Strange Route Lines on the ND

[Guest kame]

Gentlmen,I have flown "AROUND THE WORLD OVER BOTH THE EARTH'S POLES" of the http://www.concorde-spirit-tours.com/ with PMDG 747-400X. The route is ZBAA - YPPH - SAWG - CYMX - ZBAA.At the south pole in the YPPH - SAWG leg (YPPH-MJM-S90E116-SOM-GAL-GAL12-SAWG):http://www.cpaj.net/fushi/fushi/capture_14122007_124039.jpgAt the north pole in the CYMX - ZBAA leg (CYMX-UFX-N90W073-ZBK-KNNB-HUR20-ZBAA):http://www.cpaj.net/fushi/fushi/capture_14122007_124500.jpgAnother one at the SOM when S90E116 has been deleted from the leg:http://www.cpaj.net/fushi/fushi/capture_14122007_124912.jpgWhat is the cause of the trouble?Sincerely,Kan-ichiro Fushihara

[Mats_J 2]

Kan-ichiro,Looks like ACES didn't get the poles quite right. My guess is that this is a FSism.N90W073 is by the way something of an ugly duckling. At latitude N90 or S90 you really only have one point with a infinitesimal number of longitudes as opposed to all other latitudes which are circles.Hope it helps,

[Guest kame]

Dear Mats,Thank you for your kind suggestion.I understand at altitude N90 or S90 are really one point, I think only going up north along with W073 from UFX and going down south along with E166 from MJM.What do you think at the SOM? It seems that the route line is once going back. Sincerely,Kan-ichiro Fushihara

[Mats_J 2]

Kan-ichiro,What lat/lon do you have at SOM? The route seems a bit confused here. Can you share the rest of the flight plan for us to try to replicate?BTW. It would be interesting to see what the real world FMC would do if you tried to enter a waypoint starting with N90... or S90...? Alex, Jon can you try this on your next trip? ;-) Cheers,

[Guest kame]

Dear Mats,LAT/LON of the SOM(NDB) is S52 43,63/W69 20.27 (according to the FS World -> Map...).The flight plan of this case:YPPH -> MJM -> SOM -> SAWG (APPRORCHES ILS25), FL 290/370.Thanks again,Kan-ichiro Fushihara

[Guest Just747-400]

Hi Mats,I just caught this before going out for ORD JFK and I will check, but this is no event in the airplane, there is something related to how magenta line is depicted on the ND and the variation on FS9 or FSX. I noticed this situation a few times before even in other situations (like SIDS while on ground) but as soon as the aircraft was moved or in a T.O. position that discrepancy went away. Next for Mr. Kan-ichiro Fushihara I would like you telling us if after you moved the aircraft or after T.O. you still noticed that discrepancy on ND.

[Guest gregsh00]

Hi All,I just flew over the north pole last night (NPOLE from FSNav) and saw much the same thing. PANC to ESSA.Lucky I save the flight just before NPOLE. This is how it looked during the flight.http://forums.avsim.net/user_files/181944.jpgThe fix kept moving a few degrees left/right as the 400X crossed the track. I finally flew a heading to stop the constant rolling left/right. I did have TRUE headings selected.Even though I flew right past the NPOLE, the FMC didn't change waypoint so I had to manually select the next.Cheers,Greg Smith

[Guest kame]

Dear Alex,It's only strange magenta line, there is no problem on the navigation.I'm ashamed to say this, but I don't know "T.O.".Thanks a lot,Kan-ichiro Fushihara

[Guest kame]

Dear Greg,Thanks, I feel easy to know your state is also as same as me.As you said, I have switched to HDG hold from LNAV just before N90/S90 and HDG selected to 180/0 right after N90/S90.Sincerely,Kan-ichiro Fushihara

[Mats_J 2]

Kan-ichiro,Don't feel ashamed. T.O is pilot lingo for take-off. Cheers,

[Guest Just747-400]

Dear Kan and Mats,I just got home and looked in my notes and found out that during testing there where some problems with magenta line. To be honest it looks like this area (N90 or S90) we didn

[Guest kame]

Dear all,The strange magenta line at the SOM has been eliminated when the waypoint S90/W116 insert between MJM and SOM.I don't understand why this happen.Sincerely,Kan-ichiro Fushihara