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Bug - HSI wrong heading indication


TurboHog
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The heading as indicated by the HSI is 10 degrees off.

 

To reproduce this bug:

 

- Start a mission.

- Press Ctrl + y in outside view to show your 'real' heading.

- Compare to heading on HSI.

 

Error is about 10 degrees.

 

Or use the Bearing/range finder on the F10 map to find bearing to a point and use your HSI. You will end up somewhere else.


Edited by TurboHog

'Frett'

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In the SU-25T at Batumi runway 31

 

F2 view shows 305,

Required heading on HSI = 306

HSI outer scale = 304


Edited by xracer

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Intel Core i7 920@4.2Ghz (stable, 65degC fully loaded), EVGA GTX-780, Asus P6T Deluxe V2 v.5.04 BIOS, Saitek X52, 1TB/500GB WD HD for system/storage. Kingston SSD 120 GB for DCS, 250GB Samsung 840 SSD for the rest. 16GB Kingston KHX1600C9D3 Memory, 9 GB Pagefile, EK HFX-240 Watercooling, Corsair HX-1000 PSU. HAF-932 Tower, TrackIR-5, Win64Ult

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Very strange. I start on batumi runway and it is fine.

 

Then again I've had several occasions where it was absolutely incorrect. 10 degrees is way too much for magnetical deviation by the airplane's own magnetic field.

 

I will further investigate and post screenshots to show you what the problem is.

'Frett'

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Try this:

 

On the ground turn 360 degrees during taxi.

 

This resulted for me in an error of 100 degrees. Not good. It seems likely that your aircraft's movement (on the ground) has something to do with it.

 

Further testing tomorrow (how it behaves in the air while turning)

'Frett'

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Ok. There is a bug here.

 

See attached track file.

 

Starting at Batumi, I check my true heading (305) with my indicated heading (305). Correct. Right after taxi (easy and coordinated turns as you can see) I line up with the runway and my true heading is 305 degrees again. Indication is way off.

 

I then try to navigate to Kobuleti (HDG 026 from Batumi) and you can see I will never get there if I have to believe my HSI.

 

Note that significant errors under normal conditions like these have nothing to with magnetical deviation.

 

Looking forward to confirmation and eventually (V1.2.6?) a fix.

Heading bug Su-25.trk

'Frett'

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Wonder if it's a bug in the SU-25/A. Did a couple of 360's in the SU-25T at Batumi, but no deviations for me.

 

EDIT: Yes, got the same as you in the SU-25 included in FC3. Error is in the HSI. F2 -> CTRL -y = ok. Didn't have to do any abrupt moves. Still got it.

EDIT2: Yout totally right. Tried again the SU-25T. Did some really abrupt moves and got 260 instead of 305 on the outer scale of the HSI.

 

Haven't you heard about hysteresis? You have to tick the glass to make it right :D

 

 

Important and well spotted!

-


Edited by xracer

System spec:

Intel Core i7 920@4.2Ghz (stable, 65degC fully loaded), EVGA GTX-780, Asus P6T Deluxe V2 v.5.04 BIOS, Saitek X52, 1TB/500GB WD HD for system/storage. Kingston SSD 120 GB for DCS, 250GB Samsung 840 SSD for the rest. 16GB Kingston KHX1600C9D3 Memory, 9 GB Pagefile, EK HFX-240 Watercooling, Corsair HX-1000 PSU. HAF-932 Tower, TrackIR-5, Win64Ult

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Wonder if it's a bug in the SU-25/A. Did a couple of 360's in the SU-25T at Batumi, but no deviations for me.

 

It seems to happen only on the first few turns on the ground. Same thing happened in the Su-25T. Make a fast turn and stop turning abruptly. However it seemed to stabilize at the correct heading after a while. In the Su-25A you will be fed up with an error throughout your flight as there is no way to reset the instrument.

 

Need some more people testing...

'Frett'

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Could an ED tester take a look? This is a very annoying bug because the HSI is your main navigation instrument in the Su25.

 

I'm bringing up my post because I hope the fix can be included in the final update for V1.2.5 as V1.2.6 is going to take a while.

 

EDIT:

 

See this thread

 

Just allowed some more time for the instrument to align and all seems fine now even after taxi!

 

I thought the avionics were also very simple? Is this a hint towards DCS Su-25A then?

 

But please, if you add features please document them. Nothing in the manual sais something about aligning your HSI/gyro.


Edited by TurboHog

'Frett'

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True, but it has been like that since FC 1.12b as far as i can remember.

I always power on the aircraft first, refuel / ream.

Close canopy, light on etc etc and very last thing i do is start the engines.

 

All this gives me about 30 seconds of line up time for the HSI which normally seems to be enough.

 

Still, on occasion i notice rather large deviation's on the HSI, maybe i just need to give it more time to align though.

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I believe a 3-minute gyro spin up time has been modeled for the Su-25 and Su-25T since their first creation as AFM aircraft in LO 1.1/original FC.

 

Good, I will watch my clock then.

 

Nothing about it in the latest version of the manual though. Or am I missing something?

 

That should really be added because navigation can be really annoying if you don't know about this hidden feature.

'Frett'

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I believe a 3-minute gyro spin up time has been modeled for the Su-25 and Su-25T since their first creation as AFM aircraft in LO 1.1/original FC.

 

Yes, that must be more like it. I was waiting at least 2 mins and no change at all on the HSI.

System spec:

Intel Core i7 920@4.2Ghz (stable, 65degC fully loaded), EVGA GTX-780, Asus P6T Deluxe V2 v.5.04 BIOS, Saitek X52, 1TB/500GB WD HD for system/storage. Kingston SSD 120 GB for DCS, 250GB Samsung 840 SSD for the rest. 16GB Kingston KHX1600C9D3 Memory, 9 GB Pagefile, EK HFX-240 Watercooling, Corsair HX-1000 PSU. HAF-932 Tower, TrackIR-5, Win64Ult

[sIGPIC][/sIGPIC]

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Keep in mind that deviation is modeled in game.

 

Then again, on occasion i have seen errors ranging anywhere between 10 and a full 180 degrees though.

 

Its a tough one to replicate, and hence to solve.

 

 

Deviation only affects actual DCS aircraft, FC3 type aircraft only reference True heading.

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Deviation only affects actual DCS aircraft, FC3 type aircraft only reference True heading.

 

+ if deviation caused by the aircraft's own magnetic field would result in 180 degrees differences, all compasses would point to your aircraft :lol:

 

When you look at the inside of the canopy to your right, slightly behind you, there is a magnetical deviation chart (I think.) Interesting.

'Frett'

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