investigating AiM-9X Weird behavior / logic

[Xhonas]

Hello there, not sure if this could be considered a bug, but the Aim-9x behavior in the F/A-18 is questionable. I'm providing 3 tracks to help explain what the issues are.

Aim9x no radar lock.trk

In this first track, i acquire the target with the Aim-9x without the help of the radar, only slaved to the HMD. I put the aiming circle at the target, and press the cage/uncage button and the missile seeker is now locked into the target. Nothing wrong so far. The problem is, the moment that i take the HMD fov off the target, the Aim-9x loses the lock on the target and is slaved into my helmet again. I didn't press anything, i just moved the HMD Fov off the target. I belive that the missile should stay locked into the target, and only be slaved back to my helmet if i pressed cage/uncage button again. The way it is working now is very inconvenient.

Aim9x with radar acm lock.trk

In this second track, i acquire the target with an ACM mode and with the Aim-9x selected. As soon as i get a radar lock, the Aim-9x is slaved to the target the radar is tracking, no problem. Now, if you press the cage/uncage button, sometimes the missile will get slaved to the hud (but not to the helmet), and sometimes it won't. Also, when it gets slaved to the hud, if you press cage/uncage again to slave it back to the radar, sometimes the missile will fail to track the target being followed by the radar, as you can see in the trackfile.

Aim9x with radar bvr lock.trk

In this last track, i acquire the target with the B-Scope and the 9X selected. For some reason, it is impossible to uncage the missile into the target while looking at it with the Helmet. The missile sees the target, you get the tone, but pressing cage/uncage does not achieve a seeker lock, neither slaves it to the designated L+S. The only way to slave the missile to the radar lock, is looking directly at the hud (if the HMD is on). If you take the hmd fov off the hud, the missile will be slaved into the helmet, and unable to achieve a seeker lock. Also, by the end of the track, you will see that the missile slaved to the L+S doesn't get a seeker lock. Just hear the tone, you get that  tone that indicates that the missile sees something, but isn't in the threshold to get a lock (it makes that bap-bap-bap-bap-bap sound), despite being in perfect parameters to achieve a lock. Sometimes you get a more high pitched tone, indicating that you can achieve a seeker lock, but pressing cage/uncage does nothing. 

 

Sorry if some of the descriptions were confusing, just watch the tracks to be clearer. 

[BIGNEWY]

Edit: 

Ignore my last message that was for the Viper, we will take a look at this report soon in more detail

thank you

[Xhonas]

Hello there ! @BIGNEWY Any news regarding this? 

[BIGNEWY]

On 4/20/2024 at 3:05 PM, Xhonas said:

Hello there ! @BIGNEWY Any news regarding this? 

Sorry I have overlooked this thread, I will ask the team again. 

[falcon_120]

This is working really strange since some months for the hornet. I can reproduce all of the above behavior.

Enviado desde mi ELE-L29 mediante Tapatalk

[falcon_120]

Any news from the team @BIGNEWY? Not being able to take your head off the target even for a second (i mean after uncaging and getting a good tone on the bandit) its really a bummer.

[Corrigan]

I also see this issue.

[Nevan Nedall]

Is it possible you have to hold Cage/Uncage (correct or not)?

[Flogger23m]

On 5/10/2024 at 3:18 AM, falcon_120 said:

Any news from the team @BIGNEWY? Not being able to take your head off the target even for a second (i mean after uncaging and getting a good tone on the bandit) its really a bummer.

 

This seems to be an issue for me as well. This thread is already a few months since the last reply. My AIM-9X accuracy is extremely low, even if I keep my head looking at the target. The F-16C, F-14 (without HMD) with AIM-9M is more accurate. The F-16 with HMD and AIM-9X is not even comparable, night and day. Almost like two entirely different weapons.

[falcon_120]

This has been finally solved with the latest patch. You can now again cage the Aim9x through the JHMCS and take your head off the target but it will stay locked to it, as it worked many month before and the way it works with the F16.

There is a still some weirdness in that sometimes the seeker cage itself without hitting cage/uncage, but i will make a bug report specifically for that.

[Phil C6]

Hi guys, a question aim9M works fine for you?

Best regards

Edited July 23, 2024 by Phil C6

[falcon_120]

Yes. Tested in MP mostly before yesterday’s patch.

What’s your experience?


Sent from my iPhone using Tapatalk

[Phil C6]

Hi, I don't know nothing sure but sometimes i have feeling something is broken specially about IR with the F18
F18 with high alpha must be very good with 9M, but from my feeling it's easier with F16.
In F18 i have feeling the aim9M lost the track easier or doesn't use max G
But it's certainly i don't know how to use it correctly in F18. Maybe i have feeling to be in the good parameters but it's not the case?
Radar lock and Seeker lock seem slower too in F18 but here too it's just a feeling

Best regards

9M from F16.trk 9M.trk

Edited July 23, 2024 by Phil C6

[BIGNEWY]

Thank you for the new tracks we will take a look

[itsthatguy]

@BIGNEWY

I've been trying to boil this issue down and I think I've done a fairly good job here:

There are 3 states that the AIM-9 seeker can be in, in the hornet.

1) Slaved to HUD Boresight/HMD LOS, depending on whether pilot is looking inside our outside of cockpit, and whether the radar is in HACQ mode or not.
2) Slaved to Radar L&S/STT (looking at target but not actually locked on)
3) Locked on to Target.

When the radar is off, or if there is no L&S or STT, the behavior is rather simple. The seeker will do (1), and upon pressing uncage, will attempt to do (3).
However, once there is a L&S or STT, the behavior of the uncage button becomes unclear. It seems to move the seeker between the 3 states randomly, with no clear logic.
In any case, the only reliable way to get the seeker back to HMD LOS is to drop all radar tracks in one way or another.

Edited September 3, 2024 by itsthatguy

[itsthatguy]

21 hours ago, itsthatguy said:

@BIGNEWY

I've been trying to boil this issue down and I think I've done a fairly good job here:

There are 3 states that the AIM-9 seeker can be in, in the hornet.

1) Slaved to HUD Boresight/HMD LOS, depending on whether pilot is looking inside our outside of cockpit, and whether the radar is in HACQ mode or not.
2) Slaved to Radar L&S/STT (looking at target but not actually locked on)
3) Locked on to Target.

When the radar is off, or if there is no L&S or STT, the behavior is rather simple. The seeker will do (1), and upon pressing uncage, will attempt to do (3).
However, once there is a L&S or STT, the behavior of the uncage button becomes unclear. It seems to move the seeker between the 3 states randomly, with no clear logic.
In any case, the only reliable way to get the seeker back to HMD LOS is to drop all radar tracks in one way or another.

 

I've done a little more testing and it seems in situations where the target is too far away for the missile to see, it will happily switch between states (1) and (2). 
It appears as though what is happening is that when the seeker is in state (2) or (3), and the uncage button is pressed, it will attempt to return to state (1) - however, the seeker will often achieve a lock on the target before the missile LOS is able to move back to the HUD or HMD LOS, causing it to snap right back onto the target.

In summary,

When there is no L&S/STT, but there is a target within range of the seeker, Uncage will toggle between states 1 & 3.
When there is an L&S/STT, but no target within range of the seeker, Uncage will toggle between states 1 &2.
When there is an L&S/STT, AND there is a target within range of the seeker, Uncage will switch between the 3 states randomly.

To be clear, the problems described in this thread (apart from the first one that was already fixed where the seeker would unlock if you looked away) only occur when trying to use the AIM-9 with HMD cueing while also having a L&S/STT designated. There is some conflict in the seeker behavior logic when the cage/uncage button is pressed.

In any case, for those browsing about the issue, the easiest workaround is to SCS Up to enter HACQ mode, then immediately hit the undesignate button to "reset" the radar and clear all track files. Just be aware that if you are in TWS mode, as soon as the radar sees something, it'll automatically assign it as the new L&S and you'll be back in problemville.

@BIGNEWY Please pass these findings along, I hope they can be helpful.

Edited September 3, 2024 by itsthatguy

[itsthatguy]

Reviving this thread because it has been 7 months with no word on the issue, and my (hopefully) more clear description of the issue was never acknowledged.

[itsthatguy]

Okay so I did some quick testing after today's patch and while the cage/uncage button behavior certainly is different I'm not sure I'd call it "fixed".

I need to do some more digging to figure out exactly what's happening now with the relationship between the 3 "states" that I mention in previous posts, but it's different now than it was before. It's still seemingly somewhat random, but it's now more complicated than it was before.

One observation is that the button now functions on both press AND release, whereas before it only functioned on a press. This is readily apparent and easily testable by silencing the radar so it can't interfere:

Looking at a target with the AIM-9X slaved to the HMD, then pressing and holding the uncage button will cause the seeker to lock on. If you keep your HMD reticle over the target, then release the cage/uncage button, the seeker will briefly unlock and then re-lock the target.

Repeating the same procedure, except looking away when you release the cage/uncage button, will cause the seeker to snap back to the HMD line of sight - HOWEVER, the seeker will automatically lock onto the next target it sees without you pressing anything.

This means that if you quickly press and release the uncage button, the seeker will briefly lock on, the unlock, then re-lock onto the target (assuming you don't look away too quickly). I don't think this behavior is intended.

@BIGNEWYPlease pass this on.

Edited April 17 by itsthatguy

[itsthatguy]

I created a video as a visual aid for all of the problem(s) I've described in this thread.

I'd like to re-iterate that not only did the April 2025 patch not fix the seeker behavior, it actually introduced even more problems (see my prior post). Another issue I discovered, which I didn't cover in the video, is that when the seeker is slaved to the HMD, and the HMD becomes masked, the seeker just gets stuck wherever it was at the moment the HMD became masked. So, if you look at the HUD, the seeker will be stuck off to the side of the HUD.
 

 

AIM-9X_Problems.log AIM-9X_Problems.trk

Edited May 21 by itsthatguy

[falcon_120]

Thanks for the video it clearly showcase the problem starting at 4:05. This is specially problematic when you use the HACQ mode as once the contact is locked (designated as the L&S) the AIM9x seeker logic start to make funky things. Its been more than once that in the seek of the battle you waste a AIM9x as you dont get the tone and the reason is this strange bug where the seeker is actually seeing the target randomly after some seconds or not at all, once you use the cage/uncage button is moving between states in such a manner is a bit unpredictable

[miguelaco]

I did my own tests with latest patch (2.9.16.10523) and I'll try to showcase the results here as briefly and simple as possible. I focused on testing the AIM-9X boresight mode with no radar, since I think any issues when slaving to L&S target are related to cage/uncage behavior as well. Please, feel free to comment below if I missed something:

HUD only (HMD off):

Seeker placed over the target:

1. Press and release CAGE/UNCAGE button: a lock cannot be achieved
2. Press and hold CAGE/UNCAGE button: a lock is achieved whenever the button is pressed. As soon as it is released the lock breaks.
3. After a lock is achieved it is no longer possible to achieve a lock again as described in point 2.

HUD + HMD:

• Seeker in HUD placed over the target:

1. Press and release CAGE/UNCAGE button: a lock cannot be achieved
2. Press and hold CAGE/UNCAGE button: a lock is achieved whenever the button is pressed. As soon as it is released the lock breaks.
3. After a lock is achieved it is possible to lock again by holding the button as described in point 2.

• Seeker in HMD and placed over the target:

1. Press and release CAGE/UNCAGE button: when pressed, a lock is achieved and upon release the lock briefly breaks and locks again as described previously in the thread.
2. Press and hold CAGE/UNCAGE button: a lock is achieved and when released, there are three possible outcomes depending where you're looking when that happens:
   1. If released over a target, the first lock is broken and it will lock again on the new (or same) target
   2. If released while looking at the HUD (the HMD is masked as a result), the lock breaks and if placed again over the target it will not reacquire again automatically.
   3. If released while HMD is not masked, the lock breaks and if placed again over the target it will reacquire the lock automatically

Find attached two tracks showing the described behavior. Do not reset view while playing them and feel free to take control and experiment by yourselves. Looking at my findings and assuming I didn't do something wrong, I think the boresight mode is broken and not reliable at all, as pointed out by other users in this thread.

aim9x_hud_only.trk aim9x_hud_hmd.trk

Edited May 23 by miguelaco

[TK-421]

Any updates on this?

[inZane]

@BIGNEWY has there been any updates on this? I have skimmed patch notes and have not found any mention of it.

[miguelaco]

There's a mention in today's patch:

Quote

• Fixed: Randomly can't uncage AIM-9.

I'll give it some testing once I have some time.

[itsthatguy]

The most recent update has FINALLY brought some much needed consistency to the original issue I discussed, where pressing the uncage button would randomly switch between the three states when an L&S is present. It seems as though the new implementation is working mostly as intended. It has a strange side effect, mostly manifesting as the strange "auto-lock" behavior that's discussed in many posts above. The one thing that still seems off is that the behavior is different depending on whether the L&S is created with a normal radar mode or an ACM radar mode.

The seeker behavior when there is no L&S is still the same as @miguelaco describes a few replies above.

What's finally fixed is the seeker behavior when the HMD is on and and there is an L&S that is acquired with a NON-ACM radar mode:
1) Upon designating L&S, seeker will auto-slave to L&S. Will also auto-lock if target is within range.
2) When pressing uncage button, seeker will return to HMD slave. 
3) Next press will attempt to lock target within line of sight as long as uncage button is held.
    3a) If no target is in sight, seeker will return to L&S. When button is released, seeker will briefly unlock and re-lock. Seeker is now back to step 1.
    3b) If a target is within sight, seeker will lock onto target as long as button is held. As soon as button is released, seeker will return to and auto-lock to L&S (if possible).                    If target is L&S, seeker will briefly unlock and re-lock when button is released. Seeker is now back to step 1.

For whatever, reason, if the L&S is designated thru an ACM mode (HACQ), the seeker behavior is different and still wonky:
1) Upon creating L&S with ACM mode, seeker will auto-slave to L&S. Will also auto-lock if target is within range.
2) Upon pressing uncage button, seeker will slave to HUD only.
3a1) IF pressing and releasing uncage button, seeker will return to L&S slave, but NOT locked on.
     3a2) IF pressing and releasing button, seeker will return to step 2.
     3a3) IF pressing and holding uncage button, seeker will lock onto L&S. Upon release, seeker will briefly unlock then re-lock L&S. Seeker is now back to step 1.
3b) IF pressing and holding uncage button, seeker will lock onto L&S. Upon release, seeker will briefly unlock then re-lock L&S. Seeker is now back to step 1.
 

Edited June 26 by itsthatguy