The tile says it all...Was flying from PHNL. Upon approach to KMSF (V1 simulation freeware scenery), runway 34L, I lost the magnetic deviation, resulting in a mess with the autopilot.The plane was level-d 767.After manual landing, I closed FS9 and launched it again. The mag dev had was still gone.I made the scenery unable in the scenery.cfg and after launching FS9 again, the mag dev was back!I enabled it back and surprisingly, the mag dev was back as normal.Do you know what could have triggered all this?ThanksGhiom

Some scenery files are buggy. Try putting a copy of your magdec.bgl file in your highet sceney layer. That has worked well for me. I think magdec.bgl normally lives in scenery/generic/scenery. Cheers,Bryn.

The tile says it all...Was flying from PHNL. Upon approach to KMSF (V1 simulation freeware scenery), runway 34L, I lost the magnetic deviation, resulting in a mess with the autopilot.The plane was level-d 767.After manual landing, I closed FS9 and launched it again. The mag dev had was still gone.I made the scenery unable in the scenery.cfg and after launching FS9 again, the mag dev was back!I enabled it back and surprisingly, the mag dev was back as normal.Do you know what could have triggered all this?ThanksGhiom

Are you perhaps referring to magnetic variation? That is, the change in the earth's magnetic field relative to true north, depending on geographic location?Magnetic deviation is the compass correction to take into account magnetic fields within the the ship or aircraft that affect compass headings. Deviation is a constant value for the specific compass installation.Reminded me of the old rule for determining a course- TVMDC. (Often remembered by sailors, as: True Virgins Make Dull Company !)(TRUE heading +- Variation = Magnetic Course +- Deviation = Compass course)To correct True heading for Variation, the rule is "East is Least & West is best". Ie- subtract east variations and add west variations.Cheers AR

Some scenery files are buggy. Try putting a copy of your magdec.bgl file in your highet sceney layer. That has worked well for me. I think magdec.bgl normally lives in scenery/generic/scenery. Cheers,Bryn.

Thanks for the advice.Highest, means with the highest number, right?Ghiom

Highest Priority for scenery other than terrain mesh is the lowest number in your scenery lib setup. In other words, position 1 is highest priority. The 'Move Up' buttion means (to me) move up in priority and the entry moves 'up' to the next lowest number in the list.

Thanks for the advice.Highest, means with the highest number, right?Ghiom

To me it means the highest layer number in the scenery.cfg file. Low numbers are terrain and vectors, mid numbers, photscenery and other regional sceney, higher numbers are detailed airports and stuff. I think of it like layering... Higher numbers layered on lower numbers. i put magdec.bgl in the highest layer. Perhaps I should not call this the highest priority.I should add that I still sometimes get weird ND issues wih the PSS 777, but I think thats not related to magdec but to the ND programming. Cheers,Bryn

Position 1 in the settings/scenery library list is the highest number layer. The layer numbers are reorganized when FS indexes the scenery.Here is the highest Layer No. section in my scenery.cfg:[Area.196]Title=AES-BasePackLocal=aerosoft\AesActive=TRUELayer=203Required=FALSERemote= attached is the image of the top of the list as seen in settings\scenery library.