PMDG 747 X off course

[blake7 5]

Evening all,I've recently been having this problem with the 747X losing its course when on LNAV mode and also on HDG mode.It happens during flights randomly when all of a sudden the auto pilot decides to go swaning off in its own direction for about a minuite before coming back on course to follow the FMC pink line ... when it dives off course i try to correct it by selecting an appropriate heading on the HDG selector and activating it but this has no effect.Even the HDG selected on the autopilot alone does the same thing of wandering off course.I have tried the other autopilot command switches along with switiching on and off the auto system and still it will do its own thing until it decides to start following orders again ...A complete uninstall then a reinstall has no result either ?Anyone else had this problem or could steer me in the right direction for a solution ???Thanks,Gary B.

[Turbine777 13]

I hate to reply without a resolution, just a comment to say that, yes I have seen this behavior many times. At first I thought it was wind but had weather set to (and reset to) clear with no winds. Even then it should stay on course. I have been waiting for it to happen again since my guess is that somehow I hit a possible keyboard shortcut to change the heading from Magnetic north (the default) to True north. It is a switch above the Eicas display. The difference is usually about the same distance the plane strays. It's either that or maybe somehow it got a command to offset the course buy 10 degrees? Again though, I amwaiting for it to happen again to see, but since now I am waiting for it to happen, it probably won't, haha.Dan

[blake7 5]

Thanks for replying Dan,Its not the mag / true hdg selector and I also have had the weather set to calm ... it still does it ...Somtimes the aircraft will make a complete 180 degree turn or more off track before correcting ...Happens pretty much every time I use the #### thing !I have even tried re-alighning the IRS's before use but stil has no effect ...Anyways it's too much of a good product for FSX to leave it in the hanger gathering dust ... so I will just have to fight her until there is some sort of a solution ...Gary B ;o)

[downscc 1,327]

This is an unusual problem, not one widely reported or seen during beta testing. Maybe some screen shots will get us going in the right direction.

[Guest Oz_Animal]

Hi GaryCan you give us just a tad more info please. I would like to know 1..Where in the route does it happen. Start, M, End..Near ToD etc etc.2..Does it correct over time or just go crazy?3..Do you have a STAR programmed when it happens?4.. When it does it on HDG SEL is this after you have switched from FMC?5..Does it do it if you fly manually then go to autopilot (No FMC programming)If you could answer these or test them it could help with detection.ThanksSteve

[blake7 5]

Thanks for the responses chaps ...Im going to conduct a few flights with screenies for a more detailed result ...Get back soon, maybe 24 - 48 Hrs or so as work commitments will interupt ;o(Thanks,Gary ...

[Guest jfsp]

Hi,I have exactly the same problem. After a little testing I found out that the display of the PFD is freezing after a little while in the VC (but not in the 2d view). It mostly happens during cruise or during long climbs. In order to "reactivate" the PFD I switch to the 2d view, then back again. This works, but it is a little bit tiresome to do this every minute or so.Regards,Juergen

[blake7 5]

I've only been using the 2d but will be looking to that !Sorry no screen shots yet , I've had two days of he'll at work covering sick and extra flights ... The recession don't seem to be affecting my company too much at the moment !Thanks,Gary B

[Guest jfsp]

..just did a short 1 hour flight. I stayed in the VC all the timeand didn't switch to any exterior views at all. Everything was working fine during the whole flight, no deviation at all!So for me it is pretty much clear that when switching to exterior views and then directly back to VC, the PFD is not updated correctly. But switching shortly to the 2D cockpit and then to the VC fixes it.Regards,Juergen

[blake7 5]

Juergen,Thanks for that I will try it and see if that's the solution to my problem ...Gary B

[Guest Rup]

Hello! have the same problem.... I Only use 2d no VC but switch alot between interior and exterior views..Regards Jean

[Guest Rup]

Hello againi have tried the above mentioned fixes, but no luck.. after about 5 minutes of flight in heading mode, speed mode, and AP on, the 747 starts to bank to left/right and then FSX freezes. anyone have some idea what might be wrong? Jean

[Guest jfsp]

Hi Jean,I think your problem is different from the topic we are discussing here - for me, the 747 keeps on flying (FSX does not freeze), but the PFD does not reflect the changes to course or altitude correctly. Your problem sounds more like an out-of-memory problem. Does FSX crash after the freeze?Regards,Juergen

[blake7 5]

This is typical !!!Do you think I can get it to misbehave again now I need screen shots ... no chance !I will keep trying ...Murphy's law I think they call it ...Thanks.Gary B.

[Guest Rup]

Hello again I Have tested it again, and for 1 hour or so this time it didnt freeze, but it still began to turn left and right. It only seems to be in HDG mode and when in approach mode with the ils captured..Jean