[BUG] lateral guidance during short approach landing phase 2 without TILS buggy (OB , MT)

[TOViper]

@Snappy Can you still reprodoce the issue? I did a test today, and I wasn't able to reprocude the issue. I was landing at Vaziani Airbase, starting hot in the air.

[Snappy]

On 10/23/2024 at 9:34 PM, TOViper said:

@Snappy Can you still reprodoce the issue? I did a test today, and I wasn't able to reprocude the issue. I was landing at Vaziani Airbase, starting hot in the air.

Hi TOViper, nice to hear from you! .

I had/have taken a break from DCS, because of the lack of progress with many core problems and EDs attitude/business behaviour.

So I haven’t flown in a while.

Still I’d like to see the Viggen get improved . I’ll try to take a look in the next days and get back to you on this issue.

Thank you very much for your dedication to testing and re-checking older bug reports!!

Edited October 25, 2024 by Snappy

[Snappy]

On 10/23/2024 at 9:34 PM, TOViper said:

@Snappy Can you still reprodoce the issue? I did a test today, and I wasn't able to reprocude the issue. I was landing at Vaziani Airbase, starting hot in the air.

Hi @TOViper,

I tested this again today, and the issue is still present. To be honest , currently I find the whole  approach phase pretty inconsistently modelled (the HUD guidance and yellow CI course pointer are wrongly leading to different directions most of the time, not matching the manual description) 

Can you please try to refly the following attached mission? (Its from the older Viggen training mission pack from the user files library by cornivus.

This mission sets up you up airborne about 20 nautical miles southeast of Senakhi for a landing in westerly direction on runway 27.

I did the following, immediately after mission start,:
1. I selected ALT hold (I didnt want to land, just check HUD lateral guidance). 
2.I selected LANDN NAV ,  You can see the HUD guidance is correctly, slightly to the right to the curved LB final approach course intercept

(but the yellow CI course index pointer wrongly points to LF, despite  LB1 being the current destination waypoint , this is another separate bug, CI  should only point to LF when Landing Phase 2 begins, which is AFTER passing LB)

null

3. Immediately afterwards I did the flip flop LANDN NAV/ PO / LANDN NAV: ( the system correctly shortens the approach and provides guidance to the left to the new shortened final approach intercept course intercept) 

4. On the way to the shortened final approach course intercept, everything seems correct.

5. Before actually reaching the intercept point to final, the HUD suddenly again starts guiding to the left (the bug I originally reported)

( you can see the HUD turns me left, parallel to the approach course, and as you can see on the CI, where the extended centerline is drawn to my right , the nav system itself knows where he airport is , so its not a navigation accuracy error it seems , the HUD guidance itself is wrong.

Interestingly , shortly afterwards , almost as soon as I roll out on the parallel heading  the HUD seems to realise its error and jumps far to the right, to guide to the actual airport, but unfortunately  by now the approach is a mess and the new guidance seems to the airport itself and not an actual intercept to final approach course... 
Sometimes the HUD seems to catch its own error earlier, while you are still in the turn to the parallel course. But I've flown this multiple times now and never did the HUD once guide correctly a contineous smooth intercept to the shortened final approach course. 

Could you kindly refly this mission on your computer  and follow my sequence exactly? Its important that you start the LANDN NAV mode and Flip Flop immediately and that you also follow any change in HUD guidance immediately and just stupidly fly  following the HUD , ignore the yellow course pointer on the CI.

Sorry for the low quality screen shots, I dont know why the pictures became so low res during forum upload. The originals are much sharper, but you can view them if you click on the pictures.

Kind regards,

Snappy

 

M06 - Landing - Clear Sky.miz

Edited October 26, 2024 by Snappy
Spelling errors

[TOViper]

Hey Snappy, good morning!

After reading through, I went back to watch my own track once more. And yes, point 5. is exactly what is happening: First the HUD turns way from the approach course / track, then it seems to realize its fault and comes back. I didn't notice that when flying, maybe I looked at something else in the pit during the time of occurence.

I hope that @MYSE1234 will dig in soon, and gives us a little hope that this becomes repaired someday (e.g. in the next 24 hours)
So we have two obvious bugs: The first one is described in section 2., and the second one is described in section 5.

I will leave everything as you have written here, since you have done that very professional manner, and everything needed is there I think.

Edited October 26, 2024 by TOViper
needed to check something ...

[Snappy]

14 minutes ago, TOViper said:

Hey Snappy, good morning!

After reading through, I went back to watch my own track once more. And yes, point 5. is exactly what is happening: First the HUD turns way from the approach course / track, then it seems to realize its fault and comes back. I didn't notice that when flying, maybe I looked at something else in the pit during the time of occurence.

I will leave everything as you have written here, since you have done that very professional manner, and everything needed is there I think.

I hope @MYSE1234 will dig in soon, and gives us a little hope that this becomes repaired someday (e.g. in the next 24 hours) .
So we have two obvious bugs: The first one is described in section 2., and the second one is described in section 5.

Anyway, I will watch your track right now....

Good Morning to you too Viper!

 there is actually another 3rd bug in here, which I had also already reported long ago , thread link below. You can see it in my section 4 picture :

After I shortened the approach via Flip Flop, the destination waypoint is still shown as LB1 , this is wrong according to the manual. By shortening the approach/flip flopping, I manually started approach Phase 2, during this phase the destination Waypoint should be LF . (Phase 2 can be entered either manually via shortening approach , or automatically during normal approach by overflying LB point) 

 

[TOViper]

I am currently in the process of finding out if the distance to the runway has an influence on that, and if the TILS does something to that, because initially, the TILS is blinking, despite I had turned it to another channel (in this case to 01, and not to A - which would be 12 for Kholki) which would mean it uses the localizer for horizontal guidance for a short period of time.

Edited October 26, 2024 by TOViper

[TOViper]

I was able to exaclty replicate this situation, where the HUD + ADI leads me to the wrong point of the circle:
 

[Snappy]

19 minutes ago, TOViper said:

I was able to exaclty replicate this situation, where the HUD + ADI leads me to the wrong point of the circle:
 

Very nice . At least I'm not going mad.
 

I just tried another thing and now I think its not necessarily related to short approaches, but either the HUD guidance for approach in general is buggy or its something related to TILS interferrence. I flew the attached night mission from the same training mission pack ( you are set up at the same spot, southeast of Kolhki).

This time I flew the full approach several times, just selected LANDN NAV and followed the HUD guidance to LB. 

The same thing seems to happen on a full approach there . Before reaching LB, the guidance goes to the left to parallel course and after a short while ( which seems not always the same. sometimes it notices pretty fast ) it catches the error.

 

 

Also, another question:

During approach slightly after point 5, after the HUD catches its error  , when the CI no longer shows the final approach intercept circle radius, but instead puts the circle on the destination airport with the centreline extending from it.

Do you also see this glitch on your CI that the runway centerline indication seems to be sometimes either flashing or  not visible at all? Heres a picture I took, when the line was flashing. Right now the line is not there at all, but it should be where I put the red line:

 

M08 - Landing - Dark.miz

Edited October 26, 2024 by Snappy

[TOViper]

The line not beeing visible or blinking is a current bug, which Myse is aware of, and I think for the upcoming patch he already solved that issue.
Can you remove the above info about the line not showing from your post please, just to keep the necessary info there and throw away the uneccesary one...

Edited October 26, 2024 by TOViper

[Snappy]

23 hours ago, TOViper said:

The line not beeing visible or blinking is a current bug, which Myse is aware of, and I think for the upcoming patch he already solved that issue.

Ah, very good! Thanks for the info!

  I just noticed another unrelated bug though , which I hadn't realised before: 

During landing phase 1 on a normal  full approach,once you select LANDN NAV ,  the active waypoint is correctly set as LB1, however I notice the waypoint distance readout is showing distance to LF/the destination airport)  I dont think this is correct.

Also,on a seperate note,  the go-around functionality described in the manual is still not working at all . If you are in phase 2/3 and turn more than 90 degrees away from final approach course,  the active waypoint should automatically switch back to LB for a new approach. In DCS it doesn't.

This is what I meant in my post, unfortunately the approach system logic at the moment looks like it needs a big overhaul.

So as far I understand it as a quick approach system summary, there a 5 bugs there.

1. the wrong HUD guidance to the parallel final course (original topic of this thread)

2. During Approach phase I with LB being the active waypoint , the yellow course index on CI wrongly points to LF instead

3.During approach phase I with LB being the active waypoint, the  waypoint distance readout dial instead shows distance to LF (may be related to above bug no2.)

4. After manually entering  approach phase II via flip flop, the active waypoint is initially still wrongly shown as LB, it should actually switch to LF. 

5. automatic go-around functionality not working at all ( turning more than 90 degrees away from final approach course during phase II/III doesn't prompt automatic switching of active waypoint back to LB for a new approach like it should. Manual Go-around function also doesnt work ,you should be able to  trigger it by switching mode selector to NAV  and then back to LANDN NAV , to set LB as active waypoint. If you do it, it just switches back wrongly to LF as active waypoint

 

Edited October 27, 2024 by Snappy