I am having something strange happen. It seems that the headings are all offset about 10-12 degrees clockwise - for example, suppose I'm lined up with runway 18, which is at 180 degrees. The heading indicator will show that I am heading 192 degrees or so. This is consistant across planes and locations. Actually the offset varies by location as if the magnetic variation for the entire world has disappeared. I recently updated the airac cycle, but I'm not sure how this (or anything else) could have affected this. Any ideas would be greatly appreciated.Drew

never heard of that happening befor. If no1 can figure out what is wrong for you, and if you cant get it fixed, i know this is the most dreaded result,but reinstall fs. that always fixes everything. happy holidays! :-wave

There are some sceneries designed for FS2002 that cause this to happen in FS9. Have you installed any new sceneries lately? If so disable ones that don't specify that they were designed for FS9. Dick Bixler

Read the compass not the runway numbers. Actual runway directions can be +/- 5 deg for a start. The approach plate will show you the actual mag direction for a runway.If EFIS, ensure you have Mag heading selected and not True (only on some).If not EFIS, is the indicator a gyro? If the Heading Indicator you refer to is a gyro then just align it to the compass.

Dimbo,Don't know enough about this topic to offer solid advice, but perhaps you have a saved flight in which gyroscopic precession or a slew heading change had messed up your DG. Not likely to fix it due to the behavior changing across magnetic variation boundaries..., but have you pressed 'D' to align the DG with your compass?Just a thought,KevinEDIT: Sorry, Kefuddle, just reread your post in which you said much the same.

Sorry I wasn't clear about it - yes I was reading the compass heading - for example if I start a flight at KSLC the heading for runway 34R is 341. However, the comapss heading in the aircraft will read 354, which is offset by the exact magnetic declination there. I had actually recently installed Shehryar Ansaris KCLE scenery (2002 but patched for 2004) and that was one of the first things I did was to remove it. I also tried you r suggestion of pressing d to re-center but that didn't work either. FS seems to be doing everything in true headings now, not magnetic heading. Did I inadvertantly uncheck something somewhere? Thanks again for the help.Drew

I would like to add to this old discussion as I had it happen to me as well on numerous occasions lately.Problem is exactly as described. Both compass and HSI are showing the same heading, yet they are both offset by some 20-30 degrees clockwise.Interestingly enough, that does not occur every time - it seems to be random.Had it happen to me twice last night at Simflyers KIAH airport.Aircraft lined up at runway 27 and the compass and HSI showing 295 degrees.I have my compass precession option unchecked in FS menu.It is very pronounced again when being established on a localiser.I am tracking both the localiser signal and the glideslope, yet my HSI is showing my course to be turned 20 degrees counterclockwise.Your help would be greatly appreciated,Dom

This has cropped up before. The most likely culprit is a bad AFCAD file somewehere on your system. How you can track it down is a more difficult problem as AFCAD's can be installed in a variety of folders.Try a search for files beginning with AF2_ (Ultimate Traffic users may also need to look for F1UT_ files too). You could try moving the lot out to a temporary folder.If this works then isolating the specific file will be a greater headache but it would be worth the effort.boneshttp://fsaviation.nethttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Bones,Thanks for taking time to reply.Is it airport specific problem with particular AFCAD file you mean?or perhaps any AFCAD in any folder, not directly related to an airport I am currently in, could cause a havoc elsewhere?ThanksDom

I've been looking at this lately, but don't have the full story yet. What I've found is that the file magdec.bgl in the worldscenery folder which sets the local magnetic variation for the aircraft compass. The file is defined in 1 deg increments, and it appears that FS just takes a linear interpolation of the 4 nearest values. The values in this file are known to be poor, and this can result in compass readings not in agreement with the charts. I've found a replacement magdec.zip, but now I don't know where it came from (IIRC a link to it was posted in f-s-n- Airport for Windows forum).But there are also Magvar values associated with airports, ILS, VORs, NDBs, and waypoints. For some reason, approach legs have true course and magnetic course entries.Some of these I believe simply provide data which is displayed on the map. Not sure abou the navaids though. It might impact setting a radial to correctly follow an airway.Of course if there is cross wind, heading does not equal track.scott s..

Hi Scott,Are you actually saying that this parrticular file is corrupt?What's really strange is the randomness of this.It does not come up on the forums very often, so I guess this bug must be marginal in existence.ThanksDom