Here's the basic method:
- Move the IRS selectors from OFF to NAV
- Open the FMC and go to the POS INIT page, downselect the GPS
Position into the ENTER IRS POS prompt (LSK 6R).
- Wait the specified time (set in the PMDG/General/IRS
dialog) - a countdown is visible in the upper left corner of the ND.
- IRS alignment is complete when you have a full PFD and ND
If you see the
ENTER IRS POS prompt twice
This is a feature of the real aircraft's IRS and happens because the
plane has been moved from the IRS's last known position while the gyros
were powered down. In FS this can happen easily if you start your next
flight after a shutdown from a new airport or gate location. The FMC
will ask for the current position twice just to make absolutely sure
that it's accurate.