November 10, 200223 yr While on a flight from PHNL to PGUM (Guam) I lost my IRU alignment hence also lost EHSI, EADI & AFDS. I switched the alignment switches to ATT, entered my current heading and regained the EADI but nothing else.So there I was lost over the Pacific somewhere between PHNL and PGUM. I called Flight Services (FSNAV) and obtain a direct heading to Wake Island. Initiated an emergency landing, realigned the IRU, chased down one of the passengers who fell in love with one of the native ladies and continued the flight without incident.I didn't see it covered in the manual but maybe I missed it. I didn't realize you lose the aircraft's autopilot when you lose your IRU alignment. I had to handfly some 400 miles to Wake Island including no autothrottle. Somehow this doesn't seem right. I understand you won't have any FMC input but I don't see why I couldn't invoke the autopilot. Perhaps someone can enlighten me.
November 10, 200223 yr Hi Lamont,funny you should mention that, as the same thing happened to me a while ago on a flight from YSSY to KLAX. I lost all the instruments as you described, but they came back a while later. Is it a weird bug that occurs occasionally in the South Pacific? I never had that happen anywhere else.Cheers,Gosta.
November 10, 200223 yr I think it's a bug when crossing the 180 degree meridian, hence the problem only occurring in the South Pacific - a fix? - I don't know if there is one.Dave
November 10, 200223 yr Same thing happens to me also on a flight from NSTU to NFFN. Ecactly85nm from TOD. Must be a bug somewere!!!SK945
November 10, 200223 yr I'm pretty sure the North Pacific also has the 180W/E too! ;-)Lee Hetherington (KBED)
November 10, 200223 yr Thanks for the input guys. At least I know it wasn't me but it sure is a scarry feeling though.
November 10, 200223 yr Must be because I'm from the southern hemisphere - we tend to be forgotten down here sometimes ;-)Dave
November 11, 200223 yr "I switched the alignment switches to ATT, entered my current heading and regained the EADI but nothing else."Did you get any compass information on your HSI, Lamont? (VOR /ILS displays, not MAP)I'm wondering if the IRS ATT function was operating correctly after the malfunction."I had to handfly some 400 miles to Wake Island including no autothrottle."This seems odd. Did you try cycling the A/T ARM switch and selecting SPD or the N1 buttons on the MCP?I also noticed that when I switched the IRS's to ATT in flight with no malfunctions, I also got a few unexpected results, MCP-wise and display-wise. I may have to check these out at work. E.g. I thought the V/S display would have been available (as it is in PS1 in this situation). Unfortunately, the last big sim I played with didn't even generate attitude displays in ATT mode in the air (you would have expected more for tens of millions of dollars, wouldn't you!). I won't be back at work for a few weeks, but I'll try not to forget ;-)Cheers.Ian.
November 11, 200223 yr Hi Ian,I wish now I had taken some pics. To answer your questions yes I placed the HSI in VOR mode and I got compass info. Nothing I did would restore the autopilot or autothrottle. I found this strange too, especially after restoring the EADI it would annuciate the various MCP modes but the CMD would not work.I'll wait to see what you dig up.
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