AIM-54 Hotfix PSA and Feedback Thread - Guided Discussion

[nighthawk2174]

Does the AIM-54 use the APN stuff that ED added?

[Zaphael]

3 hours ago, IronMike said:

Dear all,

I would like to apologize to all of you - as you may have seen we changed the AIM-54 guidance from parallel to PN this patch. Both ED and us have been under the impression all these years that it had been set to PN already, and luckily ED spotted the issue. This is ofc an oversight, and was owed to the fact that the setting is hidden behind a value that does not indicate this on first sight and the differences in guidance are very difficult to spot, if at all, in game, when monitored under the wrong assumption.

However, you should notice a difference now, where the missile will have slightly less energy on the fly-out while maintaining more energy during the terminal phase, as it should. We're very grateful to ED for spotting this, and ofc feel somewhat embarrassed to have been under the wrong impression all along. The AIM-54 ofc should have always been set to PN guidance.

The positive note is that the terminal guidance should be improved through this, and we are happy that this step brings us closer to the completion of the AIM-54 overhaul. We would like to thank you ever so kindly for your tremendous patience with us and I hope you enjoy the changes this patch brings.

Thank you and our sincere apologies again.

 

Well its fixed now. Many of us have observed the conversion into lag or tail chase over the year. Who would have known? 

 

[Zaphael]

1 hour ago, DSplayer said:

The only thing I noticed in my own testing (and not using these tracks) is that sometimes the missile will lead too much, especially against a maneuvering target, and could cause the missile to drain some more energy than it really needs to.

If I understand the TWS refresh and update rate correctly, it should, and should not, do that depending whether TWS sees a heading change in the bandit.  If it during the refresh, I think it should update the supported missile's trajectory accordingly

At terminal, I think the missile has to respond to target maneuvering fairly quickly.

 I think it is a fair tactic to make multiple heading changes while trying to press a section of F-14s. Possibly why the Gulf of Sidra Migs were doing so at mid-low Altitude, giving the Phoenix some due respect. 

[Quid]

Just ran a test scenario against AI F-5s trying to splash an E-2D.  The missile is definitely even more deadly since this update - lobbed one AIM-54A at 60NM and another at 50NM, both killed their targets with speed to spare at terminal in spite of their best efforts to dive and run.  Nota Bene: I launched at Angels 31 and 1.2M against the F-5s at about 25,000 feet and 0.6M - the missiles definitely had both the altitude and launch speed to their advantage, but still, they had a lot of Schlitz (1.95M and 1.86M, respectively).  Haven't tested the low-altitude regime yet, but up high, they're a force to be reckoned with.

[Coldwarrior000]

1 hour ago, Quid said:

Just ran a test scenario against AI F-5s trying to splash an E-2D.  The missile is definitely even more deadly since this update - lobbed one AIM-54A at 60NM and another at 50NM, both killed their targets with speed to spare at terminal in spite of their best efforts to dive and run.  Nota Bene: I launched at Angels 31 and 1.2M against the F-5s at about 25,000 feet and 0.6M - the missiles definitely had both the altitude and launch speed to their advantage, but still, they had a lot of Schlitz (1.95M and 1.86M, respectively).  Haven't tested the low-altitude regime yet, but up high, they're a force to be reckoned with.

Thanks for sharing. It's always great news hearing the AIM-54 is getting better. Props to Heatblur and ED.

[captain_dalan]

Only did 3 tests on my usual go-to instant action, Persian Gulf BVR. Overall, no perceived changes in the PK. If an AI bandit decides to Split-S out of Dodge, it will evade the missile, but that is to be expected. But, the terminal energy of the missile has indeed improved at the expense of some other flight and trajectory parameters. More tests are needed. So far, i like this change even though it may need some adaptation by both shooters and defenders. 

[DSplayer]

So I decided to run some tests utilizing the older PN_coefficients and associated PN_gain from older DCS versions of the AIM-54 (the one prior to June 21, 2022 specifically) since I was rather concerned at the increased amount of defeats from beaming attacks recently and I was able to find that the older PN coefficients have a better chance against targets that are almost beaming as they are faster once they start turning into the targets along with leading more smoothly than the latest PN coefficients. I fired at a Mach 2 F-15 at various beaming angles with an AIM-54A-Mk60 with target size small while active paused at Mach 1 at 30000 ft and utilized the same track for both old and current PN coefficients. Here are some examples from my testing where the current PN values didn't allow the missile to hit the target:

 

Current PN coefficient from "PN Test 4 BEAM4" track:

Spoiler

Old PN coefficient from "PN Test 4 BEAM4" track:

Spoiler

 

Current PN coefficient from "PN Test 4 BEAM5" (this barely missed):

Spoiler

Old PN coefficient from "PN Test 4 BEAM5" track:

Spoiler

 

Current PN coefficient from "PN Test 3":

Spoiler

Old PN coefficient from "PN Test 3":

Spoiler

 

The flight path of the current PN coefficient values also shows that it currently has a slight curve when trying to hit the beaming target when compared to the straight line that the older PN coefficient takes.

Old

Spoiler

New

Spoiler

 

In conclusion I think that there should be some further testing to improve the PN coefficients of the AIM-54 as they are currently subpar when used against targets that go into the beam (or do a split S) or targets that are nearly beaming already when compared to the older PN coefficients. I've included a version of the modified "Weapons.lua" that I used in order to test the old vs current PN coefficients if you want to test it out yourself (I highly recommend using OVGME or a similar application) for your own scenarios.

Here's the difference between the unmodified lua and the lua with the older PN coefficients: https://www.diffchecker.com/39xPQ15T

 

PN Test 3.trkPN Test 4 BEAM4.trkPN Test 4 BEAM5.trkDCS-BEAM5 NEW PN.trk.zip.acmiDCS-BEAM5 OLD.zip.acmiDCS-PN TEST 3 NEW PN.zip.acmiDCS-PN Test 3 OLD PN.trk.zip.acmiDCS-BEAM4 NEW.zip.acmiDCS-BEAM4 OLD.trk.zip.acmiWeapons.lua

 

 

Edited July 24, 2022 by DSplayer

[draconus]

7 hours ago, DSplayer said:

PN coefficients

I suspect these are not taken from any available docs. They are made up and tweaked by the devs to match some RL test shots and to get decent in game pk, right?

[DSplayer]

1 hour ago, draconus said:

I suspect these are not taken from any available docs. They are made up and tweaked by the devs to match some RL test shots and to get decent in game pk, right?

Well it's basically impossible to find information regarding missile flight paths and terminal behavior so I'd assume HB tweaked their PNs in order to squeeze PKs out and ensure the missile is performing the best it can (which I'm sure is what Deka and ED do when they make tweaks to their Fox 3s).

[LetMePickThat]

1 hour ago, DSplayer said:

Well it's basically impossible to find information regarding missile flight paths and terminal behavior so I'd assume HB tweaked their PNs in order to squeeze PKs out and ensure the missile is performing the best it can (which I'm sure is what Deka and ED do when they make tweaks to their Fox 3s).

This is what most module makers do, I assume, regardless of whether the missile is a Fox 1, 2 or 3. Guidance algorithms aren't discussed in detail in open source litterature when dealing with specific missiles, even if the theory is well known. 

[DSplayer]

Ok I found out that the PN_gain value and not the PN_coefficient values were the things that drastically effected lead when I decided to redo some tests. And since I had thought that the PN_gain had to be the same value as the number of PN_coeff entries, I had thought that the older PN_coeff values made the difference when I initially ran the tests. Utilizing the "PN Test 3" track I found that a PN gain value (in combination with the current PN coeffs) between 5-20 (maximum number I tested) allowed the missile to hit with a bell shaped curve on how fast the missile was when it hit the F-15 (5 and 20 resulting in lower speeds than 12).

 

EDIT: I've done some testing where I am the defending plane against an F-15 AI firing an AIM-54A-Mk60 and you can dodge AIM-54s with last minute with the current PN gain values vs a PN gain value of 11.

PN GAIN 4DCS PLAYER 1.zip.acmiPN GAIN 4DCS PLAYER 2.zip.acmiPN GAIN 11DCS PLAYER 1.zip.acmiPN GAIN 11DCS PLAYER 2.zip.acmiPN Test 5PLAYER.trkPN Test 5PLAYER2.trk

Perspective of the missile from both tracks with both versions:

 

Edited July 25, 2022 by DSplayer

[JNelson]

On 7/25/2022 at 11:45 AM, DSplayer said:

Ok I found out that the PN_gain value and not the PN_coefficient values were the things that drastically effected lead when I decided to redo some tests. And since I had thought that the PN_gain had to be the same value as the number of PN_coeff entries, I had thought that the older PN_coeff values made the difference when I initially ran the tests. Utilizing the "PN Test 3" track I found that a PN gain value (in combination with the current PN coeffs) between 5-20 (maximum number I tested) allowed the missile to hit with a bell shaped curve on how fast the missile was when it hit the F-15 (5 and 20 resulting in lower speeds than 12).

 

EDIT: I've done some testing where I am the defending plane against an F-15 AI firing an AIM-54A-Mk60 and you can dodge AIM-54s with last minute with the current PN gain values vs a PN gain value of 11.

PN GAIN 4DCS PLAYER 1.zip.acmi 94.76 kB · 1 download PN GAIN 4DCS PLAYER 2.zip.acmi 84.16 kB · 0 downloads PN GAIN 11DCS PLAYER 1.zip.acmi 91.26 kB · 0 downloads PN GAIN 11DCS PLAYER 2.zip.acmi 81.66 kB · 0 downloads PN Test 5PLAYER.trk 133.04 kB · 0 downloads PN Test 5PLAYER2.trk 63.76 kB · 1 download

Perspective of the missile from both tracks with both versions:

 

 

Hi we had already increased the PN_gain to 5 internally for the next update it was too late to make it into this last update. Increasing the PN_gain is a double edged sword, lower PN_gains will increase miss distance as you have seen but higher values will reduce energy retention. Values are typically between 3-5. Higher gain values will also increase the distance the missile has to travel if the target is manoeuvring at a longer distance. 

 

As far as I can tell the pn coefficients relate to the parallel guidance mode which the AIM-54 no longer uses. 

[GGTharos]

^^^^ And there is plenty of actual research into the sensitivity of PN coefficients out there to back IM up.

[DSplayer]

15 hours ago, JNelson said:

Hi we had already increased the PN_gain to 5 internally for the next update it was too late to make it into this last update. Increasing the PN_gain is a double edged sword, lower PN_gains will increase miss distance as you have seen but higher values will reduce energy retention. Values are typically between 3-5. Higher gain values will also increase the distance the missile has to travel if the target is manoeuvring at a longer distance. 

 

As far as I can tell the pn coefficients relate to the parallel guidance mode which the AIM-54 no longer uses. 

That's good that an improvement is inbound. A lot of people I've been talking to have had problems with AIM-54s missing recently, especially if they used the lower power Mk47 motor variants. PN coeffs no longer is the reason applying to proportional navigation is why the AIM-120's files no longer mention those lines at all which is nice to learn (and the SD-10 uses parallel guidance still which is pretty interesting).

 

14 hours ago, GGTharos said:

^^^^ And there is plenty of actual research into the sensitivity of PN coefficients out there to back IM up.

Good thing it seems like its a science and not the guess and check thing that I was doing.

Edited July 27, 2022 by DSplayer

[GGTharos]

11 hours ago, DSplayer said:

Good thing it seems like its a science and not the guess and check thing that I was doing.

Trial and error is a well known, accepted and useful part of science and engineering.

Basically to avoid doing what you did you'd need to be able to run the same (or similar, but prefer the same) algorithm for PN as DCS does, and run the graphs on it.  Since we're not going to be getting our hands on that algorithm, trial and error it is

[Маэстро]

On 7/25/2022 at 3:13 AM, DSplayer said:

So I decided to run some tests utilizing the older PN_coefficients and associated PN_gain from older DCS versions of the AIM-54 (the one prior to June 21, 2022 specifically) since I was rather concerned at the increased amount of defeats from beaming attacks recently and I was able to find that the older PN coefficients have a better chance against targets that are almost beaming as they are faster once they start turning into the targets along with leading more smoothly than the latest PN coefficients. I fired at a Mach 2 F-15 at various beaming angles with an AIM-54A-Mk60 with target size small while active paused at Mach 1 at 30000 ft and utilized the same track for both old and current PN coefficients. Here are some examples from my testing where the current PN values didn't allow the missile to hit the target

Hi, can you please try on more thing? Retain PN_gain = 4, but replace these numbers (just above DLZ data):

36.0, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K0
7.8, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K1
1.0, -- характеристика системы САУ-РАКЕТА,  полоса пропускания контура управления

with these ones

1.2, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K0
1.0, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K1
2.0, -- характеристика системы САУ-РАКЕТА,  полоса пропускания контура управления

This should reduce excessive guidance smoothing and make missile more agile.

 

Simple increasing of PN_gain is not the way, bc it's not realistic. There is some limitations on this value IRL(increasing may cause overall system instability or/and missdistance growth). Also higher values are not optimal in terms of kinetic energy saving.

[DSplayer]

1 hour ago, Маэстро said:

Hi, can you please try on more thing? Retain PN_gain = 4, but replace these numbers (just above DLZ data):

36.0, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K0
7.8, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K1
1.0, -- характеристика системы САУ-РАКЕТА,  полоса пропускания контура управления

with these ones

1.2, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K0
1.0, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K1
2.0, -- характеристика системы САУ-РАКЕТА,  полоса пропускания контура управления

This should reduce excessive guidance smoothing and make missile more agile.

 

Simple increasing of PN_gain is not the way, bc it's not realistic. There is some limitations on this value IRL(increasing may cause overall system instability or/and missdistance growth).

My results with these new САУ-РАКЕТА values (with PN_gain =4) concluded that they didn't really improve the overall PK with the tracks that I had previously tested with since none of them hit but they did get a bit closer (couple of hundreds of feet) to the enemy aircraft. 

New САУ-РАКЕТА-DCS-PN Test 4 BEAM4.trk.zip.acmiNew САУ-РАКЕТА-DCS-PN Test 4 BEAM5.trk.zip.acmiNew САУ-РАКЕТА-DCS-PN Test 5PLAYER.trk.zip.acmiNew САУ-РАКЕТА-DCS-PN Test 5PLAYER2.trk.zip.acmiNew САУ-РАКЕТА-DCS-PN Test 3.trk.zip.acmi

 

My initial hypothesis was that if these САУ-РАКЕТА values were combined with a PN_gain value of 5, it would improve the PK but that didn't happen most of the time. It actually caused the AIM-54 to miss and hit the same amount when compared to if the PN_gain = 5 just by itself. There were only 2 times out of the 5 tests where the AIM-54s with this combination of new САУ-РАКЕТА values and PN_gain = 5 actually hit: "PN Test 3" and "PN Test 5PLAYER2".

New САУ-РАКЕТА + PN GAIN 5-DCS-PN Test 4 BEAM4.trk.zip.acmiNew САУ-РАКЕТА + PN GAIN 5-DCS-PN Test 4 BEAM5.trk.zip.acmiNew САУ-РАКЕТА + PN GAIN 5-DCS-PN Test 5PLAYER.trk.zip.acmiNew САУ-РАКЕТА + PN GAIN 5-DCS-PN Test 5PLAYER2.trk.zip.acmiNew САУ-РАКЕТА + PN GAIN 5-DCS-PN Test 3.trk.zip.acmi

 

EDIT: Here are the tests with only PN_gain = 5 and no other values changed (2/5 tests resulted in a hit):

PN Gain 5-DCS-PN Test 4 BEAM4.trk.zip.acmiPN Gain 5-DCS-PN Test 4 BEAM5.trk.zip.acmiPN Gain 5-DCS-PN Test 5PLAYER.trk.zip.acmiPN Gain 5-DCS-PN Test 5PLAYER2.trk.zip.acmiPN Gain 5-DCS-PN Test 3.trk.zip.acmi

 

EDIT 2: The lowest non-decimal PN_gain value that allowed a hit in all the tests was a 6 (no new САУ-РАКЕТА).

Edited July 28, 2022 by DSplayer

[DSplayer]

Yo, I'm back with a rivet counting AIM-54 test.

This is a test where an F-16 going Mach 1.1 zigzags (but not AI set to no reaction to threat) in an effort to make the AIM-54 lose energy since it now uses proportional navigation and an AIM-54A-Mk60 is launched at maximum detection range (missile falls off the rail at 83.9nm) with target size small at Mach 1.0. What I've found is that PN_gain values below 5 cause the AIM-54 to not hit the F-16 while using parallel navigation allows it to hit with no problem (this is due to the rather less aggressive flight path that it takes in order to steer towards not exactly hot targets).

 

Parallel Navigation (Hit) (PN_gain line missing an using current PN_coeffs):

Spoiler

 

 

PN_gain = 4 (Missed with closest range to F-16 being 5,342ft)

Spoiler

 

 

PN_gain = 5:

Spoiler

 

 

PN_gain = 6:

Spoiler

 

 

PN_gain = 7:

Spoiler

 

 

PN_gain = 11:

Spoiler

 

 

In conclusion, with the limited capabilities of DCS, I think that a PN_gain value between 5 and 6 (learning towards 6 since even with a decimal value of 5.80 resulted in misses in 3/5 of the previous tests) will be the best. Maybe in the future, the missile speed gate knob in the RIO pit could be used to get rid of these issues relating to proportional navigation,

 

Here's an image that visualizes the differences in PN_gain

 

PN GAIN 4 DCS-PN Test 6-1.zip.acmiPN GAIN 5 DCS-PN Test 6-1.trk.zip.acmiPN Gain 6-DCS-PN Test 6-1.trk.zip.acmiPN GAIN 7 DCS-PN Test 6-1.trk.zip.acmiPN GAIN 11 DCS-PN Test 6-1.trk.zip.acmiPN GAIN NO DCS-PN Test 6-1.trk.zip.acmiPN Test 6-1.trk

Edited July 28, 2022 by DSplayer

[Hobel]

vor 8 Stunden schrieb DSplayer:

Yo, I'm back with a rivet counting AIM-54 test.

This is a test where an F-16 going Mach 1.1 zigzags (but not AI set to no reaction to threat) in an effort to make the AIM-54 lose energy since it now uses proportional navigation and an AIM-54A-Mk60 is launched at maximum detection range (missile falls off the rail at 83.9nm) with target size small at Mach 1.0. What I've found is that PN_gain values below 5 cause the AIM-54 to not hit the F-16 while using parallel navigation allows it to hit with no problem (this is due to the rather less aggressive flight path that it takes in order to steer towards not exactly hot targets).

 

Parallel Navigation (Hit) (PN_gain line missing an using current PN_coeffs):

  Versteckten Inhalt anzeigen

 

 

PN_gain = 4 (Missed with closest range to F-16 being 5,342ft)

  Inhalt verstecken

 

 

PN_gain = 5:

  Inhalt verstecken

 

 

PN_gain = 6:

  Inhalt verstecken

 

 

PN_gain = 7:

  Inhalt verstecken

 

 

PN_gain = 11:

  Inhalt verstecken

 

 

In conclusion, with the limited capabilities of DCS, I think that a PN_gain value between 5 and 6 (learning towards 6 since even with a decimal value of 5.80 resulted in misses in 3/5 of the previous tests) will be the best. Maybe in the future, the missile speed gate knob in the RIO pit could be used to get rid of these issues relating to proportional navigation,

 

Here's an image that visualizes the differences in PN_gain

 

PN GAIN 4 DCS-PN Test 6-1.zip.acmi 53.27 kB · 0 Downloads PN GAIN 5 DCS-PN Test 6-1.trk.zip.acmi 52.67 kB · 0 Downloads PN Gain 6-DCS-PN Test 6-1.trk.zip.acmi 54.18 kB · 2 Downloads PN GAIN 7 DCS-PN Test 6-1.trk.zip.acmi 51.97 kB · 0 Downloads PN GAIN 11 DCS-PN Test 6-1.trk.zip.acmi 55.5 kB · 0 Downloads PN GAIN NO DCS-PN Test 6-1.trk.zip.acmi 53.1 kB · 1 Download PN Test 6-1.trk 96.97 kB · 1 Download

 

Interesting stuff, have you done similar tests with the aim120? 

[JNelson]

20 hours ago, Маэстро said:

Hi, can you please try on more thing? Retain PN_gain = 4, but replace these numbers (just above DLZ data):

36.0, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K0
7.8, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K1
1.0, -- характеристика системы САУ-РАКЕТА,  полоса пропускания контура управления

with these ones

1.2, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K0
1.0, -- характеристика системы САУ-РАКЕТА,  коэф фильтра второго порядка K1
2.0, -- характеристика системы САУ-РАКЕТА,  полоса пропускания контура управления

This should reduce excessive guidance smoothing and make missile more agile.

 

Simple increasing of PN_gain is not the way, bc it's not realistic. There is some limitations on this value IRL(increasing may cause overall system instability or/and missdistance growth). Also higher values are not optimal in terms of kinetic energy saving.

The reason we had those filter settings was the transients in terminal guidance were still present with one of the last patches so we put them back on. I have done a fair amount of testing and they don't really increase the miss distance at all. The other reason is that without them there is a large transient during the loft due to some internal guidance transition. I think the terminal guidance transient is fixed with the pure proportional navigation so we can look into putting them back to their original values.

[DSplayer]

7 hours ago, JNelson said:

The reason we had those filter settings was the transients in terminal guidance were still present with one of the last patches so we put them back on. I have done a fair amount of testing and they don't really increase the miss distance at all. The other reason is that without them there is a large transient during the loft due to some internal guidance transition. I think the terminal guidance transient is fixed with the pure proportional navigation so we can look into putting them back to their original values.

When I was testing with the САУ-РАКЕТА values that Маэстро had suggested, I did notice that the AIM-54 was able to pull rather violent and abrupt Gs once terminal that could drain it of energy. The current САУ-РАКЕТА values really help smooth out the flight path when it's active (at least visually), especially when a target is notching or the missile loses lock momentarily since the missile won't do super hard sudden pulls once it regains lock and will do a smoother transition. In my opinion, this should require further testing but my opinion is coming from a minimal understanding of what the three САУ-РАКЕТА values do and with my handful of tests that possibly aren't 100% representative of real gameplay.
 

15 hours ago, Hobel said:

Interesting stuff, have you done similar tests with the aim120? 

I could probably run a similar test for the AIM-120s (and probably SD-10) but will have to drop the range of course.

Edited July 29, 2022 by DSplayer

[JNelson]

1 hour ago, DSplayer said:

When I was testing with the САУ-РАКЕТА values that Маэстро had suggested, I did notice that the AIM-54 was able to pull rather violent and abrupt Gs once terminal that could drain it of energy. The current САУ-РАКЕТА values really help smooth out the flight path when it's active (at least visually), especially when a target is notching or the missile loses lock momentarily since the missile won't do super hard sudden pulls once it regains lock and will do a smoother transition. In my opinion, this should require further testing but my opinion is coming from a minimal understanding of what the three САУ-РАКЕТА values do and with my handful of tests that possibly aren't 100% representative of real gameplay.
 

I could probably run a similar test for the AIM-120s (and probably SD-10) but will have to drop the range of course.

 

ED gave us the transfer function for those three constants, I made sure to tune the response curve to reduce those high frequency components. So while they look kinda weird compared to the other values there is a sensible frequency response.

[Hobel]

vor 1 Stunde schrieb DSplayer:

I could probably run a similar test for the AIM-120s (and probably SD-10) but will have to drop the range of course.

For a little more context.

I think it's a similar problem, and I'd be interested to see what other results might look like.

I would do it myself, but do not have time at the moment

 

[DSplayer]

Heyo! Another week, another potentially useless AIM-54 test.

This time I tested the straight line performance of the AIM-54 if you change the nozzle_exit_area value. This is after I read a forum thread that said that it nozzle_exit_area value could potentially increase the performance of a missile if the missile didn't have this value previously. Currently the AIM-54s have a nozzle_exit_area value of 1e-6 aka 0.000001. Compared to the R-33E, a rough equivalent that we have in-game, that missile has a nozzle_exit_area value of 0.025. Even the AIM-9L has a nozzle_exit_area value of 0.0068 so I assumed that the 1e-6 value was a placeholder value that never got changed. So I decided to test how the AIM-54 variants performed with the R-33E's nozzle_exit_area value in a straight line test similar to those in the AIM-54 Whitepaper.

 

What I've found is that at higher altitudes, the increased nozzle_exit_area will allow all the AIM-54 variants to achieve an increased speed of at least 0.1 Mach with the largest difference being roughly an additional 0.5 Mach at 12km altitude with the AIM-54A-Mk60. 

 

Graphs:

Link to graphs on Google Sheets so you can hover over the lines 

500m

Spoiler

 

6km

Spoiler

 

12km

Spoiler

 

The performance improvement thanks to an increased nozzle exit area was staggering in my opinion. But, of course, that value of 1e-6 could've been intentional the entire time and this test was purely academic on what the nozzle exit area can do. With the upcoming reassessment of the AIM-54 motors by HB, maybe this can be possibly addressed.

AIM-54 Normal.acmiAIM-54 New Nozzles.acmi

[RustBelt]

What do you mean by “addressed”? That’s clearly some modeling fudge factor that doesn’t actually have anything to do with an actual measurement of any sort if a change of that magnitude makes such a moderate difference. 
 

We come down this road a lot with DCS, where numbers in a LUA are dimensionless coefficients used to fudge the old game engine.