Heading offset?

I noticed that the heading showing on the hud is not accurate (8° off). I always align INS before taking off. Is this a bug or am i missing something?

Magnetic deviation? You've not said what it's 'off' from.

He probably means the F10 map. It's known that aircraft heading is 7-8 degrees off from the F10 map heading.

Hornet shows magnetic heading by default, you can switch to true north via HSI->DATA->A/C->MAGN HDG

F10 map, AWACS calls and editor are all referencing true north.

By default Hornet uses magnetic heading but you can change that to true heading in HSI-> DATA-> A/C page.

EDIT: Sniped :D

Yes i was refering to the F10 map heading. Thanks all for the responces! I'll try that later when i'm back home.

EDIT: That was it! Appreciate for the help.

Let me understand... if i set TRUE HEADING in F/A18 the heading indicator on HUD compass is shifted of about 12° in NTTR (as referenced in true and magnetic heading offset) ... but it's a tacan .... why is it influences from magnetic heading? it should works with INS and GPS that could work on true heading...

Let me understand... if i set TRUE HEADING in F/A18 the heading indicator on HUD compass is shifted of about 12° in NTTR (as referenced in true and magnetic heading offset) ... but it's a tacan .... why is it influences from magnetic heading? it should works with INS and GPS that could work on true heading...

Aircraft predominantly navigate in regards to Magnetic North rather than True North (hence why the names of runways change over the years) so its perfectly normal for the Hornet to be set to Magnetic by default.

Most VOR and TACAN are aligned to magnetic north because many users of these systems have only compass reference. It doesn't use GPS or INS but it is true that alignment is a choice since it only radio signals which can be independent of magnetic compass.

Other VOR and TACAN are aligned but true north but this is only in places like north and south pole where magnetic variation is very high and changes much for short flights so users are referencing true north for everything anyway.

Not sure if it's a real reference, but a while ago in a different post on the same subjet, someone wrote:

There is a rule in all aviation : what is WRITTEN is true, what is SAID is magnetic (including of course the instruments in the aircraft)... therefore, maps are ALWAYS true (with the proper deviation indicated in the legend). On the other hand, if you listen to the ATIS before taking off (I mean IRL), the weather described is SAID therefore magnetic (contrarily to the weather in the METARs which is WRITTEN therefore TRUE).

I saw a big difference between the HUD heading and the radar heading today. Something's definitely gakked up there. Never really looked at radar heading before, though, so it may have always been that way.

HUD is magnetic by default. Radar is true. AFAIK it's been that way for a while (since release ? ).

https://forums.eagle.ru/showthread.php?p=3639336

Not sure if it's a real reference, but a while ago in a different post on the same subjet, someone wrote:There is a rule in all aviation : what is WRITTEN is true, what is SAID is magnetic (including of course the instruments in the aircraft)... therefore, maps are ALWAYS true (with the proper deviation indicated in the legend). On the other hand, if you listen to the ATIS before taking off (I mean IRL), the weather described is SAID therefore magnetic (contrarily to the weather in the METARs which is WRITTEN therefore TRUE).

Actually, I am the one who wrote this, and, yes, it is a fact in aviation (I am a private pilot).

Now, in DCS 2.5 in general and in the F/A-18C in particular, the situation is right and wrong at the same time...

What is totally like real life is the fact that the ME map, as well as the F10 map while in the game, are both in TRUE degrees (for example when one checks a distance and direction with the ruler). In real life, aeronautical maps are always in TRUE degrees. The other thing that is totally similar to real aviation is that in the cockpit, all the NAVIGATION instruments are in MAGNETIC degrees (in the Hornet we are talking about the HUD, the HSI and the backup COMPASS), of course if one doesn’t touch the option to change the HUD to TRUE in the DATA page.

The Air Air Radar is in TRUE degrees in the Hornet (but I have no real-life experience of flying with an ATK radar, I have no idea why only the radar is in TRUE, but I will ask a friend of mine who is has flown the Hornet just to check on this one, and will report later here.

This is why we see a 7 degrees difference between the 2 : the magnetic declination in the region of the Black Sea now in 2018 is around 7 degrees East. That means that from TRUE to MAG, one must subtract 7 degrees

If one wants to have TRUE degrees in the HUD and HSI, (I have no idea why one would want that, although, it might be a good thing because of what I will say later...), this can be dialed in the DATA page of the HSI under A/C with the button labelled MAG HDG, changing it to TRUE HDG. Then, the word TRUE appears at the top of the HSI and a T appears under the heading tape of the HUD.

Now, what is less compliant to real life practices is the fact that the runways at all Air Bases are labelled with their TRUE headings where in real life they are always labelled according to their MAG headings, and this is why their numbers might change over time because the magnetic declination varies with the years passing, as did point out Deano87 in a previous post.

The other thing that is very strange is the fact that ATC gives you vectors in TRUE degrees (I just made a quick experiment to make sure and it is unfortunately the case!! And it is the same with the AWACS BRA calls, they are given in TRUE degrees… In real life, when ATC gives you a vector, it is always in MAG degrees. (Not sure about AWACS, no experience there…)

So to summerise, as El Bastardo just said above about the game:

‘Hornet shows magnetic heading by default, and F10 map, AWACS calls and Mission Editor are all referencing true north’

And I would add that :

-magnetic for navigation instruments in the Hornet are like in real life to be MAG

-F10 map and ME are right to be TRUE

BUT!:

-Runway headings are wrong to be in TRUE and ATC calls are wrong to be in TRUE

(a good example is something we all learn when you learn to fly: when you taxi to the runway, and you are cleared by ATC to LINE UP RUNWAY XYZ, you enter the runway and you always check if the big numbers printed in big white paint on the runway are the same as your heading in your navigation instruments: HSI if you have one, but usually DG and compass)

THANK you everybody for the answers ... but what i found a little bit strange is that if i set the TANKER TACAN and i change from Magnetic to True HDG what i expect is that the HDG on the HUD compass ruler it changes not that it changes the direction to meet the Tanker (away from radar lock)

what i expect is that the HDG on the HUD compass ruler it changes not that it changes the direction to meet the Tanker (away from radar lock)

????? could you explain more clearly what you mean? I dont understand your words??

ME/F10 map while in the game, are both in TRUE degrees (for example when one checks a distance and direction with the ruler).

Not exactly. Ruler is giving angle with respect to XYZ grid. If you measure longitude line you will find it isn't 360. But DCS is using XYZ grid as substitute for true in all modules in flight but not for the map projection.

The Air Air Radar is in TRUE degrees in the Hornet (but I have no real-life experience of flying with an ATK radar, I have no idea why only the radar is in TRUE, but I will ask a friend of mine who is has flown the Hornet just to check on this one, and will report later here.

Please do. I do not know why real airplane would not have radar same reference as HUD.

Now, what is less compliant to real life practices is the fact that the runways at all Air Bases are labelled with their TRUE headings where in real life they are always labelled according to their MAG headings

DCS runways are named for their real life magnetic heading. The runways are placed according to their true position relative to longitude lines. Essentially this is a map projection error. To find the true heading of a runway in DCS measure both the grid direction of the runway and the grid direction of a nearby line of longitude. The true heading is the relative angle.

So to understand DCS runway direction compared to real life it requires two steps. Find grid direction and convert to longitude direction. Next apply magnetic variation. Search for example Vaziani real runway heading in true and compare to DCS Vaziani with ruler. They won't match. But apply correction because DCS longitude isn't vertical on paper. Now they will match.

Imagine you fly an airplane set to 'true' heading reference and fly over a runway which has a real heading of 360T. Also you can watch your longitude position in a display. What you will find is that flying 360 "up" on the map that you will cross this runway which is 360 relative to longitude at an angle. Also your longitude position numbers will change.

The other thing that is very strange is the fact that ATC gives you vectors in TRUE degrees (I just made a quick experiment to make sure and it is unfortunately the case!! And it is the same with the AWACS BRA calls, they are given in TRUE degrees… In real life, when ATC gives you a vector, it is always in MAG degrees.

You are thinking about United States. Russia ATC and GCI gives headings in true. This is historically accurate. System was designed for airplanes like MiG-29. What DCS does not do is changeover to magnetic reference in cases where nation would use it.

????? could you explain more clearly what you mean? I dont understand your words??

I have to do more tests... but i set the TACAN on TANKER with magnetic hdg and i take the tacan direction marker in the center of my hud compass ruler , i lock the tanker and my direction was right straight to tanker then i change it in true and the TACAN direction marker shifted on the left but as the radar confirmed the tanker was still in front of me (about 15nm).

I noticed that the heading showing on the hud is not accurate (8° off). I always align INS before taking off. Is this a bug or am i missing something?

What are you using for the MAGVAR when you align the INS?

I have to do more tests... but i set the TACAN on TANKER with magnetic hdg and i take the tacan direction marker in the center of my hud compass ruler , i lock the tanker and my direction was right straight to tanker then i change it in true and the TACAN direction marker shifted on the left but as the radar confirmed the tanker was still in front of me (about 15nm).

Think you might have found a bug.

What's the mag dec in PG?

I found a copy of ONC H-7 dated 1994 which shows 1-2 degrees for the area the DCS PG map centers on. Doesn't state what the drift is, though, not sure what it is today.

EDIT: This chart indicates that the current (is) magnetic declination for the Persian Gulf is more or less bang on 2 Degrees East.

 

 

Please do. I do not know why real airplane would not have radar same reference as HUD.

 

 

 

You are thinking about United States. Russia ATC and GCI gives headings in true. This is historically accurate. System was designed for airplanes like MiG-29. What DCS does not do is changeover to magnetic reference in cases where nation would use it.

Yes I was thinking in North American and European terms... Didnt know the Russians would give ATC headings in True...

Here is the answer about Magnetic and True in the Hornet... I was puzzled by the fac that our HSI and HUD is in Magnetic and our Radar in True, which seems totally not practical. I asked Vincent 'Jell-o' Aiello from the great 'Fighter Pilot Podcast' and here is his textual answer:

Regarding your question:

1) everything in the aircraft is in magnetic, unless true is selected on the MPCD and I believe that only effects the HSI and HUD.

2) all AIC calls are also in magnetic.

Bottom line, we almost never use true headings except when going between charts and actual heading, which we almost never do anymore.

Thanks to Jell-o for answering this for us!:thumbup:

Or at high latitudes, but that doesn't apply in DCS. Thanks for confirming!

yes of course, that disctinction about high latitude is a real life thing that doesnt apply at all, unless one day we do have a high arctic map !!!!!

or Antartica?

This topic continues to annoy me a lot, I dont know about you all...

Look at this picture:

I have both the HSI and the Radar visible... on the HSI, one can see that I am heading about 315 degrees and I had designated WP1 as AA WP, and one can see in the top right corner of the HSI that indeed WP1 is at 314 degrees! That is MAGNETIC.

Looking left at the radar, right away one can see that our heading (top center of the radar display) is 328 degrees... In Nevada where I am now, the Magnetic Variation is around 13 degrees EAST, therefore one needs to substract it to go from TRUE to MAGNETIC (which is almost exactly what it is, 328 TRUE minus 13 is very close to our 315 MAGNETIC...

Furthermore, looking at the BRA reading on the radar display (bottom left BRA) that shows where my cursor is looking (exactly on the AA WP 1), it shows TRUE as well... (328 DEGREES)

I found the same discrepancies with the new SA page we got today in the update...

It is not possible to have one display in TRUE and another in MAGNETIC... this is very poor SITUATIONAL AWARENESS:cry:

This topic continues to annoy me a lot, I dont know about you all...

Look at this picture:

I have both the HSI and the Radar visible... on the HSI, one can see that I am heading about 315 degrees and I had designated WP1 as AA WP, and one can see in the top right corner of the HSI that indeed WP1 is at 314 degrees! That is MAGNETIC.

Looking left at the radar, right away one can see that our heading (top center of the radar display) is 328 degrees... In Nevada where I am now, the Magnetic Variation is around 13 degrees EAST, therefore one needs to substract it to go from TRUE to MAGNETIC (which is almost exactly what it is, 328 TRUE minus 13 is very close to our 315 MAGNETIC...

 

Furthermore, looking at the BRA reading on the radar display (bottom left BRA) that shows where my cursor is looking (exactly on the AA WP 1), it shows TRUE as well... (328 DEGREES)

 

I found the same discrepancies with the new SA page we got today in the update...

It is not possible to have one display in TRUE and another in MAGNETIC... this is very poor SITUATIONAL AWARENESS:cry:

SA is - supposedly - a moving Map, thus True Headings, probably all the calculations are compared with GPS which is True

HSI is - supposedly - a enhanced compass with a map projected underneath, thus Magnetic

I'd say.

I'm also a licensed skipper and all this happened with the introduction of GPS, you just know what you're working with.