HMD alignment

[Goliathus]

Hey guys,

anyone having issues these days with HMD alignment, too?

In the past, it was common after I did the HMD alignment and looked on my wingman, I saw the circle marking my wingman falling from the place he was at to the ground and then it recentered and started to fall again. I think, it was because of the small distance between us and refresh rate of the datalink.

But now I have strange behavior of the HMD and it seems to be misaligned someplace above the center even if I do the alignment procedure (correctly). Thus I see enemy contacts few centimeters off the place they are at (even if they are like 40 nm away) and the thing that really bothers me - even ground targets and tpod marks are not positioned correctly. 

What am I missing? Is alignment procedure broken since some last update? Because I do the alignment procedure the very same way for a looooong time without any having issues ... but I do have now.

Thanks,

Goliathus

[Crashdown2]

I have the same issue from time to time, but I look away and then look back a couple of times and it straightens out. I also notice looking at something for a while it will trail and then update and be on target. I agree, this is annoying when looking for the target in the circle, but the aircraft is somewhere offset, so I can never tell exactly what I am looking at, whether it be my target, another opposing aircraft in the same general area or a friendly that is sitting outside of the circle and then the circle snaps over the aircraft. Sometimes it is too late, especially when waiting on and confirming IFF.

[Goliathus]

Thx for your reply. I finaly had some time to play DCS again and I can post some screenshots of the issue I was talking about. Drifting cues aren´t the thing I meant, because it happened since like forever.

My issue is that my HMD is misaligned even after I do the aligment process and everything shown in the HMD is offset from the spot it should be. I did the aligment procedure dozens of times before, I do nothing differently. Hence I have this issue now.

In the pictures you can see my wingman in the red circle and the "B" sign is flying somewhere far above him. The other picture is maybe not that clear, but you can see on the flir where I´m looking and on the HMD you can see, that the mark is quite offset. I tried aligment on the deck, even in the air, or do the realigment process... nothing helped.

[Goliathus]

Another crazy picture - it seems like even HUD is affected by this "bug".

In this mission there is target marked by the red smoke, it is laser designated. I locked the target using the FLIR LSTD with the help of grid coordinates entered as my waypoint. In the picture you can see on the HUD my waypoint as if it was ahead of my aircraft. Except it isn´t, cause it is to my left, as you can clearly see the red smoke and on the FLIR you can see that the target I´m looking at is on a distinguishable field to the left.

Anyone experience this too?

[fagulha]

Nothing unusual here. Going to test tomorrow tough.

[War_Pig]

It works great for me.  I do it during INS alignment unless on a scramble, then I do it in cruise if necessary.  

The HMD is mostly aligned (95% perfectly) by default anyway, whether you do it or not it seems.  But doing the alignment yourself seems to tighten it up just that extra bit of precision that makes finding ground targets and waypoint fixes visually much easier, and BVR with the HMD is awesome!

[Crashdown2]

The second image you showed is what happens to me, however I don't have any issues with A/G mode. Since I can't see how you are aligning the HMD, all I can say is, try to keep your head centered while pushing the align button on the DDI when done with alignment. I wonder if you are turning your head to the right DDI and it somehow ruins the centering. I know it's a far off guess, but it's the only thing I have at this point.

[markturner1960]

Surely though, if you did not do the alignment correctly, it won’t give you the “Alignment OK” message…….? Can we assume if we get that , it is correctly aligned. Must admit, I do notice similar issues at times as well……

[Goliathus]

Thx guys for your replies. Unofortunatelly I don´t have time for DCS any other day than on Friday and Saturday evening, so I wasn´t able to do more tests yet. Maybe I won´t be able to play DCS this weekend at all, because I was asked to go and help on the Ukraine border with transporting friend´s family fleeing from the war zone. I don´t know yet when or if they manage to get to the border, so we´ll see, and it is more than 1000km trip for me too. So mabye no DCS for me this weekend. 

Just to explain what I was experiencing - I play DCS solely using the Liberation campaign generator, I´m not sure if this mission generator can influence how HMD alignment is working, but I don´t think it can. At the moment I run the USA vs. IRAN campaign that is taking place in 2021, so I don´t think I can have any issues with doing the quick INS alignment using the stored heading, so even this shouldn´t be the culprit what could affect my HMD not aligning properly in the advance.

While doing the HMD alignment, sometimes I´m not able to hold my head still enough to align the crosses properly at first attempt, but I always do the fine tuning until crosses match perfectly. And I get the "Aligment OK" message all the time. I didn´t have any issues with HMD aligning before...

 

 

[Sacarino111]

Hi.

Worth to ask: INS in IFA, right? Otherwise, the problem is alignement, not HMD.

Saludos.

Saca111

[Goliathus]

Hey Sacarino111,

yes, INS was in IFA, after I did the CV stored heading alignment (because I was on a carrier).

Now after you asked - I did find it strange after I started this new campaign, that after I switch the INS to IFA, I can still see on my HSI page the "OK" message. It stays there all the time, and that´s definately strange behavior. It never did before, so maybe there is something wrong with the INS in this campaign and I´m missing GPS in my Hornet despite the fact it´s taking place in 2021.

Maybe I should try the slow INS method and put the INS to NAV to see whether it make some difference or not. If yes, then I should report a bug to the Liberation Campaign creators, because it´s not DCS related.

[rob10]

4 hours ago, Goliathus said:

... after I switch the INS to IFA, I can still see on my HSI page the "OK" message. It stays there all the time, and that´s definately strange behavior....

I think you're on the right track here.  There is something with that symptom, but I can't remember right now what causes it.

Are you keeping parking brake on the whole time of alignment (or check that it IS on at mission start)?

[Goliathus]

Guys it is definitely INS related. Despite the fact I'm not sure what am I doing wrong. 

I tried to run a different Liberation campaign and whole issue was gone, the HMD was absolutely fine. Then I switched back to the first campaign and the HMD was disaligned. 

Only thing I can tell is, that if I move the INS to IFA, there is an "INS RDR" warning on my MFD and it goes away only if I switch the INS to NAV. Unfortunately it doesn't solve the imprecise HMD.

Now I'm sure it is a Liberation campaign issue, for some reason there must be something set differently in this particular scenario. I thought maybe I'm missing the GPS, but that shouldn't be the case because the campaign takes place in the 2021 and I tried the INS aligning with moving the switch only to the NAV and it didn't change anything. 

There is still a decent chance that I'm doing something wrong in the INS aligning process, something that I'm not aware of.

Do you know what does the "INS RDR" message mean and what should I do with it? I play DCS for more than a year and I saw it for the first time only after I started this USA vs. Iran campaign. 

Thx. 

Goliathus

[Tholozor]

It means you don't have GPS available in the mission. Without GPS, putting the INS knob to IFA will command the In-Flight Alignment procedure using the radar (IFA RDR) for precision velocity updates (PVU). Once alignment quality reaches 'OK' the knob should be placed to NAV. I would double-check either the mission date or player coalition to ensure GPS is available.

Edited March 6, 2022 by Tholozor

[Goliathus]

Thanks for your answear, Tholozor!

Ok so for some reason my campaign runs without GPS at the moment, I´ll try to look more into it and to find why the GPS is missing (the date when its happening is may 2021, but OK, maybe I messed something up when starting the campaign or it´s some kind of Liberation campaign bug for this specific campaign).

Just to be sure I aligned the INS properly even with GPS missing - I ran all fire tests, started the APU, then the right engine... after the right engine is lit up, I usually run the BIT test, then I swith the radar to stby and INS switch to CV (I was taking off from a carrier) to get the INS aligned - I speed things up by using the stored heading button. Meanwhile the INS gets aligned I turn on the IFF and DLINK, start the left engine and do other settings, that are not important to mention.

After I get the "OK" message and information about the alignment quality (0.5) I switch the INS knob to NAV. Doing this cleared all INS messages from the MFD, so I didn´t get the "INS RDR" message. But the HMD is still not centered properly even after I do the HMD aligment

So my last question and then I´ll solve the whole thing by running a new campaign - am I missing something important in the INS aligning process (when aligning without GPS), that could cause the HMD in advance not to align properly? Maybe I forgot something, but I fly the DCS for 1.5 years now in the F/A 18 C with zilion cold startups without having almost any issues.

 

[Tholozor]

Remember that aligning the HMD doesn't change the position of the display on the screen, it merely makes sure the information displayed through it is aligned to the aircraft. In INS-only mode without GPS, the INS is subject to drifting. So while the HMD may be correctly aligned to the aircraft, it's also subject to the INS drift since its data is provided to it by the aircraft computers.

If the aircraft's INS is out of position due to drift, everything in the HMD will be drifted by the same amount.

Edited March 7, 2022 by Tholozor

[Goliathus]

Hi,

I started another DCS Liberation campaign and I´m not experiencing any issues with HMS or INS anymore.

Seems like there was just something bugged in my previous campaign, because even after aligning the INS properly (no GPS -> turning the knob after INS aligned into NAV position) the HMD symbology was still drifted elsewhere than it should be.

Just wanted to let you know.

Goliathus