said:

Yes, the same sourced used to took that “validation” shot mentioned as a performance validation metric earlier in this topic.

So the "validation shot" used by developer shouldn't be taken into consideration, since they come from the same source, right? 

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In this case, as I mentioned above, as there is no consistency in the data (where many can be altered by psyops) the best way is to use calculations based on engine studies to check the approximate thrust. 

If you were to use the motor info that you highlighted from the Outsiders document, you wouldn’t get an accurate simulation of that AIM-54 test shot.

[Katsu]

24 minutes ago, DSplayer said:

If you were to use the motor info that you highlighted from the Outsiders document, you wouldn’t get an accurate simulation of that AIM-54 test shot.

Yes, that's what we've been talking about all along here

The document contradicts itself, so there's no reliable source of information, since the same information is in the same document.

If we even take NASA's simulations into account, the game's performance doesn't match up.
 

Spoiler

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So there's no way of validating that the missile today is correct.

Unless you choose one of these sources and supposedly assume that one source that is part of the same document is correct and another is not. 

(In our case it seems that the developer chose to assume as correct the source where the missile showed the lowest performance) 

And then we understand the importance of Tavarish's work in this study , because it eliminates much of the guesswork and turns it into something scientifically valid. 

[DSplayer]

19 minutes ago, Katsu said:

Yes, that's what we've been talking about all along here

The document contradicts itself, so there's no reliable source of information, since the same information is in the same document.

If we even take NASA's simulations into account, the game's performance doesn't match up.
 

  Hide contents

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So there's no way of validating that the missile today is correct.

Unless you choose one of these sources and supposedly assume that one source that is part of the same document is correct and another is not. 

(In our case it seems that the developer chose to assume as correct the source where the missile showed the lowest performance) 

And then we understand the importance of Tavarish's work in this study , because it eliminates much of the guesswork and turns it into something scientifically valid. 

It is possible for the AIM-54 tests in DCS to match or get close to the NASA simulations: 

 

[Naquaii]

14 hours ago, Katsu said:

In fact it was becoming just more like intimidation based on an appeal to authority and ironies and not a healthy discussion, so I decided that it wouldn't be worth my time anymore to keep trying to argue anything  

But if you want to stir up the hornet's nest, they're there on developers Discord, but don't question where the data comes from 

Well, I think there's not much more to be done here, you've done everything and delivered valuable research that can help them, if I ever find more sources I'll post it here just like I posted earlier about the publicly released average of the missile's total thrust. 

It's up to them to continue not being transparent about the data, or to present something else that can prove the current state of the missile is correct and everything presented here is incorrect, I think it's the least that can be done.

When that's proven, I'll shut up, admit that I was wrong and I apologize because this is what you expect when you learn something. 

 impulse modulation may not even be corrected but total impulse can be corrected independently of these other factors.  

But I believe that nothing will be corrected just as it hasn't been during these almost 6 years of many inconsistencies, always blamed on other factors such as (AI, API, even lack of player skill ), but now here we're not talking about other factors, we're talking about the total impulse that the missile is missing. 

Regardless, I wish everyone the best.

Our answers aren't different on the Discord than they are here but it all still boils down to the fact that there hasn't really been anything new presented.

I've said it before that it's not about wether we believe the math presented here is correct or not but rather that we have data we trust more than those that what you guys present here is based on and the fact that those match available real test data also kinda reinforces that. Digging deeper into the equations and data here doesn't really change those facts.

We still believe the current missile in DCS is as kinematically correct as we can make it atm, unfortunately a large part of the guidance and seeker modelling is out of our hands and that's what we would like to improve as it currently stands.

You're ofc free to continue discussing this here but as it stands we don't really have anything much to add here from our side.

Edited November 29, 2024 by Naquaii

[Katsu]

48 minutes ago, DSplayer said:

It is possible for the AIM-54 tests in DCS to match or get close to the NASA simulations: 

 

 

Try reproduce this one then please:







This is the only simulation in which the altitude chart is also provided, making it the most accurate way of validating both speed and altitude and the interference of atmospheric density.

Edited November 29, 2024 by Katsu

[DSplayer]

39 minutes ago, Katsu said:

 

Try reproduce this one then please:







This is the only simulation in which the altitude chart is also provided, making it the most accurate way of validating both speed and altitude and the interference of atmospheric density.

Can you send the entire paper? I no longer have that entire document and I would like to double check it.

[Katsu]

40 minutes ago, DSplayer said:

Can you send the entire paper? I no longer have that entire document and I would like to double check it.

Here it is, it's part of a larger document but the part that focuses on Phoenix is this one: 
 

[Katsu]

2 hours ago, Naquaii said:

Our answers aren't different on the Discord than they are here but it all still boils down to the fact that there hasn't really been anything new presented.

I've said it before that it's not about wether we believe the math presented here is correct or not but rather that we have data we trust more than those that what you guys present here is based on and the fact that those match available real test data also kinda reinforces that. Digging deeper into the equations and data here doesn't really change those facts.

We still believe the current missile in DCS is as kinematically correct as we can make it atm, unfortunately a large part of the guidance and seeker modelling is out of our hands and that's what we would like to improve as it currently stands.

You're ofc free to continue discussing this here but as it stands we don't really have anything much to add here from our side.

Understood Naquaii, in fact in this you are right the answer has not changed.

You have a representation of a missile that you say is correct, a whole theory has been presented here contesting this, and zero technical answers because yours is more accurate simply “because yes”

The theory applied here is the same source of correction for other DCS weapons such as HARM, Hellfire and some others

But being honest with yourself, which do you think I'm going to believe? a study where formulas and data can be validated or just you saying that yours is right and that's that? In fact, all this would have been much more transparent if it had been disclosed how you came to the conclusion that yours is right.

And I even accepted all this since there was no way to contest it: 


But now there is and as I said, I will continue to think that yours is wrong, until proven otherwise, which for me is no problem, I have no problem assuming that I was wrong and learning from it, as I said I am here looking for the truth (or something closer to it) the world is moved by people who question and who simply do not accept that this is the way it is because it is.

Edited November 29, 2024 by Katsu

[Naquaii]

23 minutes ago, Katsu said:

Understood Naquaii, in fact in this you are right the answer has not changed.

You have a representation of a missile that you say is correct, a whole theory has been presented here contesting this, and zero technical answers because yours is more accurate simply “because yes”

The theory applied here is the same source of correction for other DCS weapons such as HARM, Hellfire and some others

But being honest with yourself, which do you think I'm going to believe? a study where formulas and data can be validated or just you saying that yours is right and that's that? In fact, all this would have been much more transparent if it had been disclosed how you came to the conclusion that yours is right.

And I even accepted all this since there was no way to contest it: 


But now there is and as I said, I will continue to think that yours is wrong, until proven otherwise, which for me is no problem, I have no problem assuming that I was wrong and learning from it, as I said I am here looking for the truth (or something closer to it) the world is moved by people who question and who simply do not accept that this is the way it is because it is.

The fact that you guys present your viewpoint here with data built from calculations and study of data doesn't change the fact that the data you built it on might not be entirely correct. The calculations can only be as good as the data it's built on. So the simple fact that calculations and science is used to arrive at this conclusion doesn't outright make it better than other data. In general it's a good thing to look at where the data is from and during what timeframe, if it's openly available and from a point in time where the real data would be classified you can be quite sure that it will not be entirely accurate or even intentionally fudged as to not reveal the real data.

And yes, we have other data which we value as more accurate than what is presented here, which we at this time aren't willing to share due to various reasons. It is how it is and by far not the only thing modelled in DCS that is based on data not available to the end users.

Continueing to argue your point won't change our stance on this unless you provide new sources of information, but like I said you're free to do so just don't expect us to be a part of the discussion that much.

Edited November 29, 2024 by Naquaii

[draconus]

Btw, I simply asked ED about it and they say they plan to take on AIM-54 at some point.

 

[TomcatFan1976]

I just want the dang thing to track, right now it doesn't track anything

[Nealius]

9 hours ago, Naquaii said:

The fact that you guys present your viewpoint here with data built from calculations and study of data doesn't change the fact that the data you built it on might not be entirely correct. The calculations can only be as good as the data it's built on. So the simple fact that calculations and science is used to arrive at this conclusion doesn't outright make it better than other data. In general it's a good thing to look at where the data is from and during what timeframe, if it's openly available and from a point in time where the real data would be classified you can be quite sure that it will not be entirely accurate or even intentionally fudged as to not reveal the real data.

And yes, we have other data which we value as more accurate than what is presented here, which we at this time aren't willing to share due to various reasons. It is how it is and by far not the only thing modelled in DCS that is based on data not available to the end users.

Essentially, any effort by the users to discuss or fix any potential or perceived issues is absolutely pointless because it can be waived away with "our data is better but we won't let you see it." All we can do is pray that the developers, whoever they may be, are acting in good faith with accurate interpretations of that data.

Not very comforting. And to be clear, I'm not directing this specifically at HB, I'm commenting on this from a wider DCS ecosystem perspective. ED devs have many times been caught using inaccurate data or inaccurate interpretations of data and given us the same "our data is better" reasoning until years later someone finally finds counterevidence that ED will take a look at and fix. Or never fix at all.  

[DSplayer]

12 hours ago, Katsu said:

Here it is, it's part of a larger document but the part that focuses on Phoenix is this one: 
 

The report discusses that it would guide the missile toward an optimal trajectory to optimize the Mach number achieved. This would mean it would be nearly impossible to do in DCS since you can't make a missile in DCS go perform an exact trajectory like the one shown on Figure 2. This is most likely why your tests that you posted in your previous post didn't result a max Mach similar to the NASA simulation (as seen by the completely different trajectory that the missile took when looking at the altitude graph):

 

15 hours ago, Katsu said:

 

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The tests performed 2 years ago that JNelson posted should thoroughly demonstrate just how close our missile is to the NASA simulations.

[Alcatraz SVK]

Yeah tracking of phoenix is miserable for some time. Its better to use only sparrows for its more reliable than phoenix and tws auto even if i can see targets launch ang guide t doesnt track or goes to hunt satellites. Only way its good for use ow is medium - short range fox 3 in STT.

[Karon]

6 hours ago, Alcatraz SVK said:

Yeah tracking of phoenix is miserable for some time. Its better to use only sparrows for its more reliable than phoenix and tws auto even if i can see targets launch ang guide t doesnt track or goes to hunt satellites. Only way its good for use ow is medium - short range fox 3 in STT.

"tws" - there found your primary source of issues. How does the DDD look like when you launch in TWS?

[tavarish palkovnik]

@Naquaii

Appreciated for came by and shared your points. It’s pity to hear not to expect your participation in discussion that much, it is kind of hard that way to have normal exchange of thoughts and in this case arguments. Saying, you have your source trusting more. And I guess 13595 N for 27 seconds is from that source which is not for sharing. To be clear, I’m not asking from you to disclose it, if it exists after all, here we already disclosed so many sources that motor actually and literally “drew” itself

 

Having no intention to participate in sharing arguments, and keeping your side on the trust base, is accepted although disappointed in same time. Honestly I was expected more from you guys work ( and sell ! ) this products, more than just “we trust more” in opinion A than opinion B or C without even trying to disprove others.

All right, then I will disprove 13595 N and 27s the only way I know, by mathematics. Indisputable method always and every time.

So let’s see shortly what is behind these numbers above. If we have nozzle data (hopefully nobody will doubt in CPIA data) and if we put it in thrust formula we got equation with two unknowns, pressure and thrust coefficient. Hard but not impossible to solve, with making iteration matrix we come to chamber pressure of 41,6 bar to make 13595N through this nozzle.

Now when having chamber pressure we can come to burning rate (hopefully nobody will doubt in W.T.Brooks data, this engineer literally “had hands” in this motor. So 6,22mm/s is burning rate in your motor. To have constant chamber pressure 41,6bar (600psi) burning surface of that grain must be constantly 0,6 square meters. Having burning surface, burning rate and expected propellant density we get mass flow in your motor as 6,531 kilograms per second. Your motor blows 27 seconds so it means your motor is looking for 176,3 kilograms of fuel…oops…isn’t it 163kg in your motor!? Let’s continue with 176,3 because that much must be to have selected thrust output since nobody disapprove nozzle geometry, who would dare disapprove NASA and CPIA.

And at the end we get specific impulse 212s what is exactly something as expected to be with 18,5 nozzle expansion ratio, at sea level and with chamber pressure 600psi.

I know you guys from terrace will find some explanations in form that I don’t know what all and what exactly is in their codes etc etc … come on … like it or not … but you have fake product 

[Naquaii]

11 hours ago, Nealius said:

Essentially, any effort by the users to discuss or fix any potential or perceived issues is absolutely pointless because it can be waived away with "our data is better but we won't let you see it." All we can do is pray that the developers, whoever they may be, are acting in good faith with accurate interpretations of that data.

Not very comforting. And to be clear, I'm not directing this specifically at HB, I'm commenting on this from a wider DCS ecosystem perspective. ED devs have many times been caught using inaccurate data or inaccurate interpretations of data and given us the same "our data is better" reasoning until years later someone finally finds counterevidence that ED will take a look at and fix. Or never fix at all.  

All I can say is that yes, you can't really validate our data in this case, and like I said, this isn't unique in DCS and it's by far not unique in this module. There's quite a lot of other aspects about the F-14 module that is built on information you can't find openly on the net for various reasons. (And no, we would never deal with classified data but just because it's unclassified doesn't mean you can find it on the net.) So if you can't trust us in this case you kinda invalidate quite a large part of the module itself as it is. The same goes for quite a few of the other modules in DCS as well I'm sure.

All I can ask you to do is to look at the aspects of the module that you can validate from openly available documents like the Natops and see if you think those are accurately represented and judge the module from that. I can assure you that we try to hold the same standard for all parts of the module, regardless of if the data we built it on are openly available. Same thing with the weapons systems (within DCS limitations ofc).

And as always, if you find new data we're always willing to look at it and try to improve our module. In this case this thread has been going on for a while and we've already commented that we judge our data better, but if new sources are made available we will for sure have a look at it.

Edited November 30, 2024 by Naquaii

[Alicatt]

11 hours ago, DSplayer said:

The report discusses that it would guide the missile toward an optimal trajectory to optimize the Mach number achieved. This would mean it would be nearly impossible to do in DCS since you can't make a missile in DCS go perform an exact trajectory like the one shown on Figure 2. This is most likely why your tests that you posted in your previous post didn't result a max Mach similar to the NASA simulation (as seen by the completely different trajectory that the missile took when looking at the altitude graph):

 

The tests performed 2 years ago that JNelson posted should thoroughly demonstrate just how close our missile is to the NASA simulations.

The NASA simulation, not an actual live test then with the AIM54? 

This AIM54 in DCS is a simulation of a simulation then?