747-400X won't turn when commanded

[Richard McDonald Woods 168]

Dear All,I think that I am losing my touch....On flight EGLL-KJFK today, I was commanded by KJFK ATC to turn left on 180 deg. Currently on auto-pilot with A/T, LNAV and VNAV engaged, and annunciation of SPD, LNAV, VNAV PATH all correct.I dial in 180 on hdg select, and press SEL. The annunciation changes to SPD, CMD HDG, VNAV PTH, but aircraft does not alter current course.What am I doing wrong?Cheers, Richard

[downscc 1,327]

Push the SEL button in the HDG selector knob and you should see HDG SEL on the annuciator. Maybe you had HDG HOLD (that is the square button below the heading knob)? The CMD means that the a/p is engaged and working. See AOM 8-6.

[Richard McDonald Woods 168]

Hi Dan,I was incorrect in my question. I had selected my heading, pressed SEL and had HDG SEL annunciated. But he aircraft would not turn.Cheers, Richard

[downscc 1,327]

Richard, can you reproduce this? The HDG SEL should work, and has been working, so there is an additonal element in this that is causing the problem. Off the top of my head, I can't anticipate what that might be.

[Richard McDonald Woods 168]

Hi Dan,That means that I will have to work out how to cature the image. Not done that before.I have had this same problem before but put it down to my error.Cheers, Richard

[downscc 1,327]

Use Print Screen, which pastes an image to the clipboard. Open a picture editor, use paste from clipboard to create an image and save it as a jpg, then attach to the forum message. I use Paint Shop and resize it down by 50%, depending on how much detail I need to show.

[Richard McDonald Woods 168]

Dan,Here is a .jpg of my problem. Anybody any ideas why the a/c will not turn?I have tried to change my heading from the 229 deg by LNAV to 250 deg and pressing HDG SEL. The mode on the AI shows HDG SEL, the LNAV light has extinguished but the aircraft does not turn.http://forums.avsim.net/user_files/192164.jpgCheers, Richard

[Guest PSFlyer]

I m not sure If this will help but I seemed to have a similar issue and here is what fixed it:1. Make sure you run your fsx in admin mode. To start FSX right click on the program icon and you will see an option to "run as admin". 2. On the PMDG menu, go to the AFDS section and make sure that the "follow the heading bug" is selected.Yes I know that this only applies if the AC is in the TOGA mode, but for some reason this fixed my problem with following the hdg bug in other modes as well.Hope that works for youPete

[Richard McDonald Woods 168]

Gents,Many thanks for your help on this.I decided to test whether my save file was corrupted by loading the Cold & Dark at Everett (a proven clean situation), moving my a/c to ESSA and starting again. And would you believe, it works OK when commanding a turn!It appears that, somewhere in previous saves, erroneous values have got into the file (perhaps because sometimes I haven't paused the a/c before saving, or overwriting the save partially with data from the PMDG SavePanel State process???). So now I am always going to start a flight by loading the Everett file, and I am not going to use the PMDG Save process. Let's hope that this is the end of this problem!Thanks again,Regards, Richard

[MELKOR 5]

I've had really, really bizarre behavior w.r.t. modes a few times since the latest patch for 747X (example: VNAV refusing the engage, HDG SEL not working as expected).I believe that - under certain circumstances - there is some sort of corruption occuring in the MCP (or related) code.Unfortunately, I have not come up with a repro case for this...So: You might want to mail your save file to PMDG support - maybe they will discover something.- Bill

[Guest tff325]

Hi guys,I'm experiencing simular problems with HDG SEL mode (747X). Normally, I take off with LNAV and VNAV enabled, Autopilot off. Then manually fly the departure route, following the FD. However, when i engage the AP after departure, the ac will follow the LNAV route but fails to react on HDG SEL, even though the display does show the HDG SEL Mode. Switching off and on the AP does not work, the ac won't react anymore on HDG SEL.I've had this situation many times and hope there will be a way to prevent or fix this. The problem only occured after the latest patch, it never happened before.rgds,Ben

[MELKOR 5]

If you are able to reproduce this everytime - then please write out your case in detail (i.e. absolutely every step you do from the moment you start FSX), and mail it to support@precisionmanuals.com.That may take some time to do, but the only way PMDG is going to be able to fix this, is if THEY are able to reproduce the issue.- Bill