IRS Aligns and then error

[abh_jc_03 0]

I started the battery and did the IRS alignment.  It did the normal countdown and then I put the IRS position in.  I got the magenta which showed the alignment was done.  After I started my APU the screen  next to the PFD showed C-1, R-1 and L-1 and then it would keep increasing.  What is this about?  I am assuming I can still fly since the display shows the magenta and no longer have the map not knowing where I am.

[hornet65 0]

I believe you still have the overhead dials in the "allign" position. You need to dial all three one click to the right in the "NAV" position. If you leave them in allign, the counter will keep ticking off the minutes since alignment was complete.

 

Regards,

 

Tom S.

[abh_jc_03 0]

I made sure all three were in the NAV position. That's what doesn't make sense

I made sure all three were in the NAV position. That's what doesn't make sense

[JRBarrett 3,070]

Reading your initial post, are you saying that you powered up the aircraft (using battery power), aligned the IRS system, and THEN stated the APU? That could be part of the problem. The main aircraft batteries have limited power capacity. After powering up the battery, you should either start the APU, or plug in the external power cart, as soon as possible - BEFORE activating any other aircraft systems - especially the IRS.

 

Perhaps I have misunderstood what you were saying, but when running on battery power only, many parts of the aircraft avionics and FMS systems are not fully functional, and this could explain why your IRS alignment is not working.