F-15 navigation discrepancy bug

[Tallyho1961]

Hello,

 

I'm new to LOMAC, so this may already have been identified.

 

The F-15 heading tape and HSI do not agree with one another. The HUD appears to carry the correct course information, the HSI is incorrect.

[Brit_Radar_Dude]

http://forum.lockon.ru/showthread.php?t=8714

 

Part way down this thread is something by TekaTeka which is a partial fix I think?

[Guest IguanaKing]

Tell those guys at ED to stop installing steel screws in that F-15 compass housing. ;)

 

TallyHo, are there problems with the heading tape on the HUD compared to the HSI as well? I don't notice any problems in the quick fly F-15 mission. What mission do you notice the problem in? I have a theory that maybe this behavior is somewhat realistic. If the HSI slaving were referenced to a flux gate, and the HUD was referenced to the INS, that could explain a difference between the two. An HSI gives magnetic information (when slaved of course ;) ), while INS gives your actual track (with wind).

[Tallyho1961]

Hi,

 

I'm testing this right now in one of Thomas Weiss' missions and it look like a couple of things are askew.

 

For NAV info on the F-15 we've got five sources:

 

1. The HSI and its course/distance-to-next-waypoint indicators.

2. The HUD heading tape

3. The HUD heading steering index and assigned heading indicators

4. The canopy frame-mounted compass

5. The NAV block in the lower right hand corner of the HUD.

 

I now see that the 90-degree error on (4) is well known and slated for repair in the next patch. So let's leave that out.

 

What I'm seeing is that the NAV block info (5) disagrees with what is on the HSI time-to-next-waypoint readout.

 

I'm going to fly the same mission and report back with more specific info.

[Tallyho1961]

Caveat: I'm normally not this anal, but this is such a fantastic sim, and errors are immersion killers, so here goes:

 

I started by writing down the waypoint headings and distances so I could cross-check the various instruments along the way. On this particular mission, although I will try others, it is mostly the NAV block that is fouled up.

 

Observations:

 

1. The HSI gave course/time-to-waypoint indications that were as per the mission briefing 4 out of 5 times. On the final leg, the mission briefing gave a heading of 86 degrees, while the HSI brought me in at 99. It didn't really matter because I could see the airfield at that point, but it was an error nonetheless.

 

2. The NAV block readings agreed with the HSI and mission briefing only on the first leg. After that, the NAV block was fouled up all the way along and in different ways each leg. It would give distances like 1.4nm when it should have been giving, like, 36nm. Then, on one leg, it seemed to catch up with the HSI all of a sudden. On the last leg it was just behind the HSI and, like I said, it didn't matter because I was about to make a VFR landing anyway.

 

3. The heading tape waypoint index can also be off the HSI/mission briefing by a couple of degrees. It doesn't really matter but you would assume it would agree with the other settings.

 

The problem with the NAV block being fouled up is that it the most convenient way to keep track of where you are. You can keep dipping your head to check the HSI, but who wants to do that.

 

I've only been with LOMAC for about a month and until a few days ago was flying only the A-10 to help me learn the ropes. I didn't notice any errors on its NAV block/HSI/HUD/compass readouts, and I assume this sort of thing is part of 'core code' as opposed to aircraft-specific stuff, so I find it odd that the F-15 is out of whack.

 

Anyway, I'd love to know if I'm the only one who's noticed this.

[GGTharos]

These problems are not going to be fixed in 1.11.

 

In general,

 

1. Ignore the nav block and only use the HSI for range reading

2. HSI is accurate only when in nav mode.

3. The compass on the canopy frame will be fixed to display the correct heading.

[Tallyho1961]

Hi,

It's great to hear from somebody on the Dev Team :)

 

1. Understood - I thought I might have a corrupt installation.

2. Does this mean the HSI is inaccurate in ILS mode?

3. Good news - saw this in another thread.

 

Are these issues slated for repair in the 1.2 add-on I've been reading about?

 

Thank you.

 

Dave.

 

PS - Love your product.

[GGTharos]

Well, I'm not the dev team, just a beta tester, but I'm just repeating what has been said before :)

 

I'm not certain if 1.2 will see these things repaired, mostly because the devs are reluctant to do anything with current cockpit technology when new cockpit technology will be getting introduced in 1.2 in the Ka-50 (clickable pit etc) ... not that I'm particualrely happy about that, I want working navigation on the 15 as well, since its my main ride ;)

 

About 2. No, it's accurate, ILS is a NAV sub-mode.

I should be clearer: In combat modes, the F-15's HSI ceases to update the course needle (it shows you current heading properly, but the course 'freezes') and it also ceases to update range.

Switch to any nav mode and it works fine.

[Tallyho1961]

Roger that.

 

I hadn't noticed the combat mode/HSI bug - you've saved me another thread :)

 

I'll keep my fingers crossed that some F-15 lover will convince them to fix these issues. I figure if you're 90% of the way there, finish the job right.

 

But that's me.

 

Thanks for clearing this up for me, I'm off to learn more about using my A2A missiles. Even if I get lost doing it.

[GGTharos]

Cool. Keep in mind we made a really big fuss about A2A missiles being fixed in this patch. You may or may not notice the bugs quickly, they're not necessarily glaringly obvious ;)

[169th_Crusty]

Roger that.

 

I hadn't noticed the combat mode/HSI bug - you've saved me another thread :)

 

I'll keep my fingers crossed that some F-15 lover will convince them to fix these issues. I figure if you're 90% of the way there, finish the job right.

 

But that's me.

 

Thanks for clearing this up for me, I'm off to learn more about using my A2A missiles. Even if I get lost doing it.

 

90% of the way there :) ... well, perhaps slightly less.

Oh, since you mentioned HUD heading tape in your previous post - another

annoying thing is the steering bug. Let's say your current heading is 360,

your selected waypoint is 325. The bug should be on the left side of the tape,

right? Well, sometimes it will point you to the right... If you follow it, it'll take

you all the way around to get to 325. So, for NAV I use HSI all the time.

(in the NAV mode :D)

[Tallyho1961]

Hi Krusty,

 

Ya know, I had noticed the steering bug error, but it was getting late and I began to weaken :icon_jook The more I think about it, it would be nice if the F-15 navigation bugs could be addressed. I've learned to love complex flight sims (two years with IL2) and I'm a full-out immersion nut.

 

Aside: For my radio commands in LOMAC I use a voice recognition program and figured out how to disable both the audio repeat of the command I issue and the on-screen text message that accompanies it - you just rename a pair of folders. I love speaking a command and hearing a response without any visual backup. It really feels real. Sometimes the message can be hard to hear - but I'm sure it sometimes is in R/L :cool:

 

Anyway, because these F-15 bugs are very visible, and learning to interpret the HUD is a big part of flying a modern combat jet, seeing them hurts immersion. Sure, they can be ignored and worked around, but wouldn't it be nice...

 

 

Hi GGTharos,

 

When you mention the A2A missiles, is the problem that they don't spin when in flight (the Hydra-70s do) as announced in the 1.1 ReadMe? I noticed that because I like to use chase weapon view from time-to-time.

[GGTharos]

A2A missiles don't spin in flight in general - the very few that do are the exception, not the rule.

 

No, I'm referring to guidance :)

[Tallyho1961]

I like this modern flight combat world - there's lots to learn. I was a big jet nut back in my early teen years. I built models of the F-105, F-22, F-111, Mig-15, Mig-21 and others, then completely forgot about the whole thing for like 30 years. What I like about LOMAC, like IL2's WWII world, is that it's re-connected me with all this stuff.

 

The reason I bought LOMAC/FC is that I attended an airshow about six weeks ago to see the WWII a/c: P-51, Spitfire, B-25 and B-17. Then an F-18 did a flypast and a few flashy manouevers and I figured I should try a jetsim out.

 

Glad I did - it's great fun.

 

PS - For what it's worth, this is the line on missile flight from the 1.1 ReadMe:

'Rockets and missiles now rotate around their longitudinal axis when in flight.'

Do they mean A2G missiles? Because the Mavericks don't rotate either.

[GGTharos]

They mean rockets without guidance which are spin-stabilized, and the single-axis controlled vikhr (it can only turn left/right, say, so it has to spin to turn in any direction) missile. The rest of the weaponry doesn't need to roll.

[Tallyho1961]

Roger that. Thanks for your time!

[S77th-GOYA]

The F-15 nav is screwed up?

 

 

 

;)

[Tallyho1961]

Am I the only one who wasn't copied on the memo? :cool:

[S77th-GOYA]

My apologies, Tally. I think I wrote the memo. And wrote it, and wrote it...

 

I have no doubt I will write it again.

[Tallyho1961]

Let me know. I'll co-sign.

[Brit_Radar_Dude]

1. The HSI gave course/time-to-waypoint indications that were as per the mission briefing 4 out of 5 times. On the final leg, the mission briefing gave a heading of 86 degrees, while the HSI brought me in at 99. It didn't really matter because I could see the airfield at that point, but it was an error nonetheless.

 

Might this be because the mission briefing shows the course straight to the airfield for the final leg, whereas the NAV system will take you to the Initial Approach Fix for your landing.......

[Tallyho1961]

AFAIK, the final leg always point straight to the airfield. An offset to the IAF makes very good sense and would be a fine piece of programming.

 

Thanks for that one!

[SwingKid]

beta7 of the v1.11 patch appears to have fixed the distance-to-next-waypoint bug in the HUD block, at least. Thanks to all who helped.

 

-SK

[Guest IguanaKing]

You know? I just noticed this problem in the A-10 as well, although I usually fly the A-10 IFR (I Follow Roads). But, I DID notice that the difference between HUD NAV bug and HSI course is less if you turn tight enough to keep your CDI centered (Not a difference in heading...YES, there IS a difference between course and heading. Where's the heading bug, BTW? ;) ). Perhaps the HSI course shown is to intercept the desired track between waypoints. BTW...IRL, the couse on the HSI is actually set manually, and the distance reading has at least one number to the right of the decimal point. ;) Its great that the HSI changes its course needle automatically in LOMAC, but that's not how it actually works. ;)

[Tallyho1961]

beta7 of the v1.11 patch appears to have fixed the distance-to-next-waypoint bug in the HUD block, at least. Thanks to all who helped.

 

-SK

 

Excellent news! Thanks for the update.