Set IRS Position

[Guest mickhug]

I have the PMDG 747 on FS2004, and previously it was working ok.Coming back to it after a few months I am having problems setting the IRS Position on the FMCI start from cold and dark, follow the manual set the IRS switches to allign, afte this has completed I start setting up the FMC. I switch to the POS Init page and I am asked to Set IRS Pos.I copy it to the scratch pad and when trying to insert it into LSK 6R, this section goes blank with no GPS Positions.I can then go no further, and auto pilot etc. will not engage.Is there anything I am missing?Regards,Mick Huggett

[JBZ 13]

I have the PMDG 747 on FS2004, and previously it was working ok.Coming back to it after a few months I am having problems setting the IRS Position on the FMCI start from cold and dark, follow the manual set the IRS switches to allign, afte this has completed I start setting up the FMC. I switch to the POS Init page and I am asked to Set IRS Pos.I copy it to the scratch pad and when trying to insert it into LSK 6R, this section goes blank with no GPS Positions.I can then go no further, and auto pilot etc. will not engage.Is there anything I am missing?Regards,Mick Huggett

I'm not sure why, but I just had this problem with my FSX version. I set all three IRS switches to OFF and then back to NAV and it allowed me to enter the IRS position in the FMC. At least I'm not the only one.

[basa 0]

I'm not sure why, but I just had this problem with my FSX version. I set all three IRS switches to OFF and then back to NAV and it allowed me to enter the IRS position in the FMC. At least I'm not the only one.

Yes, first OFF, then NAV.

[Guest mickhug]

Yes, first OFF, then NAV.

Many thanks for the prompt replies, but I have tried turning the IRS switches off then back on, I have also restarted Flight Sim, and tried different panel states.Regards,Mick Huggett

[Farlis 2,355]

If you had parked your 747 at a different airport it will remember this as it's last positon. If you now enter a deviating position because you switched airports then you have to enter the position TWICE.

[brian747 5]

Of course, if Microsoft had written the FMC software, the prompt would simply have asked "Are You Sure???" :( B.

[Guest mickhug]

If you had parked your 747 at a different airport it will remember this as it's last positon. If you now enter a deviating position because you switched airports then you have to enter the position TWICE.

Thanks for the reply, but I have not parked my 747, I have started a completely new flight, after restarting flight sim, and computer, and tried many times to enter the position a lot more than twice, it just does not want to accept it.Regards,Mick Huggett

[Paul_Smith 92]

...I copy it to the scratch pad and when trying to insert it into LSK 6R, this section goes blank with no GPS Positions....

You don't put it into LSK6R, this is the GPS pos and you are trying to set the IRS pos. When you get the prompt to set the IRS POS, press CLR to clear the prompt, select LSK6R to transfer the GPS pos to the scratch pad, then press LSK8R to transfer the scratch pad to the IRS. If the system thinks the aircraft has moved since last time, it will ask you to repeat this procedure. If you waited too long between the IRS has aligning and initialising the position, then the prompts will come thick and fast and will interupt this procedure. Just keep clearing the prompts as they come up until you are successful.

[787flyer 648]

Hi Mick,Sorry to be "picky" but on my system, essentially you down-select GPS POS co-ordinates (shown at LSK 4R) into the scratchpad of the FMC and then up-select by pressing the LSK 5R. I suspect Paul made a small typo in his response, but no worries. I assume you're already doing this? As Paul indicated, you need to make sure the scratch pad only contains the co-ordinates and no other messages or text otherwise it will not be uploaded.Are you then getting the ND message that the IRS' are aligning? Usually there's a countdown in the top left corner of the ND.I can't tell from your initial message if you getting to that point or not?? If not, then I suspect it may have something to do with Ground Power and/or APU. Re-check your Overhead conpanel settings versus the tutorial in the manual. Sometimes I have had a problem in getting the IRS' to activate and it's usually in this area I have found.If you are getting the countdown to complete on the ND, what messages are you getting on the FMC once you try and enter the GPS POS co-ords into the Set IRS POS field?If you can provide update, we'll try and get you back into the air (ash clouds precluded!).Regards,