Hey guys,I saw a few posts on the subject but none of them really answer my question. The manual says the MD11 will auto switch to TRU mode when passing north of 73 degrees latitude. How about when you're heading back south of 73? I guessed it would auto switch back to MAG? My ND remained in TRU mode the rest of the way. Thanks in advance for any replies. Flying FS9 on WinXP.Rob

Manual switch back. The auto switch to TRU is because MAG can no longer be trusted, but once you are below 73 north, it is the pilots discretion which mode they want, so no auto option is available.

Thanks, Paul!

Hey guys,I saw a few posts on the subject but none of them really answer my question. The manual says the MD11 will auto switch to TRU mode when passing north of 73 degrees latitude. How about when you're heading back south of 73? I guessed it would auto switch back to MAG? My ND remained in TRU mode the rest of the way. Thanks in advance for any replies. Flying FS9 on WinXP.Rob

Rob,For your information,The real plane will automatically switch back to MAG once heading south of 72.5N.The switch to TRU when heading North is at 73.5N.What I see in the simulation is an auto switch to TRU at 72.5N going North (real is 73.5N) but more importent, no auto-switch back when going south below 72.5N.This switch-back to MAG does not happen automatically in the sim, as you observed, and I consider it a minor bug.The Manual for the simulation states correct what it offers, but the real plane offers a more logic auto-presentation of the item at hand.And regarding "pilots discretion": it's an MD11 option to select whatever reference you want, wherever you are on the globe, to have MAG or TRU reference, but the real plane switches automatically to TRU when areas of magnetic variation become unreliable for navigation.For the Southern Latitudes there are also some auto switching moments that I don't remember exactly. Feel free to ask if intersted how the real plane is programmed.Regards,Harry

Feel free to ask if intersted how the real plane is programmed.

My interest is piqued. Please, tell us more.Paul

I had a quick look on Smartcockpits and in the FMS guide is some supplemental information on Polar navigation. It says that above 73 north and 60.5 south, the;IRU enters a true heading mode,PFD dusplays TRU in CyanND MAP displays TRU in white, It says flying down through 72.5 north or 59.5 south causes the IRU heading to display normally, but it does not say it changes to MAG. (Mind you, it doesn't say it doesn't)

Thanks for your insight, Harry. Good to know that sort of stuff.Man, I forgot all about smartcockpits! Haven't been on that site in years! Time to make a visit.Thanks again for the replies.Rob

My interest is piqued. Please, tell us more.Paul

Paul,My interest was piqued also on this subject.Tell us more is subject to what the real plane does and what the simulation within the restrictions of FS(-) can do.With the knowledge I have about Polar(TRUE) operation of the MD11, I've been flying around in that area quite a lot the last couple of days, with a focus on Thule AFB.My reasons for that:- I like to look at any problems, where I have a knowledge of the real plane and the simulation of it. - I remember this field when it was part of a recurrent training (in the real simulator), as an enroute diversion, even before FS9 was released.- As BGTL has STAR procedures for the simulation, that reveal NONE for stars and NONE for runways when selected in the FMC, I started to focus on the possible why's.In the mean time I've found a way to get the STAR's working with proper runway alignment and constructed SID's as well from a proper aligned runway.Maybe not an answer to the question: tell us more. For the time being I'am only finding solutions to my own questions in this polar region and untill now not without succes (= ways I can live with)Hope also PMDG Group will find a way to integrate extreme north or south latitude into the planes. These products deserve it.Regards,Harry