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ccaughie

No artificial horizon even after IRS alignment

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This is driving me crazy. I thought I had figured out how to get the artificial horizon etc. to come on reliably (set IRS knobs to NAV then ALIGN, enter position in FMC, wait for alignment to finish, set back to NAV) but since upgrading my computer and reinstalling everything it just doesn't seem to work any more. See screenshot attached. I'm pretty sure I've followed the normal startup procedures to the letter.In the Options pages I've set my alignment time to 2 minutes (120 seconds). This shot was taken about 10 minutes after alignment should have completed.I had set the position in the POS INIT page when the FMC message came up asking me to do so. Oddly, after clearing the message and entering the position (copied from the GPS position), the "Enter IRS position" immediately came up again. Not sure if this has any bearing on the matter.Can anyone tell me exactly what is required for the artificial horizon, and any other displays I may be missing, to initialize correctly?Thanks in advance,Colinhttp://forums.avsim.net/user_files/188084.jpg

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I had this problem also. The FMC was asking for position initialization. I clicked on the GPS position immediately above the blank boxes, and loaded the position into the blank boxes. The message appeared again "SET GPS POSITION" and I ignored it.It turns out that you have to set the GPS position ***twice***. Click on the GPS position to copy it into the scratchpad and then click on the same (R5K?) button as you did the first time. Once that is done, *then* the IRS clock starts. If you go to the PMDG wiki, do a search on "pos int", you'll find a longer description. It's also in the PDF manual, chapter 12 I think, but not enough emphasis is placed on initializing the position twice.dan

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If you look at your ND, it says that the system is still aligning (upper left corner of the ND). It should be counting down and when it hits +0 MIN, the ND and PFD should come online when you move the switches to NAV. Also, from the off position, you can put the IRS selectors straight to NAV and it will automatically align. Then when it's done, the IRS will switch to NAV on it's own.With regards to the FMC asking you to, "ENTER IRS POS", that happens when the position you entered doesn't match something (can't remember what). The system will flash that message when it wants you to make sure that position is correct. If it is correct (which it usually is), enter the position a second time to tell the FMC that you are sure you want to use those coordinates. It isn't required to enter to GATE or GPS position (whichever you use) a second time if "ENTER IRS POS" doesn't come up.Ryan GamurotLucky to live Hawai'ihttp://www.virtualpilots.org/signatures/vpa296.png

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If memory serves the second (confirmation) position entry is required if you're starting the 744 from a different position than the last time you parked.regards,Mark

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Thank you all, that did the trick. I guess this being my first flight in the plane since I reinstalled, I was always going to need that confirmation. Not sure how I got it working on my old machine, blind luck I suppose.Colin

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I usually turn the IRS switches to OFF... then NAV... when fully aligning the IRS system. If you enter the position into the FMC and it says "ENTER IRS POSITION" it is because the difference between the last known position is significantly different to the position you are entering as the current position.. Essentially the FMC is saying "Are you sure this is right? The last position is quite different, please confirm this by entering it again.."If you look at your FMC.. your last known position is..N42.21.1 W071.0.7As far as the aircraft is concerned, it's expecting to be around this area when it's next powered up, but your new position is..N52.18.8 E004.46.1This is very, very different from your original position.. The FMC will require confirmation in this case, and requests it by giving you the message ENTER IRS POSITION...Obviously this is not something that happens too often while the aircraft is in normal service. The last known position will probably be the gate, and since it's still on the gate, the FMC will accept the position entered with no question.. If perhaps the aircraft was shut down and towed to a hanger.. which was some distance away.. the FMC might require confirmation when re-powered up... Since we're often changing airports in FS when we fly.. this will happen a lot when configuring your IRS.CheersCraig

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