PMDG 747-400 for FSX.Problem with ND and PFD

[Guest mark_j]

Hi I seem to be having a slight problem with my 744 for FSX. Starting cold and dark, as soon as I go to align the IRS system I lose my ND and PFD.Has this happened to anyone else and if so, how did you get around it?Any assistance greatly appreciated.Mark

[Richard McDonald Woods 168]

Mark,You will lose the ND and PFD until the IRS system is aligned. This can take up to 7 mins, depending on the Option you have chosen.So, just be patient.Cheers, Richard

[Guest mark_j]

Thanks for that Richard. I'll try it again tomorrow and see how we go.

[Guest hangar744]

Hi Mark,no it is not normal behavior. You shouldn't "loose" the PFD and ND formats during IRS alignment. What do you mean by loosing them? Do the DU's go totally blank? Perhaps a screenshot would be handy.regards,delcom

[Guest mark_j]

Hi DelcomNo, not totally blank. I lose the heading bug, map, and compass points on the ND. On the PFD I still have Airspeed indicator and Altitude but no verticle speed indication, Flight Director, pitch/bank indication, etc.I'll do a screenshot and see if I can get it up here. (I haven't done it for a while and I have to remember how). Maybe in the meantime that's enough info to give you or someone else some kind of clue as to what might be happening.CheersMark

[Guest mark_j]

Hi DelcomHere's a screenshot of what it looks like AFTER IRS alignment. Also note that at the top lefthand corner of the ND 'Time to Align' is still being shown but with negative values. Is this normal?CheersMark

[Guest hangar744]

Hi Mark,well...first of all it is clearly an IRS issue. The IRS information can be NCD (no computed data), or invalid. If invalid, there are flags displayed and some IRS information removed. It's not the case.Your PFD and ND clearly show the signs of NCD. It's about 9 items removed and/or dashed on your PFD. And I think about 10 items removed and/or replaced with dashes on your ND.Something clearly inhibiting the (otherwise operational) IRS entering NAV mode. At this point I can see two reasons for it. (Plus a lot more if someone is not familiar with this system.)1. The IRS mode select switches are left in ALIGN instead of NAV.2. You are trying to align some place far north or south. Just to stay on the safe side, pick an airport between 73 degrees north and 60 degrees south latitude.About the negative values concerning time to align...I've never seen it on a real kite. This could be some airline/software option though.I hope you'll get things sorted out.sincerely,delcom

[Guest mark_j]

Hi DelcomI'm currently working around the problem by using the option to have the IRS align instantly so I don't have to even touch it. When I was trying to use it, when the 747 is launched I would go to the overhead panel and turn on the battery, Standby power, and then ground power. The IRS was already in NAV when the panel opens so I'd switch it to OFF then to ALIGN. Then I'd wait the 10 minutes then switch it over to NAV and it's at that point that i lose everything off the ND and PFD.It's a mystery. Other than that everything else about the aircraft is awesome and I've completed several flights over this weekend without trouble. It's just annoying because I can find no reason for the IRS not to function properly.Anyway, thanks for all your help.CheersMark

[Headley 26]

>Hi Delcom>The IRS was already in NAV when>the panel opens so I'd switch it to OFF then to ALIGN. Then>I'd wait the 10 minutes then switch it over to NAV and it's at>that point that i lose everything off the ND and PFD.>MarkIn a cold&dark situation the IRS-knobs are in the OFF position.On start up you have to set these knobs from OFF to NAV, leaving the "ALIGN" position alone, and they stay in the NAV-position untill you shutdown the plane.Don't know what the ALIGN-position is for, but on normal operation it is not used.So : from OFF to NAV and back to OFF!I know it is mentioned in the manuals, but there was a topic - long time ago - witch explained this "error".

[Mats_J 2]

Mark,Have you entered your present position in the CDU? Without that the IRS units cannot align and will wait for your input.Hope it helps,