Recently, I noticed a strange event when flying the PMDG 737 from PAKT to PANC. After programming the FMC, I lined the plane up on Runway 29. FS Nav says the approach course for that runway is 290 however the heading bug in the plane and the heading at the top of the screen (when you hit shift Z) reads 306.I then moved the plane from PAKT to KBUF runway 5 with an approach course of 54 degrees. Now the heading bug and the heading reading at the top of the screen reads 44 instead of 54.As I have recently installed Misty Fjords and a lot of their add ons, I deleted them from the scenery library thinking that one of them might be causing the problem.What I have discovered is that for some strange reason, if I either add or remove a file from the scenery library, regardless of what file it is, then close FS9 and restart, the heading bugs now line up properly. If I then shut down FS9 and restart without adding or removing a file from the scenery library, the heading now is off by 10 degrees(44 instead of 54)at KBUF runway 5.I have played around with everything I can think of to see what is causing this but cannot figure it out.I would appreciate any help or advice on what might be causing this problem.Thanks for any help with thisRoger Hollands

I have had this problem before with FS2002. Check your Gyro drift under the Aircraft / Realism menu. Sometime Gyro drift checked here will cause this problem.Mark.

Aren't those things supposed to be slaved to at least flux-gate compass in those aircraft? That should just about eliminate any drift when slaved.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satillite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

Yes John, they are supposed to be. Ever since downloading one of my payware aircraft with "sophisticated" avionics I've had the same problem. I just hit the "d" button and all works fine afterwards. The drift won't show on the HSI/EFIS type gauge but the offset for the heading bug will make the autopilot act erratically. This can also show up when flying a trip over 1,000 nm, if you've passed through a change in the magnetic deviation you should probably update.Enjoy flyin'Zane

Thank you all for your input. I have tried to uncheck the gyro drift box but no luck.I guess I just need to keep adding or subtracting scenery files in order to get it right!!Roger

I had the same problem, magnetic and true bearing read the same where the declination was 21degrees. I eventually traced it to a recent scenery addition and I resolved it by re-layering (trial and error as you have already surmised!)NigelVancouver

I had the same problem and traced it to a Kcle scenery and afcad file.After deleting the two files and replacing the afcad file with the original, everything was back to normal.Hope you solve your problem.Arnold

Arnold and Nigel:Thank you both for the info. As a matter of fact, I did a recent install of KCLE and a new afcad. I will try deleting it and see what happens. The strange thing that I am finding is that it doesn't seem to matter which scenery file I delete from the FS9 scenery file.I need to either delete or add to the file and this seems to make the heading bug sinc with the actual heading.Nigel, do you remember which scenery you found to be faulty?Again,thanks for the help.Roger

Hi,I had this bug recently. I saved my default flight with dark cockpit and with a flightplan that was not cleared before I saved the flight. Maybe you did this too. Try deleting your default startup flight. Maybe it helps.Regards,Jeroen van SchoneveldVelserbroekThe Netherlandshttp://fs2crew.com/linepilot.jpghttp://www.precisionmanuals.com/images/forum/800driver.jpg

I am happy to report that I have found the problem. Arnold you were right!! I deleted CLE2004 from my scenery files and the problem went away.I sincerely thank you for your input. All is well.Thanks againRoger

How very strange this is!! My problem resurrected itself again in August where the true heading and magnetic bearing were the same, notwithstanding a deviation of 21 degrees(my previous layering solution was local scenery but obviously wasn't the solution). I have just read this string by chance and previously it had not registered that others had been having this problem with KCLE.Independently in August, by trial and error I eliminated my addon sceneries in blocks of ten and eventually found that KCLE was the culprit!! I messaged extensively with the "Shez" and he could not replicate this problem on his own machine and sent me his scenery folder, which I tried and my problem was resolved.So I did a new download of KCLE and everything works fine, now my headings at CYVR are correct and I attribute this problem to corruption of some sort in the earlier KCLE download.Absolutely amazing that an airport geographically so far removed could do this. Actually, not amazing - more likely scary!NigelVancouver

I haven't loaded KCLE But I've had it happen with an exclude file for a scenery for YHLI, one for an airport in Croatia, one for an airport in Venzuela and I've had it happen after loading an airport environment texture update.What all those in common could have done to kill the magnetic deveation world wide I have no idea.I'll add KCLE to my list of things to check next time someone reports this problem.